AdultPediatricDosage Forms & Strengths capsule 0.4mg Benign Prostatic Hypertrophy Indicated for treatment of signs and symptoms of benign prostatic hyperplasia (BPH) 0.4 mg PO qDay; take 30 minutes after same meal each day If inadequate response after 2-4 weeks, may increase to 0.8 mg qDay If therapy interrupted or discontiniued for several days, resume at 0.4 mg/day and increase if needed Bladder Outlet Obstruction (Off-label) Relief of symptoms 0.4 mg PO qDay Ureteral Stones (Off-label) Facilitation of kidney stone expulsion 0.4 mg PO qDay; discontinued after successful expulsion (average, 1-2 weeks) Double-blind, placebo-controlled trial found tamsulosin did not significantly increase stone passage rate compared with placebo for stones <9 mm (JAMA Intern Med. 2018 Aug 1;178(8):1051-1057) Dosing Modifications Renal impairment CrCl ≥10 mL/min: Dosage adjustment not necessary CrCl <10 mL/min: Not studied Hepatic impairment Mild to moderate: Dosage adjustment not necessary Severe: Not studied Dosing Considerations Not indicated for hypertensionSafety and efficacy not establishedInteraction CheckerEnter a drug name and tamsulosinNo Results No Interactions Found Interactions FoundContraindicatedSerious - Use AlternativeSignificant - Monitor CloselyMinorAll Interactions Sort By: SeverityName Contraindicated (1)ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increased risk for hypotensioSerious - Use Alternative (50)abametapirabametapir increases levels of tamsulosin 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.alfuzosinalfuzosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.apalutamideapalutamide will decrease the level or effect of tamsulosin 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.atazanaviratazanavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. .carbamazepinecarbamazepine will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.ceritinibceritinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.chloramphenicolchloramphenicol will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.clarithromycinclarithromycin increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.cobicistatcobicistat will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.conivaptanconivaptan increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.dacomitinibdacomitinib 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. darunavirdarunavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.doxazosindoxazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.enzalutamideenzalutamide will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.fexinidazolefexinidazole 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.fosamprenavirfosamprenavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.fosphenytoinfosphenytoin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.givosirangivosiran 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.idelalisibidelalisib 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 substratesimatinibimatinib increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.indinavirindinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. .isoniazidisoniazid increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.itraconazoleitraconazole 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. .ivosidenibivosidenib 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.ketoconazoleketoconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity.levoketoconazolelevoketoconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity.lonafarniblonafarnib 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.lopinavirlopinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity.nefazodonenefazodone increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nelfinavirnelfinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nicardipinenicardipine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nirmatrelvir/ritonavirnirmatrelvir/ritonavir will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Tamsulosin metabolized mainly by CYP3A4 and to a lesser extent by CYP2D6. Pause tamsulosin and restart 3 days after completing nirmatrelvir/ritonavir given that CYP3A4 inhibition takes several days to resolve. phenobarbitalphenobarbital will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.phenoxybenzaminephenoxybenzamine, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.phentolaminephentolamine, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.phenytoinphenytoin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.posaconazoleposaconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.prazosinprazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.primidoneprimidone will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.quinidinequinidine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rifampinrifampin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.ritonavirritonavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.saquinavirsaquinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.secobarbitalsecobarbital will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.silodosinsilodosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.terazosinterazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.tipranavirtipranavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tucatinibtucatinib will increase the level or effect of tamsulosin 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.voriconazolevoriconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.voxelotorvoxelotor will increase the level or effect of tamsulosin 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.Monitor Closely (96)abirateroneabiraterone increases levels of tamsulosin 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.amifostineamifostine, tamsulosin. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.amiodaroneamiodarone increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be neeed for coadministered drugs that are predominantly metabolized by CYP3A.amiodarone increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.amobarbitalamobarbital will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.aprepitantaprepitant 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.avanafilavanafil, tamsulosin. Either increases effects of the other by additive vasodilation. Use Caution/Monitor. Risk of hypotension.bicalutamidebicalutamide 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.bortezomibbortezomib increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.bosentanbosentan will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.bupropionbupropion increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cenobamatecenobamate 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.chloroquinechloroquine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.chlorpromazinechlorpromazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cimetidinecimetidine 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.cinacalcetcinacalcet increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.clobazamclobazam increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.clomipramineclomipramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.clozapineclozapine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cocaine topicalcocaine topical increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.crizotinibcrizotinib 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.crofelemercrofelemer 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.cyclosporinecyclosporine 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.dabrafenibdabrafenib will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.darifenacindarifenacin increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.desipraminedesipramine 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.dexmedetomidinedexmedetomidine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.diltiazemdiltiazem 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.diphenhydraminediphenhydramine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.disulfiramdisulfiram increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.doxycyclinedoxycycline 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.dronedaronedronedarone 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