Version July 2025
Because the use of levorphanol exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death, assess each patient's risk prior to prescribing and reassess all patients regularly for the development of these behaviors and conditions.
Health care providers are strongly encouraged to complete a REMS-compliant education program and to counsel patients and caregivers on serious risks, safe use, and the importance of reading the Medication Guide with each prescription.
Serious, life-threatening, or fatal respiratory depression may occur with use of levorphanol, especially during initiation or following a dose increase. To reduce the risk of respiratory depression, proper dosing and titration of levorphanol is essential.
Accidental ingestion of even one dose of levorphanol, especially by children, can result in a fatal overdose of levorphanol.
If opioid use is required for an extended period of time in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome (NOWS), which may be life-threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery.
Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of levorphanol and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate.
Dosage guidance :
Safety: Consider prescribing naloxone or nalmefene for patients with factors associated with an increased risk for overdose, such as history of overdose or substance use disorder, patients with sleep-disordered breathing, higher opioid dosages (≥50 morphine milligram equivalents [MME]/day orally), and/or concomitant benzodiazepine use (Ref).
Dosing: Dosing provided is based on typical doses; some patients may require higher or lower doses. Individualize dosing based on patient-specific factors (eg, comorbidities, severity of pain, degree of opioid experience/tolerance) and titrate to patient-specific treatment goals (eg, improvement in function and quality of life, decrease in pain using a validated pain rating scale). Use the lowest effective dose for the shortest period of time.
Clinical considerations: Opioids may be part of a comprehensive, multimodal, patient-specific treatment plan for managing moderate to severe pain. Maximize nonopioid analgesia, if appropriate, prior to initiation of opioid analgesia (Ref).
Pain management:
Oral: Initial: 1 to 2 mg every 6 to 8 hours as needed; reduce initial dose by ≥50% in patients with conditions affecting respiratory reserve or with coadministration with other drugs affecting the respiratory center. May gradually increase dose (no more often than every 3 days) to 3 mg every 6 to 8 hours if needed; higher doses may be appropriate in opioid tolerant patients.
Conversion from morphine to levorphanol : 1) Calculate the total daily dose of morphine. 2) Multiply the total daily dose of morphine by 1/15 to 1/12 to determine the total daily dose of levorphanol. 3) Consider reducing the total daily dose of levorphanol by up to 50% to account for incomplete cross-tolerance. 4) The total daily dose of levorphanol should then be divided to reflect the intended dosing schedule (ie, divide by 3 or 4 and administer every 6 to 8 hours) (Ref).
Discontinuation of therapy: When reducing the dose, discontinuing, or tapering long-term opioid therapy, the dose should be gradually tapered. An optimal tapering schedule has not been established. Individualize tapering based on discussions with patient to minimize withdrawal, while considering patient-specific goals and concerns and the opioid's pharmacokinetics. Proposed initial schedules range from slow (eg, 10% reduction per week or 10% reduction per month depending on duration of long-term therapy) to rapid (eg, 25% to 50% reduction every few days) (Ref). Slower tapers may be appropriate after long-term use (eg, >1 year), whereas more rapid tapers may be appropriate in patients experiencing severe adverse effects. During tapering, patients may be at an increased risk of overdose if they return to their original (or higher) opioid dose or use illicit opioids, due to rapid loss of tolerance; consider prescribing naloxone or nalmefene. Monitor carefully for signs/symptoms of withdrawal. If the patient displays withdrawal symptoms, consider slowing the taper schedule; alterations may include increasing the interval between dose reductions, decreasing amount of daily dose reduction, pausing the taper and restarting when the patient is ready, and/or coadministration of an alpha-2 agonist (eg, clonidine) to blunt autonomic withdrawal symptoms and other adjunctive agents to treat GI symptoms and muscle spasms, as needed. Continue to offer nonopioid analgesics as needed for pain management during the taper (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 specific dosage adjustments provided in the manufacturer's labeling; use with caution.
There are no specific dosage adjustments provided in the manufacturer's labeling; use with caution.
Note: Minimize opioid use in older adults unless for the management of severe acute pain. Opioids are associated with an increased risk of falls and inducing or worsening delirium in older adults (Ref).
Reduce initial doses by 50% or more. Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Frequency not defined.
Cardiovascular: Bradycardia, cardiac arrest, hypotension, palpitations, peripheral vasodilation, shock, tachycardia
Central nervous system: Amnesia, central nervous system depression, coma, confusion, convulsions, depression, dizziness, drowsiness, drug dependence, fatigue, hallucination, headache, increased intracranial pressure, insomnia, malaise, nervousness, paradoxical central nervous system stimulation, restlessness
Dermatologic: Pruritus, skin rash, urticaria
Endocrine & metabolic: Antidiuretic hormone disease
Gastrointestinal: Abdominal pain, anorexia, biliary tract spasm, constipation, dyspepsia, nausea, paralytic ileus, stomach cramps, vomiting, xerostomia
Genitourinary: Decreased urine output, urinary retention, urinary tract abnormality
Hypersensitivity: Histamine release
Neuromuscular & skeletal: Weakness
Ophthalmic: Diplopia, miosis
Respiratory: Apnea, cyanosis, hypoventilation, respiratory depression
Postmarketing and/or case reports: Allodynia (opioid-induced hyperalgesia) (FDA Safety Communication 2023), hypogonadism (Brennan, 2013; Debono, 2011)
Hypersensitivity (eg, anaphylaxis) to levorphanol or any component of the formulation; acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment; GI obstruction, including paralytic ileus (known or suspected); significant respiratory depression.
Concerns related to adverse effects:
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).
• Constipation: May cause constipation which may be problematic in patients with unstable angina and patients post-myocardial infarction. Consider preventive measures (eg, stool softener, increased fiber) to reduce the potential for constipation.
• Hyperalgesia: Opioid-induced hyperalgesia (OIH) has occurred with short-term and prolonged use of opioid analgesics. Symptoms may include increased levels of pain upon opioid dosage increase, decreased levels of pain upon opioid dosage decrease, or pain from ordinarily nonpainful stimuli; symptoms may be suggestive of OIH if there is no evidence of underlying disease progression, opioid tolerance, opioid withdrawal, or addictive behavior. Consider decreasing the current opioid dose or opioid rotation in patients who experience OIH.
• Hypotension: May cause severe hypotension (including orthostatic hypotension and syncope); use with caution in patients with hypovolemia, cardiovascular disease (including acute myocardial infarction), or drugs which may exaggerate hypotensive effects (including phenothiazines or general anesthetics). Monitor for symptoms of hypotension following initiation or dose titration. Avoid use in patients with circulatory shock.
• Phenanthrene hypersensitivity: Use with caution in patients with hypersensitivity reactions to other phenanthrene derivative opioid agonists (codeine, hydrocodone, hydromorphone, oxycodone, oxymorphone).
• Respiratory depression: Fatal respiratory depression may occur. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. Patients and caregivers should be educated on how to recognize respiratory depression and the importance of getting emergency assistance immediately (eg, calling 911) in the event of known or suspected overdose.
Disease-related concerns:
• Abdominal conditions: May obscure diagnosis or clinical course of patients with acute abdominal conditions.
• Adrenocortical insufficiency: Use with caution in patients with adrenal insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to mood disorders and osteoporosis (Brennan 2013).
• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction, or acute pancreatitis; opioids may cause constriction of sphincter of Oddi. Not recommended for use in biliary surgery.
• CNS depression/coma: Avoid use in patients with impaired consciousness or coma as these patients are susceptible to intracranial effects of CO2 retention.
• Delirium tremens: Use with caution in patients with delirium tremens.
• Head trauma: Use with extreme caution in patients with head injury, intracranial lesions, or elevated intracranial pressure; exaggerated elevation of ICP may occur.
