water retention or electrolyte imbalance.solifenacinsolifenacin and venlafaxine both decrease QTc interval. Use Caution/Monitor.stiripentolstiripentol, venlafaxine. 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 SLsufentanil SL, venlafaxine. 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.sulfamethoxazolesulfamethoxazole and venlafaxine both increase QTc interval. Use Caution/Monitor.sulfasalazinevenlafaxine, sulfasalazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.sulindacvenlafaxine, sulindac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.sumatriptansumatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.sumatriptan intranasalsumatriptan intranasal and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.sunitinibsunitinib and venlafaxine both decrease QTc interval. Use Caution/Monitor.tacrolimustacrolimus and venlafaxine both decrease QTc interval. Use Caution/Monitor.tamoxifenvenlafaxine decreases effects of tamoxifen by decreasing metabolism. Use Caution/Monitor. Inhibition of CYP2D6 metabolism to tamoxifen's active metabolite, endoxifen.tapentadolvenlafaxine and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.tazemetostattazemetostat will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tecovirimattecovirimat will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.telavancintelavancin and venlafaxine both increase QTc interval. Use Caution/Monitor.terbinafineterbinafine will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.thiothixenevenlafaxine, 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).timololvenlafaxine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tipranavirtipranavir, venlafaxine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor.tipranavir will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tolfenamic acidvenlafaxine, tolfenamic acid. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.tolmetinvenlafaxine, tolmetin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.tramadolvenlafaxine and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.trazodonetrazodone and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.trifluoperazinevenlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.trifluoperazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.venlafaxine, 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).trimethoprimtrimethoprim and venlafaxine both increase QTc interval. Use Caution/Monitor.trimipraminetrimipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.tropisetrontropisetron and venlafaxine both increase QTc interval. Use Caution/Monitor.valbenazinevalbenazine and venlafaxine both decrease QTc interval. Use Caution/Monitor.valerianvalerian and venlafaxine both increase sedation. Use Caution/Monitor.vorapaxarvenlafaxine, vorapaxar. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive antiplatelet effect may occur; SSRIs and SNRIs may cause platelet serotonin depletion .voriconazolevenlafaxine and voriconazole both increase QTc interval. Use Caution/Monitor.vorinostatvorinostat and venlafaxine both decrease QTc interval. Use Caution/Monitor.warfarinvenlafaxine, warfarin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Serotonin release by platelets plays an important role in hemostasis. SSRIs and SNRIs may increase anticoagulation effect of warfarin. .ziprasidonevenlafaxine and ziprasidone both increase QTc interval. Modify Therapy/Monitor Closely.venlafaxine, 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).zolmitriptanzolmitriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (37)acetazolamideacetazolamide will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.almotriptanvenlafaxine, almotriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.anastrozoleanastrozole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.azithromycinazithromycin and venlafaxine both increase QTc interval. Minor/Significance Unknown.bumetanidebumetanide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.celandinecelandine decreases effects of venlafaxine by pharmacodynamic antagonism. Minor/Significance Unknown. Based on animal studies.codeinevenlafaxine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.cyclophosphamidecyclophosphamide will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.dexfenfluraminevenlafaxine will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.dexmethylphenidatedexmethylphenidate increases effects of venlafaxine by decreasing metabolism. Minor/Significance Unknown.donepezilvenlafaxine will increase the level or effect of donepezil by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.eletriptanvenlafaxine, eletriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.encainidevenlafaxine will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.ethacrynic acidethacrynic acid, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.fesoterodinevenlafaxine will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.fluoxetinevenlafaxine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.frovatriptanvenlafaxine, frovatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.furosemidefurosemide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.galantaminevenlafaxine will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.larotrectiniblarotrectinib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.lithiumvenlafaxine, lithium. Mechanism: unknown. Minor/Significance Unknown. Risk of neurotoxicity.naratriptanvenlafaxine, naratriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.oxycodonevenlafaxine decreases effects of oxycodone by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of oxycodone to active metabolite morphine.panax ginsengpanax ginseng increases effects of venlafaxine by pharmacodynamic synergism. Minor/Significance Unknown.paroxetinevenlafaxine will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.pazopanibpazopanib and venlafaxine both increase QTc interval. Minor/Significance Unknown.perhexilinevenlafaxine will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.pleurisy rootpleurisy root decreases effects of venlafaxine by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.promazinevenlafaxine will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.rizatriptanvenlafaxine, rizatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.serdexmethylphenidate/dexmethylphenidateserdexmethylphenidate/dexmethylphenidate increases effects of venlafaxine by decreasing metabolism. Minor/Significance Unknown.sumatriptanvenlafaxine, sumatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.sumatriptan intranasalvenlafaxine, sumatriptan intranasal. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.tolterodinevenlafaxine will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.torsemidetorsemide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.tropisetronvenlafaxine will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.zolmitriptanvenlafaxine, zolmitriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.5-HTPMonitor Closely (1)venlafaxine and 5-HTP both increase serotonin levels. Modify Therapy/Monitor Closely.abametapirSerious - Use Alternative (1)abametapir will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.abirateroneMonitor Closely (1)abiraterone increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.aceclofenacMonitor Closely (1)venlafaxine, aceclofenac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.acemetacinMonitor Closely (1)venlafaxine, acemetacin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.acetazolamideMinor (1)acetazolamide will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.alfentanilSerious - Use Alternative (1)venlafaxine and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndromealmotriptanMonitor Closely (1)almotriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, almotriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.amifampridineMonitor Closely (1)venlafaxine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.amiodaroneSerious - Use Alternative (1)amiodarone and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.amisulprideSerious - Use Alternative (1)amisulpride and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.amitriptylineMonitor Closely (1)amitriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and amitriptyline both increase serotonin levels. Avoid or Use Alternate Drug.amoxapineMonitor Closely (1)amoxapine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and amoxapine both increase serotonin levels. Avoid or Use Alternate Drug.anagrelideSerious - Use Alternative (1)anagrelide and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.anastrozoleMinor (1)anastrozole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.apalutamideSerious - Use Alternative (1)apalutamide will decrease the level or effect of venlafaxine 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.apixabanSerious - Use Alternative (1)venlafaxine and apixaban both increase anticoagulation. Avoid or Use Alternate Drug.aripiprazoleMonitor Closely (2)venlafaxine, 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). venlafaxine will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.arsenic trioxideSerious - Use Alternative (1)arsenic trioxide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.artemether/lumefantrineMonitor Closely (1)artemether/lumefantrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.asenapineMonitor Closely (1)venlafaxine, 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).Serious - Use Alternative (1)asenapine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.asenapine transdermalSerious - Use Alternative (1)asenapine transdermal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.aspirinMonitor Closely (1)venlafaxine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.aspirin rectalMonitor Closely (1)venlafaxine, aspirin rectal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.aspirin/citric acid/sodium bicarbonateMonitor Closely (1)venlafaxine, aspirin/citric acid/sodium bicarbonate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.atomoxetineMonitor Closely (1)venlafaxine will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.azithromycinMinor (1)azithromycin and venlafaxine both increase QTc interval. Minor/Significance Unknown.benzhydrocodone/acetaminophenMonitor Closely (2)venlafaxine will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone. benzhydrocodone/acetaminophen, venlafaxine. 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,