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 of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of 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 approximately 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 patients is not clear. Perphenazine is not approved for the treatment of patients with dementia-related psychosis.
Schizophrenia: Note: In the management of pediatric patients with schizophrenia, use has generally been replaced by second-generation antipsychotics (Ref). Dosage should be individualized; use lowest effective dose and shortest effective duration; periodically reassess the need for continued treatment.
Children ≥12 years and Adolescents: Oral: Initial: 8 to 16 mg/day in divided doses 2 to 4 times daily; titrate based on response and tolerability. Doses as high as 32 mg/day have been shown to have similar efficacy and tolerability compared to some second-generation antipsychotics; doses as high as 64 mg/day may be appropriate in some situations based on experience in adult patients (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in manufacturer's labeling; use with caution.
There are no dosage adjustment provided in manufacturer's labeling; contraindicated in patients with liver damage
(For additional information see "Perphenazine: Drug information")
Dosage guidance:
Safety: Antipsychotics are not indicated for use in catatonia and may worsen psychosis and increase the risk for neuroleptic malignant syndrome in patients with catatonia (Ref).
Clinical considerations: For the treatment of psychiatric disorders, consult a psychiatry specialist for all management decisions; select antipsychotic carefully based on patient preference, clinical characteristics, history, comorbidities, and medication adverse effects profile (Ref).
Nausea/vomiting: Oral: 8 to 16 mg/day in divided doses; occasionally, doses as high as 24 mg/day may be necessary. Reduce dose as soon as possible to minimum effective dosage.
Schizophrenia:
Note:
Clinical use: Some experts prefer second generation antipsychotics for initial treatment due to the potential for fewer extrapyramidal symptoms (Ref); data suggesting differences in efficacy are lacking (Ref).
Oral: Initial: 8 to 16 mg/day in 2 or 3 divided doses, or if this is a first episode of psychosis, consider initiating at a reduced dose (eg, 4 to 8 mg/day in divided doses) because these patients will be more sensitive to adverse effects. May increase daily dose based on response and tolerability in increments of 8 mg every 4 to 7 days; monitor for akathisia, anticholinergic effects, orthostatic hypotension, parkinsonism, and sedation during titration. Usual maintenance dose range: 8 to 32 mg/day in 2 to 3 divided doses; use lowest effective maintenance dose. Maximum: 64 mg/day (Ref).
Discontinuation of therapy: 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.
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.
There are no dosage adjustments provided in manufacturer's labeling; use with caution.
There are no dosage adjustment provided in manufacturer's labeling; contraindicated in patients with liver damage.
The following adverse drug reactions are derived from product labeling unless otherwise specified. Reactions listed may be based on reports for other agents in this same pharmacologic class and may not be specifically reported for perphenazine.
Frequency not defined:
Cardiovascular: Bradycardia, orthostatic hypotension, peripheral edema, tachycardia
Dermatologic: Contact dermatitis, eczema, erythema of skin, exfoliative dermatitis, pruritus, skin photosensitivity, skin pigmentation, urticaria
Endocrine & metabolic: Amenorrhea, change in libido, galactorrhea not associated with childbirth, gynecomastia, hyperglycemia, hypoglycemia, increased protein-bound iodine (not attributable to an increase in thyroxine), menstrual disease, SIADH, weight gain
Gastrointestinal: Dysphagia, increased appetite, parotid gland enlargement
Genitourinary: Breast hypertrophy, ejaculatory disorder, glycosuria, lactation
Hematologic & oncologic: Agranulocytosis, eosinophilia, hemolytic anemia, immune thrombocytopenia, leukopenia, pancytopenia
Hypersensitivity: Hypersensitivity reaction (including angioedema, nonimmune anaphylaxis)
Nervous system: Abnormal proteins in cerebrospinal fluid, bizarre dream, brain edema, catatonic-like state, confusion (nocturnal), dizziness, drowsiness, extrapyramidal reaction (including aching limbs, akathisia, ataxia, dyskinesia, dystonia [including aching and rounding of the tongue, protrusion of the tongue, tongue discoloration], muscle rigidity [masticatory], numbness of extremities, oculogyric crisis, opisthotonos, parkinsonism, retrocollis, slurred speech, torticollis, trismus), headache, hyperactive behavior, hyperreflexia, insomnia, lethargy, myasthenia, paradoxical central nervous system stimulation, paranoid ideation, polyphagia, psychotic symptoms (exacerbation), restlessness, seizure
Neuromuscular & skeletal: Lupus-like syndrome
Ophthalmic: Corneal deposits, epithelial keratopathy, lens disease (deposits), photophobia, retinitis pigmentosa, star-shaped cataract
Respiratory: Asthma, laryngeal edema, pharyngeal edema
Miscellaneous: Fever, hyperpyrexia
Postmarketing:
Genitourinary: Priapism (Chan 1990)
Hepatic: Jaundice (chronic)
Hypersensitivity to perphenazine or any component of the formulation; severe CNS depression (comatose or patients receiving large doses of CNS depressants); subcortical brain damage with or without hypothalamic damage (known or suspected); bone marrow suppression; blood dyscrasias; liver damage.
