congestive heart failure should be monitored carefully while taking tamsulosin. Alpha blockers, including prazosin, terazosin, doxazosin, or tamsulosin, do not appear to affect all-cause mortality in heart failure rehospitalization in those also receiving β-blockers. Tamsulosin can also cause retrograde ejaculation, which occurs when semen is redirected to the urinary bladder instead of being ejaculated normally. This is because tamsulosin relaxes the muscles of the urethral sphincters, which are normally closed during ejaculation. This side effect can be mitigated by regular pelvic floor (Kegel) exercise and contracting the pelvic floor during ejaculation. Mechanism Tamsulosin is a selective α1 receptor antagonist that has preferential selectivity for the α1A receptor in the prostate versus the α1B receptor in the blood vessels. When alpha 1 receptors in the bladder neck, prostate, ureter, and urethra are blocked, a relaxation in smooth muscle tissue results. This mechanism decreases resistance to urinary flow, reduces discomfort associated with BPH, and facilitates passage of kidney stones. Selective action of tamsulosin in alpha 1A/D receptors is controversial and over three-quarters of tamsulosin registered human studies are unpublished. Brand names Tamsulosin was first marketed in 1996 under the trade name Flomax. The U.S. patent expired in October 2009. The U.S. Food and Drug Administration (FDA) approved generics in March 2010. In 2010, tamsulosin was available as OTC medication in UK. It is marketed by various companies under licence, including Boehringer Ingelheim and CSL. Tamsulosin hydrochloride extended-release capsules are marketed under the trade names Urimax 0.4 (India), Flomax, Flomaxtra, Contiflo XL, bestflo, Mecir LP (France), Urimax, Pamsvax, and Pradif, although generic, unmodified-release capsules are still approved and marketed in many countries (such as Canada). Generic extended-release tablets are marketed in most countries of the EEA. In Mexico, it is marketed as Secotex and as Harnal D in Japan and Indonesia and as Harnal OCAS (oral controlled absorption system) in Thailand. In Egypt, Italy, Russia and Iceland, it is marketed under the trade name Omnic by Astellas Pharma Europe. The largest manufacturer of tamsulosin, drug substance, is Synthon BV (the Netherlands). Tamsulosin hydrochloride is marketed in Bangladesh under the trade names Uromax, Prostanil MR, Tamisol MR, and Tamsin. References External links Alpha-1 blockers Astellas Pharma Phenethylamines Phenol ethers Prostate disorders Substituted amphetamines Sulfonamides Wikipedia medicine articles ready to translate