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Generic name: tamsulosin hydrochloride

What is Flomax?

Flomax is a prescription alpha-blocker medicine used to treat the signs and symptoms of benign prostatic hyperplasia (BPH), a condition your doctor may refer to as an enlarged prostate.

  • Flomax is not for women.
  • Flomax is not for children.

Who should not take Flomax?

Do not take Flomax capsules if you are allergic to any of its ingredients. See the end of this leaflet for a complete list of ingredients in Flomax capsules.

What should I tell my healthcare provider before taking Flomax?

Before taking Flomax capsules, tell your doctor about all your medical conditions, including:

  • any kidney or liver problems.
  • any history of low blood pressure.
  • any allergies to sulfa or any other medicines.
  • if you are planning to have cataract or glaucoma surgery.

Tell your doctor about all the medicines you take, including:

  • any prescription medicines, including blood pressure medicines.
  • any non-prescription medicines, including vitamins and herbal supplements.

Some of your other medicines may affect the way Flomax capsules work. Especially tell your doctor if you take a medicine for high blood pressure. You should not take Flomax if you are already taking certain blood pressure medicines.

Know the medicines you take. Keep a list of them and show it to your doctor and pharmacist when you get a new medicine.

How should I take Flomax?

  • Take Flomax exactly as prescribed by your doctor.
  • Do not crush, chew, or open Flomax capsules.
  • Take Flomax one time each day, about 30 minutes after the same meal each day. For example, you may take Flomax 30 minutes after dinner each day.
  • If you miss a dose of Flomax, take it as soon as you remember. If you miss your dose for the whole day, continue with your next dose on your regular schedule. Do not take two doses at the same time.
  • If you stop or forget to take Flomax for several days, talk with your doctor before starting again.
  • If you take more Flomax capsules than prescribed, call your doctor right away.

What should I avoid while taking Flomax?

  • Avoid driving, operating machinery, or other dangerous activities, until you know how Flomax affects you.
  • Flomax capsules may cause a sudden drop in blood pressure upon standing, especially after the first dose or when changing doses.
  • See “What are the possible side effects of flomax capsules?"

What are the possible side effects of Flomax?

Possible side effects of Flomax may include:

  • Decreased blood pressure when changing positions. Flomax capsules may cause a sudden drop in blood pressure upon standing, especially after the first dose or when changing doses. Symptoms may include:
    • fainting
    • dizziness
    • lightheadedness

Change positions slowly from lying down to sitting up or from a sitting to a standing position until you learn how you react to Flomax capsules. If you begin to feel dizzy, sit or lie down until you feel better. If the symptoms are severe or do not improve, call your doctor.

  • Allergic reactions. Make your doctor aware of any allergic reactions you may experience while taking Flomax. Allergic reactions may include:
    • rash
    • itching
    • hives
  • Rare and more serious allergic reactions may also occur. Get medical help right away if you have any of the following reactions:
    • swelling of face, tongue, or throat
    • difficulty breathing
    • blistering of the skin
  • Priapism - a painful erection that will not go away. Flomax capsules can cause a painful erection (priapism), which cannot be relieved by having sex. If this happens, get medical help right away. If priapism is not treated, you may not be able to get an erection in the future.
  • Eye problems during cataract or glaucoma surgery. During cataract or glaucoma surgery, a condition called intraoperative floppy iris syndrome (IFIS) can happen if you take or have taken Flomax capsules. If you need to have cataract or glaucoma surgery, be sure to tell your surgeon if you take or have taken Flomax capsules.

Common side effects of Flomax capsules may include:

  • runny nose
  • dizziness
  • decreased semen

These are not all the possible side effects with Flomax capsules. Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088, or by visiting

General information about the safe and effective use of Flomax

This medicine was prescribed for you by your doctor for your condition. Do not use it for another condition. Do not give Flomax to other people, even if they have the same symptoms that you have. It may harm them.

While taking Flomax, you must have regular checkups. Follow your doctor's advice about when to have these checkups.

BPH can occur with other more serious conditions, including prostate cancer. Therefore, ask your doctor about screening for prostate cancer prior to treatment with Flomax capsules and at regular intervals afterwards.

This patient information guide summarizes the most important information about Flomax. If you would like more information, talk with your doctor. You can ask your pharmacist or doctor for information about Flomax that is written for health professionals. For current prescribing information, access or call sanofi-aventis U.S. LLC at 1-800-633-1610.

How should I store Flomax?

Store Flomax capsules at Room Temperature 68°F to 77°F (20°C to 25°C). Short-term exposure to higher or lower temperatures (from 59°F [15°C] to 86°F [30°C]) is acceptable. Ask your doctor or pharmacist if you have any questions about storing your capsules.

Keep Flomax capsules and all medicines out of the reach of children.

What are the ingredients in Flomax?

Active Ingredient: tamsulosin hydrochloride

Inactive Ingredients: microcrystalline cellulose; methacrylic acid copolymer dispersion; triacetin; calcium stearate; talc; gelatin; iron oxide; FD&C blue No. 2; titanium dioxide; propylene glycol; and shellac.

Source: National Library of Medicine. Last updated April 16, 2019.