Version July 2025
Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of 17 placebo-controlled trials (modal duration, 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients between 1.6 and 1.7 times the risk of death in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was approximately 4.5%, compared with a rate of about 2.6% in the placebo group. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature. Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality. The extent to which the findings of increased mortality in observational studies may be attributed to the antipsychotic drug as opposed to some characteristic(s) of the patient is not clear. Olanzapine is not approved for treatment of patients with dementia-related psychosis.
Adverse reactions with signs and symptoms consistent with olanzapine overdose, in particular, sedation (including coma) and/or delirium, have been reported following injections of long-acting injectable olanzapine. Long-acting injectable olanzapine must be administered in a registered health care facility with ready access to emergency response services. After each injection, patients must be observed at the health care facility by a health care provider for at least 3 hours. Because of this risk, long-acting injectable olanzapine is available only through a restricted distribution program called Zyprexa Relprevv Patient Care Program, and requires health care provider, health care facility, patient, and pharmacy enrollment.
Dosage guidance:
Safety: Antipsychotics are not indicated for use in catatonia and may worsen psychosis and increase risk for neuroleptic malignant syndrome in patients with catatonia (Ref).
Clinical considerations: For treatment of psychiatric disorders, consult a psychiatry specialist for all management decisions; select antipsychotic carefully based on patient preference, clinical characteristics, history, comorbidities, and adverse effect profile (Ref).
Agitation/Aggression (severe, acute) associated with psychiatric disorders (eg, schizophrenia, bipolar disorder) (labeled use), substance intoxications (off-label use), or other organic causes (off-label use):
Note: Antipsychotics are appropriate when psychosis is suspected to be the primary cause of agitation/aggression (Ref). Avoid in suspected or confirmed intoxications with anticholinergic substances; other agents are used preferentially in some intoxications (eg, stimulants) or alcohol withdrawal (Ref). The olanzapine prescribing information recommends against concomitant administration of parenteral olanzapine with a benzodiazepine due to risk of respiratory depression (Ref); however, recent studies did not find an increased risk of respiratory depression when the two medications were administered within 1 hour of one another (Ref). Appropriate monitoring is recommended when administering medications that cause sedation.
IM: Short-acting injection: Initial: 5 to 10 mg; may repeat based on response and tolerability 2 hours after initial dose and 4 hours after second dose; maximum: 30 mg/day (including oral olanzapine) (Ref).
Oral (off-label route): Initial: 5 to 10 mg; may repeat based on response and tolerability every 2 hours up to 20 mg/day (Ref).
IV: Short-acting injection (alternative agent) (off-label route): Note: IM administration is preferred in most clinical situations. If IV administration is used, limit to settings where patients can be closely monitored for respiratory depression (eg, emergency department) (Ref).
Initial: 5 to 10 mg single dose; if needed, may repeat once with an additional 2.5 to 5 mg dose ≥10 minutes after initial dose based on response and tolerability; total maximum dose: 10 mg (Ref).
Agitation/Aggression and psychosis associated with dementia, severe or refractory (alternative agent) (off-label use): Note: Patients with dementia with Lewy bodies are at increased risk for severe adverse reactions; caution is required even with low doses (Ref).
IM: Short-acting injection: Initial dose: 2.5 or 5 mg; may repeat based on response and tolerability with up to 2 additional 1.25 to 5 mg doses at intervals ≥2 hours after the initial dose and ≥1 hour after the second dose; maximum: 12.5 mg per episode (Ref).
Oral: Initial: 2.5 mg once daily, may increase dose based on response and tolerability in increments of 2.5 to 5 mg/day at intervals ≥1 week up to 10 mg/day (De Deyn 2004; Street 2000; Verhey 2006). In patients without a clinically significant response after an adequate trial (eg, up to 4 weeks), taper and withdraw therapy. Only continue in patients with demonstrated benefit; attempt to taper and withdraw at regular intervals (eg, within 4 months of initiation) (Ref).
Bipolar disorder:
Acute mania, acute episodes with mixed features (labeled use), and acute hypomania (off-label use) (monotherapy or adjunctive therapy): Oral: Initial: 10 to 15 mg once daily; may increase dose based on response and tolerability in 5 mg increments at intervals of ≥1 day up to 20 mg/day (maximum per manufacturer's labeling); however, experts suggest some patients may require doses up to 50 mg/day for optimal response (Ref).
Bipolar major depression, acute (alternative agent; monotherapy or adjunctive therapy) (off-label, except labeled use as adjunctive to fluoxetine): Oral: Initial: 5 mg once daily; may increase dose based on response and tolerability in 5 mg increments at intervals of every 1 to 7 days up to 15 mg/day (adjunctive therapy) or up to 20 mg/day (monotherapy) (Ref). A fixed-dose olanzapine/fluoxetine combination may be used instead of separate components. See “Dosing Conversion” below.
Maintenance treatment (monotherapy [labeled use for mania or episodes with mixed features; off-label use for depression episodes] or adjunctive therapy [off-label use]): Note: Continue dose and combination regimen that was used to achieve control of the acute episode (Ref).
Oral: Usual dose: 5 to 20 mg/day; maximum dose: 20 mg/day (Ref); however, for patients who required doses up to 50 mg/day to achieve remission, continue remission-achieving dose, as tolerated (Ref).
Cancer-related anorexia and cachexia (off-label use): Note: In the study, all randomized patients had received antiemetic prophylaxis with olanzapine 5 mg once daily for 4 days plus dexamethasone during/following each cycle of chemotherapy, followed by low-dose olanzapine for cancer-related anorexia (Ref).
Oral: 2.5 mg once daily for 12 weeks (Ref).
Chemotherapy-induced nausea and vomiting, acute and delayed (high emetic risk [>90%]), prevention (off-label use): Oral: 5 or 10 mg on day of chemotherapy (day 1), followed by 5 or 10 mg once daily on days 2 to 4, in combination with antiemetics used for high emetic risk agents (Ref). For cisplatin-based high emetic-risk therapy, the 5 mg dose (in combination with triplet antiemetic therapy) is effective and may be associated with less daytime sedation (Ref).
Chemotherapy-induced breakthrough nausea or vomiting, treatment (off-label use): Oral: 5 to 10 mg once daily for 3 days (Ref).
Delirium, hyperactive (treatment): Note: Nonpharmacologic interventions and treatment of underlying conditions are initial steps to prevent and manage delirium. Antipsychotics may be used as short-term adjunctive treatment if distressing symptoms (eg, agitation, anxiety, combative behavior) are present (Ref). Reassess daily for continued need; consider discontinuation and/or taper as symptoms resolve, especially at transitions of care to prevent unnecessary continuation of therapy (Ref).
ICU (off-label use):
Oral or via NG tube: Initial: 5 to 10 mg once daily (or 2.5 mg once daily in patients >60 years of age); titrate daily as needed in 2.5 to 5 mg increments up to 20 mg/day (Ref).
IM: Short-acting injection: 5 to 10 mg once; may repeat if needed after 2 to 4 hours; maximum total dose including oral: 30 mg/day (Ref).
Non-ICU (off-label use):
Oral: Initial: 1.25 to 5 mg once daily or as needed; titrate daily based on symptoms in 2.5 to 5 mg increments up to 20 mg/day (Ref).
IM: Short-acting injection: Initial: 2.5 to 5 mg once daily or as needed. Maximum dose (including oral): 20 mg/day (Ref).
Delusional infestation (delusional parasitosis) (off-label use): Oral: Initial: 2.5 mg once daily; increase daily dose based on response and tolerability in 2.5 mg increments at intervals ≥1 week up to 7.5 mg/day (Ref). Further increases up to 20 mg/day may be necessary in some patients for optimal response (Ref). After achieving adequate response, maintain for ≥1 to 12 months before attempting to taper (Ref).
Huntington disease–associated chorea, moderate to severe (alternative agent) (off-label use): Oral: Initial: 2.5 mg once daily; may increase dose based on response and tolerability in 2.5 to 5 mg increments at intervals ≥3 days up to 10 mg/day (Ref). Further increases up to 30 mg/day may be necessary in some patients for optimal response (Ref).
Major depressive disorder (unipolar):
Depression with psychotic features (adjunctive therapy with an antidepressant) (off-label use): Oral: Initial: 5 mg once daily; may increase dose based on response and tolerability in increments of 5 mg at intervals of 3 to 7 days up to 20 mg/day (Ref). After 4 to 6 months of sustained recovery, some experts suggest discontinuing the antipsychotic and continuing antidepressant monotherapy (Ref).
Treatment-resistant depression (adjunctive therapy with an antidepressant) (off-label, except labeled use as adjunctive to fluoxetine): Oral: Initial: 5 mg once daily; may gradually increase dose based on response and tolerability up to 20 mg/day (Ref). A fixed-dose olanzapine/fluoxetine combination may be used instead of separate components. See “Dosing Conversion” below.
Nausea and vomiting (persistent) associated with advanced cancer (off-label use): Oral: 5 mg once daily for 7 days; treatment may be continued beyond 7 days if clinically beneficial (Ref).
Obsessive- compulsive disorder, treatment resistant (augmentation to antidepressants) (off-label use): Oral: Initial: 2.5 mg once daily; increase dose by 2.5 mg every 2 weeks based on response and tolerability up to 10 mg/day (Ref).
Postpartum psychosis (off-label use): Oral: Initial: 5 to 10 mg at bedtime; increase daily dose by 5 mg every 2 days to a target dose of 10 to 20 mg. Increase to 30 mg/day after 2 to 3 days, if needed based on response and tolerability. Continue treatment for 3 to 6 months (Ref).
Schizophrenia:
Oral: Initial: 5 to 10 mg once daily or if this is a first episode of psychosis, consider initiating at a reduced dose (eg, 2.5 to 5 mg/day) because these patients will be more sensitive to adverse effects. May increase daily dose based on response and tolerability in increments of 5 mg no sooner than every 3 days; monitor for akathisia, anticholinergic effects, orthostatic hypotension, parkinsonism, and sedation during titration. Usual dose range: 10 to 20 mg/day; use lowest effective maintenance dose. Although the manufacturer's labeling includes a maximum dose of 20 mg/day, doses up to 40 mg/day may be necessary in some patients for optimal response (Ref).
IM (long-acting injectable suspension):
Note: Establish tolerability with oral olanzapine prior to initiating long-acting IM olanzapine. Due to the potential for a severe adverse reaction (postinjection delirium/sedation syndrome), patients must be observed in a health care setting for at least 3 hours after every injection.
Initial: IM: Administer the initial dose of long-acting IM olanzapine based on current oral olanzapine dose (see "Dose Conversions That Attain Similar Steady-State Olanzapine Exposure During Maintenance Treatment" table). The recommended initial long-acting IM dose regimen should be followed for 8 weeks before beginning maintenance phase (see "Dose Conversions That Attain Similar Steady-State Olanzapine Exposure During Maintenance Treatment" table). Maximum dose: 300 mg every 2 weeks or 405 mg every 4 weeks. Initiate maintenance dosing 2 to 4 weeks after completion of initial 8-week long-acting IM dose series (Ref).
Oral overlap: It is not necessary to continue oral olanzapine following the first long-acting IM olanzapine dose (Ref).
Maintenance dose: IM: Administer maintenance dose of long-acting IM olanzapine based on current oral olanzapine dose (see "Dose Conversions That Attain Similar Steady-State Olanzapine Exposure During Maintenance Treatment" table.) Adjust maintenance dose and frequency based on response and tolerability. Maximum dose: 300 mg every 2 weeks or 405 mg every 4 weeks (Ref).
|
Oral olanzapine dose |
Initial long-acting IM olanzapine dose during first 8 weeksa |
Maintenance long-acting IM olanzapine dose |
|---|---|---|
|
a A lower long-acting IM olanzapine starting dose of 150 mg every 4 weeks is recommended in patients who are debilitated, at risk for orthostatic hypotension, may metabolize olanzapine more slowly (eg, nonsmoking, female, patients ≥65 years of age), or may be more sensitive to adverse effects; increase dose with caution as clinically indicated (Lauriello 2024). | ||
|
10 mg/day |
210 mg every 2 weeks for four doses OR 405 mg every 4 weeks for two doses |
150 mg every 2 weeks OR 300 mg every 4 weeks |
|
15 mg/day |
300 mg every 2 weeks for four doses |
210 mg every 2 weeks OR 405 mg every 4 weeks |
|
20 mg/day |
300 mg every 2 weeks for four doses |
300 mg every 2 weeks |
Dosing conversion:
Olanzapine/fluoxetine fixed-dose combination: When using individual components of olanzapine with fluoxetine rather than the fixed-dose combination product, corresponding approximate dosage equivalents are as follows:
Olanzapine 2.5 mg + fluoxetine 20 mg = combination strength 3/25
Olanzapine 5 mg + fluoxetine 20 mg = combination strength 6/25
Olanzapine 12.5 mg + fluoxetine 20 mg = combination strength 12/25
Olanzapine 5 mg + fluoxetine 50 mg = combination strength 6/50
Olanzapine 12.5 mg + fluoxetine 50 mg = combination strength 12/50
Discontinuation of therapy:
Oral: In the treatment of chronic psychiatric disease switching therapy rather than discontinuation is generally advised if side effects are intolerable or treatment is not effective. If patient insists on stopping treatment, gradual dose reduction (ie, over several weeks to months) is advised to detect a re-emergence of symptoms and to avoid withdrawal reactions (eg, agitation, alternating feelings of warmth and chill, anxiety, diaphoresis, dyskinesias, GI symptoms, insomnia, irritability, myalgia, paresthesia, psychosis, restlessness, rhinorrhea, tremor, vertigo) unless discontinuation is due to significant adverse effects. Monitor closely to allow for detection of prodromal symptoms of disease recurrence (Ref).
Long-acting injectable: Switching to other treatments is generally advised if side effects are intolerable or treatment is not effective. However, if a patient insists on stopping treatment, gradual dose reduction to avoid withdrawal reactions is generally not needed with long-acting injectable antipsychotics. The risk of withdrawal symptoms from discontinuation of long-acting injectables is low because the rate of drug elimination is slow. Monitor closely to allow for detection of prodromal symptoms of disease recurrence (Ref).
Switching antipsychotics: An optimal universal strategy for switching antipsychotic drugs has not been established. Strategies include: Cross-titration (gradually discontinuing the first antipsychotic while gradually increasing the new antipsychotic) and abrupt change (abruptly discontinuing the first antipsychotic and either increasing the new antipsychotic gradually or starting it at a treatment dose). In patients with schizophrenia at high risk of relapse, the current medication may be maintained at full dose as the new medication is increased (ie, overlap); once the new medication is at therapeutic dose, the first medication is gradually decreased and discontinued over 1 to 2 weeks (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Injection, Oral:
Altered kidney function: No dosage adjustment necessary for any degree of kidney impairment (Ref).
Hemodialysis, intermittent (thrice weekly): Not dialyzed (Ref): No supplemental dose or dosage adjustment necessary (Ref).
Peritoneal dialysis: Unlikely to be significantly dialyzed: No dosage adjustment necessary (Ref).
CRRT: Unlikely to be significantly dialyzed: No dosage adjustment necessary (Ref).
PIRRT (eg, sustained, low-efficiency diafiltration): Unlikely to be significantly dialyzed: No dosage adjustment necessary (Ref).