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Mental health conditions: Use opioids with caution for chronic pain in patients with mental health conditions (eg, depression, anxiety disorders, post-traumatic stress disorder) due to potential increased risk for opioid use disorder and overdose; more frequent monitoring is recommended (CDC [Dowell 2022]).
• Obesity: Use with caution in patients who are morbidly obese.
• Psychosis: Use with caution in patients with toxic psychosis.
• Prostatic hyperplasia/urinary stricture: Use with caution in patients with prostatic hyperplasia and/or urinary stricture.
• Psychosis: Use with caution in patients with toxic psychosis.
• Renal impairment: Use with caution in patients with renal impairment.
• Respiratory disease: Use with caution and monitor for respiratory depression in patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or preexisting respiratory depression, particularly when initiating and titrating therapy; critical respiratory depression may occur, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Seizures: Use with caution in patients with a history of seizure disorders; may cause or exacerbate preexisting seizures.
• Sleep-related disorders: Use with caution in patients with sleep-related disorders, including sleep apnea, due to increased risk for respiratory and CNS depression. Monitor carefully and titrate dosage cautiously in patients with mild sleep-disordered breathing. Avoid opioids in patients with moderate to severe sleep-disordered breathing (CDC [Dowell 2022]).
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Benzodiazepines or other CNS depressants: Concomitant use may result in respiratory depression and sedation, which may be fatal. Consider prescribing naloxone or nalmefene for emergency treatment of opioid overdose in patients taking benzodiazepines or other CNS depressants concomitantly with opioids.
Special populations:
• Cachectic or debilitated patients: Use with caution in cachectic or debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Older adult: Use opioids with caution in older adults; may be more sensitive to adverse effects. Clearance may also be reduced in older adults (with or without renal impairment) resulting in a narrow therapeutic window and increased adverse effects. Monitor closely for adverse effects associated with opioid therapy (eg, respiratory and CNS depression, falls, cognitive impairment, constipation) (CDC [Dowell 2022]). Consider the use of alternative nonopioid analgesics in these patients when possible.
• Neonates: Neonatal withdrawal syndrome: Prolonged use of opioids during pregnancy can cause neonatal withdrawal syndrome, which may be life-threatening if not recognized and treated according to protocols developed by neonatology experts. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available. Signs and symptoms include irritability, hyperactivity and abnormal sleep pattern, high-pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity depend on the drug used, duration of use, maternal dose, and rate of drug elimination by the newborn.
Other warnings/precautions:
• Abrupt discontinuation/withdrawal: Abrupt discontinuation in patients who are physically dependent to opioids has been associated with serious withdrawal symptoms, uncontrolled pain, attempts to find other opioids (including illicit), and suicide. Use a collaborative, patient-specific taper schedule that minimizes the risk of withdrawal, considering factors such as current opioid dose, duration of use, type of pain, and physical and psychological factors. Monitor pain control, withdrawal symptoms, mood changes, suicidal ideation, and for use of other substances and provide care as needed. Concurrent use of mixed agonist/antagonist (eg, pentazocine, nalbuphine, butorphanol) or partial agonist (eg, buprenorphine) analgesics may also precipitate withdrawal symptoms and/or reduced analgesic efficacy in patients following prolonged therapy with mu opioid agonists.
• Abuse/misuse/diversion: Levorphanol exposes patients and other users to the risks of substance use disorder, abuse, and misuse, potentially leading to overdose and death. Assess each patient's risk prior to prescribing; monitor all patients regularly for development of these behaviors or conditions. Use with caution in patients with a history of substance use disorder; potential for drug dependency exists. Other factors associated with increased risk for misuse include concomitant depression or other mental health conditions, higher opioid dosages, or taking other CNS depressants. Consider offering naloxone or nalmefene prescriptions in patients with an increased risk for overdose, such as history of overdose or substance use disorder, higher opioid dosages (≥50 morphine milligram equivalents [MME]/day orally), concomitant benzodiazepine use, and patients at risk for returning to a high dose after losing tolerance (CDC [Dowell 2022]).
