Systematic (IUPAC) name
Clinical data
Trade names Flomax
AHFS/Drugs.com monograph
MedlinePlus a698012
Licence data US FDA:link
Pregnancy cat. B2(AU) B(US)
Legal status Prescription Only (S4) (AU) POM (UK) -only (US)
Routes oral
Pharmacokinetic data
Bioavailability 100% (oral)
Metabolism hepatic
Half-life 9–13 hours
Excretion 76% renal
CAS number 106133-20-4 YesY
ATC code G04CA02
PubChem CID 129211
IUPHAR ligand 488
DrugBank APRD00036
ChemSpider 114457 YesY
KEGG D08560 YesY
Chemical data
Formula C20H28N2O5S 
Mol. mass 408.51
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Tamsulosin (rINN) (pronounced /tæmˈsuːlɵsɨn/ or tæmsʉˈloʊsɨn) is an α1a-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. Tamsulosin hydrochloride extended-release capsules are marketed under the trade names Flomax, Flomaxtra, Contiflo XL, and Urimax, though generic non-modified release capsules are still approved and marketed in many countries, such as Canada. It is marketed under Harnal D in some places.[1] The U.S. patent for Flomax expired in October 2009.[citation needed] The U.S. Food and Drug Administration (FDA) approved generic Flomax in March 2010.[2]

In Egypt[3] Italy and Iceland it is marketed under the trade Omnic by Astellas Pharma Europe.



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.[4]

Clinical uses

Flomax 0.4 MG Oral Capsule

Tamsulosin is primarily used for benign prostatic hyperplasia, but is sometimes used for the passage of kidney stones by the same mechanism of smooth muscle relaxation via alpha antagonism.[citation needed]

Adverse effects

Two ADRs (Adverse Drug Reactions) have been reported:

  • Immunologic: It contains a sulfa moiety, thus causing typical reactions to sulfa drugs.[citation needed]
  • Ophthalmologic: Patients 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 surgeon's prior knowledge of the patient's history with this drug, and thus having the option of alternative techniques.[5]

Tamsulosin has also affected the sexual function in men. Tamsulosin can cause males to experience retrograde ejaculation.[6] In males, retrograde ejaculation occurs when the fluid to be ejaculated, which would normally exit the body via the urethra, is redirected to the urinary bladder. Normally, the sphincter of the bladder contracts and the ejaculate goes to the urethra, the area of least pressure. In retrograde ejaculation, this sphincter does not function properly.

Occasionally, tamsulosin can cause a drop in blood pressure, rarely resulting in dizziness or fainting.[citation needed] Other reported side effects include headache, dizziness, nasal congestion, and palpitations.[citation needed]

Clinical comparison

Although prostate specific, it does not have the prostate apoptotic effects of other alpha-blockers such as doxazosin and terazosin.[citation needed]

Use in combination therapy

The results of the CombAT (Combination of Avodart and Tamsulosin) trial have recently demonstrated that treatment with the combination of Avodart and tamsulosin provides greater symptom benefits compared with either monotherapy for treatment of benign prostatic hyperplasia.[7]


  1. ^ "Drugs.com Database". http://www.drugs.com/international/harnal-d.html. 
  2. ^ "FDA Approves First Generic Tamsulosin to Treat Enlarged Prostate Gland" (Press release). U.S. Food and Drug Administration (FDA). March 2, 2010. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm202728.htm. 
  3. ^ "Novartis hits Astellas with transplant drug generic". Reuters. 11 August 2009. http://www.reuters.com/article/americasRegulatoryNews/idUST34424920090811. Retrieved 11 August 2009. 
  4. ^ Shen, Howard (2008). Illustrated Pharmacology Memory Cards: PharMnemonics. Minireview. p. 13. ISBN 1-59541-101-1. 
  5. ^ Medscape, Good Cataract Surgery Outcomes Possible in Intraoperative Floppy Iris Syndrome Due to Tamsulosin.
  6. ^ "Tamsulosin Side Effects". Drugs.com. http://www.drugs.com/sfx/tamsulosin-side-effects.html. Retrieved 2011-04-27 
  7. ^ Roehrborn CG, Siami P, Barkin J, et al. (February 2008). "The effects of dutasteride, tamsulosin and combination therapy on lower urinary tract symptoms in men with benign prostatic hyperplasia and prostatic enlargement: 2-year results from the CombAT study". J. Urol. 179 (2): 616–21; discussion 621. doi:10.1016/j.juro.2007.09.084. PMID 18082216. 

External links

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Tamsulosin — Strukturformel Allgemeines Freiname Tamsulosin …   Deutsch Wikipedia

  • tamsulosin — A drug used to treat urinary problems caused by an enlarged prostate. Tamsulosin relaxes the muscles of the prostate and bladder, which helps the flow of urine. It is a type of alpha blocker. Also called tamsulosin hydrochloride and Flomax …   English dictionary of cancer terms

  • tamsulosin — noun A particular kind of alpha 1a selective alpha blocker …   Wiktionary

  • tamsulosin — tam·su·lo·sin tam sü lə sən n an alpha adrenergic blocking agent administered orally in the form of its hydrochloride C20H28N2O5S·HCl to treat benign prostatic hyperplasia see flomax * * * n. a highly selective alpha blocker taken by mouth to… …   Medical dictionary

  • tamsulosin — n. a highly selective alpha blocker taken by mouth to treat lower urinary tract symptoms thought to be due to benign prostatic hyperplasia (see prostate gland). Side effects include retrograde ejaculation that is reversible on stopping the drug.… …   The new mediacal dictionary

  • tamsulosin hydrochloride — A drug used to treat urinary problems caused by an enlarged prostate. Tamsulosin hydrochloride relaxes the muscles of the prostate and bladder, which helps the flow of urine. It is a type of alpha blocker. Also called tamsulosin and Flomax …   English dictionary of cancer terms

  • tamsulosin hydrochloride — tam·su·lo·sin hy·dro·chlo·ride (tam sooґlo sin) an α1 adrenergic blocking agent specific for the receptors in the prostate; used to improve urine flow rate and reduce symptoms of benign prostatic hyperplasia, administered orally …   Medical dictionary

  • Omnic — Strukturformel Allgemeines Freiname Tamsulosin Andere Namen …   Deutsch Wikipedia

  • Intraoperative floppy iris syndrome — (IFIS) is a complication that may occur during cataract extraction in certain patients. This syndrome is characterized by a flaccid iris which billows in response to ordinary intraocular fluid currents, a propensity for this floppy iris to… …   Wikipedia

  • Alpha-1 blocker — Alpha 1 blockers (also called alpha adrenergic blocking agents) constitute a variety of drugs which block α1 adrenergic receptors in arteries and smooth muscles.IndicationsThese drugs may be used to treat: * benign prostatic hyperplasia (BPH)cite …   Wikipedia

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