The liver dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Matt Harris, PharmD, MHS, BCPS, FAST, FCCP; Jeong Park, PharmD, MS, BCTXP, FCCP, FAST; Arun Jesudian, MD; Sasan Sakiani, MD.
Note: Based on no overall differences in olanzapine pharmacokinetics in patients with liver impairment compared to healthy controls and an observed increase in the urinary excretion of the olanzapine glucuronide metabolite (inactive) in patients with Child-Turcotte-Pugh class C, no specific dosage adjustments are likely needed in patients with liver impairment; however, use of lower initial doses to establish tolerability and response may be prudent (Ref).
Baseline liver chemistries should be obtained prior to initiation to allow for appropriate identification of liver disease progression during use; more periodic monitoring may be appropriate in patients with metabolic risk factors (Ref).
Liver impairment prior to treatment initiation:
Initial or dose adjustment in patients with preexisting liver cirrhosis:
Child-Turcotte-Pugh class A to C: Oral, Parenteral : Initiate therapy at the lowest end of the indication-specific dosing range; if needed, dosage adjustments and maximum recommended doses should follow the usual indication-specific dosing recommendations (Ref).
Liver impairment developing in patients already receiving olanzapine:
Acute worsening of liver function (eg, requiring hospitalization):
Child-Turcotte-Pugh class A to C: Oral, Parenteral : When feasible, reduce dose to the lowest effective dose during the acute event; discontinue therapy if olanzapine induced liver injury is suspected (Ref).
Note: Avoid for behavioral problems associated with dementia or delirium unless alternative nonpharmacologic therapies have failed and patient may harm self or others. If used, consider deprescribing attempts to assess continued need and/or lowest effective dose. Of note, use in certain indications may be appropriate (eg, adjunctive treatment of unipolar major depressive disorder, antiemetic, schizophrenia, bipolar disorder) (Ref). For the treatment of psychiatric disorders, consult a psychiatry specialist for all management decisions (Ref).
All indications:
Short-acting IM, oral: Refer to adult dosing for full details. Consider lower starting dose of 2.5 to 5 mg daily for older adults.
Long-acting IM: Refer to adult dosing for full details. Consider lower starting dose of 150 mg every 4 weeks for older adults.
(For additional information see "Olanzapine: Pediatric drug information")
Agitation: Limited data available: Note: Due to risk of sedation and respiratory depression, separate parenteral olanzapine and benzodiazepine doses by at least 1 hour (oral dosing may need longer separation of doses due to delayed onset and peak effect relative to parenteral) (Ref).
Oral (preferred): Recommended for psychiatric emergencies in patients with developmental delay or who have been diagnosed with autism for severe or refractory agitation and in patients with oppositional defiant or conduct disorder and others (Ref).
Children and Adolescents: Oral: Tablet, orally disintegrating tablet: 2.5 to 10 mg. Dosing based on expert recommendations and very limited retrospective data (Ref).
Parenteral: Recommended for psychiatric emergencies in patients with developmental delay or who have been diagnosed with autism for severe or refractory agitation (although ideally want to avoid IM in these patients) and in patients with oppositional defiant or conduct disorder, mania, or psychosis (Ref).
Children <10 years: IM (short acting): 1.25 mg to 5 mg (Ref).
Children ≥10 years and Adolescents: IM (short acting): 5 to 10 mg; dose may be repeated >2 hours post initial injection based on pharmacokinetic data and experience in adults (Ref).
Dosing based on retrospective reports of IM olanzapine use in an emergency department (n=124; age range: 10 to 18 years) which showed efficacy in 77% of patients (ie, no further sedation required) (Ref); and in an inpatient psychiatric setting to treat acute agitation associated with bipolar disorder or schizophrenia which included 50 pediatric patients (children [n=15; mean age: 11 years]; adolescents [n=35; mean age: 15 years]) and evaluated 163 doses administered; results showed a 90.2% response rate (Ref).
Anorexia nervosa : Limited data available; efficacy results variable; in trials, poor tolerability reported (Ref):
Note: Olanzapine role in management of anorexia nervosa not defined; some suggest a short-term trial in patients with severe anxiety, obsessive thinking, extreme agitation, or hyperactivity, and resistance to refeeding or weight phobia as adjunct therapy (Ref).
Children ≥9 years and Adolescents: Oral: Initial: 0.625 to 1.25 mg once daily; may titrate; reported range: 1.25 to 12.5 mg/day; however, it has been suggested that higher doses (>2.5 mg once daily) may not be associated with greater efficacy. In small trials and several case reports, 1.25 to 2.5 mg once daily was shown to improve BMI and other disease-related symptoms (eg, eating attitudes, anxiety, sleep); another case series used initial doses of 2.5 mg once daily and final doses of 5 to 10 mg once daily (Ref).
Bipolar I disorder (acute mania or episodes with mixed features):
Note: Olanzapine is not considered first-line therapy due to increased incidence of adverse effects identified in adolescent trials including weight gain, lipid abnormalities, and other metabolic adverse effects; neurological side effects may also occur; consider risks versus benefits prior to therapy initiation (Ref). The immediate-release tablet or orally disintegrating tablet (ODT) may be used; however, not all doses may be achievable with the ODT dosage form.
Children 4 to <6 years: Limited data available: Oral: Initial: 1.25 mg once daily; increase at weekly intervals according to response and tolerability to target dose: 10 mg/day. Dosing based on an open-label trial in 15 children (mean age: 5 ± 0.8 years; mean weight: 20.8 kg; mean required dose: 6.3 ± 2.3 mg/day) that showed significant improvement in manic symptoms (Ref).
Children 6 to 12 years: Limited data available: Oral: Initial: 2.5 mg once daily; increase dose in 2.5 or 5 mg increments at weekly intervals to target dose of 10 mg once daily; maximum dose: 20 mg/day (Ref).
Adolescents: Oral: Initial: 2.5 to 5 mg once daily; increase dose in 2.5 or 5 mg increments at weekly intervals to target dose of 10 mg once daily; maximum dose: 20 mg/day. In adolescent flexible-dosing (2.5 to 20 mg/day) clinical trials, the mean modal dose was 10.7 mg/day (mean dose: 8.9 mg/day) (Ref).
Chemotherapy-induced nausea and vomiting (CINV): Limited data available:
Note: For highly and moderate emetogenic chemotherapy, evidenced-based clinical practice guidelines suggest considering the addition of olanzapine to existing CINV regimen for prevention of acute or delayed CINV (Ref) or the treatment of breakthrough CINV and for prevention of CINV in patients who have refractory CINV (Ref).
Children ≥3 years and Adolescents: Oral: Tablet, orally disintegrating tablet: 0.1 to 0.14 mg/kg/dose once or twice daily; round dose to nearest 1.25 mg; in trials, olanzapine was combined with standard CINV regimens that included aprepitant, dexamethasone, and ondansetron or granisetron (Ref). Dosing based on a prospective, open-label, parallel group trial in 231 pediatric patients ≥5 years of age (n=115 olanzapine treatment group; median age: 12.5 years; median weight: 34 kg). In the olanzapine treatment group, patients received olanzapine throughout the chemotherapy block and for 3 days at the conclusion; results showed a significantly higher proportion of patients had a complete response (no nausea and no rescue medication) (Ref). A retrospective evaluation of 60 pediatric patients (128 chemotherapy blocks; median age: 13.2 years; range: 3 to ~18 years) with poorly controlled CINV received olanzapine and reported complete vomiting control in the acute phase in 65% of the evaluated chemotherapy blocks (Ref).
Delirium, refractory:
Note: Antipsychotics are not recommended for routine use to prevent or decrease duration of delirium; reserve use for severe manifestations after discontinuation of deliriogenic medications if possible and implementation of nonpharmacological interventions (eg, environmental optimization). Consider adverse effect profile and available dosage forms when utilizing olanzapine or other antipsychotics (Ref).
Infants ≥7 months to Children <3 years: Very limited data available: Oral: Orally disintegrating tablets: Reported range: 0.625 to 1.25 mg once daily (at bedtime) or twice daily; based on experience in older pediatric patients, therapy should be initiated at low dose and then titrated as needed (Ref).
Children ≥3 years and Adolescents: Limited data available: Oral: Tablets, orally disintegrating tablets: Usual initial range: 1.25 to 5 mg once daily (at bedtime) or twice daily; doses on the higher end of the range should be reserved for larger or extremely agitated patients; therapy should be initiated at low dose and then titrated as needed (Ref). In trials, once symptoms were controlled, doses were decreased over time; average reported duration of therapy was 26.5 days (range: 1 to 132 days) (Ref). A retrospective, descriptive trial (n=78, age range: 1 to 18 years) reported a mean initial total daily dose of 4 mg/day and a mean maximum total daily dose of 10 mg/day (Ref).
Schizophrenia: Note: Olanzapine may not be considered first-line therapy by clinicians due to increased incidence of adverse effects identified in adolescent trials including weight gain, lipid abnormalities, and other metabolic adverse effects; neurological side effects may also occur; consider risks versus benefits prior to therapy initiation (Ref).
Children ≥8 years (limited data available in ages <13 years) and Adolescents: Oral: Initial: 2.5 to 5 mg once daily; increase dose in 2.5 or 5 mg increments at weekly intervals to target dose of 10 mg once daily; maximum dose: 20 mg/day. Note: Doses up to 30 mg/day were used in one study of adolescents who were treatment refractory; however, some patients did not tolerate doses >20 mg/day (Ref); safety and efficacy of doses >20 mg/day have not been fully evaluated. In adolescent flexible-dosing (2.5 to 20 mg/day) clinical trials, the mean modal dose was 12.5 mg/day (mean dose: 11.1 mg/day). Dosing in children is based on 2 double-blind comparison studies which included both children and adolescents (n=35, age: 8 to 19 years with seven children; n=13, age: 7 to 16 years [mean age: 12.8 + 2.4 years]) (Ref).
Tourette syndrome, tic disorder: Limited data available: Note: Not considered a therapeutic option in expert guidelines (Ref) due to increased incidence of adverse effects identified in pediatric patients including weight gain, lipid abnormalities, and other metabolic adverse effects; neurological side effects may also occur; consider risks versus benefits prior to therapy initiation (Ref).
Children ≥7 years and Adolescents:
Patient weight ≤40 kg: Oral: Initial: 2.5 mg every other day for 3 days, increase to 2.5 mg every day for remainder of week; increase to 5 mg/day by second week if needed; then increase in 5 mg increments at weekly intervals as tolerated; maximum dose: 20 mg/day.
Patient weight >40 kg: Oral: Initial: 2.5 mg every day for 3 days; increase to 5 mg every day for remainder of week if needed, then increase in 5 mg increments at weekly intervals as tolerated; maximum dose: 20 mg/day.
An open-label study of 10 pediatric patients (7 to 13 years of age) reported significant reductions in tic severity (Yale Global Tic Severity Scale [YGTSS]) from baseline at a mean final dose of 14.5 mg/day after 8 weeks of treatment (Ref). An open-label trial of 12 children and adolescents (7 to 14 years of age) reported a significant reduction (30%) in total tic severity (YGTSS) at a final mean dose of 11.3 mg/day (range: 2.5 to 20 mg/day) (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Adolescents: No dosage adjustment required. Not removed by dialysis.
Adolescents: Use with caution. Dosage adjustment may be necessary; however, no specific recommendations exist. Monitor closely.
Angioedema may occur with use of olanzapine (Ref).
Mechanism: Unknown; both a nonallergic and allergic mechanism have been proposed with antipsychotic-induced angioedema, including IgE-related hypersensitivity, kinin-dependent processes, or C1-esterase inhibition deficiencies (Ref).
Onset: Varied; onset following olanzapine use has been described within several days (Ref). When angioedema has occurred following use of other antipsychotics, onset has occurred within minutes to years (Ref).
Risk factors:
• Cross-reactivity: The risk of cross-reactivity between antipsychotics as it relates to angioedema events is not well established; however, cross-reactivity has been described between clozapine and olanzapine, haloperidol and iloperidone, and haloperidol and aripiprazole (Ref).
Anticholinergic activity at usual therapeutic doses is generally considered to be moderate, relative to other second-generation antipsychotics (other than clozapine) (Ref). However, dose-dependent increases in anticholinergic activity have been observed (Ref). Anticholinergic effects include constipation, urinary retention, and xerostomia. In older adults, some scales have classified olanzapine as having a high anticholinergic burden which may lead to new-onset delirium, cognitive dysfunction, and falling. However, there is no standardized tool for measuring anticholinergic burden in older adults and varying scales have also ranked olanzapine as low or moderate (Ref).
Mechanism: Dose-related; believed to be mediated primarily through antagonism at muscarinic receptors (Ref).
Risk factors:
Variable and dependent upon:
• Total cumulative anticholinergic burden (Ref)
• Baseline cognitive function (Ref)
• Comorbidities (Ref)
• Older adults (Ref)
• Interindividual variability of the pharmacokinetic and pharmacodynamic parameters (Ref)
Olanzapine is strongly associated with dyslipidemia in adult and adolescent patients, which is a component of the metabolic syndrome observed with this pharmacologic class. Dyslipidemia observed with olanzapine primarily manifests as hypercholesterolemia and/or hypertriglyceridemia, including cases of severe hypertriglyceridemia (>600 mg/dL) and acute pancreatitis (Ref).
Mechanism: The mechanism is not entirely understood and is likely multifactorial (Ref).
Onset: Varied; metabolic alterations from antipsychotics can develop in as short as 3 months after initiation (Ref). One case series observed olanzapine-induced hypertriglyceridemia occurred with a time to peak as early as 2 months following initiation in some patients (Ref). Increases in fasting total cholesterol, LDL cholesterol, and triglycerides were generally greater in adolescent patients when compared to adults.
Risk factors:
• Family history of hyperlipidemia (Ref)
• BMI >25 kg/m2 (Ref)
• Adolescents (Ref)
• Schizophrenia (regardless of medication use) is associated with a higher rate of morbidity/mortality compared to the general population primarily due to cardiovascular disease (Ref).
• Specific antipsychotics: Risk of dyslipidemia and overall metabolic disturbances appears to be high with olanzapine (Ref).
Olanzapine may cause extrapyramidal symptoms (EPS), also known as drug-induced movement disorders. Antipsychotics can cause four main extrapyramidal reactions: Acute dystonia, drug-induced parkinsonism, akathisia, and tardive dyskinesia (Ref). EPS presenting as dysphagia, esophageal dysmotility, or aspiration have also been reported with antipsychotics, which may not be recognized as EPS (Ref).
Mechanism: EPS: Dose-related; due to antagonism of dopaminergic D2 receptors in nigrostriatal pathways (Ref). Tardive dyskinesia: Time related (delayed); results from chronic exposure to dopamine 2 receptor antagonists leading to up-regulation of these receptors over time (Ref).
Onset:
Antipsychotics in general:
Acute dystonia: Rapid; in the majority of cases, dystonia usually occurs within the first 5 days after initiating antipsychotic therapy (even with the first dose, particularly in patients receiving parenteral antipsychotics) or a dosage increase (Ref).