• Accidental ingestion: Accidental ingestion of even one dose, especially in children, can result in a fatal overdose of levorphanol.
• Appropriate use: Outpatient setting: Opioids should not be used as first-line therapy for acute (<1-month duration), subacute (1- to 3-month duration), or chronic pain (>3-month duration [outside of end-of-life or palliative care, active cancer treatment, sickle cell disease, or medication-based opioid use disorder treatment]). Preferred management includes nonpharmacologic therapy and nonopioid therapy (eg, nonsteroidal anti-inflammatory drugs, acetaminophen, certain antiseizure medications and antidepressants) as appropriate for the specific condition. If opioid therapy is initiated, it should be combined with nonpharmacologic and nonopioid therapy, as appropriate. Prior to initiation, known risks and realistic benefits of opioid therapy should be discussed with the patient. Therapy should be initiated at the lowest effective dosage using IR opioids (instead of ER/long-acting opioids). For the treatment of acute pain, therapy should only be given for the expected duration of pain severe enough to require opioids and prescribed as needed (not scheduled). For the treatment of subacute and chronic pain, realistic treatment goals for pain/function should be established, including consideration for discontinuation if benefits do not outweigh risks. Therapy should be continued only if clinically meaningful improvement in pain/function outweighs risks. Risk to patients increases with higher opioid dosages. Dosages ≥50 MME/day are likely to not have increased benefit to pain relief or function relative to overall risk to patients; before increasing dosage to ≥50 MME/day, readdress pain and reassess evidence of individual benefits and risks (CDC [Dowell 2022]).
• Naloxone/Nalmefene access: Discuss the availability of naloxone or nalmefene with all patients who are prescribed opioid analgesics, as well as their caregivers, and consider prescribing it to patients who are at increased risk of opioid overdose. These include patients who are also taking benzodiazepines or other CNS depressants, have an opioid use disorder (OUD) (current or history of), or have experienced opioid-induced respiratory depression/opioid overdose. Additionally, health care providers should consider prescribing naloxone or nalmefene to patients prescribed medications to treat OUD; patients at risk of opioid overdose even if they are not taking an opioid analgesic or medication to treat OUD; and patients taking opioids, including methadone or buprenorphine for OUD, if they have household members, including children, or other close contacts at risk for accidental ingestion or opioid overdose. Inform patients and caregivers on options for obtaining naloxone or nalmefene (eg, by prescription, directly from a pharmacist, a community-based program) as permitted by state dispensing and prescribing guidelines. Educate patients and caregivers on how to recognize respiratory depression, proper administration of naloxone or nalmefene, and getting emergency help (FDA 2020).
• Optimal regimen: An opioid-containing analgesic regimen should be tailored to each patient's needs and based upon the type of pain being treated (acute versus chronic), the route of administration, degree of tolerance for opioids (naive versus chronic user), age, weight, and medical condition. The optimal analgesic dose varies widely among patients; doses should be titrated to pain relief/prevention.
• REMS program: To ensure that the benefits of opioid analgesics outweigh the risks of substance use disorder, abuse, and misuse, a REMS is required. Drug companies with approved opioid analgesic products must make REMS-compliant education programs available to health care providers. Health care providers are encouraged to complete a REMS-compliant education program; counsel patients and/or their caregivers, with every prescription, on safe use, serious risks, storage, and disposal of these products; emphasize to patients and their caregivers the importance of reading the Medication Guide every time it is provided by their pharmacist; and consider other tools to improve patient, household, and community safety.
• Surgery: Opioids decrease bowel motility; monitor for decrease bowel motility in postoperative patients receiving opioids. Use with caution in the perioperative setting; individualize treatment when transitioning from parenteral to oral analgesics.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral, as tartrate:
Generic: 2 mg, 3 mg
Yes
Tablets (Levorphanol Tartrate Oral)
2 mg (per each): $53.40
3 mg (per each): $80.10
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.
