alfentanil (Rx)

Brand and Other Names:Alfenta, Rapifen

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

injectable solution: Schedule II

  • 0.5mg/mL

Dose should be calculated based on ideal body weight

Incremental Injection: Anesthesia <30 Minutes

Induction: 8-20 mcg/kg IV  

Maintenance: 3-5 mcg/kg IV increments q5-20min, or 0.5-1 mcg/kg/min IV

Total dose: 8-40 mcg/kg IV

Incremental Injection: Anesthesia 30-60 Minutes

Induction: 20-50 mcg/kg IV  

Maintenance: 5-15 mcg/kg IV increments q5-20min

Total dose: Up to 75 mcg/kg IV

Anesthetic Induction: Anesthesia >45 Minutes

Induction: 130-245 mcg/kg IV  

Maintenance: 0.5-1.5 mcg/kg/min IV or other general anesthetic

Total dose: depends on duration of operation

Continuous Infusion: For Anesthesia >45 Minutes

Induction: 50-75 mcg/kg IV  

Maintenance: 0.5-3 mcg/kg/min IV

Total dose: depends on duration of operation

Postherpetic Neuralgia (Orphan)

Management of postherpetic neuralgia

Orphan indication sponsor

  • Cinergen, LLC; 146 Medinah Drive; Blue Bell, PA 19422-3212

HIV-Associated Neuropathy (Orphan)

Treatment of painful HIV-associated neuropathy

Orphan indication sponsor

  • Cinergen, LLC; 146 Medinah Drive; Blue Bell, PA 19422-3212

Administration

Total dose: depends on duration of operation

Dosage Forms & Strengths

injectable solution: Schedule II

  • 0.5mg/mL

Dose should be calculated based on ideal body weight

<12 years

Anesthesia

  • Not recommended

>12 years

Incremental Injection: Anesthesia <30 Minutes

  • Induction: 8-20 mcg/kg IV
  • Maintenance: 3-5 mcg/kg IV increments q5-20min, or 0.5-1 mcg/kg/min IV
  • Total dose: 8-40 mcg/kg IV

Incremental Injection: Anesthesia 30-60 Minutes

  • Induction: 20-50 mcg/kg IV  
  • Maintenance: 5-15 mcg/kg IV increments q5-20min
  • Total dose: Up to 75 mcg/kg IV

Anesthetic Induction: Anesthesia >45 Minutes

  • Induction: 130-245 mcg/kg IV  
  • Maintenance: 0.5-1.5 mcg/kg/min IV or other general anesthetic
  • Total dose: depends on duration of operation

Continuous Infusion: For Anesthesia >45 Minutes

  • Induction: 50-75 mcg/kg IV  
  • Maintenance: 0.5-3 mcg/kg/min IV
  • Total dose: depends on duration of operation
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Interactions

Interaction Checker

and alfentanil

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    Interactions Found

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      Serious - Use Alternative

        Significant - Monitor Closely

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            Contraindicated (2)

            • alvimopan

              alvimopan, alfentanil. receptor binding competition. Contraindicated. Contraindicated in opioid tolerant patients (ie, those who have taken therapeutic doses of opioids for >7 consecutive days immediately prior to taking alvimopan). Patients recently exposed to opioids are expected to be more sensitive to the effects of alvimopan and therefore may experience abdominal pain, nausea and vomiting, and diarrhea.

            • olanzapine/samidorphan

              olanzapine/samidorphan will decrease the level or effect of alfentanil by pharmacodynamic antagonism. Contraindicated. Samidorphan elicits opioid antagonistic effects and increases risk of precipitating acute opioid withdrawal in patients dependent on opioids. Prescribing information recommends at least a 7-day opioid-free interval for short-acting opioids and at least a 14-day opioid-free interval for long-acting opioids before starting olanzapine/samidorphan.

            Serious - Use Alternative (74)

            • acrivastine

              acrivastine and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • amisulpride

              amisulpride and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • apalutamide

              apalutamide will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

            • asenapine

              asenapine and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • asenapine transdermal

              asenapine transdermal and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • avapritinib

              avapritinib and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • benzhydrocodone/acetaminophen

              benzhydrocodone/acetaminophen, alfentanil. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

              benzhydrocodone/acetaminophen and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • brexpiprazole

              brexpiprazole and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • brigatinib

              brigatinib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Brigatinib induces CYP3A4 in vitro. Coadministration with CYP3A4 substrates, particularly those with a narrow therapeutic index, can result in decreased concentrations and loss of efficacy. If unable to avoid coadministration, monitor CYP3A4 substrate levels and adjust dose as needed.

            • brimonidine

              brimonidine and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • brivaracetam

              brivaracetam and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • buprenorphine

              buprenorphine, alfentanil. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.

            • buprenorphine buccal

              buprenorphine buccal, alfentanil. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.

            • buprenorphine subdermal implant

              buprenorphine subdermal implant and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • buprenorphine transdermal

              buprenorphine transdermal and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • buprenorphine, long-acting injection

              buprenorphine, long-acting injection and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • butorphanol

              butorphanol, alfentanil. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.

            • calcium/magnesium/potassium/sodium oxybates

              alfentanil, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

            • cariprazine

              cariprazine and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • citalopram

              alfentanil, citalopram. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • clonidine

              clonidine, alfentanil. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration enhances CNS depressant effects.

            • desvenlafaxine

              desvenlafaxine and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

            • diazepam intranasal

              diazepam intranasal, alfentanil. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

            • escitalopram

              alfentanil, escitalopram. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • fentanyl

              fentanyl and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • fentanyl intranasal

              fentanyl intranasal and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • fentanyl iontophoretic transdermal system

              fentanyl iontophoretic transdermal system and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • fentanyl transdermal

              fentanyl transdermal and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • fentanyl transmucosal

              fentanyl transmucosal and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • fexinidazole

              fexinidazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

            • fluoxetine

              alfentanil, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • fluvoxamine

              fluvoxamine and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug.

            • hydrocodone

              hydrocodone, alfentanil. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

            • idelalisib

              idelalisib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

            • isocarboxazid

              isocarboxazid increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.

