mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible. bupropion will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.promazineMinor (2)bupropion will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown. promazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.promethazineMonitor Closely (1)bupropion will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)promethazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.propafenoneMonitor Closely (1)bupropion will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)propafenone will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.propranololMonitor Closely (1)bupropion will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.protriptylineMonitor Closely (2)protriptyline 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 protriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)protriptyline and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.quetiapineMonitor Closely (1)dextromethorphan, 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).quinacrineMinor (1)quinacrine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.quinidineMonitor Closely (1)quinidine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.ranolazineMinor (1)ranolazine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.rasagilineContraindicated (2)rasagiline 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 rasagiline and dextromethorphan both increase serotonin levels. Contraindicated. Risk of psychosis episodes or bizarre behavior.remimazolamMonitor Closely (1)remimazolam, bupropion. 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.rifampinMonitor Closely (1)rifampin will decrease the level or effect of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor.risperidoneMonitor Closely (2)dextromethorphan, 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). bupropion will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.ritonavirMonitor Closely (1)ritonavir decreases levels of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Ritonavir decreases levels of bupropion by inducing CYP2B6. Bupropion levels decreased by 20-80%, increased doses of bupropion may be required .Minor (1)ritonavir will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.rizatriptanMonitor Closely (1)rizatriptan and dextromethorphan both increase serotonin levels. Modify Therapy/Monitor Closely.rolapitantMonitor Closely (1)rolapitant will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor for adverse reactions when unable to avoid coadministration with narrow therapeutic index CYP2D6 substrates.safinamideContraindicated (1)dextromethorphan, safinamide. Other (see comment). Contraindicated. Comment: Coadministration of MAOIs and dextromethorphan has been reported to cause episodes of psychosis or bizarre behavior.SAMeMonitor Closely (1)dextromethorphan and SAMe both increase serotonin levels. Modify Therapy/Monitor Closely.secobarbitalMonitor Closely (1)secobarbital, bupropion. increasing metabolism. Use Caution/Monitor. Decr levels of bupropion, but incr levels of active metabolites. .selegilineContraindicated (2)selegiline 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 selegiline and dextromethorphan both increase serotonin levels. Contraindicated.selegiline transdermalContraindicated (1)selegiline transdermal 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 bupropionSerious - Use Alternative (1)selegiline transdermal and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.sertralineMonitor Closely (2)bupropion will increase the level or effect of sertraline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. sertraline increases levels of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Sertraline may inhibit hydroxylation of bupropion to its major active metabolite hydroxybupropion.Serious - Use Alternative (1)sertraline and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.Minor (1)sertraline will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.solriamfetolMonitor Closely (1)bupropion and solriamfetol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.sorafenibMonitor Closely (1)sorafenib, bupropion. decreasing metabolism. Use Caution/Monitor. Incr levels of bupropion, but decr levels of active metabolites. .sparsentanMonitor Closely (1)sparsentan will decrease the level or effect of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Sparsentan (a CYP2B6 inducer) decreases exposure of CYP2B6 substrates and reduces efficacy related to these substrates.St John's WortSerious - Use Alternative (1)dextromethorphan and St John's Wort both increase serotonin levels. Avoid or Use Alternate Drug.stiripentolMonitor Closely (1)stiripentol, bupropion. affecting hepatic enzyme CYP2B6 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP2B6 inhibitor and inducer. Monitor CYP2B6 substrates coadministered with stiripentol for increased or decreased effects. CYP2B6 substrates may require dosage adjustment.sufentanil SLMonitor Closely (1)sufentanil SL, 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.sumatriptanMonitor Closely (1)sumatriptan and dextromethorphan both increase serotonin levels. Modify Therapy/Monitor Closely.sumatriptan intranasalMonitor Closely (1)sumatriptan intranasal and dextromethorphan both increase serotonin levels. Modify Therapy/Monitor Closely.tamoxifenMonitor Closely (2)bupropion decreases effects of tamoxifen by decreasing metabolism. Use Caution/Monitor. Inhibition of CYP2D6 metabolism to tamoxifen's active metabolite, endoxifen. bupropion will decrease the level or effect of tamoxifen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Inhibition of CYP2D6 decreases metabolism of tamoxifen to active metabolite, endoxifentamsulosinMonitor Closely (1)bupropion increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tapentadolMonitor Closely (1)bupropion and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.tedizolidSerious - Use Alternative (1)tedizolid, bupropion. Either increases levels of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.telotristat ethylMonitor Closely (1)telotristat ethyl will decrease the level or effect of bupropion by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Consider increasing dosage of interacting drug, if necessarytemocillinMonitor Closely (1)temocillin increases toxicity of bupropion by unspecified interaction mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible.theophyllineSerious - Use Alternative (1)theophylline increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible.thioridazineSerious - Use Alternative (1)bupropion will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.Minor (2)thioridazine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown. thioridazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.thiothixeneMonitor Closely (1)dextromethorphan, 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).ticarcillinMonitor Closely (1)ticarcillin increases toxicity of bupropion by unspecified interaction mechanism. Use Caution/Monitor. May lower seizure threshold; keep bupropion dose as low as possible.timololMonitor Closely (1)bupropion will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tipranavirMinor (1)tipranavir will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.tolterodineMonitor Closely (1)bupropion will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tramadolMonitor Closely (2)bupropion will increase the level or effect of tramadol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. dextromethorphan and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.tranylcypromineContraindicated (2)tranylcypromine 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 tranylcypromine and dextromethorphan both increase serotonin levels. Contraindicated.trazodoneSerious - Use Alternative (2)trazodone increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible. trazodone and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.trifluoperazineMonitor Closely (2)dextromethorphan, 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). bupropion will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)trifluoperazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.trimipramineMonitor Closely (2)trimipramine 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 trimipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)trimipramine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.tropisetronMinor (1)bupropion will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.valbenazineMonitor Closely (1)bupropion will increase the level or effect of valbenazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Consider reducing valbenazine dose based on tolerability if coadministered with a strong CYP2D6 inhibitor.venlafaxineMonitor Closely (1)bupropion will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (3)venlafaxine increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible. venlafaxine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug. venlafaxine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.vilazodoneSerious - Use Alternative (1)dextromethorphan, vilazodone. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Concomitant therapy should be discontinued immediately if signs or symptoms of serotonin syndrome emerge and supportive symptomatic treatment should be initiated. .vortioxetineSerious - Use Alternative (1)bupropion, vortioxetine. Either increases effects of the other by serotonin levels. Avoid or Use Alternate Drug.ziprasidoneMonitor Closely (1)dextromethorphan, 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).zolmitriptanMonitor Closely (1)zolmitriptan and dextromethorphan both increase serotonin levels. Modify Therapy/Monitor Closely. >10% Dizziness (16%) Nausea (13%) 1-10% Headache (8%) Diarrhea (7%) Somnolence (7%) Dry mouth (6%) Sexual dysfunction (6%) Hyperhidrosis (5%) Anxiety (4%) Constipation (4%) Decreased appetite (4%) Insomnia (4%) Arthralgia (3%) Fatigue (3%) Paresthesia (3%) Vision blurred (3%) Postmarketing Reports Dextromethorphan Drowsiness, dizziness, nervousness or restlessness, nausea, vomiting, and stomach pain Bupropion Body: Arthralgia, myalgia, and fever with rash and other symptoms suggestive of delayed hypersensitivity Cardiovascular: Complete atrioventricular block, extrasystoles, hypotension, hypertension (in some cases