Tamsulosin (Flomax) is an alpha-blocker that 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).
Tamsulosin is not FDA approved for use in women or children.
You should not use tamsulosin if you are allergic to it. Do not take tamsulosin together with similar medicines such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), silodosin (Rapaflo), or terazosin (Hytrin).
To make sure tamsulosin is safe for you, tell your doctor if you have:
- liver or kidney disease;
- a history of prostate cancer;
- low blood pressure; or
- an allergy to sulfa drugs.
Tamsulosin can affect your pupils during cataract surgery. Tell your eye surgeon ahead of time that you are using this medicine. Do not stop using tamsulosin before surgery unless your surgeon tells you to.
Although this medicine 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.
This medicine is not approved for use by anyone younger than 18 years old.
How to take tamsulosin
Take tamsulosin exactly as it was prescribed for you. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Tamsulosin is usually taken once a day, approximately 30 minutes after a meal. Try to take this medication at the same time each day.
Do not crush, chew, or open a capsule. Swallow the capsule whole.
Tamsulosin lowers blood pressure and may cause dizziness or fainting, especially when you first start taking it, or when you start taking it again. Call your doctor if you have severe dizziness or feel like you might pass out.
Some things can cause your blood pressure to get too low. This includes vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low-salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.
Your blood pressure will need to be checked often. You will also need to be checked for prostate cancer before and during treatment with tamsulosin.
You may feel very dizzy when you first wake up. Be careful when standing or sitting up from a lying position.
If you stop taking tamsulosin for any reason, call your doctor before you start taking it again. You may need a dose adjustment.
Store at room temperature away from moisture and heat.
Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.
Get emergency medical help if you have signs of an allergic reaction to tamsulosin: hives, rash, itching; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using this medicine and call your doctor at once if you have:
- a light-headed feeling, like you might pass out;
- penis erection that is painful or lasts 4 hours or longer; or
- severe skin reaction – fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Common tamsulosin side effects may include:
- low blood pressure;
- dizziness, drowsiness, weakness;
- nausea, diarrhea;
- headache, chest pain;
- abnormal ejaculation, decreased amount of semen;
- back pain;
- blurred vision;
- tooth problems;
- fever, chills, body aches, flu symptoms;
- runny or stuffy nose, sinus pain, sore throat, cough;
- sleep problems (insomnia); or
- decreased interest in sex.