Drug-induced parkinsonism: Varied; onset may be delayed from days to weeks, with 50% to 75% of cases occurring within 1 month and 90% within 3 months of antipsychotic initiation, a dosage increase, or a change in the medication regimen (such as adding another antipsychotic agent or discontinuing an anticholinergic medication) (Ref).
Akathisia: Varied; may begin within several days after antipsychotic initiation but usually increases with treatment duration, occurring within 1 month in up to 50% of cases, and within 3 months in 90% of cases (Ref).
Tardive dyskinesia: Delayed; symptoms usually appear after 1 to 2 years of continuous exposure to a dopamine 2 receptor antagonist and almost never before 3 months, with an insidious onset, evolving into a full syndrome over days and weeks, followed by symptom stabilization, and then a chronic waxing and waning of symptoms (Ref).
Esophageal dysfunction (associated with extrapyramidal symptoms): Varied; ranges from weeks to months following initiation (Ref).
Risk factors:
EPS (in general):
• Prior history of EPS (Ref)
• Higher doses (Ref)
• Younger age (in general, children and adolescents are usually at higher risk for EPS compared to adults) (Ref)
• Specific antipsychotic: Olanzapine has a mild to moderate propensity to cause EPS; however, risk is dose-dependent (Ref)
Acute dystonia:
• Males (Ref)
• Young age (Ref).
Drug-induced parkinsonism:
• Females (Ref)
• Older patients (Ref)
Akathisia:
• Higher antipsychotic dosages (Ref)
• Polypharmacy (Ref)
• Mood disorders (Ref)
• Females (Ref)
• Older patients (Ref)
Tardive dyskinesia:
• Age >55 years (Ref)
• Cognitive impairment (Ref)
• Concomitant treatment with anticholinergic medications (Ref)
• Diabetes (Ref)
• Diagnosis of schizophrenia or affective disorders (Ref)
• Females (Ref)
• Greater total antipsychotic exposure (especially first-generation antipsychotics) (Ref)
• History of extrapyramidal symptoms (Ref)
• Substance misuse or dependence (Ref)
• Race (White or African descent). Note: Although early literature supported race as a potential risk factor for tardive dyskinesia (Ref), newer studies have challenged this assertion (Ref).
Esophageal dysfunction (associated with EPS):
• Certain comorbidities such as neurologic degenerative disease, dementia, stroke, Parkinson disease, or myasthenia gravis (Ref)
• Older adults >75 years of age (may be risk factor due to age-related muscle atrophy, cognitive impairment, reduced esophageal peristalsis) (Ref)
Leukopenia, neutropenia, and thrombocytopenia have been reported with olanzapine (Ref). Agranulocytosis and pancytopenia have also been reported (Ref).
Mechanism: Unknown; olanzapine has a chemical structure similar to clozapine (which also has hematologic side effects) (Ref).
Onset: Varied; in general, drug-induced neutropenia usually manifests after 1 or 2 weeks of exposure and agranulocytosis usually appears 3 to 4 weeks following initiation of therapy; however, the onset may be insidious (Ref).
Risk factors:
• History of drug-induced leukopenia/neutropenia or low white blood cell count/absolute neutrophil count
• Older adults (Ref)
Olanzapine is strongly associated with hyperglycemia in adult and pediatric patients, which is a component of the metabolic syndrome observed with this pharmacologic class. Glycemic abnormalities range from mild insulin resistance to new-onset diabetes mellitus, hyperglycemic hyperosmolar coma, and diabetic ketoacidosis, including fatal cases (Ref).
Mechanism: The mechanism is not entirely understood and is likely multifactorial (Ref).
Onset: Varied; new-onset diabetes has been observed within the first 3 months to a median onset of 3.9 years (Ref)
Risk factors:
• African American race (Ref)
• Males (Ref)
• Younger adults (Ref)
• Patients with preexisting obesity, poor exercise habits, or other risk factors for diabetes, including family history of diabetes (Ref)
• Exposures to other agents that also increase the risk of hyperglycemia (Ref)
• Specific antipsychotic: Risk of metabolic disturbances appears to be high with olanzapine (Ref).
In adults, olanzapine is typically associated with a moderate risk of causing significant effects on prolactin compared to other second-generation antipsychotics with a higher risk (such as risperidone), although there are case reports of hyperprolactinemia in olanzapine-treated adults (Ref). However, in pediatric patients, the risk may be higher. A higher incidence of hyperprolactinemia has been observed in adolescents receiving olanzapine compared to adults. Studies involving both children and adolescents (mostly short-term data) have also observed a statistically significant increase in serum prolactin levels during therapy compared to baseline levels (Ref). Hyperprolactinemia may lead to gynecomastia, galactorrhea not associated with childbirth, amenorrhea, sexual disorder, and infertility (Ref). Although long-term effects of elevated prolactin levels have not been fully evaluated, some studies have also suggested a possible association between hyperprolactinemia and an increased risk for breast and/or pituitary tumors and osteopenia/osteoporosis (Ref).
Mechanism: Dose-related (although some data involving olanzapine are inconsistent); antagonism of dopamine D2 receptors in the tuberoinfundibular dopaminergic pathway which causes disinhibition of prolactin release resulting in hyperprolactinemia (Ref).
Onset: Varied; onset of antipsychotic-induced hyperprolactinemia is typically within a few weeks following initiation or dosage increase but may also arise after long-term stable use (Ref). Data involving children and adolescents receiving olanzapine showed significantly higher prolactin levels at months 3 and 6 compared to month 1, and a lower level at month 12 compared to month 1 (although that difference was not statistically significant) (Ref). Although data are limited, a study involving patients 15 to 60 years suggests olanzapine does not significantly affect serum prolactin levels in the long term (eg, >1 year) (Ref).
Risk factors:
Antipsychotics in general:
• Higher doses (Ref) Note: Some data with olanzapine show inconsistent evidence for a dose relationship (Ref)
• Females (particularly those of reproductive age) (Ref)
• Children and adolescents (Ref)
Olanzapine specifically:
• Some D2 receptor and 5-HT2A receptor gene polymorphisms (potential risk factor affecting prolactin levels with olanzapine therapy) (Ref)
Delayed hypersensitivity reactions with olanzapine range from benign skin photosensitivity, purpuric rash, and fixed drug eruptions to more serious reactions, such as vasculitis and severe cutaneous adverse reactions (SCARs), including acute generalized exanthematous pustulosis and drug reaction with eosinophilia and systemic symptoms (DRESS) (Ref).
Mechanism: Non-dose-related; immunologic. Delayed hypersensitivity reactions, including fixed drug eruptions and SCARs are T-cell-mediated (Ref). Olanzapine can form N-oxide metabolites, which may contribute to the development of these reactions (Ref).
Onset: Delayed hypersensitivity reactions: Fixed drug eruptions: Intermediate; occur 7 to 10 days after initiation. Other reactions (including SCARs): Varied; usually occur between 7 to 14 days and up to 3 months (Ref) but may also occur within 4 to 5 days (Ref).
Risk factors:
• Although potential cross-reactivity has been postulated between olanzapine and carbamazepine in a patient who developed DRESS to both agents, this may represent a reaction to 2 unrelated drugs (Ref) or neosensitization to multiple drugs (Ref). Despite the chemical similarity between clozapine, olanzapine, and quetiapine, no cross-reactions have been reported between these atypical antipsychotics to date.
Olanzapine-induced liver injury can manifest as cholestatic, hepatocellular, or a mixed pattern liver injury that resolves upon discontinuation (Ref). Olanzapine is also known to cause dysregulation in several endocrine and metabolic pathways, which results in an increased incidence of steatotic liver disease (liver steatosis) (Ref). Asymptomatic increased liver enzymes may require interruption or modification in olanzapine exposure and should warrant evaluation of other causes (eg, steatotic liver disease) (Ref).
Mechanism: Unknown; idiosyncratic and likely immunologic (Ref). Steatotic liver disease: Exposure-related with an increased incidence after prolonged use, but the exact mechanism has not been elucidated; may be related to disruption in lipid metabolism observed in in vitro and animal models (Ref).
Onset: Varied; can occur as early as 12 days after initiation up to 8 years (Ref).
Risk factors:
• Concurrent active viral hepatitis (eg, hepatitis C) (Ref)
• Concurrent use of divalproex (Ref)
• Undernourished (Ref)
• Concurrent substance use (eg, alcohol) (Ref)
• Type 2 diabetes (Ref)
• Limited access to primary care services (Ref)
• Increased BMI (Ref)
Older adults with dementia-related psychosis treated with antipsychotics are at an increased risk of death compared to placebo. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature (Ref). In addition, an increased incidence of cerebrovascular effects (eg, cerebrovascular accident, transient ischemic attacks), including fatalities, have been reported in placebo-controlled olanzapine trials in elderly patients with dementia-related psychosis (Ref). Of note, olanzapine is not approved for the treatment of dementia-related psychosis.
Mechanism: Unknown; possible mechanisms include arrhythmia, cardiac arrest, and extrapyramidal effects that may increase the risk of falls, aspirations, and pneumonia (Ref).
Risk factors:
• Higher antipsychotic dosage (Ref)
• Dementia-related psychosis (eg, Lewy body dementia, Parkinson disease dementia)
• Older adults
All antipsychotics have been associated with neuroleptic malignant syndrome (NMS) in all ages. First-generation antipsychotic-associated NMS seems to occur at a higher frequency, severity, and lethality compared to second-generation antipsychotic-associated NMS (Ref). There are case reports of NMS with olanzapine, including monotherapy (Ref).
Mechanism: Non-dose-related; idiosyncratic. Believed to be due to a reduction in CNS dopaminergic tone, along with the dysregulation of autonomic nervous system activity (Ref).
Onset: Varied; in general, most patients develop NMS within 2 weeks of initiating an antipsychotic, and in some patients, prodromal symptoms emerge within hours of initiation; once the syndrome starts, the full syndrome usually develops in 3 to 5 days (Ref). However, there are many cases of NMS occurring months after stable therapy (Ref).
Risk factors:
Antipsychotics in general:
• Males are twice as likely to develop NMS compared to females (Ref)
• Dehydration (Ref)
• High-dose antipsychotic treatment (Ref)
• Concomitant lithium or a benzodiazepine (potential risk factors) (Ref)
• Catatonia (Ref)
• Disorganized speech or behavior (Ref)
• Polypharmacy (Ref)
• Pharmacokinetic interactions (Ref)
• Intramuscular administration of an antipsychotic (Ref)
• Rapid dosage escalation (Ref)
• Psychomotor agitation (Ref)
Olanzapine may cause orthostatic hypotension (although at a lower prevalence compared to first generation antipsychotics and certain atypicals, such as clozapine, risperidone, and quetiapine) and accompanying tachycardia and dizziness in adults, particularly with rapid titration (Ref). Orthostatic hypotension may result in a subsequent falling and fracture, particularly in older adults (Ref).
Mechanism: Orthostatic hypotension is attributed to alpha-1 adrenergic receptor antagonism (Ref).
Onset: Rapid; per the manufacturer’s labeling, orthostatic hypotension is most common during the initial dose titration but can also occur following subsequent dose increases.
Risk factors:
• Known cardiovascular diseases (history of myocardial infarction or ischemic heart disease, heart failure, or conduction abnormalities) or cerebrovascular disease
• Known predisposing conditions (eg, hypovolemia/dehydration)
• Concomitant medications that also cause or exacerbate orthostatic hypotension (eg, tricyclic antidepressants, antihypertensive medications)
• Older adults
• Rapid dose titration (Ref)
Olanzapine pamoate, the long-acting intramuscular injectable formulation, is associated with cases of post-injection delirium/sedation syndrome (PDSS), characterized by sedation (ranging from mild in severity to a coma-like state) and/or delirium (eg, agitation disorientation, confusion, irritability). Recovery is expected by 72 hours. Due to the risk of PDSS, a risk evaluation and mitigation strategy (REMS) program, called the Patient Care Program, is required with olanzapine pamoate use (Ref).
Mechanism: Since patients with PDSS exhibit symptoms consistent with an oral overdose of olanzapine, the mechanism is believed to be due to accidental intravascular entry of a portion of the dose, likely following vessel injury during the injection (Ref).
Onset: Rapid; the vast majority of patients (80% to 90%) experience PDSS within the first hour of IM injection (median onset: 25 minutes postinjection), with most of the remainder of patients experiencing an onset between 1 hour and ≤3 hours; however, some patients have a time to onset at >3 hours (Ref). PDSS may occur with any injection; one case report describes PDSS following a patient’s 31st scheduled injection (patient previously received 1.5 years of injections without PDSS) (Ref).
Risk factors:
Note: No clear risk factors have been identified (Detke 2010), although the following have been suggested:
• Although PDSS can occur even with proper injection technique, improper injection technique and/or improper aspiration (to verify blood is not visible prior to injection) may increase the risk (Ref)
• Decreased BMI (weak evidence) (Ref)
• Older patients (weak evidence) (Ref)
• Higher doses (weak evidence) (Ref)
• Males (weak evidence) (Ref)
Olanzapine has been associated with prolonged QT interval on ECG (Ref). Of the antipsychotics, olanzapine is usually associated with a moderate risk for QTc-prolongation (Ref); contrasting data also exist which may indicate a milder impact on QT interval (Ref). In a study of 24 healthy patients receiving psychiatric care reaching steady state on olanzapine 20 mg/day, the mean change in QTc was 1.7 msec (Ref).
Mechanism: Likely dose-related (but some evidence is inconsistent/conflicting); olanzapine prolongs cardiac repolarization by blocking the rapid component of the delayed rectifier potassium current (Ref)
Risk factors:
Drug-induced QTc prolongation/torsades de pointes (TdP) (in general):
• Females (Ref)
• Age >65 years (Ref)
• Structural heart disease (eg, history of myocardial infarction or heart failure with a reduced ejection fraction) (Ref)
• History of drug-induced TdP (Ref)
• Genetic defects of cardiac ion channels (Ref)
• Congenital long QT syndrome (Ref)
• Baseline QTc interval prolongation (eg, >500 msec) or lengthening of the QTc by ≥60 msec (Ref)
• Electrolyte disturbances (eg, hypokalemia, hypocalcemia, hypomagnesemia) (Ref)
• Bradycardia (Ref)
• Hepatic impairment (Ref)
• Kidney impairment (Ref)
• Coadministration of multiple medications (≥2) that prolong the QT interval or increase drug interactions that increase serum drug concentrations of QTc prolonging medications (Ref)
• Substance use (Ref)
Sedated state (drowsiness) has been reported with use in all ages and may cause nonadherence, impair physical and mental abilities, and may result in subsequent falli ng and fracture, particularly in older adults (Ref).
Mechanism: Sedation is believed to be due to H1 antagonism, leading to potential CNS depressant effects; olanzapine is considered a potent H1 receptor blocker (Ref).
Risk factors:
• Pediatric patients (sedation appears to be more prevalent compared to adults) (Ref)
• Higher doses (may increase risk) (Ref)
Antipsychotics have been associated with sexual disorder in both males and females. Antipsychotic treatment has been associated with effects on all phases of sexual activity (libido, arousal, and orgasm); however, many patients with schizophrenia experience more frequent sexual dysfunction, with or without antipsychotic treatment. Decreased libido, erectile dysfunction, and abnormal orgasm have been reported with olanzapine (Ref). Conversely, there are also case reports of increased libido occurring with use (Ref).
