of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.sumatriptanMonitor Closely (1)sumatriptan and nefazodone both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)nefazodone, sumatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.sumatriptan intranasalMonitor Closely (1)sumatriptan intranasal and nefazodone both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)nefazodone, sumatriptan intranasal. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.sunitinibSerious - Use Alternative (1)nefazodone will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.suvorexantSerious - Use Alternative (1)nefazodone increases levels of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Suvorexant not recommended with use of strong CYP3A4 inhibitors.tacrolimusMonitor Closely (1)nefazodone will increase the level or effect of tacrolimus by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tacrolimus ointmentMonitor Closely (1)nefazodone will increase the level or effect of tacrolimus ointment by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tadalafilMonitor Closely (1)nefazodone will increase the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. For ED limit tadalafil to max of 2.5 mg/day (for daily use) or 10 mg dose every 72 hr (for use as needed). Avoid concurrent use of tadalafil for pulmonary HTN in patients taking strong CYP3A4 inhibitors.tamoxifenSerious - Use Alternative (1)nefazodone, tamoxifen. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibition decreases metabolism of tamoxifen to N-desmethyl tamoxifen (active metabolite with similar biologic activity).tamsulosinMonitor Closely (1)nefazodone increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tapentadolMonitor Closely (1)nefazodone and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.tasimelteonMonitor Closely (1)nefazodone will increase the level or effect of tasimelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tazemetostatMonitor Closely (1)tazemetostat will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of tazemetostat with strong CYP3A4 inhibitors.tecovirimatMonitor Closely (1)tecovirimat will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.tedizolidSerious - Use Alternative (1)tedizolid, nefazodone. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.temsirolimusSerious - Use Alternative (1)nefazodone will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.terbinafineMonitor Closely (1)nefazodone will increase the level or effect of terbinafine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tezacaftorMonitor Closely (1)nefazodone will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust tezacaftor dosage regimen if coadministered with a strong CYP3A inhibitor.theophyllineSerious - Use Alternative (1)nefazodone will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tiagabineSerious - Use Alternative (1)nefazodone will increase the level or effect of tiagabine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.ticagrelorMonitor Closely (1)nefazodone increases levels of ticagrelor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Ticagrelor is metabolized by CYP3A4/5. Avoid use with strong CYP3A inhibitors.tipranavirMonitor Closely (1)nefazodone will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)tipranavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tisotumab vedotinMonitor Closely (1)nefazodone increases levels of tisotumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tisotumab vedotin?s active metabolite (MMAE) is a CYP3A4 substrate. Coadministration with strong CYP3A4 inhibitors may increase unconjugated MMAE systemic exposure and increase risk of adverse effects.tobramycinMonitor Closely (1)nefazodone will increase the level or effect of tobramycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.tofacitinibSerious - Use Alternative (1)nefazodone increases levels of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce tofacitinib dose to 5 mg qDay when coadministered with potent CYP3A4 inhibitors.tolfenamic acidMonitor Closely (1)nefazodone, 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.tolmetinMonitor Closely (1)nefazodone, 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.tolterodineSerious - Use Alternative (1)nefazodone will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tolvaptanMonitor Closely (1)nefazodone will increase the level or effect of tolvaptan by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.toremifeneMonitor Closely (1)nefazodone increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.torsemideMinor (1)torsemide, nefazodone. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.trabectedinSerious - Use Alternative (1)nefazodone will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If strong CYP3A inhibitor must be used, short-term (eg, less than 14 days), administer strong CYP3A inhibitor 1 week after trabectedin infusion, and discontinue the day prior to next trabectedin infusiontramadolMonitor Closely (2)nefazodone will increase the level or effect of tramadol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nefazodone and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.tranylcypromineContraindicated (1)tranylcypromine and nefazodone both increase serotonin levels. Contraindicated.trazodoneSerious - Use Alternative (2)nefazodone and trazodone both increase serotonin levels. Avoid or Use Alternate Drug. nefazodone will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.triamcinolone