Bisoprolol may increase the orthostatic hypotensive activities of Tamsulosin. Tamsulosin may decrease the vasoconstricting activities of Phenylpropanolamine. The serum concentration of Tamsulosin can be increased when it is combined with Palbociclib. The risk or severity of adverse effects can be increased when Levosimendan is combined with Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Amyl Nitrite. The metabolism of Tamsulosin can be decreased when combined with Erythromycin. The risk or severity of adverse effects can be increased when Obinutuzumab is combined with Tamsulosin. Tamsulosin may increase the hypotensive activities of Carboxyamidotriazole. The risk or severity of adverse effects can be increased when Pramipexole is combined with Tamsulosin. The metabolism of Tamsulosin can be decreased when combined with Olaparib. The risk or severity of adverse effects can be increased when Hydroflumethiazide is combined with Tamsulosin. The risk or severity of adverse effects can be increased when Paclitaxel is combined with Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Benazepril. The metabolism of Tamsulosin can be decreased when combined with Clomipramine. The risk or severity of adverse effects can be increased when Pipamperone is combined with Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Aldesleukin. Thiamylal may increase the hypotensive activities of Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Methyclothiazide. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Brimonidine. The metabolism of Tamsulosin can be increased when combined with Rifabutin. The serum concentration of Tamsulosin can be decreased when it is combined with Bosentan. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Minoxidil. The serum concentration of Tamsulosin can be increased when it is combined with Fosaprepitant. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Valsartan. Tamsulosin may decrease the vasoconstricting activities of Naphazoline. Tamsulosin may increase the hypotensive activities of Tetrahydropalmatine. Tamsulosin may decrease the vasoconstricting activities of Formoterol. Tamsulosin may increase the hypotensive activities of Vinpocetine. Avanafil may increase the hypotensive activities of Tamsulosin. Tamsulosin may decrease the vasoconstricting activities of Droxidopa. The serum concentration of Tamsulosin can be decreased when it is combined with Peginterferon alfa-2b. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Chlorthalidone. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Telmisartan. The metabolism of Tamsulosin can be decreased when combined with Ticlopidine. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Empagliflozin. The serum concentration of Tamsulosin can be increased when it is combined with Delavirdine. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Metipranolol. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Dinutuximab. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Tizanidine. The serum concentration of Tamsulosin can be increased when it is combined with Ceritinib. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Olmesartan. The serum concentration of Tamsulosin can be increased when it is combined with Aprepitant. Tamsulosin may increase the hypotensive activities of Eperisone. The risk or severity of adverse effects can be increased when Apomorphine is combined with Tamsulosin. Oxprenolol may increase the orthostatic hypotensive activities of Tamsulosin. Methohexital may increase the hypotensive activities of Tamsulosin. Barbital may increase the hypotensive activities of Tamsulosin. Mirodenafil may increase the hypotensive activities of Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Cimetidine. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Isoxsuprine. The serum concentration of Tamsulosin can be increased when it is combined with Fusidic Acid. The metabolism of Tamsulosin can be decreased when combined with Crizotinib. Aripiprazole may increase the hypotensive activities of Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Dosulepin. Tamsulosin may increase the hypotensive activities of Gallopamil. Landiolol may increase the orthostatic hypotensive activities of Tamsulosin. Tamsulosin may increase the hypotensive activities of Barnidipine. The risk or severity of adverse effects can be increased when Amphotericin B is combined with Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Eprosartan. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Apraclonidine. The serum concentration of Tamsulosin can be increased when it is combined with Saquinavir. The metabolism of Tamsulosin can be decreased when combined with Dihydroergotamine. Tamsulosin may increase the hypotensive activities of Nimesulide. Udenafil may increase the hypotensive activities of Tamsulosin. Nadolol may increase the orthostatic hypotensive activities of Tamsulosin. Hexobarbital may increase the hypotensive activities of Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Bupropion. The metabolism of Tamsulosin can be decreased when combined with Isradipine. Penbutolol may increase the orthostatic hypotensive activities of Tamsulosin. Tamsulosin may decrease the vasoconstricting activities of Fenoterol. Alfuzosin may increase the antihypertensive activities of Tamsulosin. Tamsulosin may decrease the vasoconstricting activities of Racepinephrine. The metabolism of Tamsulosin can be decreased when combined with Nicardipine. Tamsulosin may decrease the vasoconstricting activities of Anisodamine. Tamsulosin may decrease the vasoconstricting activities of Guanabenz. The risk or severity of adverse effects can be increased when Selegiline is combined with Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Lopinavir. Acebutolol may increase the orthostatic hypotensive activities of Tamsulosin. The metabolism of Tamsulosin can be decreased when combined with Haloperidol. The risk or severity of adverse effects can be increased when Sacubitril is combined with Tamsulosin. Carteolol may increase the orthostatic hypotensive activities of Tamsulosin. The serum concentration of Tamsulosin can be decreased when it is combined with Enzalutamide. Tamsulosin may increase the hypotensive activities of Xylometazoline. Tamsulosin may decrease the vasoconstricting activities of Salmeterol. Nebivolol may increase the orthostatic hypotensive activities of Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Mecamylamine. The metabolism of Tamsulosin can be decreased when combined with Artemether. The risk or severity of adverse effects can be increased when Levobupivacaine is combined with Tamsulosin. The therapeutic efficacy of Tamsulosin can be decreased when used in combination with Sarilumab. The serum concentration of Tamsulosin can be increased when it is combined with Abiraterone. Tamsulosin may decrease the vasoconstricting activities of Etilefrine. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Azilsartan medoxomil. The serum concentration of Tamsulosin can be increased when it is combined with Fluoxetine. The metabolism of Tamsulosin can be decreased when combined with Isoniazid. The serum concentration of Tamsulosin can be increased when it is combined with Simeprevir. The metabolism of Tamsulosin can be decreased when combined with Rolapitant. The risk or severity of adverse effects can be increased when Sodium Nitrite is combined with Tamsulosin. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Canagliflozin. Tamsulosin may increase the hypotensive activities of Amlodipine. The metabolism of Tamsulosin can be decreased when combined with Imatinib. The risk or severity of adverse effects can be increased when Morphine is combined with Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Clarithromycin. The risk or severity of adverse effects can be increased when Sevoflurane is combined with Tamsulosin. Thiopental may increase the hypotensive activities of Tamsulosin. The serum concentration of Tamsulosin can be decreased when it is combined with Vemurafenib. The metabolism of Tamsulosin can be decreased when combined with Promazine. Tamsulosin may decrease the vasoconstricting activities of Ritodrine. The metabolism of Tamsulosin can be decreased when combined with Ropinirole. The risk or severity of adverse effects can be increased when Rotigotine is combined with Tamsulosin. The metabolism of Tamsulosin can be decreased when combined with Clozapine. The metabolism of Tamsulosin can be increased when combined with Fosphenytoin. The serum concentration of Tamsulosin can be increased when it is combined with Osimertinib. The metabolism of Tamsulosin can be decreased when combined with Lorcaserin. Tamsulosin may decrease the vasoconstricting activities of Norepinephrine. The risk or severity of adverse effects can be increased when Tamsulosin is combined with Dipyridamole. The risk or severity of adverse effects can be increased when Bupivacaine is combined with Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Midostaurin. The serum concentration of Tamsulosin can be increased when it is combined with Panobinostat. Tamsulosin may increase the antihypertensive activities of Trimazosin. The metabolism of Tamsulosin can be decreased when combined with Bortezomib. Bevantolol may increase the orthostatic hypotensive activities of Tamsulosin. The risk or severity of adverse effects can be increased when Isoflurane is combined with Tamsulosin. The metabolism of Tamsulosin can be decreased when combined with Venlafaxine. The risk or severity of adverse effects can be increased when Iloprost is combined with Tamsulosin. The serum concentration of Tamsulosin can be increased when it is combined with Tipranavir. The serum concentration of Tamsulosin can be increased when it is combined with Dasatinib. The serum concentration of Tamsulosin can be decreased when it is combined with Siltuximab. The metabolism of Tamsulosin can be decreased when combined with Clobazam. Tamsulosin may decrease the vasoconstricting activities of Xamoterol. The serum concentration of Tamsulosin can be decreased when it is combined with St. John's Wort.