Mechanism: Antipsychotic-induced sexual dysfunction has been attributed to many potential mechanisms, including dopamine receptor antagonism, dopamine D2 receptor antagonism in the infundibular dopaminergic pathway causing hyperprolactinemia, histamine receptor antagonism, cholinergic receptor antagonism, and alpha-adrenergic receptor antagonism (Ref). Of note, in adults, olanzapine is associated with a lower propensity for hyperprolactinemia compared to certain other antipsychotics with a high risk, such as risperidone (Ref).
Risk factors:
• Hyperprolactinemia (although a correlation with sexual dysfunction has been observed, a relationship has not been confirmed) (Ref)
• Schizophrenia (the prevalence of antipsychotic-induced sexual dysfunction in patients with schizophrenia is high [~50% to 60% compared with 31% of men in the general population]) (Ref)
• Specific antipsychotic: Contrasting evidence; some studies have found a high prevalence of sexual dysfunction with olanzapine, while other studies have reported lower rates (Ref)
Antipsychotics may impair the body’s ability to regulate core body temperature, which may cause a potentially life-threatening heatstroke during predisposing conditions such as a heat wave or strenuous exercise. There are also several case reports of potentially life-threatening hypothermia associated with olanzapine use (Ref).
Mechanism: Non-dose-related; idiosyncratic. Exact mechanism is unknown; however, body temperature is regulated by the hypothalamus with involvement of the dopamine, serotonin, and norepinephrine neurotransmitters. D2 antagonism may cause an increase in body temperature, while 5-HT2a (serotonin) receptor antagonism may cause a decrease in body temperature. Of note, olanzapine has a stronger affinity for serotonin 5-HT2a receptors compared to D2 receptors. In addition, antagonism of peripheral alpha-adrenergic receptors has also been suggested as a factor in the hypothermic effect by inhibiting peripheral responses to cooling (vasoconstriction and shivering) (Ref).
Onset: Hypothermia: Varied; antipsychotic-induced hypothermia cases indicate a typical onset in the period shortly after initiation of therapy or a dosage increase (first 7 to 10 days) (Ref)
Risk factors:
Heat stroke:
• Psychiatric illness (regardless of medication) (Ref)
• Strenuous exercise, heat exposure, dehydration, and concomitant medication possessing anticholinergic effects (Ref).
Hypothermia:
• In general, predisposing risk factors include advanced age, a cerebrovascular accident or preexisting brain damage, hypothyroidism, malnutrition, shock, sepsis, adrenal insufficiency, diabetes, disability, burns, exfoliative dermatitis benzodiazepine use, alcohol intoxication, or kidney or liver failure (Ref)
• Schizophrenia (regardless of antipsychotic use) (Ref)
Olanzapine is strongly associated with significant weight gain (increase of ≥7% from baseline) in children, adolescents, and adults, which is a component of the metabolic syndrome observed with this pharmacologic class (Ref). Compared to adult patients, adolescent patients had both greater magnitude of weight gain and greater proportion of patients with clinically significant weight gain.
Mechanism: Dose-related (Ref); multiple proposed mechanisms, including actions at serotonin, dopamine, histamine, and muscarinic receptors, with differing effects on weight gain by the different antipsychotic agents explained by differing affinity at these receptors. (Ref).
Onset: Varied; antipsychotic-induced weight gain usually occurs rapidly in the period following initiation, then gradually decreases and flattens over several months with patients continuing to gain weight in the long term (Ref).
Risk factors:
• Family history of obesity; parental BMI (Ref)
• Children and adolescents (Ref)
• Factors associated with rapid weight gain in the initial period include: Younger age, lower BMI, more robust response to antipsychotic and increase in appetite; rapid weight gain of >5% in the first month has been observed as the best predictor for significant long-term weight gain (Ref)
• Duration of therapy (although weight gain plateaus, patients continue to gain weight over time) (Ref)
• Schizophrenia (regardless of medication) is associated with a higher prevalence of obesity compared to the general population due to components of the illness, such as negative symptoms, sedentary lifestyles, and unhealthy diets (Ref)
• Specific antipsychotic: Olanzapine is considered to have a high propensity for causing weight gain in children, adolescents, and adults (Ref).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
Oral:
>10%:
Cardiovascular: Orthostatic hypotension (adults: 3% to 21%) (table 1)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
5% |
2% |
Adults |
N/A |
Immediate-release oral |
Schizophrenia |
248 |
118 |
|
21% |
N/A |
Adults |
N/A |
Immediate-release oral |
N/A |
6,030 |
N/A |
|
3% |
1% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
Endocrine & metabolic: Hypercholesterolemia (fasting, increase by ≥40 mg/dL or from baseline normal [<200 mg/dL] or borderline [≥200 mg/dL to <240 mg/dL] to high [≥240 mg/dL]: 3% to 58%), hyperprolactinemia (adolescents: 47%; adults: 30%) (table 2), increased LDL cholesterol (fasting, increase by ≥30 mg/dL or from baseline normal [<100 mg/dL] or borderline [≥100 mg/dL and <160 mg/dL] to high [≥160 mg/dL]: 7% to 48%); increased serum glucose (fasting, from baseline normal [<100 mg/dL] or borderline [≥100 and <126 mg/dL] to high [≥126 mg/dL]: ≤26%), increased serum triglycerides (fasting, increase by ≥50 mg/dL or from baseline normal [<150 mg/dL] or borderline [<150 mg/dL to <200 mg/dL] to high [≥200 mg/dL]: 9% to 71%), weight gain (adolescents: 29% to 31%, has been reported as high as 89%; adults: 5% to 6%, has been reported as high as 64%) (table 3)
|
Drug (Olanzapine) |
Placebo |
Population |
Indication |
|---|---|---|---|
|
47% |
7% |
Adolescents |
Schizophrenia or bipolar I disorder |
|
30% |
11% |
Adults |
N/A |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
29% |
4% |
Adolescents |
N/A |
Immediate-release oral |
Bipolar I Disorder |
107 |
54 |
|
31% |
9% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia |
72 |
35 |
|
6% |
1% |
Adults |
N/A |
Immediate-release oral |
Schizophrenia |
248 |
118 |
|
5% |
3% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
Gastrointestinal: Constipation (4% to 11%) (table 4), dyspepsia (adolescents: 3%; adults: 7% to 11%), increased appetite (adolescents: 17% to 29%; adults: 3% to 6%), xerostomia (adolescents: 4% to 7%; adults: 3% to 22%) (table 5)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
4% |
0% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia or Bipolar I Disorder |
179 |
89 |
|
11% |
5% |
Adults |
N/A |
Immediate-release oral |
Bipolar I Disorder |
125 |
129 |
|
9% |
3% |
Adults |
N/A |
Immediate-release oral |
Schizophrenia |
248 |
118 |
|
9% |
4% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
7% |
0% |
Adolescents |
N/A |
Immediate-release oral |
Bipolar I Disorder |
107 |
54 |
|
4% |
0% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia |
72 |
35 |
|
22% |
7% |
Adults |
N/A |
Immediate-release oral |
Bipolar I Disorder |
125 |
129 |
|
13% |
4% |
Adults |
15 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
69 |
68 |
|
5% |
4% |
Adults |
10 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
64 |
68 |
|
3% |
4% |
Adults |
5 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
65 |
68 |
|
9% |
5% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
Hepatic: Decreased serum bilirubin (adolescents: 22%), increased serum alanine aminotransferase (≥3 x ULN: 5% to 12%), increased serum aspartate aminotransferase (adolescents: 28%)
Nervous system: Akathisia (3% to 27%) (table 6), asthenia (8% to 20%), dizziness (adolescents: 7% to 8%; adults: 11% to 18% (table 7)); drowsiness (20% to 48%) (table 8), extrapyramidal reaction (adolescents: 10%; adults: 15% to 32%) (table 9); fatigue (2% to 14%), headache (adolescents: 17%), insomnia (12%), parkinsonism (8% to 20%; includes akinesia, cogwheel rigidity, hypokinesia, mask-like face) (table 10), sedated state (adolescents: 39% to 48%) (table 11)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
6% |
4% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia or Bipolar I Disorder |
179 |
89 |
|
27% |
23% |
Adults |
15 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
N/A |
N/A |
|
19% |
23% |
Adults |
10 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
N/A |
N/A |
|
16% |
23% |
Adults |
5 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
N/A |
N/A |
|
11% |
1% |
Adults |
10 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
64 |
68 |
|
10% |
1% |
Adults |
15 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
69 |
68 |
|
5% |
1% |
Adults |
N/A |
Immediate-release oral |
Schizophrenia |
248 |
118 |
|
5% |
1% |
Adults |
5 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
65 |
68 |
|
3% |
2% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
7% |
2% |
Adolescents |
N/A |
Immediate-release oral |
Bipolar I Disorder |
107 |
54 |
|
8% |
3% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia |
72 |
35 |
|
18% |
6% |
Adults |
N/A |
Immediate-release oral |
Bipolar I Disorder |
125 |
129 |
|
11% |
4% |
Adults |
N/A |
Immediate-release oral |
Schizophrenia |
248 |
118 |
|
11% |
4% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
48% |
9% |
Adolescents |
N/A |
Immediate-release oral |
Bipolar I Disorder |
107 |
54 |
|
39% |
9% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia |
72 |
35 |
|
35% |
13% |
Adults |
N/A |
Immediate-release oral |
Bipolar I Disorder |
125 |
129 |
|
39% |
16% |
Adults |
15 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
69 |
68 |
|
30% |
16% |
Adults |
10 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
64 |
68 |
|
20% |
16% |
Adults |
5 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
65 |
68 |
|
29% |
13% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
10% |
6% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia or Bipolar I Disorder |
179 |
89 |
|
32% |
16% |
Adults |
15 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
69 |
68 |
|
25% |
16% |
Adults |
10 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
64 |
68 |
|
15% |
16% |
Adults |
5 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
65 |
68 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
20% |
10% |
Adults |
15 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
69 |
68 |
|
14% |
10% |
Adults |
10 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
64 |
68 |
|
8% |
10% |
Adults |
5 ± 2.5 mg/day |
Immediate-release oral |
Schizophrenia |
65 |
68 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
48% |
9% |
Adolescents |
N/A |
Immediate-release oral |
Bipolar I Disorder |
107 |
54 |
|
39% |
9% |
Adolescents |
N/A |
Immediate-release oral |
Schizophrenia |
72 |
35 |
Miscellaneous: Accidental injury (12%)
1% to 10%:
Cardiovascular: Chest pain (3%), hypertension (2%), peripheral edema (3%), tachycardia (3%) (table 12)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
3% |
1% |
Adults |
N/A |
Immediate-release oral |
N/A |
532 |
294 |
Dermatologic: Ecchymoses (5%)
Endocrine & metabolic: Increased uric acid (4%), menstrual disease (2%; including amenorrhea, delayed menstruation, hypomenorrhea, oligomenorrhea)
Gastrointestinal: Abdominal pain (adolescents: 6%), diarrhea (adolescents: 3%), vomiting (≤4%)
Genitourinary: Breast changes (male and female adolescents: ≤2%; including discharge, enlargement, galactorrhea not associated with childbirth, gynecomastia, lactation disorder), sexual disorder (≤2%; literature suggests an incidence up to 35% [Bobes 2003]; dysfunction includes abnormal orgasm, anorgasmia, delayed ejaculation, erectile dysfunction [≤1%], decreased libido, loss of libido), urinary incontinence (adults, older adults: ≥2%), urinary tract infection (2%)
Hepatic: Increased gamma-glutamyl transferase (adolescents: 10%; adults: 2%), increased liver enzymes (adolescents: ≤8%), increased serum alkaline phosphatase (≥1%)
Nervous system: Abnormal gait (6%), articulation impairment (2%), falling (older adults: ≥2%), hypertonia (3%), personality disorder (5% to 8%), restlessness (adolescents: 3%), tremor (4% to 7%)
Neuromuscular & skeletal: Arthralgia (adults: 5%; adolescents: 2%), back pain (5%), dyskinesia (1%), limb pain (5% to 6%), muscle rigidity (adolescents: 2%)
Ophthalmic: Amblyopia (3%)
Respiratory: Cough (6%), epistaxis (adolescents: 3%), nasopharyngitis (adolescents: 4%), pharyngitis (4%), respiratory tract infection (adolescents: 3%), rhinitis (7%), sinusitis (adolescents: 3%)
Miscellaneous: Fever (≤6%)
<1%:
Cardiovascular: Syncope, vasodilation
Dermatologic: Alopecia, skin photosensitivity
Endocrine & metabolic: Heavy menstrual bleeding
Gastrointestinal: Abdominal distension, intestinal obstruction, nausea
Genitourinary: Difficulty in micturition, mastalgia, polyuria, urinary frequency, urinary retention, urinary urgency
Hematologic & oncologic: Hypoproteinemia, leukocytosis (eosinophilia), thrombocytopenia
Hepatic: Hyperbilirubinemia, liver steatosis
Hypersensitivity: Facial edema, tongue edema
Nervous system: Ataxia, cerebrovascular accident, chills, coma, dysarthria, hangover effect, seizure, stupor, suicidal tendencies
Neuromuscular & skeletal: Osteoporosis
Ophthalmic: Accommodation disturbance, dry eye syndrome, mydriasis
Respiratory: Pulmonary edema
Injection: Adverse events are reported for the extended-release suspension for injection (olanzapine pamoate [Zyprexa Relprevv]) unless otherwise indicated.