C-II
Pain management: Management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate.
Limitations of use: Reserve levorphanol for use in patients for whom alternative treatment options (eg, nonopioid analgesics, opioid combination products) are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drug classes (opioids, all formulations and routes of administration) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Acute Care, Community/Ambulatory Care, and Long-Term Care Settings).
None known.
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.
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
Alizapride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Alvimopan: Opioid Agonists may increase adverse/toxic effects of Alvimopan. This is most notable for patients receiving long-term (i.e., more than 7 days) opiates prior to alvimopan initiation. Management: Alvimopan is contraindicated in patients receiving therapeutic doses of opioids for more than 7 consecutive days immediately prior to alvimopan initiation. Risk D: Consider Therapy Modification
Amisulpride (Oral): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Amphetamines: May increase analgesic effects of Opioid Agonists. 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
Azelastine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Benperidol: May increase CNS depressant effects of CNS Depressants. 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
Brimonidine (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromopride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromperidol: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
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
Buprenorphine: May decrease therapeutic effects of Opioid Agonists. Management: Seek alternatives to buprenorphine in patients receiving pure opioid agonists. If combined in certain pain management situations (eg, surgery), monitor for symptoms of therapeutic failure/high dose requirements or opioid withdrawal symptoms. Risk D: Consider Therapy Modification
BusPIRone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Cannabinoid-Containing Products: CNS Depressants may increase CNS depressant effects of Cannabinoid-Containing Products. 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
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
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
Desmopressin: Opioid Agonists may increase hyponatremic effects of Desmopressin. 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
Difelikefalin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Dihydralazine: CNS Depressants may increase hypotensive effects of Dihydralazine. Risk C: Monitor
Dimethindene (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Diuretics: Opioid Agonists may increase adverse/toxic effects of Diuretics. Opioid Agonists may decrease therapeutic effects of Diuretics. Risk C: Monitor
Dothiepin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
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: Opioid Agonists 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
Entacapone: May increase CNS depressant effects of CNS Depressants. 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
Gastrointestinal Agents (Prokinetic): Opioid Agonists may decrease therapeutic effects of Gastrointestinal Agents (Prokinetic). 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
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): May decrease therapeutic effects of Opioid Agonists. Opioid Agonists may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). 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
Lisuride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lofexidine: May increase CNS depressant effects of CNS Depressants. 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
Magnesium Sulfate: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Mequitazine: May increase CNS depressant effects of CNS Depressants. 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
Metoclopramide: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
MetyroSINE: CNS Depressants may increase sedative effects of MetyroSINE. Risk C: Monitor
Minocycline (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Monoamine Oxidase Inhibitors: Opioid Agonists may increase serotonergic effects of Monoamine Oxidase Inhibitors. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. 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
Nalfurafine: Opioid Agonists may increase adverse/toxic effects of Nalfurafine. Opioid Agonists may decrease therapeutic effects of Nalfurafine. Risk C: Monitor
Nalmefene: May decrease therapeutic effects of Opioid Agonists. Management: Avoid the concomitant use of oral nalmefene and opioid agonists. Discontinue oral nalmefene 1 week prior to any anticipated use of opioid agonists. If combined, larger doses of opioid agonists will likely be required. Risk D: Consider Therapy Modification
Naltrexone: May decrease therapeutic effects of Opioid Agonists. Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Risk X: Avoid
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