            • isoniazid

              isoniazid will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Monitor for excessive CNS and respiratory depression

            • ivosidenib

              ivosidenib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

            • levetiracetam

              levetiracetam and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • linezolid

              linezolid increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.

              alfentanil, linezolid. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • lonafarnib

              lonafarnib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

            • lopinavir

              lopinavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lorlatinib

              lorlatinib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use of lorlatinib with CYP3A substrates, where minimal concentration changes may lead to serious therapeutic failures of the substrate. If concomitant use is unavoidable, increase CYP3A substrate dosage in accordance with approved product labeling.

            • lumacaftor/ivacaftor

              lumacaftor/ivacaftor will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Lumacaftor is a strong inducer of CYP3A. Avoid coadministration with sensitive CYP3A substrates or CYP3A substrates with a narrow therapeutic index.

            • methohexital

              methohexital and alfentanil both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

            • methylene blue

              methylene blue and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

            • metoclopramide intranasal

              alfentanil, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.

            • mifepristone

              mifepristone will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • mobocertinib

              mobocertinib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use is unavoidable, increase CYP3A4 substrate dosage in accordance with its prescribing information.

            • nalbuphine

              nalbuphine, alfentanil. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.

            • nefazodone

              nefazodone will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • olopatadine intranasal

              alfentanil and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

            • olutasidenib

              olutasidenib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of olutasidenib (a CYP3A4 inducer) with sensitive CYP3A substrates unless otherwise instructed in substrates prescribing information. If unavoidable, monitor for loss of therapeutic effect of sensitive CYP3A4 substrates.

            • ozanimod

              ozanimod and alfentanil both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug. Because the active metabolite of ozanimod inhibits MAO-B in vitro, there is a potential for serious adverse reactions, including hypertensive crisis. Therefore, coadministration of ozanimod with drugs that can increase norepinephrine or serotonin is not recommended. Monitor for hypertension with concomitant use.

            • pacritinib

              pacritinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • paroxetine

              alfentanil, paroxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • pentazocine

              pentazocine, alfentanil. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.

            • pexidartinib

              pexidartinib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of pexidartinib (a CYP3A4 inducer) with sensitive CYP3A substrates may lead to serious therapeutic failures. If concomitant use is unavoidable, increase the CYP3A substrate dosage in accordance with approved product labeling.

            • phenelzine

              phenelzine increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.

            • procarbazine

              procarbazine increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. MAOIs may potentiate CNS depression and hypotension. Do not use within 14 days of MAOI use. .

            • rasagiline

              rasagiline increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. May cause additive CNS depression, drowsiness, dizziness or hypotension, so use with MAOIs should be cautious; lower initial dosages of the analgesic are recommended followed by careful titration. Avoid combination within 14 days of MAOI use.

            • repotrectinib

              repotrectinib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Repotrectinib is a CYP3A4 inducer. Avoid coadministration with CYP3A substrates where minimal concentration changes can cause reduced efficacy, unless otherwise recommended their prescribing information.

            • selegiline transdermal

              selegiline transdermal increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death.

            • selinexor

              selinexor, alfentanil. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

            • sertraline

              alfentanil, sertraline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • sodium oxybate

              alfentanil, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

            • sotorasib

              sotorasib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the CYP3A4 substrate for dosage modifications

            • sufentanil SL

              sufentanil SL, alfentanil. Either increases toxicity of the other by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

              sufentanil SL, alfentanil. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

            • tramadol

              tramadol, alfentanil. Other (see comment). Avoid or Use Alternate Drug. Comment: Tramadol may reinitiate opiate dependence in pts. previously addicted to other opiates; it may also provoke withdrawal Sx. in pts. who are currently opiate dependent.

            • tranylcypromine

              tranylcypromine increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.

            • valerian

              valerian and alfentanil both increase sedation. Avoid or Use Alternate Drug.

            • venlafaxine

              venlafaxine and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

            • vortioxetine

              alfentanil, vortioxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

            • voxelotor

              voxelotor will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

            • zuranolone

              alfentanil, zuranolone. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of zuranolone with other CNS depressants may increase impairment of psychomotor performance or CNS depressant effects. If unavoidable, consider dose reduction. .

            Monitor Closely (255)

            • albuterol

              alfentanil increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • alprazolam

              alprazolam and alfentanil both increase sedation. Use Caution/Monitor.

            • amifostine

              amifostine, alfentanil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.

            • amitriptyline

              alfentanil and amitriptyline both increase sedation. Use Caution/Monitor.

            • amobarbital

              amobarbital and alfentanil both increase sedation. Use Caution/Monitor.

            • amoxapine

              alfentanil and amoxapine both increase sedation. Use Caution/Monitor.

            • amphetamine

              alfentanil increases and amphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • apomorphine

              alfentanil and apomorphine both increase sedation. Use Caution/Monitor.

            • arformoterol

              alfentanil increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • aripiprazole

              alfentanil and aripiprazole both increase sedation. Use Caution/Monitor.

            • armodafinil

              alfentanil increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • azelastine

              azelastine and alfentanil both increase sedation. Use Caution/Monitor.

            • baclofen

              baclofen and alfentanil both increase sedation. Use Caution/Monitor.

            • belladonna and opium

              alfentanil and belladonna and opium both increase sedation. Use Caution/Monitor.

            • belzutifan

              belzutifan will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.

            • benperidol

              alfentanil and benperidol both increase sedation. Use Caution/Monitor.

            • benzphetamine

              alfentanil increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • berotralstat

              berotralstat will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor or titrate substrate dose when berotralstat is coadministered with narrow therapeutic index drugs that are CYP3A substrates.

            • brexanolone

              brexanolone, alfentanil. Either increases toxicity of the other by sedation. Use Caution/Monitor.

            • brompheniramine

              brompheniramine and alfentanil both increase sedation. Use Caution/Monitor.

            • buprenorphine

              alfentanil and buprenorphine both increase sedation. Use Caution/Monitor.

            • buprenorphine buccal

              alfentanil and buprenorphine buccal both increase sedation. Use Caution/Monitor.