Concerns related to adverse effects:
• Altered cardiac conduction: May alter cardiac conduction; life-threatening arrhythmias have occurred with therapeutic doses of phenothiazines (Haddad 2002; Stollberger 2005).
• Anticholinergic effects: May cause anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention); use with caution in patients with decreased gastrointestinal motility, paralytic ileus, urinary retention, BPH, xerostomia, or visual problems. Relative to other neuroleptics, perphenazine has a low potency of cholinergic blockade.
• Antiemetic effects: May mask toxicity of other drugs or conditions (eg, intestinal obstruction, Reye syndrome, brain tumor) due to antiemetic effects.
• Blood dyscrasias: Leukopenia, neutropenia, and agranulocytosis (sometimes fatal) have been reported in clinical trials and postmarketing reports with antipsychotic use; presence of risk factors (eg, preexisting low WBC or history of drug-induced leuko-/neutropenia) should prompt periodic blood count assessment. Discontinue therapy at first signs of blood dyscrasias or if absolute neutrophil count <1,000/mm3.
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery, driving).
• Esophageal dysmotility/Aspiration: Antipsychotic use has been associated with esophageal dysmotility and aspiration; risks increase with age. Use with caution in patients at risk for aspiration pneumonia (eg, Alzheimer disease), particularly in patients >75 years (Herzig 2017; Maddalena 2004).
• Extrapyramidal symptoms: May cause extrapyramidal symptoms (EPS), including pseudoparkinsonism, acute dystonic reactions, akathisia, and tardive dyskinesia. Risk of dystonia (and possibly other EPS) may be greater with increased doses, use of conventional antipsychotics, males, and younger patients. Factors associated with greater vulnerability to tardive dyskinesia include older in age, female gender combined with postmenopausal status, Parkinson disease, pseudoparkinsonism symptoms, affective disorders (particularly major depressive disorder), concurrent medical diseases such as diabetes, previous brain damage, alcoholism, poor treatment response, and use of high doses of antipsychotics (APA [Keepers 2020]; Soares-Weiser 2007). Consider therapy discontinuation with signs/symptoms of tardive dyskinesia.
• Falls: May increase the risk for falls due to somnolence, orthostatic hypotension, or motor and sensory instability.
• Hyperprolactinemia: Use associated with increased prolactin levels; clinical significance of hyperprolactinemia in patients with breast cancer or other prolactin-dependent tumors is unknown.
• Neuroleptic malignant syndrome: May be associated with neuroleptic malignant syndrome (NMS); monitor for mental status changes, fever, muscle rigidity, and/or autonomic instability. Following recovery from NMS, reintroduction of drug therapy should be carefully considered; if an antipsychotic agent is resumed, monitor closely for NMS.
• Ocular effects: May cause pigmentary retinopathy, and lenticular and corneal deposits, particularly with prolonged therapy.
• Orthostatic hypotension: May cause orthostatic hypotension; use with caution in patients at risk of this effect or in those who would not tolerate transient hypotensive episodes (cerebrovascular disease, cardiovascular disease, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia).
• Photosensitivity: May cause photosensitization; avoid prolonged exposure to sunlight.
• Temperature regulation: Impaired core body temperature regulation may occur; caution with strenuous exercise, heat exposure, dehydration, and concomitant medication possessing anticholinergic effects.
Disease-related concerns:
• Cardiovascular disease: Use with caution in patients with cardiovascular disease.