>10%: Nervous system: Headache (13% to 18%), sedated state (8% to 13%) (table 13)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
13% |
7% |
Adults |
405 mg/4 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
13% |
7% |
Adults |
300 mg/2 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
8% |
7% |
Adults |
210 mg/2 weeks |
Extended-release IM |
Schizophrenia |
106 |
98 |
1% to 10%:
Cardiovascular: Hypertension (2% to 3%), hypotension (short-acting: 2%), orthostatic hypotension (short-acting: 1%) (table 14), prolonged QT interval on ECG (≤2%) (table 15)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
1% |
0% |
Adults |
N/A |
Short-acting IM |
Schizophrenia or Bipolar I Mania |
415 |
150 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
2% |
1% |
Adults |
300 mg/2 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
0% |
1% |
Adults |
405 mg/4 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
0% |
1% |
Adults |
210 mg/2 weeks |
Extended-release IM |
Schizophrenia |
106 |
98 |
Dermatologic: Acne vulgaris (2%)
Endocrine & metabolic: Weight gain (short-term 8-week trial: 5% to 7%) (table 16)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
7% |
5% |
Adults |
300 mg/2 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
6% |
5% |
Adults |
210 mg/2 weeks |
Extended-release IM |
Schizophrenia |
106 |
98 |
|
5% |
5% |
Adults |
405 mg/4 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
Gastrointestinal: Abdominal pain (3%), diarrhea (5% to 7%), flatulence (1% to 2%), increased appetite (1% to 6%), nausea (long-acting: 4% to 5%; short-acting: <1%), vomiting (6%), xerostomia (2% to 6%) (table 17)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
6% |
1% |
Adults |
210 mg/2 weeks |
Extended-release IM |
Schizophrenia |
106 |
98 |
|
4% |
1% |
Adults |
300 mg/2 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
2% |
1% |
Adults |
405 mg/4 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
Genitourinary: Vaginal discharge (4%)
Hepatic: Increased liver enzymes (3% to 4%)
Infection: Viral infection (2%)
Local: Injection-site reaction (4%, including abscess at injection site), pain at injection site (both formulations: 1% to 4%)
Nervous system: Abnormal dreams (2%), akathisia (short-acting: 2% to 5%) (table 18), asthenia (short-acting: 2%), auditory hallucination (3%), changes in thinking (3%), dizziness (both formulations: 1% to 4%) (table 19), drowsiness (short-acting: 6%) (table 20), dysarthria (1% to 2%), extrapyramidal reaction (short-acting: 2% to 4%) (table 21), fatigue (3% to 4%), pain (2% to 3%), parkinsonism (short-acting: 2% to 4%) (table 22), restlessness (3%), sleep disturbance (2%), tremor (long-acting: 3%; short-acting: 1%)
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
5% |
0% |
Adults |
5 mg |
Short-acting IM |
Schizophrenia |
N/A |
N/A |
|
2% |
0% |
Adults |
2.5 mg |
Short-acting IM |
Schizophrenia |
48 |
45 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
4% |
2% |
Adults |
405 mg/4 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
4% |
2% |
Adults |
210 mg/2 weeks |
Extended-release IM |
Schizophrenia |
106 |
98 |
|
1% |
2% |
Adults |
300 mg/2 weeks |
Extended-release IM |
Schizophrenia |
100 |
98 |
|
4% |
2% |
Adults |
N/A |
Short-acting IM |
Schizophrenia or Bipolar I Mania |
415 |
150 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
6% |
3% |
Adults |
N/A |
Short-acting IM |
Schizophrenia or Bipolar I Mania |
415 |
150 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
4% |
0% |
Adults |
2.5 mg |
Short-acting IM |
Schizophrenia |
48 |
45 |
|
2% |
0% |
Adults |
5 mg |
Short-acting IM |
Schizophrenia |
45 |
45 |
|
Drug (Olanzapine) |
Placebo |
Population |
Dose |
Dosage Form |
Indication |
Number of Patients (Olanzapine) |
Number of Patients (Placebo) |
|---|---|---|---|---|---|---|---|
|
4% |
0% |
Adults |
2.5 mg |
Short-acting IM |
Schizophrenia |
48 |
45 |
|
2% |
0% |
Adults |
5 mg |
Short-acting IM |
Schizophrenia |
45 |
45 |
Neuromuscular & skeletal: Arthralgia (3%), back pain (5%), muscle spasm (1% to 3%), stiffness (4%)
Otic: Otalgia (4%)
Respiratory: Cough (9%), nasal congestion (7%), nasopharyngitis (3% to 6%), pharyngolaryngeal pain (3%), sneezing (2%), upper respiratory tract infection (3% to 4%)
Miscellaneous: Fever (2%)
<1%:
Cardiovascular: Syncope (short-acting)
Nervous system: Confusion, postinjection delirium/sedation syndrome, speech disturbance
Neuromuscular & skeletal: Increased creatine phosphokinase in blood specimen (short-acting)
Postmarketing (all formulations):
Cardiovascular: Atrial fibrillation (Ref), atrial flutter (Ref), pulmonary embolism, vasculitis (Ref), venous thrombosis
Dermatologic: Acute generalized exanthematous pustulosis (Ref), eruptive xanthoma (Ref), fixed drug eruption (Ref), pruritus, purpuric rash (Ref), skin rash, urticaria
Endocrine & metabolic: Decreased free T4 (Ref), diabetes mellitus (new-onset) (Ref), diabetic ketoacidosis (Ref), heatstroke (Ref), hyperglycemia (Ref), hyperglycemic hyperosmolar coma (Ref), hypertriglyceridemia (Ref), hyponatremia (Ref), increased libido (Ref), insulin resistance (Ref), SIADH (Ref)
Gastrointestinal: Dysphagia (Ref), fecal incontinence, ischemic colitis (Ref), necrotizing pancreatitis, pancreatitis (Ref), sialorrhea
Genitourinary: Priapism (Ref)
Hematologic & oncologic: Agranulocytosis (Ref), leukopenia (Ref), neutropenia (Ref), pancytopenia (Ref)
Hepatic: Hepatic injury (cholestatic or mixed), hepatitis, jaundice
Hypersensitivity: Anaphylactic shock (Ref), angioedema (Ref), drug reaction with eosinophilia and systemic symptoms (Ref), nonimmune anaphylaxis
Nervous system: Cognitive dysfunction (Ref), delirium (Ref), hypothermia (Ref), neuroleptic malignant syndrome (Ref), restless leg syndrome (Ref), somnambulism (Ref), transient ischemic attacks (Ref), withdrawal syndrome
Neuromuscular & skeletal: Dystonia (Ref), rhabdomyolysis, tardive dyskinesia (Ref)
Ophthalmic: Acute angle-closure glaucoma (Ref), oculogyric crisis (tardive) (Ref)
Renal: Interstitial nephritis (Ref)
Respiratory: Respiratory depression (Ref), sleep apnea (obstructive) (Ref)
There are no contraindications listed in the US manufacturer’s labeling.
Canadian labeling: Hypersensitivity to olanzapine or any component of the formulation.
Concerns related to adverse effects:
• Hyperprolactinemia: May cause dose-related increases in prolactin levels; clinical significance of hyperprolactinemia in patients with breast cancer or other prolactin-dependent tumors is unknown. Clinical manifestations of increased prolactin levels included menstrual-, sexual- and breast-related events.
• Suicidal ideation: The possibility of a suicide attempt is inherent in psychotic illness or bipolar disorder; use with caution in high-risk patients during initiation of therapy. Prescriptions should be written for the smallest quantity consistent with appropriate patient follow-up.
Disease-related concerns:
• Bariatric surgery: Presurgical assessment of the indication for use, symptoms and goals of therapy should be documented to enable postsurgical assessment. Olanzapine is strongly associated with significant weight gain (increase of ≥7% from baseline) (Ref). Monitor weight closely postoperatively and consider changing agent to alternative agent if weight loss goals are not being met.
• Cardiovascular disease: Use with caution in patients with severe cardiac disease, hemodynamic instability, prior myocardial infarction, ischemic heart disease, or hypercholesterolemia.
• GI motility: Use with caution in patients with decreased GI motility (eg, paralytic ileus) as anticholinergic effects may exacerbate underlying condition.
• Hepatic impairment: Use with caution in patients with hepatic disease or impairment; dose adjustment may be required. Olanzapine is a known risk factor for the development of steatotic liver disease; elevations in liver chemistries have been observed in patients receiving olanzapine (Gunther 2023; Todorović Vukotić 2021).
• Parkinson disease: Use with caution in patients with Parkinson disease; antipsychotic may aggravate motor disturbances (APA [Reus 2016]).
• Seizures: Use with caution in patients at risk of seizures, including those with a history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications that may lower seizure threshold. Older adult patients may be at increased risk of seizures because of an increased prevalence of predisposing factors.
• Urinary retention (eg, benign prostatic hyperplasia): Use with caution in patients with urinary retention as anticholinergic effects may exacerbate underlying condition.
Special populations:
• Tobacco smokers: Olanzapine levels may be lower in patients who smoke. Smokers may require an increased daily dose (Tsuda 2014). Discontinuation of smoking should also merit a dose reduction as olanzapine levels may be higher be smoking cessations occurs.
Dosage form-specific concerns:
• IM formulations: There are two Zyprexa formulations for IM injection: Zyprexa Relprevv is a long-acting injectable formulation and Zyprexa IntraMuscular is short-acting.
Long-acting injectable (Zyprexa Relprevv):
Postinjection delirium/sedation syndrome: Upon determining alert status, patient should be escorted to their destination and not drive or operate heavy machinery for the remainder of the day.
Unexplained deaths: Two unexplained deaths in patients who received Zyprexa Relprevv have been reported. The patients died 3 to 4 days after receiving an appropriate dose of the drug. Both patients were found to have high blood concentrations of olanzapine postmortem. It is unclear if these deaths were the result of postinjection delirium sedation syndrome (PDSS) (FDA Safety Communication 2013).
Short-acting IM injection (Zyprexa IntraMuscular): Patients should remain recumbent if drowsy/dizzy until hypotension, bradycardia, and/or hypoventilation have been ruled out. Closely monitor for orthostasis prior to any repeat dosing.
• Phenylalanine: Some products may contain phenylalanine.
• Polysorbate 80: Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson 2002; Lucente 2000; Shelley 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade 1986; CDC 1984). See manufacturer's labeling.
Other warnings/precautions:
• Discontinuation of therapy: When discontinuing antipsychotic therapy, gradually taper antipsychotics to avoid physical withdrawal symptoms and rebound symptoms (APA [Keepers 2020]; WFSBP [Hasan 2012]). Withdrawal symptoms may include agitation, alternating feelings of warmth and cold, anxiety, diaphoresis, dyskinesia, GI symptoms, insomnia, irritability, myalgia, paresthesia, psychosis, restlessness, rhinorrhea, tremor and vertigo (Lambert 2007; Moncrieff 2020). The risk of withdrawal symptoms is highest following abrupt discontinuation of highly anticholinergic or dopaminergic antipsychotics (Cerovecki 2013). Patients with chronic symptoms, repeated relapses, and clear diagnostic features of schizophrenia are at risk for poor outcomes if medications are discontinued (APA [Keepers 2020]).
• IV administration: IV administration has been studied in emergency department and inpatient settings, where patients can be closely monitored for respiratory depression (ie, pulse oximetry) (Chan 2013; Cole 2017; Hunt 2021; Martel 2016; Taylor 2017).
Pediatric psychiatric disorders are frequently serious mental disorders which present with variable symptoms that do not always match adult diagnostic criteria. Conduct a thorough diagnostic evaluation and carefully consider risks of psychotropic medication before initiation in pediatric patients. Medication therapy for pediatric patients with bipolar disorder and schizophrenia is indicated as part of a total treatment program that frequently includes educational, psychological, and social interventions.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Solution Reconstituted, Intramuscular:
ZyPREXA: 10 mg (1 ea)
Generic: 10 mg (1 ea)
Solution Reconstituted, Intramuscular [preservative free]:
Generic: 10 mg (1 ea)
Suspension Reconstituted, Intramuscular [preservative free]:
ZyPREXA Relprevv: 210 mg (1 ea [DSC]); 300 mg (1 ea [DSC]); 405 mg (1 ea [DSC]) [contains polysorbate 80]
Tablet, Oral:
ZyPREXA: 2.5 mg [DSC], 5 mg [DSC], 7.5 mg [DSC], 10 mg [DSC]
ZyPREXA: 15 mg [DSC] [contains fd&c blue #2 (indigo carm) aluminum lake]
ZyPREXA: 20 mg
Generic: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg
Tablet Disintegrating, Oral:
ZyPREXA Zydis: 5 mg [DSC], 10 mg [DSC], 15 mg [DSC], 20 mg [DSC] [contains aspartame, methylparaben sodium, propylparaben sodium]
Generic: 5 mg, 10 mg, 15 mg, 20 mg
May be product dependent
Solution (reconstituted) (OLANZapine Intramuscular)
10 mg (per each): $41.50 - $47.39
Solution (reconstituted) (ZyPREXA Intramuscular)
10 mg (per each): $60.31
Tablet, orally-disintegrating (OLANZapine Oral)
5 mg (per each): $2.08 - $14.27
10 mg (per each): $3.05 - $20.97
15 mg (per each): $4.50 - $30.93
20 mg (per each): $5.94 - $40.89
Tablets (OLANZapine Oral)
2.5 mg (per each): $10.42 - $11.20
5 mg (per each): $12.28 - $13.22
7.5 mg (per each): $14.90 - $16.08
10 mg (per each): $18.52 - $19.92
15 mg (per each): $27.77 - $29.87
20 mg (per each): $37.03 - $39.83
Tablets (ZyPREXA Oral)
20 mg (per each): $62.59
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Solution Reconstituted, Intramuscular:
ZyPREXA: 10 mg (5 mL)
Generic: 10 mg ([DSC])
Tablet, Oral:
ZyPREXA: 2.5 mg, 5 mg, 7.5 mg, 10 mg [contains polysorbate 80]
ZyPREXA: 15 mg [contains fd&c blue #2 (indigo carm) aluminum lake]
ZyPREXA: 20 mg
Generic: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg
Tablet Disintegrating, Oral:
ZyPREXA Zydis: 5 mg, 10 mg, 15 mg, 20 mg [contains aspartame, methylparaben sodium, propylparaben sodium]
Generic: 5 mg, 10 mg, 15 mg, 20 mg
Short-acting injection: May be administered IM or IV (off-label route); do not administer injection subcutaneously. For IM administration, inject slowly, deep into muscle. For off-label IV route, administer by rapid IV push (Ref). If dizziness and/or drowsiness are noted, patient should remain recumbent until examination indicates postural hypotension and/or bradycardia are not a problem.
Extended-release injection: For IM gluteal injection only; do not administer IV or subcutaneously. After needle insertion into muscle, aspirate to verify that no blood appears. Do not massage injection site. Use diluent, syringes, and needles provided in convenience kit; obtain a new kit if aspiration of blood occurs.
Tablet: May be administered without regard to meals.
Orally-disintegrating: Remove from foil blister by peeling back (do not push tablet through the foil); place tablet in mouth immediately upon removal; tablet dissolves rapidly in saliva and may be swallowed with or without liquid. May be administered with or without food/meals.
Oral:
Tablet: May be administered with or without food.
Orally disintegrating tablet: Remove from foil blister by peeling back foil (do not push tablet through the foil); place tablet in mouth immediately upon removal; tablet dissolves rapidly in saliva and may be swallowed with or without liquid. May be administered with or without food/meals.
Parenteral: IM (short-acting): Administer IM; inject slowly, deep into muscle mass. If dizziness and/or drowsiness are noted, patient should remain recumbent until examination indicates postural hypotension and/or bradycardia are not a problem.
An FDA-approved patient medication guide, which is available with the product information and as follows, must be dispensed with this medication:
Zyprexa and Zyprexa Zydis: https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/020592s077,021086s050,021253s047s066lbl.pdf#page=37
Zyprexa Relprevv: https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/022173s047lbl.pdf#page=32
Agitation/Aggression (acute) associated with psychiatric disorders (short-acting injection): Treatment of acute agitation associated with schizophrenia and bipolar I mania.
Bipolar disorder (oral): Treatment of acute mania, acute episodes with mixed features of bipolar I disorder (as monotherapy or in combination with lithium or valproate), and maintenance treatment; treatment of bipolar depression in combination with fluoxetine.
Major depressive disorder (unipolar), treatment resistant (oral): Treatment of treatment-resistant depression in combination with fluoxetine.
Schizophrenia (oral, long-acting injection): Treatment of the manifestations of schizophrenia.
