Flomax, also known as Tamsulosin, is used to treat the signs and symptoms of enlargement of the prostate. Benign enlargement of the prostate is a problem that can occur in men as they get older. As the prostate gland enlarges, certain muscles in the gland may tighten and get in the way of the tube that drains urine from the bladder. This can cause a need to urinate often, a weak stream when urinating, or a feeling of not being able to empty the bladder completely. Tamsulosin helps relax the muscles in the prostate and the opening of the bladder. This may help increase the flow of urine and/or decrease the symptoms, but it will not help shrink the prostrate.
Be sure to tell your doctor of any allergies you have whether it is to medication or food, preservatives, or dyes. Also, tell your doctor of any other medications you are taking, including vitamins and supplements, and any medical conditions you may have.
It is very important that you take this medicine exactly as your doctor tells you to. If you miss a dose of this medicine, skip it and go back to your regular schedule. Do NOT double doses.
Talk with your doctor if you have continuing or bothersome: abnormal ejaculation; back pain; diarrhea; dizziness; headache; stuffy or runny nose; unusual weakness; chest pain; decreased sexual drive or performance; difficulty in sleeping; fainting or lightheadedness, especially when getting up from a lying or sitting position; drowsiness; or nausea.
Tamsulosin hydrochloride is an antagonist of alpha1A adrenoceptors in the prostate. Tamsulosin HCl is (-)-(R)-5-[2-[[2-(o-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. Each FLOMAX (tamsulosin HCl) 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.
Flomax has the following structural formula: