What is Tamsulosin?

Tamsulosin is used to treat the symptoms of benign prostatic hyperplasia (BPH). Tamsulosin hydrochloride is an antagonist of alpha1A adrenoceptors in the prostate.

Tamsulosin HCl is (-)-(R)-5-[2-[[2-(0-ethoxyphenoxy) ethyl] amino] propyl]-2-methoxybenzenesulfonamide, monohydrochloride. Tamsulosin HCl occurs as white crystals that melt with decomposition at approximately 230°C. It is sparingly soluble in water and in methanol, slightly soluble in glacial acetic acid and in ethanol, and practically insoluble in ether. The empirical formula of tamsulosin HCl is C20H28N2O5S HCl. The molecular weight of tamsulosin HCl is 444.98. Its structural formula is:

The history of Tamsulosin

Tamsulosin was approved by the FDA in 1997.

What is Tamsulosin used for?

Tamsulosin is a drug for the treatment of men who are having difficulty urinating because of benign prostatic hyperplasia (BPH). In men, the tube which carries urine from the bladder to the penis (called the urethra) travels through the prostate gland. As men get older, the prostate gland enlarges, and the muscle cells within the prostate gland and the neck of the bladder (which control the flow of urine) tighten. The combination of enlargement and tightening of muscles compresses the urethra and obstructs the flow of urine. This results in difficulty urinating and retention of urine within the bladder. The tightening or contraction of the muscle cells is controlled by nerves.

One type of nerve, the alpha adrenergic nerves, cause the muscle cells to tighten by releasing a chemical related to epinephrine (adrenalin). Tamsulosin blocks the effects of this chemical on the muscle cells and causes the muscles to relax. This results in a decrease in obstruction to the flow of urine. There are other drugs which block alpha adrenergic nerves throughout the body and which are used in treating diseases of the heart, blood vessels, and prostate for example, prazosin (Minipress), terazosin (Hytrin), doxazosin (Cardura), and alfuzosin (Uroxatral). Tamsulosin is more active against the alpha adrenergic nerves of the prostate and bladder neck than these other drugs and has a lesser effect on alpha adrenergic nerves elsewhere in the body.

For this reason, tamsulosin causes fewer side effects, especially low blood pressure, than other alpha adrenergic blocking drugs. Moreover, tamsulosin therapy can be started at the optimum dose whereas other alpha adrenergic blocking drugs need to be started at low doses with the doses slowly increased over time in order to minimize the side effects.

Tamsulosin mode of action

Each capsule for oral administration contains tamsulosin HCl 0.4 mg, and the following inactive ingredients: methacrylic acid copolymer, microcrystalline cellulose, triacetin, polysorbate 80, sodium lauryl sulfate, calcium stearate, talc, FD&C blue No. 2, titanium dioxide, ferric oxide, gelatin, and trace amounts of shellac, industrial methylated spirit 74 OP, n-butyl, alcohol, isopropyl alcohol, propylene glycol, dimethylpolysiloxane, and black iron oxide E172.

Tamsulosin side effects

Although side effects from tamsulosin are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

Disclaimer:

Information on this page is provided for general information purposes. You should not make a clinical treatment decision based on information contained in this page without consulting other references including the package insert of the drug, textbooks and where relevant, expert opinion. We cannot be held responsible for any errors you make in administering drugs mentioned on this page, nor for use of any erroneous information contained on this page.