Agitation/Aggression and psychosis associated with dementia; Anorexia nervosa; Bipolar disorder, hypomania; Cancer-related anorexia and cachexia; Chemotherapy-induced acute and delayed nausea or vomiting (high emetic risk [>90%]), prevention; Chemotherapy-induced breakthrough nausea or vomiting, treatment; Delirium, hyperactive (ICU treatment); Delirium, hyperactive (non-ICU treatment); Delusional infestation (delusional parasitosis); Huntington disease-associated chorea; Major depressive disorder (unipolar) with psychotic features; Nausea and vomiting associated with advanced cancer; Obsessive-compulsive disorder, treatment resistant; Postpartum psychosis
OLANZapine may be confused with olsalazine, QUEtiapine
ZyPREXA may be confused with CeleXA, Reprexain, Zestril, ZyrTEC
ZyPREXA Zydis may be confused with Zelapar, zolpidem, zapelon
ZyPREXA Relprevv may be confused with ZyPREXA IntraMuscular
Beers Criteria: Antipsychotics are identified in the Beers Criteria as potentially inappropriate medications to be avoided in patients 65 years and older due to an increased risk of stroke and a greater rate of cognitive decline and mortality in patients with dementia. Evidence also suggests there may be an increased risk of mortality with use independent of dementia. Avoid antipsychotics for behavioral problems associated with dementia or delirium unless alternative nonpharmacologic therapies have failed and patient may harm self or others. In addition, antipsychotics should be used with caution in older adults due to their potential to cause or exacerbate syndrome of inappropriate antidiuretic hormone secretion (SIADH) or hyponatremia; monitor sodium closely with initiation or dosage adjustments in older adults. Use of antipsychotics may be appropriate for labeled indications including schizophrenia, bipolar disorder, Parkinson disease psychosis, adjunctive therapy in major depressive disorder, or for short-term use as an antiemetic (Beers Criteria [AGS 2023]).
Antipsychotics are identified in the Screening Tool of Older Person's Prescriptions (STOPP) criteria as a potentially inappropriate medication in older adults (≥65 years of age) with a history of recurrent falls due to an increased risk of falls. Initiation is not recommended for treatment of sleep disorder. Some disease states of concern include dementia, parkinsonism, dysphagia, benign prostatic hyperplasia, urinary retention, and coronary, cerebral, or peripheral vascular disease (O’Mahony 2023).
KIDs List: Olanzapine, when used long term (>24 weeks) in pediatric patients <18 years of age, is identified on the Key Potentially Inappropriate Drugs in Pediatrics (KIDs) list and should be used with caution due to risk of metabolic syndrome (weight gain, hyperlipidemia, hyperglycemia) (strong recommendation; high quality of evidence) (PPA [Meyers 2020]).
Substrate of CYP1A2 (Major), CYP2D6 (Minor), UGT1A4; Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential;
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Acetylcholinesterase Inhibitors: May decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Acetylcholinesterase Inhibitors. Risk C: Monitor
Aclidinium: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Acrivastine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Acrivastine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Agents with Clinically Relevant Anticholinergic Effects: May increase anticholinergic effects of OLANZapine. Risk C: Monitor
Agents With Seizure Threshold Lowering Potential: May increase adverse/toxic effects of OLANZapine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Alcohol (Ethyl): CNS Depressants may increase CNS depressant effects of Alcohol (Ethyl). Risk C: Monitor
Alizapride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Amifampridine: Agents With Seizure Threshold Lowering Potential may increase neuroexcitatory and/or seizure-potentiating effects of Amifampridine. Risk C: Monitor
Amisulpride (Oral): Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Amisulpride (Oral). Specifically, the risk of seizures may be increased. Risk C: Monitor
Amisulpride (Oral): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Amisulpride (Oral): May increase QTc-prolonging effects of QT-prolonging Agents (Moderate Risk). Risk C: Monitor
Anti-Parkinson Agents (Dopamine Agonist): Antipsychotic Agents (Second Generation [Atypical]) may decrease therapeutic effects of Anti-Parkinson Agents (Dopamine Agonist). Management: Consider avoiding atypical antipsychotic use in patients with Parkinson disease. If an atypical antipsychotic is necessary, consider using clozapine, quetiapine, or ziprasidone at lower initial doses, or a non-dopamine antagonist (eg, pimavanserin). Risk D: Consider Therapy Modification
Antidiabetic Agents: Hyperglycemia-Associated Agents may decrease therapeutic effects of Antidiabetic Agents. Risk C: Monitor
Antihepaciviral Combination Products: May decrease serum concentration of OLANZapine. Risk C: Monitor
ARIPiprazole Lauroxil: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of ARIPiprazole Lauroxil. Specifically, the risk of seizures may be increased. Risk C: Monitor
ARIPiprazole: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of ARIPiprazole. Specifically, the risk of seizures may be increased. Risk C: Monitor
Articaine: May increase CNS depressant effects of CNS Depressants. Management: Consider reducing the dose of articaine if possible when used in patients who are also receiving CNS depressants. Monitor for excessive CNS depressant effects with any combined use. Risk D: Consider Therapy Modification
Asenapine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Asenapine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Azelastine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Azithromycin (Systemic): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Benperidol: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Benperidol. Risk C: Monitor
Benperidol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Benperidol. Specifically, the risk of seizures may be increased. Risk C: Monitor
Benperidol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Benzgalantamine-Galantamine: May increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
Benzodiazepines: May increase adverse/toxic effects of OLANZapine. Management: Monitor closely for hypotension, respiratory or central nervous system depression, and bradycardia if olanzapine is combined with benzodiazepines. Use of parenteral benzodiazepines with IM olanzapine is not recommended. Risk C: Monitor
Benztropine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Benztropine. Risk C: Monitor
Biperiden: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Biperiden. Risk C: Monitor
Blonanserin: CNS Depressants may increase CNS depressant effects of Blonanserin. Management: Use caution if coadministering blonanserin and CNS depressants; dose reduction of the other CNS depressant may be required. Strong CNS depressants should not be coadministered with blonanserin. Risk D: Consider Therapy Modification
Blood Pressure Lowering Agents: May increase hypotensive effects of Antipsychotic Agents (Second Generation [Atypical]). Risk C: Monitor
Bornaprine: May increase adverse/toxic effects of Antipsychotic Agents. Specifically, tardive dyskinesia symptoms may be potentiated. Risk C: Monitor
Botulinum Toxin-Containing Products: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Brexanolone: CNS Depressants may increase CNS depressant effects of Brexanolone. Risk C: Monitor
Brexpiprazole: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Brexpiprazole. Specifically, the risk of seizures may be increased. Risk C: Monitor
Brimonidine (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Broccoli: May decrease serum concentration of CYP1A2 Substrates (High risk with Inducers). Risk C: Monitor
Bromopride: May increase adverse/toxic effects of Antipsychotic Agents. Risk X: Avoid
Bromperidol: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Buclizine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Buclizine. Risk C: Monitor
Buclizine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Buprenorphine: CNS Depressants may increase CNS depressant effects of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Risk D: Consider Therapy Modification
BuPROPion: May increase neuroexcitatory and/or seizure-potentiating effects of Agents With Seizure Threshold Lowering Potential. Risk C: Monitor
BusPIRone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Cabergoline: May decrease therapeutic effects of Antipsychotic Agents. Risk X: Avoid
Cannabinoid-Containing Products: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of Cannabinoid-Containing Products. Risk C: Monitor
Cannabinoid-Containing Products: CNS Depressants may increase CNS depressant effects of Cannabinoid-Containing Products. Risk C: Monitor
Cannabis: May decrease serum concentration of CYP1A2 Substrates (High risk with Inducers). Risk C: Monitor
CarBAMazepine: May decrease serum concentration of OLANZapine. Risk C: Monitor
Cariprazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Cariprazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Ceritinib: May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Cetirizine (Systemic): May increase CNS depressant effects of CNS Depressants. Management: Consider avoiding this combination if possible. If required, monitor for excessive sedation or CNS depression, limit the dose and duration of combination therapy, and consider CNS depressant dose reductions. Risk D: Consider Therapy Modification
Chloral Hydrate/Chloral Betaine: CNS Depressants may increase CNS depressant effects of Chloral Hydrate/Chloral Betaine. Management: Consider alternatives to the use of chloral hydrate or chloral betaine and additional CNS depressants. If combined, consider a dose reduction of either agent and monitor closely for enhanced CNS depressive effects. Risk D: Consider Therapy Modification
Chlormethiazole: May increase CNS depressant effects of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Risk D: Consider Therapy Modification
Chlorphenesin Carbamate: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Chlorprothixene: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Chlorprothixene. Risk C: Monitor
Cimetropium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Cimetropium. Risk X: Avoid
Clarithromycin: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of Clarithromycin. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
ClomiPRAMINE: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of ClomiPRAMINE. QT-prolonging Antipsychotics (Moderate Risk) may increase serotonergic effects of ClomiPRAMINE. This could result in serotonin syndrome. Management: Monitor for QTc interval prolongation, ventricular arrhythmias, and serotonin syndrome/serotonin toxicity (SS/ST) or NMS when these agents are combined. Patients with additional risk factors for QTc prolongation or SS/ST may be at even higher risk. Risk C: Monitor
Clothiapine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Clothiapine. Specifically, the risk of seizures may be increased. Risk C: Monitor
CloZAPine: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of CloZAPine. Management: Consider alternatives to this combination whenever possible. If combined, monitor closely for signs and symptoms of gastrointestinal hypomotility and consider prophylactic laxative treatment. Risk D: Consider Therapy Modification
CNS Depressants: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Cyclizine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
CYP1A2 Inducers (Moderate): May decrease serum concentration of OLANZapine. Risk C: Monitor
CYP1A2 Inducers (Weak): May decrease serum concentration of OLANZapine. Risk C: Monitor
CYP1A2 Inhibitors (Moderate): May increase serum concentration of OLANZapine. Risk C: Monitor
CYP1A2 Inhibitors (Strong): May increase serum concentration of OLANZapine. Risk C: Monitor
Dantrolene: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Daridorexant: May increase CNS depressant effects of CNS Depressants. Management: Dose reduction of daridorexant and/or any other CNS depressant may be necessary. Use of daridorexant with alcohol is not recommended, and the use of daridorexant with any other drug to treat insomnia is not recommended. Risk D: Consider Therapy Modification
Darifenacin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Darifenacin. Risk C: Monitor
Deutetrabenazine: May increase adverse/toxic effects of Antipsychotic Agents. Specifically, the risk for akathisia, parkinsonism, or neuroleptic malignant syndrome may be increased. Risk C: Monitor
DexmedeTOMIDine: CNS Depressants may increase CNS depressant effects of DexmedeTOMIDine. Management: Monitor for increased CNS depression during coadministration of dexmedetomidine and CNS depressants, and consider dose reductions of either agent to avoid excessive CNS depression. Risk D: Consider Therapy Modification
Dexmethylphenidate-Methylphenidate: Antipsychotic Agents may increase adverse/toxic effects of Dexmethylphenidate-Methylphenidate. Dexmethylphenidate-Methylphenidate may increase adverse/toxic effects of Antipsychotic Agents. Specifically, the risk of extrapyramidal symptoms may be increased when these agents are combined. Risk C: Monitor
Diazoxide Choline: May increase serum concentration of CYP1A2 Substrates (High risk with Inhibitors). Risk X: Avoid
Dicyclomine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dicyclomine. Risk C: Monitor
Difelikefalin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Difenoxin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Dihydralazine: CNS Depressants may increase hypotensive effects of Dihydralazine. Risk C: Monitor
Dimethindene (Systemic): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dimethindene (Systemic). Risk C: Monitor
Dimethindene (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Domperidone: QT-prolonging Agents (Moderate Risk) may increase QTc-prolonging effects of Domperidone. Risk X: Avoid
Donepezil: May increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
Dothiepin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Doxylamine: CNS Depressants may increase CNS depressant effects of Doxylamine. Risk C: Monitor
DroNABinol: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of DroNABinol. Risk X: Avoid
DroPERidol: May increase CNS depressant effects of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Risk D: Consider Therapy Modification
Eluxadoline: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of Eluxadoline. Risk X: Avoid
Emedastine (Systemic): May increase CNS depressant effects of CNS Depressants. Management: Consider avoiding this combination if possible. If required, monitor for excessive sedation or CNS depression, limit the dose and duration of combination therapy, and consider CNS depressant dose reductions. Risk C: Monitor
Encorafenib: May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Entacapone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Esketamine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Fesoterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Fesoterodine. Risk C: Monitor
Fexinidazole: May increase QTc-prolonging effects of OLANZapine. Fexinidazole may increase serum concentration of OLANZapine. Management: Monitor for increased olanzapine toxicities, including QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Flunarizine: CNS Depressants may increase CNS depressant effects of Flunarizine. Risk X: Avoid
Flunitrazepam: CNS Depressants may increase CNS depressant effects of Flunitrazepam. Management: Reduce the dose of CNS depressants when combined with flunitrazepam and monitor patients for evidence of CNS depression (eg, sedation, respiratory depression). Use non-CNS depressant alternatives when available. Risk D: Consider Therapy Modification
Fluorouracil Products: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of Fluorouracil Products. Management: Monitor for QTc interval prolongation and ventricular arrhythmias, including torsades de pointes when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Flupentixol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Flupentixol. Specifically, the risk of seizures may be increased. Risk C: Monitor
Flupentixol: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of Flupentixol. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
FluPHENAZine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of FluPHENAZine. Specifically, the risk of seizures may be increased. Risk C: Monitor
FluPHENAZine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Gastrointestinal Agents (Prokinetic): Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Gastrointestinal Agents (Prokinetic). Risk C: Monitor
Gepotidacin: May decrease anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Glucagon: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Risk C: Monitor
Glycopyrrolate (Oral Inhalation): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Glycopyrrolate (Oral Inhalation). Risk X: Avoid
Glycopyrrolate (Systemic): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Glycopyrrolate (Systemic). Risk C: Monitor
Glycopyrronium (Topical): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Guanethidine: Antipsychotic Agents may decrease therapeutic effects of Guanethidine. Risk C: Monitor
Haloperidol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Haloperidol. Specifically, the risk of seizures may be increased. Risk C: Monitor
Haloperidol: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of Haloperidol. Management: Monitor for QTc interval prolongation, ventricular arrhythmias, and serotonin syndrome/serotonin toxicity (SS/ST) or NMS when these agents are combined. Patients with additional risk factors for QTc prolongation or SS/ST may be at even higher risk. Risk C: Monitor
Huperzine A: May increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
HydrOXYzine: May increase CNS depressant effects of CNS Depressants. Management: Consider a decrease in the CNS depressant dose, as appropriate, when used together with hydroxyzine. Increase monitoring of signs/symptoms of CNS depression in any patient receiving hydroxyzine together with another CNS depressant. Risk D: Consider Therapy Modification
Iloperidone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Iloperidone. Specifically, the risk of seizures may be increased. Risk C: Monitor
Imipramine: May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). QT-prolonging Antipsychotics (Moderate Risk) may increase serotonergic effects of Imipramine. This could result in serotonin syndrome. Management: Monitor for QTc interval prolongation, ventricular arrhythmias, and serotonin syndrome/serotonin toxicity (SS/ST) or NMS when these agents are combined. Patients with additional risk factors for QTc prolongation or SS/ST may be at even higher risk. Risk C: Monitor
Iohexol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Iohexol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iohexol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic antiseizure drugs. Risk D: Consider Therapy Modification
Iomeprol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Iomeprol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iomeprol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic antiseizure drugs. Risk D: Consider Therapy Modification
Iopamidol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Iopamidol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iopamidol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic antiseizure drugs. Risk D: Consider Therapy Modification
Ipratropium (Nasal): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Ipratropium (Oral Inhalation): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Itopride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Itopride. Risk C: Monitor