• Dementia: [US Boxed Warning]: Elderly patients with dementia-related psychosis treated with antipsychotics are at an increased risk of death compared to placebo. Most deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature. Use with caution in patients with Lewy body dementia or Parkinson disease dementia due to greater risk of adverse effects, increased sensitivity to extrapyramidal effects, and association with irreversible cognitive decompensation or death. The APA recommends giving preference to second generation antipsychotics over first generation antipsychotics in elderly patients with dementia-related psychosis due to a potentially greater risk of harm relative to second generation antipsychotics (APA [Reus 2016]). Perphenazine is not approved for the treatment of dementia-related psychosis.
• Depression: Use with caution in patients with depression; possibility of increased risk of suicide; limit quantities of drug available until significant remission observed.
• Hepatic impairment: Monitor hepatic function during use; discontinue if abnormalities occur; contraindicated in patients with liver damage.
• Renal impairment: Use with caution in patients with renal impairment. Monitor renal function during therapy; discontinue if BUN abnormalities occur.
• Respiratory disease: Use with caution in patients with respiratory disease.
• Seizure disorder: Use with caution in patients at risk of seizures, including those with a history of seizures; first-generation antipsychotics may lower the seizure threshold (APA [Keepers 2020]).
Special populations:
• Poor metabolizers: Use with caution in patients with reduced functional alleles of CYP2D6. Poor metabolizers may have higher plasma concentrations at usual doses, increasing risk for adverse reactions.
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]).
Risk of dystonia is increased with the use of high potency and higher doses of conventional antipsychotics and in males and younger patients. Use with caution in children and adolescents; adverse effects due to elevated prolactin levels have been observed; long-term effects on growth or sexual maturation have not been evaluated. Similar to adult experience, the American Academy of Child and Adolescent Psychiatry (AACAP) guidelines recommend gradually tapering antipsychotics to avoid withdrawal symptoms and minimize the risk of relapse (AACAP [McClellan 2007]).
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral:
Generic: 2 mg, 4 mg, 8 mg, 16 mg
Yes
Tablets (Perphenazine Oral)
2 mg (per each): $1.16 - $1.75
4 mg (per each): $1.59 - $2.39
8 mg (per each): $1.93 - $2.90
16 mg (per each): $2.60 - $3.90
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.
Tablet, Oral:
Generic: 2 mg, 4 mg, 8 mg, 16 mg
Oral: May be administered without regard to meals
Store at 20°C to 25°C (68°F to 77°F). Protect from light.
Treatment of schizophrenia (FDA approved in ages ≥12 years and adults); treatment of severe nausea and vomiting (FDA approved in adults); Note: In the management of pediatric patients with schizophrenia or severe behavioral problems, use has generally been replaced by second-generation antipsychotics (AACAP [McClellan 2013]).
Trilafon may be confused with Tri-Levlen
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]).
KIDs List: Dopamine antagonists, when used in pediatric patients <18 years of age, are identified on the Key Potentially Inappropriate Drugs in Pediatrics (KIDs) list; use should be avoided in infants and used with caution in children and adolescents due to risk of acute dystonia (dyskinesia) (strong recommendation; moderate quality of evidence) (PPA [Meyers 2020]).
Substrate of CYP1A2 (Minor), CYP2C19 (Minor), CYP2C9 (Minor), CYP2D6 (Major), CYP3A4 (Minor); 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.
