hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.cenobamateMonitor Closely (1)cenobamate will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.ceritinibSerious - Use Alternative (1)ceritinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.chloramphenicolSerious - Use Alternative (1)chloramphenicol will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.chloroquineMonitor Closely (1)chloroquine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.chlorpromazineMonitor Closely (1)chlorpromazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cimetidineMonitor Closely (2)cimetidine increases levels of tamsulosin by decreasing renal clearance. Use Caution/Monitor. Decreases tamsulosin clearance by 26% resulting in increased AUC (44%). cimetidine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cinacalcetMonitor Closely (1)cinacalcet increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.clarithromycinSerious - Use Alternative (1)clarithromycin increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.clobazamMonitor Closely (1)clobazam increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.clomipramineMonitor Closely (1)clomipramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.clozapineMonitor Closely (1)clozapine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cobicistatSerious - Use Alternative (1)cobicistat will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.cocaine topicalMonitor Closely (1)cocaine topical increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.conivaptanSerious - Use Alternative (1)conivaptan increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.crizotinibMonitor Closely (1)crizotinib increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.crofelemerMonitor Closely (1)crofelemer increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.cyclophosphamideMinor (1)cyclophosphamide will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.cyclosporineMonitor Closely (1)cyclosporine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.dabrafenibMonitor Closely (1)dabrafenib will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.dacomitinibSerious - Use Alternative (1)dacomitinib will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities. darifenacinMonitor Closely (1)darifenacin increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.darunavirSerious - Use Alternative (1)darunavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.desipramineMonitor Closely (2)desipramine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A. desipramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.dexmedetomidineMonitor Closely (1)dexmedetomidine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.diltiazemMonitor Closely (1)diltiazem increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.diphenhydramineMonitor Closely (1)diphenhydramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.disulfiramMonitor Closely (1)disulfiram increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.doxazosinSerious - Use Alternative (1)doxazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.doxycyclineMonitor Closely (1)doxycycline increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.dronedaroneMonitor Closely (2)dronedarone increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A. dronedarone increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.duloxetineMonitor Closely (1)duloxetine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.duvelisibMonitor Closely (1)duvelisib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.efavirenzMonitor Closely (1)efavirenz increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.elagolixMonitor Closely (1)elagolix decreases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.eliglustatMonitor Closely (1)eliglustat increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.elvitegravir/cobicistat/emtricitabine/tenofovir DFMonitor Closely (2)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events. elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.encorafenibMonitor Closely (1)encorafenib, tamsulosin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.enzalutamideSerious - Use Alternative (1)enzalutamide will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.erythromycin baseMonitor Closely (1)erythromycin base increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.erythromycin ethylsuccinateMonitor Closely (1)erythromycin ethylsuccinate increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.erythromycin lactobionateMonitor Closely (1)erythromycin lactobionate increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.erythromycin stearateMonitor Closely (1)erythromycin stearate increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.etravirineMonitor Closely (1)etravirine will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fedratinibMonitor Closely (2)fedratinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary. fedratinib will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.fexinidazoleSerious - Use Alternative (1)fexinidazole will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.fluconazoleMonitor Closely (1)fluconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.fluoxetineMonitor Closely (1)fluoxetine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.fosamprenavirSerious - Use Alternative (1)fosamprenavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.fosaprepitantMonitor Closely (1)fosaprepitant increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.fosphenytoinSerious - Use Alternative (1)fosphenytoin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.givosiranSerious - Use Alternative (1)givosiran will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.grapefruitMonitor Closely (1)grapefruit increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.haloperidolMonitor Closely (2)haloperidol increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A. haloperidol increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.idelalisibSerious - Use Alternative (1)idelalisib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substratesiloperidoneMonitor Closely (1)iloperidone increases levels of tamsulosin 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.imatinibMonitor Closely (1)imatinib increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)imatinib increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.imipramineMonitor Closely (1)imipramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.indinavirSerious - Use Alternative (1)indinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. .isoniazidMonitor Closely (1)isoniazid increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)isoniazid increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.istradefyllineMonitor Closely (1)istradefylline will increase the level or effect of tamsulosin 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.itraconazoleSerious - Use Alternative (1)itraconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Not recommended during and 2 weeks after itraconazole treatment. .ivosidenibSerious - Use Alternative (1)ivosidenib will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.ketoconazoleMonitor Closely (1)ketoconazole increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)ketoconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity.lapatinibMonitor Closely (1)lapatinib increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.larotrectinibMonitor Closely (1)larotrectinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lenacapavirMonitor Closely (1)lenacapavir will increase the level or effect of tamsulosin 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.levoketoconazoleMonitor Closely (1)levoketoconazole increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)levoketoconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity.lidocaineMonitor Closely (2)lidocaine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A. lidocaine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lonafarnibSerious - Use Alternative (1)lonafarnib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.lopinavirMonitor Closely (1)lopinavir increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)lopinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity.lorcaserinMonitor Closely (1)lorcaserin increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lorlatinibMonitor Closely (1)lorlatinib will decrease