Ixabepilone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Kava Kava: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ketotifen (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Kratom: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Lemborexant: May increase CNS depressant effects of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Risk D: Consider Therapy Modification
Levocetirizine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Levoketoconazole: QT-prolonging Agents (Moderate Risk) may increase QTc-prolonging effects of Levoketoconazole. Risk X: Avoid
Levosulpiride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Levosulpiride. Risk X: Avoid
Lithium: May increase neurotoxic effects of Antipsychotic Agents. Lithium may decrease serum concentration of Antipsychotic Agents. Specifically noted with chlorpromazine. Risk C: Monitor
Lofepramine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lofexidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lonafarnib: May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Loxapine: CNS Depressants may increase CNS depressant effects of Loxapine. Management: Consider reducing the dose of CNS depressants administered concomitantly with loxapine due to an increased risk of respiratory depression, sedation, hypotension, and syncope. Risk D: Consider Therapy Modification
Lumateperone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Lumateperone. Specifically, the risk of seizures may be increased. Risk C: Monitor
Lurasidone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Lurasidone. Specifically, the risk of seizures may be increased. Risk C: Monitor
Magnesium Sulfate: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Maprotiline: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Maprotiline. Risk C: Monitor
Melitracen [INT]: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Melperone: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Mequitazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Metergoline: Antipsychotic Agents may decrease therapeutic effects of Metergoline. Metergoline may decrease therapeutic effects of Antipsychotic Agents. Risk C: Monitor
Metergoline: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Methotrimeprazine: CNS Depressants may increase CNS depressant effects of Methotrimeprazine. Methotrimeprazine may increase CNS depressant effects of CNS Depressants. Management: Reduce the usual dose of CNS depressants by 50% if starting methotrimeprazine until the dose of methotrimeprazine is stable. Monitor patient closely for evidence of CNS depression. Risk D: Consider Therapy Modification
Methoxyflurane: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Methscopolamine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Methscopolamine. Risk C: Monitor
Metoclopramide: May increase adverse/toxic effects of Antipsychotic Agents. Risk X: Avoid
MetyroSINE: CNS Depressants may increase sedative effects of MetyroSINE. Risk C: Monitor
MetyroSINE: May increase adverse/toxic effects of Antipsychotic Agents. Specifically, the risk for extrapyramidal symptoms and excessive sedation may be increased. Risk C: Monitor
Minocycline (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Mirabegron: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Mirabegron. Risk C: Monitor
Molindone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Molindone. Specifically, the risk of seizures may be increased. Risk C: Monitor
Moxonidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Nabilone: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Nalfurafine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Nirmatrelvir and Ritonavir: May decrease serum concentration of OLANZapine. Risk C: Monitor
Nitroglycerin: Agents with Clinically Relevant Anticholinergic Effects may decrease absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Risk C: Monitor
Noscapine: CNS Depressants may increase adverse/toxic effects of Noscapine. Risk X: Avoid
Olopatadine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Ondansetron: May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation, ventricular arrhythmias, including torsades de pointes, when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Opicapone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Opioid Agonists: CNS Depressants may increase CNS depressant effects of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider Therapy Modification
Opipramol: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Opipramol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Orphenadrine: CNS Depressants may increase CNS depressant effects of Orphenadrine. Risk X: Avoid
Oxatomide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Oxomemazine: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Oxybate Salt Products: CNS Depressants may increase CNS depressant effects of Oxybate Salt Products. Management: Consider alternatives to this combination when possible. If combined, dose reduction or discontinuation of one or more CNS depressants (including the oxybate salt product) should be considered. Interrupt oxybate salt treatment during short-term opioid use Risk D: Consider Therapy Modification
OxyBUTYnin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of OxyBUTYnin. Risk C: Monitor
OxyCODONE: CNS Depressants may increase CNS depressant effects of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider Therapy Modification
Paliperidone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Paliperidone. Specifically, the risk of seizures may be increased. Risk C: Monitor
Paliperidone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Paraldehyde: CNS Depressants may increase CNS depressant effects of Paraldehyde. Risk X: Avoid
Pentamidine (Systemic): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Perampanel: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Perazine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Periciazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Periciazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Periciazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Perphenazine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Perphenazine. Risk C: Monitor
Perphenazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Perphenazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Pimozide: May increase QTc-prolonging effects of QT-prolonging Agents (Moderate Risk). Risk X: Avoid
Pipamperone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Pipamperone. Specifically, the risk of seizures may be increased. Risk X: Avoid
Piperaquine: QT-prolonging Agents (Moderate Risk) may increase QTc-prolonging effects of Piperaquine. Risk X: Avoid
Piribedil: Antipsychotic Agents may decrease therapeutic effects of Piribedil. Piribedil may decrease therapeutic effects of Antipsychotic Agents. Management: Use of piribedil with antiemetic neuroleptics is contraindicated, and use with antipsychotic neuroleptics, except for clozapine, is not recommended. Risk X: Avoid
Pizotifen: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Polyethylene Glycol-Electrolyte Solution: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Polyethylene Glycol-Electrolyte Solution. Specifically, the risk of seizure may be increased. Risk C: Monitor
Potassium Chloride: Agents with Clinically Relevant Anticholinergic Effects may increase ulcerogenic effects of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Risk X: Avoid
Potassium Citrate: Agents with Clinically Relevant Anticholinergic Effects may increase ulcerogenic effects of Potassium Citrate. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium citrate. Risk X: Avoid
Pramlintide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. These effects are specific to the GI tract. Risk X: Avoid
Primaquine: May increase serum concentration of CYP1A2 Substrates (High risk with Inhibitors). Risk C: Monitor
Procarbazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Prochlorperazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Prochlorperazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Promazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Promazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Promethazine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Promethazine. Risk C: Monitor
Propantheline: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Propantheline. Risk C: Monitor
Propiverine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Propofol: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of Propofol. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-prolonging Agents (Highest Risk): May increase QTc-prolonging effects of OLANZapine. Management: Consider alternatives to this combination. Patients with other risk factors (eg, older age, female sex, bradycardia, hypokalemia, hypomagnesemia, heart disease, and higher drug concentrations) are likely at greater risk for these toxicities. Risk D: Consider Therapy Modification
QT-prolonging Antidepressants (Moderate Risk): QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of QT-prolonging Antidepressants (Moderate Risk). QT-prolonging Antipsychotics (Moderate Risk) may increase serotonergic effects of QT-prolonging Antidepressants (Moderate Risk). This could result in serotonin syndrome. Management: Monitor for QTc interval prolongation, ventricular arrhythmias, and serotonin syndrome/serotonin toxicity (SS/ST) or NMS when these agents are combined. Patients with additional risk factors for QTc prolongation or SS/ST may be at even higher risk. Risk C: Monitor
QT-prolonging Antipsychotics (Moderate Risk): May increase QTc-prolonging effects of OLANZapine. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-prolonging Class IC Antiarrhythmics (Moderate Risk): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-Prolonging Inhalational Anesthetics (Moderate Risk): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-prolonging Kinase Inhibitors (Moderate Risk): OLANZapine may increase QTc-prolonging effects of QT-prolonging Kinase Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-prolonging Miscellaneous Agents (Moderate Risk): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QT-prolonging Quinolone Antibiotics (Moderate Risk): May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Quinagolide: Antipsychotic Agents may decrease therapeutic effects of Quinagolide. Risk C: Monitor
Ramosetron: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of Ramosetron. Risk C: Monitor
Revefenacin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Revefenacin. Risk X: Avoid
RifAMPin: May decrease serum concentration of OLANZapine. Risk C: Monitor
Rilmenidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
RisperiDONE: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of RisperiDONE. Specifically, the risk of seizures may be increased. Risk C: Monitor
Ritonavir: May decrease serum concentration of OLANZapine. Risk C: Monitor
Rivastigmine: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Rivastigmine. Rivastigmine may decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Management: Use of rivastigmine with an anticholinergic agent is not recommended unless clinically necessary. If the combination is necessary, monitor for reduced anticholinergic effects. Risk D: Consider Therapy Modification
Ropeginterferon Alfa-2b: CNS Depressants may increase adverse/toxic effects of Ropeginterferon Alfa-2b. Specifically, the risk of neuropsychiatric adverse effects may be increased. Management: Avoid coadministration of ropeginterferon alfa-2b and other CNS depressants. If this combination cannot be avoided, monitor patients for neuropsychiatric adverse effects (eg, depression, suicidal ideation, aggression, mania). Risk D: Consider Therapy Modification
Saquinavir: QT-prolonging Antipsychotics (Moderate Risk) may increase QTc-prolonging effects of Saquinavir. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Scopolamine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Scopolamine. Risk C: Monitor
Secretin: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Risk D: Consider Therapy Modification
Serotonergic Agents (High Risk): May increase adverse/toxic effects of Antipsychotic Agents. Specifically, serotonergic agents may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotic Agents may increase serotonergic effects of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Risk C: Monitor
Sertindole: May increase QTc-prolonging effects of QT-prolonging Agents (Moderate Risk). Risk X: Avoid
Sodium Phosphates: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Sodium Phosphates. Specifically, the risk of seizure or loss of consciousness may be increased in patients with significant sodium phosphate-induced fluid or electrolyte abnormalities. Risk C: Monitor
Sofpironium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Sofpironium. Risk X: Avoid
Sulpiride: Antipsychotic Agents may increase adverse/toxic effects of Sulpiride. Risk X: Avoid
Suvorexant: CNS Depressants may increase CNS depressant effects of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Risk D: Consider Therapy Modification
Tetrabenazine: May increase adverse/toxic effects of Antipsychotic Agents. Specifically, the risk for NMS and extrapyramidal symptoms may be increased. Risk C: Monitor
Thalidomide: CNS Depressants may increase CNS depressant effects of Thalidomide. Risk X: Avoid
Thiazide and Thiazide-Like Diuretics: Agents with Clinically Relevant Anticholinergic Effects may increase serum concentration of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Thioridazine: QT-prolonging Agents (Moderate Risk) may increase QTc-prolonging effects of Thioridazine. Risk X: Avoid
Thiothixene: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Thiothixene. Risk C: Monitor
Thiothixene: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Thiothixene. Specifically, the risk of seizures may be increased. Risk C: Monitor
Tiapride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Tiapride. Risk C: Monitor
Tiotropium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tiotropium. Risk X: Avoid
Tobacco (Smoked): May decrease therapeutic effects of OLANZapine. Tobacco (Smoked) may decrease serum concentration of OLANZapine. Risk C: Monitor
Tolterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tolterodine. Risk C: Monitor
Topiramate: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Topiramate. Risk C: Monitor
Trifluoperazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Trifluoperazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Trimeprazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Trimethobenzamide: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Trimethobenzamide. Risk C: Monitor
Trospium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Trospium. Risk C: Monitor
Umeclidinium: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Valerian: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Valproic Acid and Derivatives: May decrease serum concentration of OLANZapine. Risk C: Monitor
Voriconazole: May increase QTc-prolonging effects of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
Zolpidem: CNS Depressants may increase CNS depressant effects of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Risk D: Consider Therapy Modification
Zuclopenthixol: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Zuclopenthixol. Risk C: Monitor
Zuclopenthixol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Zuclopenthixol. Specifically, the risk of seizures may be increased. Risk C: Monitor
Zuranolone: May increase CNS depressant effects of CNS Depressants. Management: Consider alternatives to the use of zuranolone with other CNS depressants or alcohol. If combined, consider a zuranolone dose reduction and monitor patients closely for increased CNS depressant effects. Risk D: Consider Therapy Modification
Evaluate pregnancy status and provide preconception counseling prior to initiating treatment in patients who could become pregnant (APA [Keepers 2020]; BAP [McAllister-Williams 2017]; CANMAT [Yatham 2018]). Patients effectively treated may continue their current antipsychotic medication when planning a pregnancy unless contraindications exist (ACOG 2023; BAP [McAllister-Williams 2017]); the lowest effective dose and avoidance of polytherapy is recommended (BAP [Barnes 2020]; BAP [McAllister-Williams 2017]; CANMAT [Yatham 2018]). Management of mental health conditions in patients who could become pregnant should be based on a shared decision-making process that considers the possibility of pregnancy during treatment and the risks of discontinuing antipsychotic therapy (ACOG 2023; BAP [McAllister-Williams 2017]; CANMAT [Yatham 2018]).
Antipsychotic agents may be associated with sexual dysfunction. Some second generation (atypical) antipsychotics (SGAs) may cause hyperprolactinemia, resulting in menstrual disorders or impaired spermatogenesis. Consider changing to a medication that is prolactin-sparing, such as olanzapine, in patients with clinical symptoms. Contraception should be provided if pregnancy is not desired as unintended pregnancies may occur when changing to a prolactin-sparing medication (APA [Keepers 2020]; BAP [McAllister-Williams 2017]).
Olanzapine crosses the placenta in variable concentrations (Schoretsanitis 2020).
Outcome data following exposure to second generation (atypical) antipsychotics (SGAs) as a class do not show a significant increased risk of major congenital malformations (BAP [Barnes 2020]); however, specific outcomes vary due to differences in study design (BAP [McAllister-Williams 2017]; Ellfolk 2021; Ennis 2015; Huybrechts 2016; Huybrechts 2023; Terrana 2015; Viguera 2021; Viguera 2023; Wang 2021). Although olanzapine is one of the SGAs with the most first trimester exposure data (BAP [McAllister-Williams 2017]), additional studies are needed for individual agents and specific outcomes (BAP [Barnes 2020]). Data related to the long-term effects of in utero antipsychotic exposure on infant neurodevelopment and behavior are limited (BAP [McAllister-Williams 2017]; Straub 2022; Swetlik 2024).
Antipsychotic use during the third trimester of pregnancy increases the risk for extrapyramidal symptoms and/or withdrawal symptoms in newborns following delivery (Viguera 2023). Symptoms in the newborn may include agitation, feeding disorder, hypertonia, hypotonia, respiratory distress, somnolence, and tremor. These effects may require prolonged hospitalization or resolve within hour or days without specific treatment. Tapering the dose late in pregnancy to reduce the risk of symptoms is not recommended (APA [Keepers 2020]).
Atypical antipsychotics are associated with metabolic changes and the risk varies by specific agent. Available studies that evaluated the risk of developing gestational diabetes mellitus (GDM) during antipsychotic therapy have conflicting results, possibly due to differences in study design (ACOG 2023; Uguz 2019). Pregnant patients with diabetes mellitus or GDM may continue antipsychotic treatment (ACOG 2023). Consider the metabolic risks of the specific antipsychotic if treatment is initiated for the first time during pregnancy. High-risk metabolic SGAs include olanzapine, which is associated with higher risk for GDM and infants born LGA than those that are nonexposed (ACOG 2023; Galbally 2019; Heinonen 2022; Park 2018). Screening for GDM should continue as part of standard prenatal care; early screening is not needed due to psychiatric medication exposure (ACOG 2023; BAP [McAllister-Williams 2017]). Some guidelines suggest avoiding initiating olanzapine in pregnant patients with risk factors for type 2 diabetes mellitus (BAP [Barnes 2020]).