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
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
Agents with Clinically Relevant Anticholinergic Effects: May increase anticholinergic effects of Perphenazine. Risk C: Monitor
Agents With Seizure Threshold Lowering Potential: May increase adverse/toxic effects of Perphenazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Ajmaline: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Amifampridine: Agents With Seizure Threshold Lowering Potential may increase neuroexcitatory and/or seizure-potentiating effects of Amifampridine. Risk C: Monitor
Aminolevulinic Acid (Systemic): Photosensitizing Agents may increase photosensitizing effects of Aminolevulinic Acid (Systemic). Risk X: Avoid
Aminolevulinic Acid (Topical): Photosensitizing Agents may increase photosensitizing effects of Aminolevulinic Acid (Topical). 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 adverse/toxic effects of Antipsychotic Agents. Specifically, the risk of neuroleptic malignant syndrome or increased QTc interval may be increased. Risk C: Monitor
Antacids: May decrease absorption of Antipsychotic Agents (Phenothiazines). Risk C: Monitor
Anti-Parkinson Agents (Dopamine Agonist): Antipsychotic Agents (First Generation [Typical]) may decrease therapeutic effects of Anti-Parkinson Agents (Dopamine Agonist). Management: Avoid concomitant therapy if possible. If antipsychotic use is necessary, consider using atypical antipsychotics such as clozapine, quetiapine, or ziprasidone at lower initial doses, or a non-dopamine antagonist (eg, pimavanserin). Risk D: Consider Therapy Modification
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
Artemether and Lumefantrine: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
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
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
Benzgalantamine-Galantamine: May increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
Benztropine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Benztropine. Risk C: Monitor
Beta-Blockers: Antipsychotic Agents (Phenothiazines) may increase hypotensive effects of Beta-Blockers. Beta-Blockers may decrease metabolism of Antipsychotic Agents (Phenothiazines). Antipsychotic Agents (Phenothiazines) may decrease metabolism of Beta-Blockers. Risk C: Monitor
Biperiden: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Biperiden. Risk C: Monitor
Blonanserin: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Blonanserin. Specifically, the risk of seizures may be increased. 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
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
Bromopride: May increase adverse/toxic effects of Antipsychotic Agents. Risk X: Avoid
Bromperidol: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Bromperidol. Risk C: Monitor
Bromperidol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Bromperidol. Specifically, the risk of seizures may be increased. Risk C: Monitor
Buclizine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Buclizine. Risk C: Monitor
BuPROPion: May increase neuroexcitatory and/or seizure-potentiating effects of Agents With Seizure Threshold Lowering Potential. 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
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
ChlorproMAZINE: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of ChlorproMAZINE. Specifically, the risk of seizures may be increased. 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
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
Cyclizine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
CYP2D6 Inhibitors (Moderate): May increase serum concentration of Perphenazine. Risk C: Monitor
CYP2D6 Inhibitors (Strong): May increase serum concentration of Perphenazine. Risk C: Monitor
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
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
Dicyclomine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dicyclomine. Risk C: Monitor
Dimethindene (Systemic): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dimethindene (Systemic). Risk C: Monitor
Donepezil: May increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
DroNABinol: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of DroNABinol. Risk X: Avoid
DroPERidol: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of DroPERidol. Specifically, the risk of seizures may be increased. Risk C: Monitor
Eluxadoline: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of Eluxadoline. Risk X: Avoid
Fesoterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Fesoterodine. 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
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
Huperzine A: May increase neurotoxic (central) effects of Antipsychotic Agents. Risk C: Monitor
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
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
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
Loxapine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Loxapine. Specifically, the risk of seizures may be increased. Risk C: Monitor
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
Maprotiline: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Maprotiline. Risk C: Monitor
Mavorixafor: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk X: Avoid
Melperone: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Metergoline: Antipsychotic Agents may decrease therapeutic effects of Metergoline. Metergoline may decrease therapeutic effects of Antipsychotic Agents. Risk C: Monitor
Methotrimeprazine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Methotrimeprazine. Risk C: Monitor
Methotrimeprazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Methotrimeprazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Methoxsalen (Systemic): Photosensitizing Agents may increase photosensitizing effects of Methoxsalen (Systemic). 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: May increase adverse/toxic effects of Antipsychotic Agents. Specifically, the risk for extrapyramidal symptoms and excessive sedation may be increased. 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
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
OLANZapine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of OLANZapine. Risk C: Monitor
OLANZapine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of OLANZapine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Opioid Agonists: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Opioid Agonists. Specifically, the risk for constipation and urinary retention may be increased with this combination. Risk C: Monitor
