Tamsulosin (rINN) (IPA: ) is an α_1a-selective alpha blocker used in the symptomatic treatment of benign prostatic hyperplasia (BPH). Tamsulosin was developed by Yamanouchi Pharmaceuticals (now part of Astellas Pharma) and is marketed by various companies under licence, including Boehringer-Ingelheim and CSL. As of 2006, tamsulosin hydrochloride extended-release tablets are marketed under the trade name Flomaxtra. It was formerly marketed as modified-release capsules under the trade name Flomax.

Clinical use