            • buprenorphine, long-acting injection

              alfentanil increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

            • butabarbital

              butabarbital and alfentanil both increase sedation. Use Caution/Monitor.

            • butalbital

              butalbital and alfentanil both increase sedation. Use Caution/Monitor.

            • butorphanol

              alfentanil and butorphanol both increase sedation. Use Caution/Monitor.

            • caffeine

              alfentanil increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • carbamazepine

              carbamazepine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • carbinoxamine

              carbinoxamine and alfentanil both increase sedation. Use Caution/Monitor.

            • carisoprodol

              carisoprodol and alfentanil both increase sedation. Use Caution/Monitor.

            • cenobamate

              cenobamate will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

              cenobamate, alfentanil. Either increases effects of the other by sedation. Use Caution/Monitor.

            • ceritinib

              ceritinib increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • chloral hydrate

              chloral hydrate and alfentanil both increase sedation. Use Caution/Monitor.

            • chlordiazepoxide

              chlordiazepoxide and alfentanil both increase sedation. Use Caution/Monitor.

            • chlorpheniramine

              chlorpheniramine and alfentanil both increase sedation. Use Caution/Monitor.

            • chlorpromazine

              alfentanil and chlorpromazine both increase sedation. Use Caution/Monitor.

            • chlorzoxazone

              chlorzoxazone and alfentanil both increase sedation. Use Caution/Monitor.

            • cimetidine

              cimetidine will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cinnarizine

              cinnarizine and alfentanil both increase sedation. Use Caution/Monitor.

            • clarithromycin

              clarithromycin will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • clemastine

              clemastine and alfentanil both increase sedation. Use Caution/Monitor.

            • clobazam

              alfentanil, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).

            • clomipramine

              alfentanil and clomipramine both increase sedation. Use Caution/Monitor.

            • clonazepam

              clonazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • clorazepate

              clorazepate and alfentanil both increase sedation. Use Caution/Monitor.

            • clozapine

              alfentanil and clozapine both increase sedation. Use Caution/Monitor.

            • cobicistat

              cobicistat will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • codeine

              alfentanil and codeine both increase sedation. Use Caution/Monitor.

            • crizotinib

              crizotinib increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of crizotinib with CYP3A substrates with narrow therapeutic indices should be avoided.

            • cyclizine

              cyclizine and alfentanil both increase sedation. Use Caution/Monitor.

            • cyclobenzaprine

              cyclobenzaprine and alfentanil both increase sedation. Use Caution/Monitor.

            • cyproheptadine

              cyproheptadine and alfentanil both increase sedation. Use Caution/Monitor.

            • dabrafenib

              dabrafenib will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • danazol

              danazol will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dantrolene

              dantrolene and alfentanil both increase sedation. Use Caution/Monitor.

            • daridorexant

              alfentanil and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

            • deferasirox

              deferasirox will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • desflurane

              desflurane and alfentanil both increase sedation. Use Caution/Monitor. Opioids may decrease MAC requirements, less inhalation anesthetic may be required.

            • desipramine

              alfentanil and desipramine both increase sedation. Use Caution/Monitor.

            • dexchlorpheniramine

              dexchlorpheniramine and alfentanil both increase sedation. Use Caution/Monitor.

            • dexfenfluramine

              alfentanil increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dexmedetomidine

              dexmedetomidine and alfentanil both increase sedation. Use Caution/Monitor.

            • dexmethylphenidate

              alfentanil increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dextroamphetamine

              alfentanil increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dextromoramide

              alfentanil and dextromoramide both increase sedation. Use Caution/Monitor.

            • diamorphine

              alfentanil and diamorphine both increase sedation. Use Caution/Monitor.

            • diazepam

              diazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • diethylpropion

              alfentanil increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • difelikefalin

              difelikefalin and alfentanil both increase sedation. Use Caution/Monitor.

            • difenoxin hcl

              alfentanil and difenoxin hcl both increase sedation. Use Caution/Monitor.

            • diltiazem

              diltiazem will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. In patients receiving both diltiazem and alfentanil, monitor for alfentanil toxicity (sedation, somnolence, confusion, impaired coordination, diminished reflexes, coma). Doses of alfentanil may need to be reduced.

            • dimenhydrinate

              dimenhydrinate and alfentanil both increase sedation. Use Caution/Monitor.

            • diphenhydramine

              diphenhydramine and alfentanil both increase sedation. Use Caution/Monitor.

            • diphenoxylate hcl

              alfentanil and diphenoxylate hcl both increase sedation. Use Caution/Monitor.

            • dipipanone

              alfentanil and dipipanone both increase sedation. Use Caution/Monitor.

            • dobutamine

              alfentanil increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dopamine

              alfentanil increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dopexamine

              alfentanil increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • dosulepin

              alfentanil and dosulepin both increase sedation. Use Caution/Monitor.

            • doxepin

              alfentanil and doxepin both increase sedation. Use Caution/Monitor.

            • doxylamine

              doxylamine and alfentanil both increase sedation. Use Caution/Monitor.

            • droperidol

              alfentanil and droperidol both increase sedation. Use Caution/Monitor.

            • duvelisib

              duvelisib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.

            • efavirenz

              efavirenz will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • elagolix

              elagolix will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

            • elranatamab

              elranatamab will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Elranatamab causes cytokine release syndrome (CRS) that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. This is more likely to occur from initiation of elranatamab step-up dosing up to 14 days after the first treatment dose and during and after CRS.

            • eluxadoline

              eluxadoline increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution when CYP3A substrates that have a narrow therapeutic index are coadministered with eluxadoline.

            • elvitegravir/cobicistat/emtricitabine/tenofovir DF

              elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

            • encorafenib

              encorafenib, alfentanil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

            • enzalutamide

              enzalutamide will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • epcoritamab

              epcoritamab, alfentanil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Epcoritamab causes release of cytokines that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. For certain CYP substrates, minimal changes in their concentration may lead to serious adverse reactions. If needed, modify therapy as recommended in the substrate's prescribing information. .

