Tamsulosin (Flomax) belongs to a group of drugs called alpha-adrenergic (AL-fa ad-ren-ER-jik) blockers. It relaxes the muscles in the prostate and bladder neck, making it easier to urinate.
Tamsulosin is used to improve urination in men with benign prostatic hyperplasia (enlarged prostate).
You should not use this medication if you are allergic to tamsulosin. Do not take tamsulosin with other similar medicines such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), silodosin (Rapaflo), or terazosin (Hytrin).
If you have a history of prostate cancer, you may need a dose adjustment or special tests to safely take this tamsulosin.
Tamsulosin can affect your pupils during cataract surgery. Tell your eye surgeon ahead of time that you are using this medication. Do not stop using tamsulosin before surgery unless your surgeon tells you to.
Although this medication is not for use in women, tamsulosin is not expected to harm an unborn baby. If you are a woman using this medication, tell your doctor if you are pregnant or breast-feeding.
Tamsulosin is not for use in children.
Get emergency medical help if you have any of these signs of an allergic reaction to tamsulosin: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using tamsulosin and call your doctor at once if you have any of these serious side effects:
- feeling like you might pass out;
- chest pain;
- fever, chills, body aches, or flu symptoms; or
- penis erection that is painful or lasts 4 hours or longer.
Less serious tamsulosin side effects may include:
- mild dizziness;
- weakness, drowsiness;
- nausea, diarrhea;
- back pain;
- blurred vision;
- dental problems;
- sleep problems (insomnia);
- abnormal ejaculation, decreased sex drive; or
- runny nose, sore throat, cough.
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.