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
Opioids (Mixed Agonist / Antagonist): May decrease analgesic effects of Opioid Agonists. Management: Seek alternatives to mixed agonist/antagonist opioids in patients receiving pure opioid agonists, and monitor for symptoms of therapeutic failure/high dose requirements (or withdrawal in opioid-dependent patients) if patients receive these combinations. Risk X: Avoid
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
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
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
Paraldehyde: CNS Depressants may increase CNS depressant effects of Paraldehyde. Risk X: Avoid
Pegvisomant: Opioid Agonists may decrease therapeutic effects of Pegvisomant. Risk C: Monitor
Periciazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Pipamperone: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Piribedil: CNS Depressants may increase CNS depressant effects of Piribedil. Risk C: Monitor
Pramipexole: CNS Depressants may increase sedative effects of Pramipexole. Risk C: Monitor
Procarbazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ramosetron: Opioid Agonists may increase constipating effects of Ramosetron. Risk C: Monitor
Rilmenidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
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
ROPINIRole: CNS Depressants may increase sedative effects of ROPINIRole. Risk C: Monitor
Rotigotine: CNS Depressants may increase sedative effects of Rotigotine. Risk C: Monitor
Samidorphan: May decrease therapeutic effects of Opioid Agonists. Risk X: Avoid
Serotonergic Agents (High Risk): Opioid Agonists may increase serotonergic effects of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Risk C: Monitor
Sincalide: Drugs that Affect Gallbladder Function may decrease therapeutic effects of Sincalide. Management: Consider discontinuing drugs that may affect gallbladder motility prior to the use of sincalide to stimulate gallbladder contraction. Risk D: Consider Therapy Modification
Somatostatin Analogs: Opioid Agonists may decrease analgesic effects of Somatostatin Analogs. Opioid Agonists may increase analgesic effects of Somatostatin Analogs. Risk C: Monitor
Succinylcholine: May increase bradycardic effects of Opioid Agonists. Risk C: Monitor
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
Thalidomide: CNS Depressants may increase CNS depressant effects of Thalidomide. Risk X: Avoid
Tilidine: May increase therapeutic effects of Opioid Agonists. Risk X: Avoid
Valerian: May increase CNS depressant effects of CNS Depressants. 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
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
Chronic opioid use may cause hypogonadism and hyperprolactinemia, which may decrease fertility in patients of reproductive potential. Menstrual cycle disorders (including amenorrhea), erectile dysfunction, and impotence have been reported. The incidence of hypogonadism may be increased with the use of opioids in high doses or long-acting opioid formulations. It is not known if the effects on fertility are reversible. Monitor patients on long-term therapy (de Vries 2020; Gadelha 2022).
Consider family planning, contraception, and the effects on fertility prior to prescribing opioids for chronic pain to patients who could become pregnant (ACOG 2017; CDC [Dowell 2022]).
Opioids cross the placenta.
Maternal use of opioids may be associated with poor fetal growth, stillbirth, and preterm delivery (CDC [Dowell 2022]). Opioids used as part of obstetric analgesia/anesthesia during labor and delivery may temporarily affect the fetal heart rate (ACOG 2019).
Neonatal abstinence syndrome (NAS)/neonatal opioid withdrawal syndrome (NOWS) may occur following prolonged in utero exposure to opioids (CDC [Dowell 2022]). NAS/NOWS may be life-threatening if not recognized and treated and requires management according to protocols developed by neonatology experts. Presentation of symptoms varies by opioid characteristics (eg, immediate release, sustained release), time of last dose prior to delivery, drug metabolism (maternal, placental, and infant), net placental transfer, as well as other factors (AAP [Hudak 2012]; AAP [Patrick 2020]). Clinical signs characteristic of withdrawal following in utero opioid exposure include excessive crying or easily irritable, fragmented sleep (<2 to 3 hours after feeding), tremors, increased muscle tone, or GI dysfunction (hyperphagia, poor feeding, feeding intolerance, watery or loose stools) (Jilani 2022). NAS/NOWS occurs following chronic opioid exposure and would not be expected following the use of opioids at delivery (AAP [Patrick 2020]).
Monitor infants of mothers on long-term/chronic opioid therapy for symptoms of withdrawal. Symptom onset reflects the half-life of the opioid used. Monitor infants for at least 3 days following exposure to immediate-release opioids; monitor for at least 4 to 7 days following exposure to sustained-release opioids (AAP [Patrick 2020]; CDC [Dowell 2022]). Monitor newborns for excess sedation and respiratory depression when opioids are used during labor.