            • ephedrine

              alfentanil increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • epinephrine

              alfentanil increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • epinephrine racemic

              alfentanil increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • erythromycin base

              erythromycin base will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • erythromycin ethylsuccinate

              erythromycin ethylsuccinate will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • erythromycin lactobionate

              erythromycin lactobionate will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • erythromycin stearate

              erythromycin stearate will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • esketamine intranasal

              esketamine intranasal, alfentanil. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

            • estazolam

              estazolam and alfentanil both increase sedation. Use Caution/Monitor.

            • ethanol

              alfentanil and ethanol both increase sedation. Use Caution/Monitor.

            • etomidate

              etomidate and alfentanil both increase sedation. Use Caution/Monitor.

            • fedratinib

              fedratinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

            • fenfluramine

              alfentanil increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • fluphenazine

              alfentanil and fluphenazine both increase sedation. Use Caution/Monitor.

            • flurazepam

              flurazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • fluvoxamine

              fluvoxamine will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • formoterol

              alfentanil increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • ganaxolone

              alfentanil and ganaxolone both increase sedation. Use Caution/Monitor.

            • givinostat

              givinostat will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Givinostat is a weak CYP3A4 inhibitor. Closely monitor if coadministered with orally administered CYP3A4 sensitive substrates for which a small change in substrate plasma concentration may lead to serious toxicities.

            • glofitamab

              glofitamab, alfentanil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Glofitamab causes release of cytokines that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. For certain CYP substrates, minimal changes in their concentration may lead to serious adverse reactions. If needed, modify therapy as recommended in the substrate's prescribing information. .

            • glycerol phenylbutyrate

              glycerol phenylbutyrate will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Glycerol phenylbutyrate is a weak inducer of CYP3A4. Monitor for decreased efficacy of CYP3A4 substrates that have a narrow therapeutic index.

            • haloperidol

              alfentanil and haloperidol both increase sedation. Use Caution/Monitor.

            • hydromorphone

              alfentanil and hydromorphone both increase sedation. Use Caution/Monitor.

            • hydroxyzine

              hydroxyzine and alfentanil both increase sedation. Use Caution/Monitor.

            • iloperidone

              alfentanil and iloperidone both increase sedation. Use Caution/Monitor.

              iloperidone increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

            • iloprost

              iloprost, alfentanil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. When administering iloprost IV, consider temporary discontinuation of concomitant vasodilators or other medications that reduce blood pressure to mitigate potential additive hypotensive effects. If hypotension persists despite discontinuing other antihypertensives and fluid resuscitation, consider iloprost dose reduction or discontinuation.

            • imipramine

              alfentanil and imipramine both increase sedation. Use Caution/Monitor.

            • isavuconazonium sulfate

              isavuconazonium sulfate will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • isoproterenol

              alfentanil increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • istradefylline

              istradefylline will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

            • itraconazole

              itraconazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ketamine

              ketamine and alfentanil both increase sedation. Use Caution/Monitor.

            • ketoconazole

              ketoconazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ketotifen, ophthalmic

              alfentanil and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

            • larotrectinib

              larotrectinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lasmiditan

              lasmiditan, alfentanil. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

            • lemborexant

              lemborexant, alfentanil. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

            • lenacapavir

              lenacapavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

            • letermovir

              letermovir increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • levalbuterol

              alfentanil increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • levoketoconazole

              levoketoconazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • levorphanol

              alfentanil and levorphanol both increase sedation. Use Caution/Monitor.

            • lisdexamfetamine

              alfentanil increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • lofepramine

              alfentanil and lofepramine both increase sedation. Use Caution/Monitor.

            • lofexidine

              alfentanil and lofexidine both increase sedation. Use Caution/Monitor.

            • lonapegsomatropin

              lonapegsomatropin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substrates

            • loprazolam

              loprazolam and alfentanil both increase sedation. Use Caution/Monitor.

            • lorazepam

              lorazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • lormetazepam

              lormetazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • loxapine

              alfentanil and loxapine both increase sedation. Use Caution/Monitor.

            • loxapine inhaled

              alfentanil and loxapine inhaled both increase sedation. Use Caution/Monitor.

            • lurasidone

              lurasidone increases effects of alfentanil by Other (see comment). Use Caution/Monitor. Comment: Potential for additive CNS effects .

            • maprotiline

              alfentanil and maprotiline both increase sedation. Use Caution/Monitor.

            • marijuana

              alfentanil and marijuana both increase sedation. Use Caution/Monitor.

            • melatonin

              alfentanil and melatonin both increase sedation. Use Caution/Monitor.

            • meperidine

              alfentanil and meperidine both increase sedation. Use Caution/Monitor.

            • meprobamate

              alfentanil and meprobamate both increase sedation. Use Caution/Monitor.

            • metaproterenol

              alfentanil increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • metaxalone

              metaxalone and alfentanil both increase sedation. Use Caution/Monitor.

            • methadone

              alfentanil and methadone both increase sedation. Use Caution/Monitor.

            • methamphetamine

              alfentanil increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • methocarbamol

              methocarbamol and alfentanil both increase sedation. Use Caution/Monitor.

            • methylenedioxymethamphetamine

              alfentanil increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • midazolam

              midazolam and alfentanil both increase sedation. Use Caution/Monitor.

            • midazolam intranasal

              midazolam intranasal, alfentanil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

            • midodrine

              alfentanil increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • mirtazapine

              alfentanil and mirtazapine both increase sedation. Use Caution/Monitor.

            • mitotane

              mitotane decreases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

            • modafinil

              alfentanil increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • morphine

              alfentanil and morphine both increase sedation. Use Caution/Monitor.

            • motherwort

              alfentanil and motherwort both increase sedation. Use Caution/Monitor.

            • moxonidine

              alfentanil and moxonidine both increase sedation. Use Caution/Monitor.

            • nabilone

              alfentanil and nabilone both increase sedation. Use Caution/Monitor.

            • nalbuphine

              alfentanil and nalbuphine both increase sedation. Use Caution/Monitor.

            • norepinephrine

              alfentanil increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • nortriptyline

              alfentanil and nortriptyline both increase sedation. Use Caution/Monitor.