The pharmacokinetic properties of olanzapine are not significantly altered by pregnancy (Westin 2018; Zheng 2022).
Untreated and undertreated mental health conditions are associated with adverse pregnancy outcomes. Adverse obstetric and neonatal outcomes are associated with schizophrenia; however, comparisons between treated and untreated pregnancies are limited (BAP [McAllister-Williams 2017]). Untreated bipolar disorder is associated with fetal growth restriction, preterm birth, adverse neurodevelopment, and may increase the risk of postpartum psychosis, worsening mood, and postpartum hospitalization. Untreated or undertreated depression is associated with preterm birth, low birth weight, preeclampsia, postpartum depression, and impaired infant attachment (associated with long-term developmental effects). Discontinuing effective medications during pregnancy increases the risk of symptom relapse (ACOG 2023).
Patients effectively treated for schizophrenia or bipolar disorder pre-pregnancy may use the same medication during pregnancy unless contraindications exist (ACOG 2023; APA [Keepers 2020]). SGAs are better tolerated than first-generation (typical) antipsychotics (ACOG 2023). SGAs are not considered a first-line medication for depression in pregnant patients who are treatment naive or who do not have a history of effective treatment in the past (ACOG 2023; BAP [McAllister-Williams 2017]). Management of mental health conditions should be made as part of a shared decision-making process (ACOG 2023; BAP [McAllister-Williams 2017]). Treatment should not be withheld or discontinued based only on pregnancy status (ACOG 2023).
When medications are used, the lowest effective dose of a single agent is recommended. Optimize dosing prior to changing a medication or adding additional agents whenever possible. Close monitoring for symptom improvement with a validated screening tool during pregnancy is recommended. Manage side effects as needed (ACOG 2023). Long-acting preparations should not be initiated during pregnancy but may be continued when the risk of recurrence is high (BAP [Barnes 2020]).
Data collection to monitor pregnancy and infant outcomes following exposure to psychiatric medications is ongoing. Encourage pregnant patients 45 years of age and younger with a history of psychiatric illness to enroll in the National Pregnancy Registry for Psychiatric Mediations (1-866-961-2388 or https://womensmentalhealth.org/research/pregnancyregistry/).
Olanzapine is present in breast milk.
Reviews are available which summarize data related to the presence of olanzapine in breast milk from multiple studies and case reports (Pacchiarotti 2016; Schoretsanitis 2020; Uguz 2016). Olanzapine can be detected in breast milk following maternal use of oral and injectable preparations (Schoretsanitis 2020).
• The relative infant dose (RID) of olanzapine was reported to be 0.3% to 4% of the weight-adjusted maternal dose based on data from 5 studies evaluated in one review article (Pacchiarotti 2016). A review article evaluated the presence of olanzapine in breast milk by taking the breast milk concentration and dividing it by the maternal blood concentration to calculate a penetration ratio. Using data from 17 patients in 6 reports, the mean penetration ratio of olanzapine in breast milk was 0.47 (range 0.1 to 0.94). Maternal doses ranged from 2.5 to 20 mg/day (Schoretsanitis 2020).
• One of the larger studies included in the reviews was done in 7 lactating patients. In 6 cases, 5 to 7 paired breast milk and maternal plasma samples were obtained over 12 or 24 hours after the dose (specific sampling times not noted). In the seventh case, paired breast milk and plasma samples were obtained prior to and after one feeding, 18 hours after the maternal dose. Olanzapine doses ranged from 5 to 20 mg/day (median 7.5 mg/day) and infants were between 0.1 and 4.3 months of age (mean 2.4 months). Using data from the 6 patients, the median time to maximum olanzapine concentration in breast milk was 5.2 hours and 2.5 hours in the maternal plasma. Maximum olanzapine breast milk concentrations ranged from 2 to 18 mcg/L. Authors of the study calculated the relative infant dose (RID) of olanzapine to be 0.22% to 1.19% of the weight adjusted maternal dose. The RID using data from the seventh patient was 1.13% based on an olanzapine milk concentration of 6 mcg/L. Plasma was also sampled in 5 infants; olanzapine concentrations were <5 mcg/L (n = 1), <3 mcg/L (n = 1), and <1 mcg/mL (n = 3) (Gardiner 2003).
• Also included in the review articles is a study of 5 lactating patients administered olanzapine in doses of 2.5 mg/day (n = 4) and 10 mg/day (n = 1) 3 to 6 months postpartum. All patients were at steady state prior to the study. Olanzapine breast milk concentrations ranged from <1 to 21 mcg/L when sampled 11 to 23 hours after the maternal dose. The highest RID calculated by the authors of the study was 2.66% using a breast milk concentration of 8 mcg/L obtained 11 hours after a maternal dose of 2.5 mg. Following a maternal dose of 10 mg, the RID of olanzapine was 2.54% using a breast milk concentration of 21 mcg/L also obtained 11 hours after the maternal dose. No clinically significant adverse events were observed in the breastfed infants observed over 8 days to 5 weeks (Croke 2002).
• Data are also available following use of long-acting olanzapine injection in a breastfeeding patient. The patient was restarted on oral olanzapine during pregnancy then switched to olanzapine injection 405 mg every 4 weeks at 25 weeks' gestation. The postpartum dose was 201 mg every 2 weeks. Breast milk concentrations of olanzapine at 6 weeks postpartum were 53 nmol/L (16.6 mcg/L) sampled 10 days after injection, then 66.4 nmol/L (20.7 mcg/L) 2 weeks after the injection. Breast milk was sampled again at 7 months postpartum. One week after the 7-month injection, olanzapine concentrations in breast milk were 76 nmol/L (23.7 mcg/L) then decreased to 46 nmol/L (14.4 mcg/L) 2 weeks later. Olanzapine was not detected in infant plasma at 6 weeks of age and infant plasma concentrations were <7.5 nmol/L (2.34 mcg/L) at 7 months of age. Breast milk concentrations were 50% of maternal plasma concentrations. Authors of the study calculated the RID of olanzapine to be 0.7% to 1% of the weight-adjusted maternal dose (Manouilenko 2018).
• In general, breastfeeding is considered acceptable when the RID of a medication is <10% (Anderson 2016; Ito 2000); however, some sources note breastfeeding should only be considered if the RID is <5% for psychotropic agents (Anderson 2021).
Outcomes of infants exposed to olanzapine via breast milk have been reported:
• Product labeling notes excess sedation, irritability, poor feeding, and extrapyramidal symptoms (tremors and abnormal muscle movements) have been reported in infants exposed to olanzapine via breast milk.
• Using data spontaneously reported to the manufacturer from 102 breastfeeding reports, somnolence (3%), irritability (2%), tremor (2%), and insomnia (2%) were the most common adverse events reported in infants exposed to olanzapine via breast milk. Adverse events were not observed in most cases (82.3%) (Brunner 2013).
• A prospective observational study compared outcomes of infants exposed to olanzapine via breast milk (n = 22), infants whose mothers took olanzapine and did not breastfeed (n = 15), and infants exposed to acetaminophen via breast milk (n = 51). The rate of adverse outcomes reported by the mothers was not significantly different between the infants in study groups. Adverse events reported by mothers taking olanzapine and breastfeeding their infants were speech delay (n = 1), motor development delay (n = 1), and failure to gain weight (n = 2). The majority were also exposed to olanzapine during pregnancy (Gilad 2011).
• Infants of mothers taking antipsychotics were evaluated for medication side effects every other day for 1 to 2 weeks while hospitalized, then up to 3 months after discharge using standardized monitoring scales. Infants were healthy, full term, and fully or partially breastfed during the study period. Data were reported for 15 infants whose mothers were taking olanzapine 2.5 to 30 mg/day. Constipation was observed in 1 infant and sedation was noted in 2 infants (in one case the mother was also taking chlorpromazine) (Sinha 2021).
According to the manufacturer, the decision to breastfeed during therapy should consider the risk of infant exposure, the benefits of breastfeeding to the infant, and the benefits of treatment to the mother. Drowsiness, irritability, motor abnormalities, poor feeding, sedation, and slowed development have been reported in infants exposed to antipsychotics via breast milk. Monitor breastfed infants, especially those who are premature or low birth weight, or when other sedative drugs are also prescribed (BAP [Barnes 2020]; BAP [McAllister-Williams 2017]).
When medications are used, the lowest effective dose and avoiding use of multiple medications is recommended. Consider sedative properties when initiating an antipsychotic medication for the first time postpartum (BAP [Barnes 2020]). Based on available data, olanzapine may be considered for use in patients who are breastfeeding (CANMAT [Yatham 2018]; Pacchiarotti 2016; Uguz 2016).
Olanzapine may be used for the treatment of postpartum psychosis. Avoidance of breastfeeding overnight during the initial stages of therapy is suggested to help maintain maternal sleep preservation (ACOG 2023).
Tablets may be taken without regard to meals. Some products may contain phenylalanine.
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Frequency of Antipsychotic Monitoring for Olanzapinea,b | ||
|---|---|---|
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Monitoring parameter |
Frequency of monitoring |
Comments |
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a For all monitoring parameters, it is appropriate to check at baseline and when clinically relevant (based on symptoms or suspected adverse reactions) in addition to the timeline. | ||
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b ADA 2004b; APA [Keepers 2020]; De Hert 2011; Gugger 2011; manufacturer's labeling. | ||
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c Risk factors for extrapyramidal symptoms (EPS) include prior history of EPS, high doses of antipsychotics, young age (children and adolescents at higher risk than adults), and dopaminergic affinity of individual antipsychotic. | ||
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d Risk factors for tardive dyskinesia include >55 years of age; females; White or African ethnicity; presence of a mood disorder, intellectual disability, CNS injury, or past or current EPS. | ||
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Adherence |
Every visit |
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Blood chemistries (electrolytes, renal function, liver function, TSH) |
Annually |
|
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CBC |
As clinically indicated |
Check frequently during the first few months of therapy in patients with preexisting low WBC or history of drug-induced leukopenia/neutropenia. |
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Extrapyramidal symptoms |
Every visit; 4 weeks after initiation and dose change; annually. Use a formalized rating scale at least annually or every 6 months if high risk.c |
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Fall risk |
Every visit |
|
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Fasting plasma glucose/HbA1c |
4 months after initiation; annually |
Check more frequently than annually if abnormal. Follow diabetes guidelines. |
|
Lipid panel |
4 months after initiation; annually |
Check more frequently than annually if abnormal. Follow lipid guidelines. |
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Mental status and alertness |
Every visit |
|
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Metabolic syndrome history |
Annually |
Evaluate for personal and family history of obesity, diabetes, dyslipidemia, hypertension, or cardiovascular disease. |
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Prolactin |
Ask about symptoms at every visit until dose is stable. Check prolactin level if symptoms are reported. |
Hyperprolactinemia symptoms: changes in menstruation, libido, gynecomastia, development of galactorrhea, and erectile and ejaculatory function. |
|
Tardive dyskinesia |
Every visit; annually. Use a formalized rating scale at least annually or every 6 months if high risk.d |
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Vital signs (BP, orthostatics, temperature, pulse, signs of infection) |
Every visit (at least weekly during first 3 to 4 weeks of treatment); 4 weeks after dose change. |
|
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Weight/Height/BMI |
8 and 12 weeks after initiation and dose change; quarterly |
Consider monitoring waist circumference at baseline and annually, especially in patients with or at risk for metabolic syndrome. Consider changing antipsychotic if BMI increases by ≥1 unit. Some experts recommend checking weight and height at every visit. |
Additional monitoring parameters with administration of injection formulations:
IM, short-acting, and IV: Sedation; vital signs (BP, pulse, respiratory rate); ECG (in patients at risk for QT prolongation) (Cole 2017; Taylor 2017).
IM, long-acting: Sedation/delirium for 3 hours after each dose.
Schizophrenia:
Timing of serum samples: Draw trough just before next dose (Hiemke 2018).
Therapeutic reference range: 20 to 80 ng/mL (SI: 64 to 256 nmol/L) (Hiemke 2018). Note: Dosing should be based on therapeutic response as opposed to serum concentrations, however therapeutic drug monitoring can be used to confirm adherence (APA [Keepers 2020]).
Laboratory alert level: 100 ng/mL (SI: 320 nmol/L) (Hiemke 2018).
Olanzapine is a second generation thienobenzodiazepine antipsychotic which displays potent antagonism of serotonin 5-HT2A and 5-HT2C, dopamine D1-4, histamine H1, and alpha1-adrenergic receptors. Olanzapine shows moderate antagonism of 5-HT3 and muscarinic M1-5 receptors, and weak binding to GABA-A, BZD, and beta-adrenergic receptors. Although the precise mechanism of action in schizophrenia and bipolar disorder is not known, the efficacy of olanzapine is thought to be mediated through combined antagonism of dopamine and serotonin type 2 receptor sites. Olanzapine’s activity at the dopamine (D2), 5-HT2C, and 5-HT3 receptors may be responsible for the antiemetic effect (Navari 2016).
Onset of action:
Agitation:
Short-acting injection:
IM: Initial effects within 15 minutes; continued effects for at least 2 hours (Huang 2015; Wright 2001).
IV: Initial effects within 5 to 10 minutes (Taylor 2017).
Bipolar disorder, acute mania: Oral and short-acting injection: Initial effects may be observed within days of treatment with continued improvements over 1 to 2 weeks (Goikolea 2013; Tohen 2000; Welten 2016).
Schizophrenia: Oral: Initial effects may be observed within 1 to 2 weeks of treatment with continued improvements through 4 to 6 weeks (Agid 2003; Levine 2010).
Absorption:
Oral: Well absorbed; not affected by food; tablets and orally disintegrating tablets are bioequivalent
Short-acting injection: Rapidly absorbed
Distribution: Vd: Extensive, 1,000 L
Protein binding, plasma: 93% bound to albumin and alpha1-glycoprotein
Metabolism: Highly metabolized via direct glucuronidation and cytochrome P450 mediated oxidation (CYP1A2, CYP2D6); 40% removed via first pass metabolism
Half-life elimination:
Oral and IM (short-acting): Children: (10 to 18 years; n=8): 37.2 ± 5.1 hours (Grothe 2000); Adults: 30 hours [21 to 54 hours (5th to 95th percentile)]; approximately 1.5 times greater in elderly.
Long-acting injection: ~30 days.
Time to peak, plasma: Maximum plasma concentrations after short-acting IM administration are 5 times higher than maximum plasma concentrations produced by an oral dose.
Long-acting injection: ~7 days.
Short-acting injection: 15 to 45 minutes
Oral: Children (10 to 18 years; n=8): 4.7 ± 3.7 hours (Grothe 2000); Adults: ~6 hours
Excretion: Urine (57%, 7% as unchanged drug); feces (30%)
Clearance: Oral:
Children (10 to 18 years; n=8): Apparent: 9.6 ± 2.4 L/hour (Grothe 2000)
Adults: Apparent: 25 L/hour [12 to 47 L/hour (5th to 95th percentile)]; 40% increase in olanzapine clearance in smokers; 30% decrease in females
Older adult: The half-life increases 1.5 times.
Sex: Clearance is approximately 30% lower in women.
Cigarette smoking: Clearance is approximately 40% higher in smokers.
