changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).pimozidephenelzine, pimozide. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).pregabalinpregabalin, phenelzine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.promethazinephenelzine increases effects of promethazine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .quetiapinephenelzine, quetiapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).remifentanilremifentanil increases toxicity of phenelzine by serotonin levels. Modify Therapy/Monitor Closely. Increases risk of serotonin syndrome.remimazolamremimazolam, phenelzine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration 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.risperidonephenelzine, risperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).tapentadolphenelzine and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.thiothixenephenelzine, thiothixene. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).tolazamidephenelzine increases effects of tolazamide by unknown mechanism. Use Caution/Monitor.tolbutamidephenelzine increases effects of tolbutamide by unknown mechanism. Use Caution/Monitor.trifluoperazinephenelzine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).valerianvalerian and phenelzine both increase sedation. Use Caution/Monitor.yohimbeyohimbe increases effects of phenelzine by pharmacodynamic synergism. Use Caution/Monitor.ziprasidonephenelzine, ziprasidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).Minor (16)amobarbitalphenelzine increases levels of amobarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.butabarbitalphenelzine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.butalbitalphenelzine increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.celandinecelandine increases effects of phenelzine by pharmacodynamic synergism. Minor/Significance Unknown. Based on animal studies.cordycepscordyceps increases effects of phenelzine by pharmacodynamic synergism. Minor/Significance Unknown.disulfiramdisulfiram, phenelzine. Mechanism: unknown. Minor/Significance Unknown. Risk of delirium (case report).panax ginsengpanax ginseng increases effects of phenelzine by pharmacodynamic synergism. Minor/Significance Unknown.pentobarbitalphenelzine increases levels of pentobarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.phenobarbitalphenelzine increases levels of phenobarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.pleurisy rootpleurisy root decreases effects of phenelzine by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.primidonephenelzine increases levels of primidone by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.secobarbitalphenelzine increases levels of secobarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.succinylcholinephenelzine increases levels of succinylcholine by decreasing metabolism. Minor/Significance Unknown.sulfadiazinephenelzine increases levels of sulfadiazine by unspecified interaction mechanism. Minor/Significance Unknown.sulfamethoxazolephenelzine increases levels of sulfamethoxazole by unspecified interaction mechanism. Minor/Significance Unknown.sulfisoxazolephenelzine increases levels of sulfisoxazole by unspecified interaction mechanism. Minor/Significance Unknown.5-HTPSerious - Use Alternative (1)phenelzine and 5-HTP both increase serotonin levels. Avoid or Use Alternate Drug.albuterolSerious - Use Alternative (1)phenelzine increases effects of albuterol by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.alfentanilSerious - Use Alternative (1)phenelzine increases toxicity of alfentanil by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.almotriptanSerious - Use Alternative (2)almotriptan and phenelzine both increase serotonin levels. Avoid or Use Alternate Drug. phenelzine increases levels of almotriptan by decreasing metabolism. Contraindicated.amitriptylineContraindicated (1)phenelzine and amitriptyline both increase serotonin levels. Contraindicated.amobarbitalMinor (1)phenelzine increases levels of amobarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.amoxapineContraindicated (1)phenelzine and amoxapine both increase serotonin levels. Contraindicated.apraclonidineContraindicated (2)apraclonidine, phenelzine. Mechanism: unknown. Contraindicated. Contraindicated in mfr. prescribing info. phenelzine, apraclonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.arformoterolSerious - Use Alternative (1)phenelzine increases effects of arformoterol by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.aripiprazoleMonitor Closely (1)phenelzine, aripiprazole. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).armodafinilContraindicated (1)phenelzine increases effects of armodafinil by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.asenapineMonitor Closely (1)phenelzine, asenapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).atomoxetineContraindicated (1)phenelzine increases effects of atomoxetine by pharmacodynamic synergism. Contraindicated. The use of atomoxetine with monoamine oxidase inhibitors (MAOIs) is contraindicated. Risk of acute hypertensive episode.belladonna and opiumSerious - Use Alternative (1)phenelzine increases toxicity of belladonna and opium by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.benazeprilMonitor Closely (1)phenelzine, benazepril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increases risk of hypotension.benzhydrocodone/acetaminophenSerious - Use Alternative (1)phenelzine increases toxicity of benzhydrocodone/acetaminophen by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression.benzphetamineContraindicated (1)phenelzine increases effects of benzphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.bretyliumMonitor Closely (1)phenelzine increases effects of bretylium by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Modify Therapy/Monitor Closely. Bretylium produces release of catecholamines from nerve endings. This increased catecholamine release is potentiated by MAOIs.brimonidineContraindicated (1)phenelzine, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.brompheniramineMonitor Closely (1)phenelzine increases effects of brompheniramine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .bupivacaine implantMonitor Closely (1)phenelzine, bupivacaine implant. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Local anesthetics may increase the risk of developing methemoglobinemia when concurrently exposed to drugs that also cause methemoglobinemia.buprenorphineSerious - Use Alternative (1)phenelzine increases toxicity of buprenorphine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.buprenorphine buccalSerious - Use Alternative (1)phenelzine increases toxicity of buprenorphine buccal by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.buprenorphine subdermal implantMonitor Closely (1)phenelzine, buprenorphine subdermal implant. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.buprenorphine, long-acting injectionMonitor Closely (1)phenelzine, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Modify Therapy/Monitor Closely. Concomitant use could result in life-threatening serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Buprenorphine long-acting injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment.bupropionContraindicated (1)phenelzine and bupropion both increase dopaminergic effects. Contraindicated. Bupropion inhibits reuptake of dopamine and norepinephrine (NE), and MAOIs decrease metabolism of dopamine and NE; coadministration increases risk for hypertensive reactions; allow at least 14 days between discontinuation of MAOI and initiating bupropionbuspironeContraindicated (2)phenelzine and buspirone both increase serotonin levels. Contraindicated. phenelzine, buspirone. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.butabarbitalMinor (1)phenelzine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.butalbitalMinor (1)phenelzine increases levels of butalbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.butorphanolSerious - Use Alternative (1)phenelzine increases toxicity of butorphanol by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.caffeineContraindicated (1)phenelzine increases effects of caffeine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.captoprilMonitor Closely (1)phenelzine, captopril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs lower blood pressure. Monitor blood pressure.carbamazepineContraindicated (1)carbamazepine increases toxicity of phenelzine by unknown mechanism. Contraindicated. D/C MAO inhibitor 2 weeks before.carbinoxamineMonitor Closely (1)phenelzine increases effects of carbinoxamine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .cariprazineMonitor Closely (1)phenelzine, cariprazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).celandineMinor (1)celandine increases effects of phenelzine by pharmacodynamic synergism. Minor/Significance Unknown. Based on animal studies.cetirizineMonitor Closely (1)phenelzine increases effects of cetirizine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .chlorpheniramineMonitor Closely (1)phenelzine increases effects of chlorpheniramine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .chlorpropamideMonitor Closely (1)phenelzine increases effects of chlorpropamide by unknown mechanism. Use Caution/Monitor.citalopramContraindicated (1)phenelzine and citalopram both increase serotonin levels. Contraindicated. At least 2 weeks should elapse between discontinuation of MAOI therapy and the start of citalopram therapy, and at least 2 weeks between discontinuation of citalopram therapy and commencement of MAOI therapy.clemastineMonitor Closely (1)phenelzine increases effects of clemastine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .clomipramineContraindicated (1)phenelzine and clomipramine both increase serotonin levels. Contraindicated.clozapineMonitor Closely (1)phenelzine, clozapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).cocaine topicalSerious - Use Alternative (1)phenelzine and cocaine topical both increase serotonin levels. Contraindicated.codeineSerious - Use Alternative (1)phenelzine increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.cordycepsMinor (1)cordyceps increases effects of phenelzine by pharmacodynamic synergism. Minor/Significance Unknown.cyclobenzaprineContraindicated (1)phenelzine and cyclobenzaprine both increase serotonin levels. Contraindicated. Do not coadminister cyclobenzaprine with MAOIs or within 14 days of discontinuing an MAOIcyproheptadineContraindicated (1)phenelzine, cyproheptadine. Other (see comment). Contraindicated. Comment: MAO inhibitors may prolong and intensify the anticholinergic effects of antihistamines. Cyproheptadine may