            • olanzapine

              alfentanil and olanzapine both increase sedation. Use Caution/Monitor.

            • oliceridine

              oliceridine, alfentanil. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

            • omaveloxolone

              omaveloxolone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Omaveloxolone may reduce systemic exposure of sensitive CYP3A4 substrates. Check prescribing information of substrate if dosage modification is needed.

            • opium tincture

              alfentanil and opium tincture both increase sedation. Use Caution/Monitor.

            • orphenadrine

              orphenadrine and alfentanil both increase sedation. Use Caution/Monitor.

            • oxazepam

              oxazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • oxycodone

              alfentanil and oxycodone both increase sedation. Use Caution/Monitor.

            • oxymorphone

              alfentanil and oxymorphone both increase sedation. Use Caution/Monitor.

            • palbociclib

              palbociclib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. The dose of sensitive CYP3A substrates with a narrow therapeutic index may need to be reduced if coadministered with palbociclib

            • paliperidone

              alfentanil and paliperidone both increase sedation. Use Caution/Monitor.

            • papaveretum

              alfentanil and papaveretum both increase sedation. Use Caution/Monitor.

            • papaverine

              alfentanil and papaverine both increase sedation. Use Caution/Monitor.

            • pegvisomant

              alfentanil decreases effects of pegvisomant by unknown mechanism. Use Caution/Monitor.

            • pentazocine

              alfentanil and pentazocine both increase sedation. Use Caution/Monitor.

            • pentobarbital

              pentobarbital and alfentanil both increase sedation. Use Caution/Monitor.

            • perphenazine

              alfentanil and perphenazine both increase sedation. Use Caution/Monitor.

            • phendimetrazine

              alfentanil increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • phenobarbital

              phenobarbital and alfentanil both increase sedation. Use Caution/Monitor.

            • phentermine

              alfentanil increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • phenylephrine

              alfentanil increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • phenylephrine PO

              alfentanil increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

            • pholcodine

              alfentanil and pholcodine both increase sedation. Use Caution/Monitor.

            • pimozide

              alfentanil and pimozide both increase sedation. Use Caution/Monitor.

            • pirbuterol

              alfentanil increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • pirtobrutinib

              pirtobrutinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Pirtobrutinib (a CYP3A4 inhibitor) may increase plasma concentrations of sensitive CYP3A4 substrate which may increase the risk of adverse reactions related to these substrates.

            • pitolisant

              pitolisant will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Pitolisant is a borderline/weak inducer of CYP3A4. Monitor sensitive CYP3A4 substrates for reduced effectiveness if coadministered.

            • primidone

              primidone and alfentanil both increase sedation. Use Caution/Monitor.

            • prochlorperazine

              alfentanil and prochlorperazine both increase sedation. Use Caution/Monitor.

            • promethazine

              promethazine and alfentanil both increase sedation. Use Caution/Monitor.

            • propofol

              propofol and alfentanil both increase sedation. Use Caution/Monitor.

            • propylhexedrine

              alfentanil increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • protriptyline

              alfentanil and protriptyline both increase sedation. Use Caution/Monitor.

            • quazepam

              quazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • quetiapine

              alfentanil and quetiapine both increase sedation. Use Caution/Monitor.

            • ramelteon

              alfentanil and ramelteon both increase sedation. Use Caution/Monitor.

            • remimazolam

              remimazolam, alfentanil. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. aCoadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

            • ribociclib

              ribociclib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Caution if ribociclib is coadministered with sensitive CYP3A4 substrates that have a narrow therapeutic index. Dose reduction for sensitive CYP3A4 substrates may be needed.

            • rifabutin

              rifabutin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rifampin

              rifampin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • risperidone

              alfentanil and risperidone both increase sedation. Use Caution/Monitor.

            • ritlecitinib

              ritlecitinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Ritlecitinib inhibits CYP3A4 substrates; coadministration increases AUC and peak plasma concentration sensitive substrates, which may increase risk of adverse reactions. Additional monitoring and dosage adjustment may be needed in accordance with product labeling of CYP3A substrates.

            • ropeginterferon alfa 2b

              ropeginterferon alfa 2b will increase the level or effect of alfentanil by Other (see comment). Use Caution/Monitor. Certain proinflammatory cytokines, including interferons, can suppress CYP450 enzymes resulting in increased exposures of some CYP substrates. Therefore, monitor patients who are receiving concomitant drugs that are CYP450 substrates with a narrow therapeutic index from toxicities to such drugs.

            • rucaparib

              rucaparib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

            • salmeterol

              alfentanil increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • saquinavir

              saquinavir increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • schisandra

              schisandra will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • scullcap

              alfentanil and scullcap both increase sedation. Use Caution/Monitor.

            • secobarbital

              secobarbital and alfentanil both increase sedation. Use Caution/Monitor.

            • selegiline

              selegiline increases toxicity of alfentanil by unknown mechanism. Modify Therapy/Monitor Closely. Potential for increased CNS depression, drowsiness, dizziness or hypotension, so use with any MAOI should be cautious.

            • sevoflurane

              sevoflurane and alfentanil both increase sedation. Use Caution/Monitor.

            • shepherd's purse

              alfentanil and shepherd's purse both increase sedation. Use Caution/Monitor.

            • sofosbuvir/velpatasvir

              sofosbuvir/velpatasvir increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Velpatasvir inhibits CYP3A4. Caution if coadministered with drugs with narrow therapeutics indexes.

            • somapacitan

              somapacitan will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substrates

            • somatrogon

              somatrogon will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substrates

            • somatropin

              somatropin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substrates

            • St John's Wort

              St John's Wort will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • stiripentol

              stiripentol, alfentanil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.

            • sufentanil

              alfentanil and sufentanil both increase sedation. Use Caution/Monitor.

            • talquetamab

              talquetamab will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Talquetamab causes cytokine release syndrome (CRS) that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. This is more likely to occur from initiation of talquetamab step-up dosing up to 14 days after the first treatment dose and during and after CRS.

            • tapentadol

              alfentanil and tapentadol both increase sedation. Use Caution/Monitor.

            • tazemetostat

              tazemetostat will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • teclistamab

              teclistamab will increase the level or effect of alfentanil by altering metabolism. Use Caution/Monitor. Teclistamab causes release of cytokines that may suppress activity of CYP450 enzymes, resulting in increased exposure of CYP substrates. Monitor for increased concentrations or toxicities of sensitive CYP substrates. Adjust dose of CYP substrate drug as needed.

            • tecovirimat

              tecovirimat will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

            • telotristat ethyl

              telotristat ethyl will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Telotristat ethyl induces CYP3A4 and may reduce systemic exposure of sensitive CYP3A4 substrates. Monitor for suboptimal efficacy and consider increasing the dose of the CYP3A4 substrate.

            • temazepam

              temazepam and alfentanil both increase sedation. Use Caution/Monitor.

            • terbutaline

              alfentanil increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • thioridazine

              alfentanil and thioridazine both increase sedation. Use Caution/Monitor.

            • thiothixene

              alfentanil and thiothixene both increase sedation. Use Caution/Monitor.

            • tipranavir

              tipranavir increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tipranavir is used with ritonavir (boosted therapy) which is a potent CYP3A4 inhibitor.

            • topiramate

              alfentanil and topiramate both increase sedation. Modify Therapy/Monitor Closely.

            • tramadol

              alfentanil and tramadol both increase sedation. Use Caution/Monitor.

            • trazodone

              alfentanil and trazodone both increase sedation. Use Caution/Monitor.

            • triazolam

              triazolam and alfentanil both increase sedation. Use Caution/Monitor.

            • triclofos

              triclofos and alfentanil both increase sedation. Use Caution/Monitor.

            • trifluoperazine

              alfentanil and trifluoperazine both increase sedation. Use Caution/Monitor.

            • trimipramine

              alfentanil and trimipramine both increase sedation. Use Caution/Monitor.

            • triprolidine

              triprolidine and alfentanil both increase sedation. Use Caution/Monitor.

            • trofinetide

              trofinetide will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor CYP3A4 substrates for which a small increase in plasma concentration may lead to serious toxicities if coadministered with trofinetide (a weak CYP3A4 inhibitor).

            • turmeric

              turmeric will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ustekinumab

              ustekinumab, alfentanil. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, normalizing the formation of CYP450 enzymes. Upon initiation or discontinuation of ustekinumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.

            • verapamil

              verapamil will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. The risk of significant hypotension and/or bradycardia during therapy with alfentanil may be increased in patients receiving calcium-channel blockers.

            • vonoprazan

              vonoprazan will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Vonoprazan is weak CYP3A inhibitor. Caution with sensitive CYP3A substrates.

            • voriconazole

              voriconazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Dose reduction of alfentanil may be warranted

            • xylometazoline

              alfentanil increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • yohimbine

              alfentanil increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

            • ziconotide

              alfentanil and ziconotide both increase sedation. Use Caution/Monitor.

            • ziprasidone

              alfentanil and ziprasidone both increase sedation. Use Caution/Monitor.

            • zotepine

              alfentanil and zotepine both increase sedation. Use Caution/Monitor.

            Minor (64)

            • acetazolamide

              acetazolamide will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • amobarbital

              amobarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • amphetamine

              amphetamine increases effects of alfentanil by unspecified interaction mechanism. Minor/Significance Unknown.

            • anastrozole

              anastrozole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • aprepitant

              aprepitant will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • armodafinil

              armodafinil will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • artemether/lumefantrine

              artemether/lumefantrine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • atazanavir

              atazanavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • bosentan

              bosentan will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • brimonidine

              brimonidine increases effects of alfentanil by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

            • budesonide

              budesonide will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • butabarbital

              butabarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • butalbital

              butalbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • conivaptan

              conivaptan will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • cortisone

              cortisone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • cyclophosphamide

              cyclophosphamide will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • cyclosporine

              cyclosporine will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • darifenacin

              darifenacin will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • darunavir

              darunavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dasatinib

              dasatinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dexamethasone

              dexamethasone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dextroamphetamine

              dextroamphetamine increases effects of alfentanil by unspecified interaction mechanism. Minor/Significance Unknown.

            • DHEA, herbal

              DHEA, herbal will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • dronedarone

              dronedarone will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • drospirenone

              drospirenone will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • eslicarbazepine acetate

              eslicarbazepine acetate will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • etravirine

              etravirine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • eucalyptus

              alfentanil and eucalyptus both increase sedation. Minor/Significance Unknown.

            • fluconazole

              fluconazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • fludrocortisone

              fludrocortisone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • fosamprenavir

              fosamprenavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • fosaprepitant

              fosaprepitant will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • fosphenytoin

              fosphenytoin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • grapefruit

              grapefruit will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • griseofulvin

              griseofulvin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • hydrocortisone

              hydrocortisone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • indinavir

              indinavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • lapatinib

              lapatinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • lidocaine

              lidocaine increases toxicity of alfentanil by pharmacodynamic synergism. Minor/Significance Unknown. Risk of increased CNS depression.

            • lumefantrine

              lumefantrine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • marijuana

              marijuana will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • methylprednisolone

              methylprednisolone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • metronidazole

              metronidazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • miconazole vaginal

              miconazole vaginal will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nelfinavir

              nelfinavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nevirapine

              nevirapine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nifedipine

              nifedipine will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nilotinib

              nilotinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • oxcarbazepine

              oxcarbazepine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • pentobarbital

              pentobarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • phenobarbital

              phenobarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • phenytoin

              phenytoin will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • posaconazole

              posaconazole will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • prednisone

              prednisone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • primidone

              primidone will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • quinupristin/dalfopristin

              quinupristin/dalfopristin will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • rifapentine

              rifapentine will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ritonavir

              ritonavir will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • rufinamide

              rufinamide will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • sage

              alfentanil and sage both increase sedation. Minor/Significance Unknown.

            • secobarbital

              secobarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • topiramate

              topiramate will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zafirlukast

              zafirlukast will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ziconotide

              ziconotide, alfentanil. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Additive decreased GI motility. Additive analgesia. Ziconotide does NOT potentiate opioid induced respiratory depression.

