Generic Name: tamsulosin (tam soo LOE sin)
Brand Name: Flomax
What is tamsulosin?
Tamsulosin 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 approved for use in women or children.
Tamsulosin may also be used for purposes not listed in this medication guide.
What is the most important information I should know about tamsulosin?
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
What should I discuss with my healthcare provider before taking tamsulosin?
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.
Tamsulosin is not approved for use by anyone younger than 18 years old.
How should I take tamsulosin?
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 tamsulosin capsule. Swallow it 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.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
If you miss your doses for several days in a row, contact your doctor before restarting the medication.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking tamsulosin?
Tamsulosin may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.
Dizziness or severe drowsiness can cause falls, accidents, or severe injuries.
To prevent dizziness, avoid standing for long periods of time or becoming overheated during exercise and in hot weather.
Drinking alcohol can increase certain side effects of tamsulosin.
Tamsulosin side effects
Get emergency medical help if you have signs of an allergic reaction: hives, rash, itching; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using tamsulosin 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 side effects may include:
dizziness, drowsiness, weakness;
headache, chest pain;
abnormal ejaculation, decreased amount of semen;
fever, chills, body aches, flu symptoms;
runny or stuffy nose, sinus pain, sore throat, cough;
sleep problems (insomnia); or
decreased interest in sex.
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.
See also: Side effects (in more detail)
Tamsulosin dosing information
Usual Adult Dose for Benign Prostatic Hyperplasia:
Initial Dose: 0.4 mg orally once a day
Maximum Dose: 0.8 mg orally once a day
-If use is discontinued or interrupted for several days at either the 0.4 mg or 0.8 mg dose, treatment should be initiated again with the 0.4 mg once a day dose.
Use: Treatment of the signs and symptoms of benign prostatic hyperplasia (BPH)
What other drugs will affect tamsulosin?
Tell your doctor about all medicines you use, and those you start or stop using during your treatment with tamsulosin, especially:
blood pressure medicine.
This list is not complete. Other drugs may interact with tamsulosin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
More about tamsulosin
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Images
- Drug Interactions
- Support Group
- Pricing & Coupons
- En Español
- 220 Reviews – Add your own review/rating
- Drug class: antiadrenergic agents, peripherally acting
Other brands: Flomax
Related treatment guides
Where can I get more information?
- Your pharmacist can provide more information about tamsulosin.
- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2012 Cerner Multum, Inc. Version: 8.01.
Date modified: March 15, 2017
Last reviewed: December 18, 2014