acetonide injectable suspensionSerious - Use Alternative (1)nefazodone will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.triazolamSerious - Use Alternative (1)nefazodone will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.trimipramineSerious - Use Alternative (2)nefazodone and trimipramine both increase serotonin levels. Avoid or Use Alternate Drug. nefazodone will increase the level or effect of trimipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tucatinibSerious - Use Alternative (1)tucatinib will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.ubrogepantSerious - Use Alternative (1)nefazodone will increase the level or effect of ubrogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.ulipristalMonitor Closely (1)nefazodone will increase the level or effect of ulipristal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.umeclidinium bromide/vilanterol inhaledMonitor Closely (1)nefazodone will increase the level or effect of umeclidinium bromide/vilanterol inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vilanterol is a CYP3A4 substrate; coadministration with potent CYP3A4 inhibitors may increase systemic exposureupadacitinibMonitor Closely (1)nefazodone will increase the level or effect of upadacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution if upadacitinib is coadministered with strong CYP3A4 inhibitors.valbenazineMonitor Closely (1)nefazodone will increase the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce valbenazine dose to 40 mg once daily when coadministered with a strong CYP3A4 inhibitor. vardenafilMonitor Closely (1)nefazodone will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors velpatasvirMonitor Closely (1)nefazodone will increase the level or effect of velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.vemurafenibSerious - Use Alternative (1)nefazodone increases levels of vemurafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.venetoclaxContraindicated (1)nefazodone will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Use of strong CYP3A4 inhibitors is contraindicated with venetoclax during the initial ramp-up dosing phase. If a strong CYP3A inhibitor must be used after the ramp-up phase, reduce the venetoclax dose by at least 75%.venlafaxineSerious - Use Alternative (2)nefazodone and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. nefazodone will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.verapamilSerious - Use Alternative (1)nefazodone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.vilanterol/fluticasone furoate inhaledMonitor Closely (1)nefazodone will increase the level or effect of vilanterol/fluticasone furoate inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Fluticasone furoate and vilanterol are both CYP3A4 substrates; coadministration with potent CYP3A4 inhibitors may increase systemic exposurevilazodoneSerious - Use Alternative (2)nefazodone, 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. . nefazodone increases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If intolerable adverse effects occur when coadministered with moderate CYP3A4 inhibitors, reduce daily dose to 20 mg.vinblastineMonitor Closely (1)nefazodone will increase the level or effect of vinblastine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.vincristineMonitor Closely (1)nefazodone will increase the level or effect of vincristine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.vincristine liposomalMonitor Closely (1)nefazodone will increase the level or effect of vincristine liposomal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.vinorelbineSerious - Use Alternative (1)nefazodone will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.voclosporinContraindicated (1)nefazodone will increase the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.vorapaxarSerious - Use Alternative (1)nefazodone increases levels of vorapaxar by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.voriconazoleMonitor Closely (1)voriconazole will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.vortioxetineSerious - Use Alternative (1)nefazodone, vortioxetine. Either increases effects of the other by serotonin levels. Avoid or Use Alternate Drug.voxelotorSerious - Use Alternative (1)voxelotor will increase the level or effect of nefazodone 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.warfarinMonitor Closely (1)nefazodone will increase the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inhibitors of these isoenzymes and adjust warfarin dose if needed. zaleplonMonitor Closely (1)nefazodone will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.zanubrutinibMonitor Closely (1)nefazodone will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib (a CYP3A4 substrate) to 80 mg PO BID when coadministered with a moderate CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous zanubrutinib dose. ziprasidoneMonitor Closely (1)nefazodone will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.zolmitriptanMonitor Closely (1)zolmitriptan and nefazodone both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)nefazodone, zolmitriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.zolpidemSerious - Use Alternative (1)nefazodone will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.zonisamideSerious - Use Alternative (1)nefazodone will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. >10% Headache (31-35%) Somnolence (21-25%) Nausea (21-25%) Xerostomia