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            Adverse Effects

            >10%

            Arrhythmia (14%)

            Bradycardia (14%)

            Chest wall rigidity (17%)

            Hypertension (18%)

            Nausea (28%)

            Vomiting (18%)

            Tachycardia (12%)

            1-10%

            Apnea (3-9%)

            Blurred vision (1-3%)

            Dizziness (3-9%)

            Hypotension (10%)

            Post-op respiratory depression (1-3%)

            Skeletal muscle movements (3-9%)

            Postoperative sedation (1-3%)

            <1%

            Sweating, flushing

            Warmness of the face/neck/upper thorax

            Pruritus

            urticaria

            Respiratory (undefined)

            Respiratory/circulatory depression

            Respiratory arrest

            Shock

            Cardiac arrest

            Nervous System (undefined)

            Dizziness

            Visual disturbances

            Mental clouding/depression

            Sedation

            Coma

            Euphoria

            Dysphoria

            Weakness

            Faintness

            Agitation

            Restlessness

            Nervousness

            Seizures

            GI (undefined)

            Nausea

            Vomiting

            Constipation

            Cardiovascular (undefined)

            QT-interval prolongation

            Severe cardiac arrhythmias

            Cardiac arrest

            ST segment elevation

            VTach

            MI

            Angina pectoris

            Syncope

            Genitourinary (undefined)

            Urinary retention

            Oliguria

            Cholinergic (undefined)

            Bradycardia

            Dry mouth

            Palpitation

            Tachycardia

            Postmarketing Reports

            Hyperalgesia and allodynia

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            Warnings

            Black Box Warnings

            Therapy 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 development of these behaviors and conditions

            Profound sedation: If decision is made to manage postoperative pain with this drug concomitantly with a benzodiazepine or other CNS depressant, start dosing with the lowest effective dosage and titrate based on clinical response; monitor patients closely for signs and symptoms of respiratory depression, sedation, and hypotension; fluids or other measures to counter hypotension should be available

            Life-Threatening Respiratory Depression

            • Serious, life-threatening, or fatal respiratory depression may occur with use, especially during initiation or following dosage increase; to reduce risk of respiratory depression, proper dosing and titration are essential

            Risks from concomitant use with benzodiazepines or other CNS depressants

            • Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death; reserve concomitant prescribing of this drug and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate

            Cytochrome P450 3A4 interaction

            • The concomitant use with all cytochrome P450 3A4 inhibitors may result in an increase in alfentanil plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression; in addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in alfentanil plasma concentration; monitor patients receiving this drug and any CYP3A4 inhibitor or inducer

            Contraindications

            Hypersensitivity

            Increased intracranial pressure

            Severe respiratory depresssion

            Cautions

            Therapy may impair mental or physical abilities needed to perform potentially hazardous activities such as driving a car or operating machinery after administering drug; warn patients not to drive or operate dangerous machinery unless they are tolerant to effects of the drug and know how they will react to the medication

            Use caution in bradycardia, compromised cardiac reserve, head injury, hypothyroidism, increased ICP, intracranial lesions, renal impairment, respiratory impairment, obesicty, history of drug abuse

            Concurrent administration of benzodiazepine or neuromuscular blocker will decrease chest wall rigidity

            Should be administered by trained individuals

            In patients who may be susceptible to intracranial effects of CO2 retention (e.g., those with evidence of increased intracranial pressure or brain tumors), therapy may reduce respiratory drive, and resultant CO2 retention can further increase intracranial pressure; monitor such patients for signs of sedation and respiratory depression, particularly when initiating therapy; opioids may obscure clinical course in a patient with a head injury; avoid the use in patients with impaired consciousness or coma

            May cause spasm of sphincter of Oddi; opioids may cause increases in serum amylase; monitor patients with biliary tract disease, including acute pancreatitis, for worsening symptoms

            Therapy may increase frequency of seizures in patients with seizure disorders and in other clinical settings associated with seizures; monitor patients for worsened seizure control during therapy

            Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients because they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients; monitor closely

            Profound sedation, respiratory depression, coma, and death may result from concomitant administration with benzodiazepines or other CNS depressants (e.g., non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, alcohol); because of these risks, reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate

            Opioids can cause sleep-related breathing disorders including central sleep apnea (CSA) and sleep-related hypoxemia; opioid use increases risk of CSA in a dose-dependent fashion; in patients who present with CSA, consider decreasing opioid dosage using best practices for opioid taper

            Muscle rigidity occurring during induction of can be treated by decreasing rate or discontinuing infusion of drug or by administering a neuromuscular blocking agent; neuromuscular blocking agents used should be compatible with patient's cardiovascular status

            Not to be administered into same IV tubing with blood due to potential inactivation by nonspecific esterases in blood products

            Proper placement of needle or catheter in epidural space should be verified before drug is injected to assure that unintentional intravascular or intrathecal administration does not occur; unintentional intravascular injection of sufentanil could result in a potentially serious overdose, including acute truncal muscular rigidity and apnea; unintentional intrathecal injection of sufentanil/bupivacaine epidural doses and volume could produce effects of high spinal anesthesia including prolonged paralysis and delayed recovery; if analgesia is inadequate, placement and integrity of catheter should be verified prior to administration of any additional epidural medications; administer epidurally by slow injection

            Bradycardia may occur; monitor heart rate during dosage initiation and titration; responsive to ephedrine or anticholinergic drugs

            Therapy may cause severe hypotension including orthostatic hypotension and syncope in ambulatory patients; there is increased risk in patients whose ability to maintain blood pressure has already been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (e.g., phenothiazines or general anesthetics); monitor patients for signs of hypotension after initiating or titrating dosage; in patients with circulatory shock, therapy may cause vasodilation that can further reduce cardiac output and blood pressure; avoid therapy in patients with circulatory shock

