Use Caution/Monitor.fedratinibfedratinib will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.fenbufennefazodone, fenbufen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.fenfluraminenefazodone and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.fenfluramine, nefazodone. 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.fenoprofennefazodone, fenoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.fesoterodinenefazodone will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.fexofenadinenefazodone will increase the level or effect of fexofenadine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.finasteridenefazodone will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fludrocortisonenefazodone will increase the level or effect of fludrocortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.flunisolide inhalednefazodone will increase the level or effect of flunisolide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.flurazepamnefazodone will increase the level or effect of flurazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.flurbiprofennefazodone, flurbiprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.fluticasone furoatenefazodone will increase the level or effect of fluticasone furoate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposurefluticasone inhalednefazodone will increase the level or effect of fluticasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposurefosphenytoinfosphenytoin will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fostamatinibnefazodone will increase the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors may increase exposure to R406 (fostamatinib major active metabolite). Monitor for toxicities that may require fostamatinib dose reduction.frovatriptanfrovatriptan and nefazodone both increase serotonin levels. Modify Therapy/Monitor Closely.gabapentingabapentin, nefazodone. 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 enacarbilgabapentin enacarbil, nefazodone. 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.galantaminenefazodone will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ganaxolonenefazodone and ganaxolone both increase sedation. Use Caution/Monitor.gefitinibnefazodone increases levels of gefitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of strong CYP3A4 inhibitors may increase risk for gefitinib adverse effects.gentamicinnefazodone will increase the level or effect of gentamicin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.glecaprevir/pibrentasvirnefazodone will increase the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.guanfacinenefazodone will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available. haloperidolnefazodone will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.hydrocodonenefazodone will increase the level or effect of hydrocodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with CYP3A4 inhibitors may increase hydrocodone plasma concentrations and can result in potentially fatal respiratory depressionhydrocodone, nefazodone. 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.hydrocortisonenefazodone will increase the level or effect of hydrocortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ibuprofennefazodone, ibuprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.ibuprofen IVnefazodone, ibuprofen IV. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.ifosfamidenefazodone will decrease the level or effect of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of CYP3A4 inhibitors may decrease the metabolism of ifosfamide to its active alkylating metabolites and decrease the efficacy of ifosfamide.iloperidoneiloperidone increases levels of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.imatinibnefazodone will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nefazodone will increase the level or effect of imatinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.imipraminenefazodone will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.indinavirnefazodone will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nefazodone will increase the level or effect of indinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.indomethacinnefazodone, indomethacin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.isoniazidnefazodone and isoniazid both increase serotonin levels. Modify Therapy/Monitor Closely.istradefyllinenefazodone will increase the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed istradefylline 20 mg/day if coadministered with strong CYP3A4 inhibitors.istradefylline will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.itraconazolenefazodone will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nefazodone will increase the level or effect of itraconazole by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ivacaftornefazodone will increase the level or effect of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce ivacaftor dose if coadministered with strong CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.ivermectinnefazodone will increase the level or effect of ivermectin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ketoconazolenefazodone will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ketoconazole will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ketoprofennefazodone, ketoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.ketorolacnefazodone, ketorolac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.ketorolac intranasalnefazodone, ketorolac intranasal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.L-tryptophannefazodone and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.lacosamidenefazodone increases levels of lacosamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider decreasing lacosamide dose when coadministered with strong CYP3A4 inhibitors.lansoprazolenefazodone will increase the level or effect of lansoprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lapatinibnefazodone will increase the level or effect of lapatinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lasmiditanlasmiditan, nefazodone. 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.lemborexantlemborexant, nefazodone. 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.lenacapavirlenacapavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.levamlodipinenefazodone will increase the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with moderate and strong CYP3A inhibitors results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is coadministered with CYP3A inhibitors to determine the need for dose adjustment.levoketoconazolelevoketoconazole will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nefazodone will increase the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.levomilnaciprannefazodone will increase the level or effect of levomilnacipran by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed 80 mg/day of levomilnacipran when coadministered with strong CYP3A4 inhibitorslevonorgestrel oral/ethinylestradiol/ferrous bisglycinatenefazodone will increase the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with CYP3A4 inhibitors may increase the plasma hormone concentrations. Use of a nonhormonal contraceptive is recommended.linagliptinnefazodone will increase the level or effect of linagliptin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lithiumnefazodone and lithium both increase serotonin levels. Modify Therapy/Monitor Closely.loperamidenefazodone will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lopinavirnefazodone will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lopinavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.loratadinenefazodone will increase the level or effect of loratadine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lorcaserinlorcaserin will increase the level or effect of nefazodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lornoxicamnefazodone, lornoxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.losartannefazodone will increase the level or effect of losartan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lovastatinnefazodone will increase the level or effect of lovastatin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lsdnefazodone and lsd both increase serotonin levels. Modify Therapy/Monitor Closely.lumacaftor/ivacaftornefazodone increases levels of lumacaftor/ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A inhibitors do not impact lumacaftor exposure, but increased ivacaftor exposure by 4.3-fold. Due to the induction effect of lumacaftor on CYP3A, at steady-state the net exposure of ivacaftor is not expected to exceed that when given in the absence of lumacaftor at a dose of 150 mg q12hr (the approved dose of ivacaftor monotherapy). Therefore, no dose adjustment is necessary when CYP3A inhibitors are initiated in patients currently taking lumacaftor/ivacaftor. However, when initiating lumacaftor/ivacaftor in patients taking strong CYP3A inhibitors, reduce the dose to 1 tablet daily (lumacaftor 200 mg/ivacaftor 125 mg total daily dose) for the first week of treatment to allow for the steady-state induction effect of lumacaftor. Following this period, continue with the recommended daily dose. No dose adjustment is required for moderate or weak CYP3A4 inhibitors.lumateperonenefazodone will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 10.5 mg/day if coadministered with strong CYP3A4 inhibitors.lurasidonelurasidone, nefazodone. 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.maravirocnefazodone will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Decrease maraviroc dose to 150 mg BID when coadministered with strong CYP3A4 inhibitorsnefazodone will increase the level or effect of maraviroc by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.marijuananefazodone will increase the level or effect of marijuana by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.meclofenamatenefazodone, meclofenamate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.medroxyprogesteronenefazodone will increase the level or effect of medroxyprogesterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.mefenamic acidnefazodone, mefenamic 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.meloxicamnefazodone, meloxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.mestranolnefazodone will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.metaxalonenefazodone will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.methylprednisolonenefazodone will increase the level or effect of