both increase serotonin levels. Avoid or Use Alternate Drug. duloxetine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.efavirenzMonitor Closely (1)efavirenz will decrease the level or effect of bupropion by increasing metabolism. Use Caution/Monitor. Coadministration with hepatic inducers reduced bupropion AUC and Cmax; hydroxybupropion (active metabolite) Cmax was increased eletriptanMonitor Closely (1)eletriptan and dextromethorphan both increase serotonin levels. Modify Therapy/Monitor Closely.eliglustatContraindicated (1)bupropion increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.eluxadolineMonitor Closely (1)bupropion increases levels of eluxadoline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. As a precautionary measure due to incomplete information on the metabolism of eluxadoline, use caution when coadministered with strong CYP2D6 inhibitors.elvitegravir/cobicistat/emtricitabine/tenofovir DFMonitor Closely (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of bupropion by unknown mechanism. Use Caution/Monitor.encainideMinor (1)bupropion will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.ergotamineMonitor Closely (1)dextromethorphan and ergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.escitalopramSerious - Use Alternative (2)escitalopram increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible. escitalopram and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.ethanolMinor (1)ethanol, bupropion. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.fenfluramineMonitor Closely (3)fenfluramine, bupropion. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration with drugs that increase serotoninergic effects may increase the risk of serotonin syndrome. fenfluramine, dextromethorphan. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration with drugs that increase serotoninergic effects may increase the risk of serotonin syndrome. dextromethorphan and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.fesoterodineMonitor Closely (1)bupropion will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.fexinidazoleSerious - Use Alternative (1)fexinidazole will decrease the level or effect of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Avoid or Use Alternate Drug. Coadministration may decrease plasma concentrations of CYP2B6 substrates owing to fexinidazole inducing CYP2B6.flecainideMonitor Closely (1)bupropion will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Coadministration of bupropion and flecainide should be approached with caution and should be initiated at the lower end of the dose range of flecainide. If bupropion is added to the treatment regimen of a patient already receiving flecainide, consider decreasing the dose of flecainide.fluoxetineMonitor Closely (1)bupropion will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (3)fluoxetine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug. fluoxetine increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible. fluoxetine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluphenazineMonitor Closely (2)bupropion will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. dextromethorphan, fluphenazine. 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 (1)fluphenazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.fluvoxamineMonitor Closely (1)fluvoxamine will increase the level or effect of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor.Serious - Use Alternative (2)fluvoxamine increases toxicity of bupropion by Other (see comment). Avoid or Use Alternate Drug. Comment: May lower seizure threshold; keep bupropion dose as low as possible. fluvoxamine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.frovatriptanMonitor Closely (1)frovatriptan and dextromethorphan both increase serotonin levels. Modify Therapy/Monitor Closely.gabapentinMonitor Closely (1)gabapentin, bupropion. 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.gabapentin enacarbilMonitor Closely (1)gabapentin enacarbil, bupropion. 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.galantamineMonitor Closely (1)bupropion will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.ganaxoloneMonitor Closely (1)bupropion and ganaxolone both increase sedation. Use Caution/Monitor.grapefruitSerious - Use Alternative (1)grapefruit will increase the level or effect of dextromethorphan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.haloperidolMonitor Closely (2)bupropion will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. dextromethorphan, haloperidol. 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 (1)haloperidol will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.hydrocodoneMonitor Closely (2)bupropion will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone. hydrocodone, bupropion. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.hydromorphoneMonitor Closely (1)bupropion will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.iloperidoneMonitor Closely (2)bupropion will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. dextromethorphan, iloperidone. 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).imatinibMinor (1)imatinib will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.imipramineMonitor Closely (2)imipramine increases toxicity of bupropion by unspecified interaction mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible. bupropion will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)imipramine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.iobenguane I 131Serious - Use Alternative (1)bupropion will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.ioflupane I 123Monitor Closely (1)bupropion decreases effects of ioflupane I 123 by receptor binding competition. Use Caution/Monitor. Drugs that bind to dopamine transporter receptor with high affinity may interfere with the image following ioflupane I 123 administration.isocarboxazidContraindicated (2)isocarboxazid 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 bupropion isocarboxazid and dextromethorphan both increase serotonin levels. Contraindicated.isoniazidMonitor Closely (1)dextromethorphan and isoniazid both increase serotonin levels. Modify Therapy/Monitor Closely.L-tryptophanMonitor Closely (1)dextromethorphan and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.lasmiditanMonitor Closely (1)lasmiditan, bupropion. 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.lemborexantMonitor Closely (2)lemborexant will decrease the level or effect of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Modify Therapy/Monitor Closely. Monitor CYP2B6 substrate for adequate clinical response. Consider increasing the CYP2B6 substrate dose according to specific prescribing recommendations. lemborexant, bupropion. 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.letermovirMonitor Closely (1)letermovir increases levels of dextromethorphan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.levodopaMonitor Closely (1)bupropion increases effects of levodopa by pharmacodynamic synergism. Use Caution/Monitor. There is a higher incidence of adverse reactions with concurrent use of bupropion with levodopa. Use small initial dosages and small, gradual dosage increases of bupropion.levomilnacipranSerious - Use Alternative (1)levomilnacipran and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.linezolidSerious - Use Alternative (2)bupropion, linezolid. serotonin levels. Avoid or Use Alternate Drug. Linezolid may increase serotonin as a result of MAO-A inhibition. If linezolid must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first. linezolid and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug. Linezolid may increase serotonin as a result of MAO-A inhibition. If linezolid must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first.lisdexamfetamineMonitor Closely (1)lisdexamfetamine increases toxicity of bupropion by unspecified interaction mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible.lithiumMonitor Closely (1)dextromethorphan and lithium both increase serotonin levels. Modify Therapy/Monitor Closely.lofepramineMonitor Closely (2)lofepramine increases toxicity of bupropion by unspecified interaction mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible. bupropion will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)lofepramine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.lofexidineMonitor Closely (1)bupropion will increase the level or effect of lofexidine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Concomitant use of lofexidine with strong CYP2D6 inhibitors may increase lofexidine plasma levels. Monitor for symptoms of orthostasis and bradycardia if coadministered with a CYP2D6 inhibitor. Consider lofexidine dose reduction.loratadineMonitor Closely (1)bupropion will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lorcaserinSerious - Use Alternative (2)dextromethorphan and lorcaserin both increase serotonin levels. Avoid or Use Alternate Drug. bupropion and lorcaserin both increase serotonin levels. Avoid or Use Alternate Drug.loxapineMonitor Closely (1)dextromethorphan, loxapine. 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).loxapine inhaledMonitor Closely (1)dextromethorphan, loxapine inhaled. 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).lsdMonitor Closely (1)dextromethorphan and lsd both increase serotonin levels. Modify Therapy/Monitor Closely.lumacaftor/ivacaftorMonitor Closely (1)lumacaftor/ivacaftor, bupropion. affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. In vitro studies suggest that lumacaftor may induce and ivacaftor may inhibit CYP2B6 substrates. .lumefantrineMonitor Closely (1)lumefantrine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lurasidoneMonitor Closely (2)lurasidone, bupropion. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity. dextromethorphan, lurasidone. unspecified interaction