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Drugs reference index «Tamsulosin hydrochloride»

Tamsulosin hydrochloride

Brand names: Flomax

Why is Tamsulosin hydrochloride prescribed?

Flomax is used to treat the symptoms of an enlarged prostate—a condition technically known as benign prostatic hyperplasia or BPH. The walnut-sized prostate gland surrounds the urethra (the duct that drains the bladder). If the gland becomes enlarged, it can squeeze the urethra, interfering with the flow of urine. This can cause difficulty in starting urination, a weak flow of urine, and the need to urinate urgently or more frequently. Flomax doesn't shrink the prostate. Instead, it relaxes the muscle around it, freeing the flow of urine and decreasing urinary symptoms.

Most important fact about Tamsulosin hydrochloride

Flomax can cause dizziness, especially when you first stand up. Be careful about driving, operating machinery, and performing any other hazardous task until you know how you react to the drug.

How should you take Tamsulosin hydrochloride?

Take Flomax once daily, half an hour after the same meal each day. Do not crush, chew, or open the capsule.

  • If you miss a dose...Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Do not take 2 doses at once.

If you miss several doses in a row, resume treatment with a dose of 1 capsule daily and check with your doctor on how to proceed.

  • Storage instructions...Store at room temperature.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Flomax.

  • Side effects may include:Abnormal ejaculation, back pain, chest pain, cough, diarrhea, dizziness, headache, infection, nausea, runny nose, sinus problems, sleepiness, sore throat, weakness

Why should Tamsulosin hydrochloride not be prescribed?

If Flomax gives you an allergic reaction, you cannot take the drug.

Special warnings about Tamsulosin hydrochloride

Remember that, in a few men, Flomax can cause a drop in blood pressure upon first standing up, which in turn can lead to dizziness or fainting. Avoid driving and other hazardous tasks for 12 hours after your first dose or a dosage increase, and be careful to stand up slowly until you're sure the drug won't make you dizzy. If you do become dizzy, sit down until it passes.

Although the problem is extremely rare (affecting perhaps 1 in 50,000) Flomax has been known to cause priapism—a painful, persistent erection unrelated to sexual activity. If you develop this side effect, call your doctor without delay. The condition can lead to permanent impotence if not treated immediately.

Possible food and drug interactions when taking Tamsulosin hydrochloride

If Flomax is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Flomax with any of the following:

Blood pressure drugs classified as alpha-blockers, such as clonidineCimetidineWarfarin

Special information if you are pregnant or breastfeeding

Flomax is for use only by men.

Recommended dosage for Tamsulosin hydrochloride


The recommended starting dose of Flomax is 1 capsule (0.4 milligram) daily, half an hour following the same meal each day. Your doctor may increase the dose to 2 capsules (0.8 milligram) once a day if needed.


Any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical treatment immediately.

  • Symptoms of Flomax overdose may include:Dizziness, fainting, headache