Flomax

Flomax Overview

Flomax (generic: tamsulosin) is a prescription medication used to treat the symptoms of enlarged prostate, known medically as benign prostatic hyperplasia (BPH). Flomax belongs to a group of drugs called alpha blockers. Unlike other BPH medicines, Flomax does not shrink the prostate. It works by relaxing the muscles in the bladder and prostate so urine can flow easily.

This medication comes as a capsule that is taken by mouth once a day. It should be taken 30 minutes after the same meal each day. 
  
Common side effects of Flomax include runny nose, dizziness, and decreased semen.

Uses of Flomax

Flomax is a prescription medication used to treat the symptoms of enlarged prostate, known medically as benign prostatic hyperplasia (BPH).

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

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
       
  • 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 surgery. During cataract 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 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. 

Flomax Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you are taking:

  • Uroxatral (alfuzosin)
  • Cardura (doxazosin)
  • Minipress (prazosin)
  • Hytrin (terazosin)
  • Coumadin (warfarin)
  • Tagamet (cimetidine)
  • Viagra (sildenafil)
  • Cialis (tadalafil)
  • Levitra (vardenafil)

This is not a complete list of Flomax drug interactions. Ask your doctor or pharmacist for more information.

Flomax Precautions

Do not take Flomax if you are allergic to any of the ingredients in Flomax. Tell your doctor if you are allergic to sulfa medicines.

Do not take Flomax with Uroxatral (alfuzosin), Cardura (doxazosin), Minipress (prazosin), Rapaflo (silodosin), or Hytrin (terazosin).

Tell your doctor if you have had prostate cancer. Your dose may need to be adjusted or special tests may be required.

Tell your doctor if you have liver or kidney problems.

If you are going to have cataract surgery, tell your surgeon that you are taking Flomax.

Flomax may make you dizzy or drowsy. Do not drive a car or operate machinery until you know how this medicine affects you.

Flomax may cause lightheadedness, dizziness, and fainting, especially when you get up too quickly from a lying position. Rest your feet on the floor for a few minutes before standing up and getting out of bed. 

 

Flomax Food Interactions

Grapefruit and grapefruit juice may interact with Flomax and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.
 

Inform MD

Before taking Flomax, 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 surgery.

Tell your doctor about all the medicines you take including any prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take other alpha blocker medicines, anticoagulants ("blood thinners") such as warfarin, cimetidine, or medicines for erectile dysfunction (ED).

Although Flomax is most often prescribed for men, it may be prescribed under certain circumstances for women. Flomax should not be taken if you are pregnant or breastfeeding. Tell your doctor if you become pregnant while using Flomax.

Flomax and Pregnancy

Tell your doctor if you are pregnant or planning to become pregnant. It is not known if Flomax will harm your unborn baby.

Flomax and Lactation

Tell your doctor if you are breastfeeding or planning to breastfeed. It is not known if Flomax will harm your nursing baby.

Flomax Usage

  • 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.

Flomax Dosage

Take Flomax exactly as your doctor prescribes it. Follow the directions on your prescription label carefully

For the treatment of the signs and symptoms of BPH (benign prostatic hyperplasia) the recommended dose of Flomax is 0.4 mg once a day. The dose may be increased to 0.8 mg once a day (2 capsules). Your doctor will determine the best dose for you.

Flomax Overdose

If you take too much Flomax call your doctor or local Poison Control Center right away.

Forms of Flomax

Flomax is available in 0.4 mg strength capsules. 

  • Active Ingredient: tamsulosin hydrochloride
  • Inactive Ingredients: methacrylic acid copolymer dispersion, NF; microcrystalline cellulose, NF; triacetin, USP; calcium stearate, NF; talc, USP; FD&C blue No. 2; titanium dioxide; ferric oxide; gelatin, and trace amounts of black edible ink.

Other Requirements

  • Store Flomax capsules at room temperature [77°F (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.

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Reviewed by: 
Beth Bolt, RPh
Last Updated:
February 26, 2013