Opipramol: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Oxatomide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
OxyBUTYnin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of OxyBUTYnin. Risk C: Monitor
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
Peginterferon Alfa-2b: May decrease serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). 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
Pimozide: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Pimozide. Specifically, the risk of seizures may be increased. Risk C: Monitor
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
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
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
Porfimer: Photosensitizing Agents may increase photosensitizing effects of Porfimer. Risk X: Avoid
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
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
QUEtiapine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of QUEtiapine. Specifically, the risk of seizures may be increased. Risk C: Monitor
Quinagolide: Antipsychotic Agents may decrease therapeutic effects of Quinagolide. Risk C: Monitor
QuiNIDine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. 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
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
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
Saquinavir: Antipsychotic Agents (Phenothiazines) may increase arrhythmogenic effects of Saquinavir. Risk X: Avoid
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: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Sertindole. Specifically, the risk of seizures may be increased. Risk C: Monitor
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
Tetrabenazine: May increase adverse/toxic effects of Antipsychotic Agents. Specifically, the risk for NMS and extrapyramidal symptoms may be increased. Risk C: Monitor
Thiazide and Thiazide-Like Diuretics: Agents with Clinically Relevant Anticholinergic Effects may increase serum concentration of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Thiopental: Antipsychotic Agents (Phenothiazines) may increase adverse/toxic effects of Thiopental. Risk C: Monitor
Thioridazine: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Thioridazine. Specifically, the risk of seizures may be increased. Risk C: Monitor
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
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
Trimethobenzamide: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Trimethobenzamide. Risk C: Monitor
Triptorelin: Hyperprolactinemic Agents may decrease therapeutic effects of Triptorelin. Risk X: Avoid
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
Verteporfin: Photosensitizing Agents may increase photosensitizing effects of Verteporfin. Risk C: Monitor
Ziprasidone: Agents With Seizure Threshold Lowering Potential may increase adverse/toxic effects of Ziprasidone. Specifically, the risk of seizures may be increased. Risk C: Monitor
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
Jaundice or hyper- or hyporeflexia have been reported in newborn infants following maternal use of phenothiazines. Antipsychotic use during the third trimester of pregnancy has a risk for abnormal muscle movements (extrapyramidal symptoms [EPS]) and withdrawal symptoms in newborns following delivery. Symptoms in the newborn may include agitation, feeding disorder, hypertonia, hypotonia, respiratory distress, somnolence, and tremor; these effects may be self-limiting or require hospitalization. If needed, the minimum effective maternal dose should be used in order to decrease the risk of EPS (ACOG 2008).
Based on experience in adult patients the following has been suggested; pediatric patients may require more frequent monitoring of some parameters as clinically indicated:
Mental status; vital signs (as clinically indicated); ECG (baseline, then periodic; do not initiate if QTc >450 msec); weight, height, BMI, waist circumference (baseline; at every visit for the first 6 months; quarterly with stable antipsychotic dose); CBC (as clinically indicated; monitor frequently during the first few months of therapy in patients with preexisting low WBC or history of drug-induced leukopenia/neutropenia); electrolytes (baseline potassium; annually and as clinically indicated); liver function (annually and as clinically indicated); fasting plasma glucose level/HbA1c (baseline, then yearly; in patients with diabetes risk factors or if gaining weight, repeat 4 months after starting antipsychotic, then yearly); lipid panel (baseline; repeat every 2 years if LDL level is normal; repeat every 6 months if LDL level is >130 mg/dL); changes in menstruation, development of galactorrhea (at each visit for the first 12 weeks after the antipsychotic is initiated or until the dose is stable, then yearly); abnormal involuntary movements or parkinsonian signs (baseline; repeat weekly until dose stabilized for at least 2 weeks after introduction and for 2 weeks after any significant dose increase); tardive dyskinesia (every 6 months; high-risk patients every 3 months); visual changes (inquire yearly); ocular examination (yearly in patients >40 years; every 2 years in younger patients) (ADA 2004; APA [Lehman 2004]; Marder 2004).
0.6 to 2.4 ng/mL (SI: 1.5 to 6 nmol/L) (Hiemke 2011).
Perphenazine is a piperazine phenothiazine antipsychotic which blocks dopamine, subtype 2 (D2), receptors in mesolimbocortical and nigrostriatal areas of the brain (APA [Lehman, 2004]).
Onset of action: Schizophrenia: Initial effects may be observed within 1 to 2 weeks of treatment with continued improvements through 4 to 6 weeks (Agid 2003; Levine 2010).
Metabolism: Extensively hepatic to metabolites via sulfoxidation, hydroxylation, dealkylation, and glucuronidation; primarily metabolized by CYP2D6 to N-dealkylated perphenazine, perphenazine sulfoxide, and 7-hydroxyperphenazine (active metabolite with 70% of the activity of perphenazine); Note: Metabolism is subject to genetic polymorphism; CYP2D6 poor metabolizers will have higher plasma concentrations of perphenazine compared with normal or extensive metabolizers.
Bioavailability: 40% (Hiemke 2018)
Half-life elimination: Perphenazine: 9 to 12 hours; 7-hydroxyperphenazine: 10 to 19 hours
Time to peak, serum: Perphenazine: 1 to 3 hours; 7-hydroxyperphenazine: 2 to 4 hours
Older adult: Plasma concentrations per daily ingested dose increase with increasing age.
