will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.pralsetinibSerious - Use Alternative (1)nefazodone will increase the level or effect of pralsetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.praziquantelMonitor Closely (1)nefazodone will increase the level or effect of praziquantel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.prednisoloneMonitor Closely (2)nefazodone will increase the level or effect of prednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nefazodone will increase the level or effect of prednisolone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.prednisoneMonitor Closely (1)nefazodone will increase the level or effect of prednisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.pregabalinMonitor Closely (1)pregabalin, 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.primidoneSerious - Use Alternative (1)primidone will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.procarbazineContraindicated (1)procarbazine and nefazodone both increase serotonin levels. Contraindicated. Combination is contraindicated within 2 weeks of MAOI use.propafenoneMonitor Closely (1)nefazodone will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.protriptylineSerious - Use Alternative (1)nefazodone and protriptyline both increase serotonin levels. Avoid or Use Alternate Drug.quazepamMonitor Closely (1)nefazodone will increase the level or effect of quazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.quetiapineSerious - Use Alternative (1)nefazodone will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.quinidineSerious - Use Alternative (1)nefazodone will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.quinineSerious - Use Alternative (1)nefazodone will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rabeprazoleMonitor Closely (1)nefazodone will increase the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ramelteonMonitor Closely (1)nefazodone will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ranolazineSerious - Use Alternative (1)nefazodone will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rasagilineSerious - Use Alternative (1)rasagiline and nefazodone both increase serotonin levels. Avoid or Use Alternate Drug. Do not use nefazodone in combination with a MAOI, or within 14 days of discontinuing treatment with a MAOI. Allow at least 1 week after stopping nefazodone before starting an MAOI.regorafenibContraindicated (1)nefazodone, regorafenib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase regorafenib levels and decrease exposure of the active metabolites M-2 and M-5.remimazolamMonitor Closely (1)remimazolam, nefazodone. 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.repaglinideSerious - Use Alternative (1)nefazodone will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.ribociclibMonitor Closely (1)ribociclib will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)nefazodone will increase the level or effect of ribociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If a strong CYP3A inhibitor must be coadministered with ribociclib, reduce the ribociclib starting dose to 400 mg/day.rifabutinMonitor Closely (2)nefazodone will increase the level or effect of rifabutin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. rifabutin will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifampinMonitor Closely (1)rifampin will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifapentineSerious - Use Alternative (1)rifapentine will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rilpivirineMonitor Closely (1)nefazodone increases levels of rilpivirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rimegepantSerious - Use Alternative (1)nefazodone will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.riociguatMonitor Closely (1)nefazodone will increase the level or effect of riociguat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of riociguat by Other (see comment). Avoid or Use Alternate Drug. Coadministration of riociguat (an ABCG2 [BCRP] substrate) with strong ABCG2 inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if neededripretinibMonitor Closely (1)nefazodone will increase the level or effect of ripretinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with a strong CYP3A inhibitor will increase systemic exposure to ripretinib and its active metabolite (DP-5439), which may increase risk of adverse reactions.risperidoneMonitor Closely (1)nefazodone will increase the level or effect of risperidone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ritonavirMonitor Closely (2)nefazodone will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nefazodone will increase the level or effect of ritonavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)ritonavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rivaroxabanMonitor Closely (1)nefazodone will increase the level or effect of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rizatriptanMonitor Closely (1)rizatriptan and nefazodone both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)nefazodone, rizatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.romidepsinMonitor Closely (1)nefazodone will increase the level or effect of romidepsin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong 3A4 inhibitors should be avoided if possible.ropeginterferon alfa 2bSerious - Use Alternative (1)ropeginterferon alfa 2b and nefazodone both increase Other (see comment). Avoid or Use Alternate Drug. Narcotics, hypnotics or sedatives can produce additive neuropsychiatric side effects. Avoid use and monitor patients receiving the combination for effects of excessive CNS toxicity.rucaparibMonitor Closely (1)rucaparib will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.ruxolitinibSerious - Use Alternative (1)nefazodone will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/Lruxolitinib topicalSerious - Use Alternative (1)nefazodone will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/LsafinamideContraindicated (1)nefazodone, safinamide. Either increases toxicity of the other by serotonin levels. Contraindicated. Concomitant use could result in life-threatening serotonin syndrome.salicylates (non-asa)Monitor Closely (1)nefazodone, salicylates (non-asa). Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.salmeterolSerious - Use Alternative (1)nefazodone will increase the level or effect of salmeterol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.salsalateMonitor Closely (1)nefazodone, salsalate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.SAMeMonitor Closely (1)nefazodone and SAMe both increase serotonin levels. Modify Therapy/Monitor Closely.saquinavirMonitor Closely (2)nefazodone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nefazodone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.saxagliptinMonitor Closely (1)nefazodone will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Limit saxagliptin dose to 2.5 mg/day when coadministered with strong CYP3A4 inhibitorsselegilineSerious - Use Alternative (1)selegiline and nefazodone both increase serotonin levels. Avoid or Use Alternate Drug.selegiline transdermalSerious - Use Alternative (1)selegiline transdermal and nefazodone both increase serotonin levels. Avoid or Use Alternate Drug.selpercatinibSerious - Use Alternative (1)nefazodone will increase the level or effect of selpercatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.selumetinibSerious - Use Alternative (1)nefazodone will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.serdexmethylphenidate/dexmethylphenidateMinor (1)serdexmethylphenidate/dexmethylphenidate increases effects of nefazodone by decreasing metabolism. Minor/Significance Unknown.sertralineSerious - Use Alternative (1)nefazodone and sertraline both increase serotonin levels. Avoid or Use Alternate Drug.sildenafilMonitor Closely (1)nefazodone will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.silodosinMonitor Closely (1)nefazodone will increase the level or effect of silodosin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.simvastatinContraindicated (1)nefazodone will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Contraindicated. Increased risk for rhabdomyolysis with drugs that increase simvastatin systemic exposure.siponimodSerious - Use Alternative (1)nefazodone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.sirolimusMonitor Closely (1)nefazodone will increase the level or effect of sirolimus by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.sofosbuvir/velpatasvirMonitor Closely (1)nefazodone will increase the level or effect of sofosbuvir/velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of sofosbuvir/velpatasvir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.solifenacinSerious - Use Alternative (1)nefazodone will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.sonidegibSerious - Use Alternative (1)nefazodone will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sonidegib with strong CYP3A4 inhibitors.sorafenibMonitor Closely (1)nefazodone will increase the level or effect of sorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.sparsentanSerious - Use Alternative (1)nefazodone, sparsentan. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. If unavoidable, interrupt treatment with sparsentan. When resuming sparsentan, consider dose titration. .St John's WortSerious - Use Alternative (1)nefazodone and St John's Wort both increase serotonin levels. Avoid or Use Alternate Drug.stiripentolMonitor Closely (2)nefazodone will increase the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. stiripentol, nefazodone. 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.streptomycinMonitor Closely (1)nefazodone will increase the level or effect of streptomycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.sufentanilSerious - Use Alternative (1)nefazodone will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.sufentanil SLMonitor Closely (2)sufentanil SL, 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. nefazodone will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.sulfasalazineMonitor Closely (1)nefazodone, 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.sulindacMonitor Closely (1)nefazodone, sulindac. Either increases toxicity