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, the prostate, the ureter, and the 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tamsulosin in alpha 1A/D receptors is controversial and over three quarters of tamsulosin registered human studies are unpublished.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, non-modified-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.
Combination therapy
The results of the CombAT (combination of dutasteride (Avodart) and tamsulosin, under the brand name Duodart) trial in 2008 demonstrated that treatment with the combination of dutasteride and tamsulosin provides greater symptom benefits compared to monotherapy with either agent alone for treatment of benign prostatic hyperplasia. The CombAT trial became the medication Jalyn. It was approved by the FDA on 14 June 2010. This combination can be useful because it may take up to six months for symptomatic relief to be found when using 5-alpha-reductase inhibitors such as dutasteride compared to alpha-1 receptor blockers, which can provide relief in some cases within 48 hours. Adverse effects
Eyes: People taking tamsulosin are prone to a complication known as floppy iris syndrome during cataract surgery. Adverse outcomes of the surgery are greatly reduced by the surgeons prior knowledge of the persons history with this drug, and thus having the option of alternative techniques. Severe hypotension. Persons with cardiac conditions including hypotension, mechanical heart failure (valvular, pulmonary embolism, pericarditis), and 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 re-hospitalization 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.