            Serotonin syndrome

            • Cases of serotonin syndrome, a potentially life-threatening condition, reported with concomitant use of serotonergic drugs; this may occur within the recommended dosage range; the onset of symptoms generally occur within several hours to a few days of concomitant use, but may occur later than that
            • Serotonin syndrome symptoms may include mental status changes (eg, agitation, hallucinations, coma), autonomic instability (eg, tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (eg, hyperreflexia, incoordination, rigidity), and/or gastrointestinal symptoms (eg, nausea, vomiting, diarrhea) and can be fatal
            • Discontinue therapy immediately if serotonin syndrome is suspected

            Addiction, abuse, and misuse

            • Opioids are sought for nonmedical use and are subject to diversion from legitimate prescribed use; consider these risks when handling this drug
            • Strategies to reduce these risks include proper product storage and control practices for a C-II drug; contact local and state professional licensing board or state-controlled substances authority for information on how to prevent and detect abuse or diversion of this product

            Opioid-induce hyperalgesia and allodynia

            • Opioid-induced hyperalgesia (OIH) occurs when opioid analgesic paradoxically causes increase in pain, or increase in sensitivity to pain; this condition differs from tolerance, which is the need for increasing doses of opioids to maintain a defined effect
            • Symptoms include (but may not be limited to) increased levels of pain upon opioid dosage increase, decreased levels of pain upon opioid dosage decrease, or pain from ordinarily non-painful stimuli (allodynia); these symptoms may suggest OIH only if there is no evidence of underlying disease progression, opioid tolerance, opioid withdrawal, or addictive behavior
            • Cases of OIH reported, both with short-term and longer-term use of opioid analgesics; though the mechanism of OIH is not fully understood, multiple biochemical pathways have been implicated; medical literature suggests a strong biologic plausibility between opioid analgesics and OIH and allodynia; if a patient is suspected to be experiencing OIH, carefully consider appropriately decreasing dose of current opioid analgesic or opioid rotation (safely switching the patient to a different opioid moiety)

            FDA-approved safety considerations for immediate-release (IR) and extended-release/long-acting (ER/LA) opioid analgesics addressing opioid crisis

            • The risk of overdose increases as the dosage increases for all opioid pain medicines
            • IR opioids should not be used for an extended period of time unless a patient’s pain remains severe enough to require them and alternative treatment options continue to be inadequate
            • Numerous acute pain conditions treated in the outpatient setting require no more than a few days of an opioid pain medicine
            • It is recommended to reserve ER/LA opioid pain medicines for severe and persistent pain that requires an extended treatment period with a daily opioid pain medicine and for which alternative treatment options are inadequate

            Concomitant use with CYP450 inducers or discontinuation of CYP450 inhibitors

            • Concomitant use with CYP3A4 inducers or discontinuation of an CYP3A4 inhibitor could result in lower than expected alfentanil plasma concentrations, decrease efficacy, or, possibly, lead to a withdrawal syndrome in a patient who had developed physical dependence to alfentanil
            • When using with CYP3A4 inducers or discontinuing CYP3A4 inhibitors, monitor patients closely at frequent intervals and consider increasing drug dosage
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            Pregnancy & Lactation

            Pregnancy

            Prolonged use of opioid analgesics during pregnancy may cause neonatal opioid withdrawal syndrome; available data in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage

            Labor or delivery

            • Opioids cross placenta and may produce respiratory depression and psycho-physiologic effects in neonates; an opioid antagonist, such as naloxone, must be available for reversal of opioid induced respiratory depression in neonate; drug is not recommended for use in women during and immediately prior to labor, when use of shorter-acting analgesics or other analgesic techniques are more appropriate; opioid analgesics can prolong labor through actions that temporarily reduce strength, duration, and frequency of uterine contractions; however, this effect is not consistent and may be offset by an increased rate of cervical dilatation, which tends to shorten labor; monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression

            Lactation

            The developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy; capsules and any potential adverse effects on breastfed infant from therapy or from underlying maternal condition

            Monitor infants exposed to drug through breast milk for excess sedation and respiratory depression; withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast- feeding is stopped

            Withdrawal signs can occur in breast-fed infants when maternal administration of an opioid analgesic is stopped or when breastfeeding is stopped; naloxone may precipitate opioid withdrawal in a breast-fed infant whose mother received opioid analgesics

            Lactation: use with caution

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

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            Pharmacology

            Mechanism of Action

            Narcotic agonist analgesic; increases pain threshold, inhibits ascending pain pathways, alters pain perception

            Pharmacokinetics

            Half-life: 5.33-8.75 hr (prematures, newborns); 40-60 min (children); 83-97 min (adults)

            Onset: Immediate

            Duration: 30-60 min

            Vd: 1 L/kg (premature, newborns); 0.163-0.48 L/kg (children); 0.46 L/kg (adults)

            Peak Plasma: distributed in decreasing order of concentration into skeletal muscle, kidneys, liver, intestinal tract, lungs, spleen, and brain

            Bioavailability: Varies

            Metabolism: liver (hepatic P450 enzyme CYP3A4), CNS, kidneys, lungs, and placenta (conjugation with glucuronic acid, hydrolysis, oxidation, N-dealkylation)

            Excretion: urine, feces

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            Administration

            IV Compatibilities

            Solution: D5W

            Syringe: atracurium, midazolam, ondansetron

            Y-site: bivalirudin, cisatracurium, dexmedetomidine, etomidate, fenoldopam, gatifloxacin, Hextend, linezolid, propofol, remifentanil

            IV Incompatibilities

            Y-site: amphotericin B cholSO4, thiopental

            IV Preparation

            Add 20 mL to 230 mL of diluent for a final concentration of 40 mg/mL

            IV Administration

            Keep Naloxone and resuscitation equip available

            By incremental injection as analgesic adjunct to anesthesia with barbiturate/nitrous oxide/oxygen for short surgical procedures (expected duration <1 hr)

            By continuous infusion as a maintenance analgesic with nitrous oxide/oxygen for general surgical procedures

            By IV injection in aesthetic doses for anesthesia induction for general surgical procedures with a minimum expected duration of 45 min

            By IV inj as the analgesic component for monitored anesthesia care (MAC)

            Storage

            Protect from light

            Store at controlled room temp

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            Images

            No images available for this drug.
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            Patient Handout

            A Patient Handout is not currently available for this monograph.
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            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
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            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.