When opioids are needed to treat acute pain in pregnant patients, the lowest effective dose for only the expected duration of pain should be prescribed (CDC [Dowell 2022]).
Opioid use for pain following vaginal or cesarean delivery should be made as part of a shared decision-making process. A stepwise multimodal approach to managing postpartum pain is recommended. A low-dose, low-potency, short-acting opioid can be used to treat acute pain associated with delivery when needed (ACOG 2021).
Opioids are not preferred for the treatment of chronic noncancer pain during pregnancy; consider strategies to minimize or avoid opioid use. Advise pregnant patients requiring long-term opioid use of the risk of NAS/NOWS and provide appropriate treatment for the neonate after delivery. NAS/NOWS is an expected and treatable condition following chronic opioid use during pregnancy and should not be the only reason to avoid treating pain with an opioid in pregnant patients (ACOG 2017; CDC [Dowell 2022]). Do not abruptly discontinue opioids during pregnancy; taper prior to discontinuation when appropriate, considering the risks to the pregnant patient and fetus if maternal withdrawal occurs (CDC [Dowell 2022]).
It is not known if levorphanol is present in breast milk; however, morphine, which is structurally similar to levorphanol, is present in human milk.
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 benefits of treatment to the mother. Nonopioid analgesics are preferred for lactating patients who require pain control peripartum or for surgery outside of the postpartum period. When opioids are needed for lactating patients, use the lowest effective dose for the shortest duration of time to limit adverse events in the mother and breastfeeding infant. When an opioid is needed to treat maternal pain, agents other than levorphanol may be preferred (AAP [Sachs 2013]; ABM [Martin 2018]; ABM [Reece-Stremtan 2017]; WHO 2002).
When chronic opioids are prescribed prenatally and continued postpartum, breastfeeding may be initiated to help mitigate potential newborn withdrawal; monitor both the mother and the infant (AAP [Meek 2022]; AAP [Patrick 2020]).
Monitor infants exposed to opioids via breast milk for drowsiness, sedation, feeding difficulties, or limpness (ACOG 2019). Withdrawal symptoms may occur when maternal use is discontinued, or breastfeeding is stopped.
Pain relief, respiratory and mental status, blood pressure; bowel function; signs/symptoms of misuse, abuse, and substance use disorder; signs or symptoms of hypogonadism or hypoadrenalism (Brennan 2013)
Alternate recommendations: Subacute or chronic pain (long-term therapy outside of end-of-life or palliative care, active cancer treatment, sickle cell disease, or medication-based opioid use disorder treatment): Evaluate benefits/risks of opioid therapy within 1 to 4 weeks of treatment initiation and with dose increases. In patients with subacute pain initially treated for acute pain, reassess pain and function after 30 days to address potentially reversible causes of pain and prevent unintentional long-term opioid therapy. In patients on long-term therapy, re-evaluate benefits/risks every 3 months during therapy or more frequently in patients at increased risk of overdose or opioid use disorder. Toxicology testing is recommended prior to initiation and at least yearly (includes controlled prescription medications, illicit drugs of abuse, and benzodiazepines). State prescription drug monitoring program (PDMP) data should be reviewed by clinicians prior to initiation and periodically during therapy (frequency ranging from every prescription to every 3 months) (CDC [Dowell 2022]).
Levorphanol is a synthetic opioid agonist that is classified as a morphinan derivative. Opioids interact with stereospecific opioid receptors in various parts of the central nervous system and other tissues. Analgesic potency parallels the affinity for these binding sites. These drugs do not alter the threshold or responsiveness to pain, but the perception of pain.
Onset of action: Oral: 10 to 60 minutes
Duration: Up to 8 hours
Distribution: Vdss: IV: 10 to 13 L/kg
Protein binding: 40%
Metabolism: Hepatic
Half-life elimination: IV: 11 to 16 hours
Time to peak, plasma: ~1 hour
Excretion: Urine (as inactive metabolite)
