Flomax (tamsulosin) is an FDA-approved medicine to treat signs and symptoms of benign enlargement of the prostate (benign prostatic hyperplasia), by helping to relax the muscles in the prostate and bladder.1 It is also prescribed to men with multiple sclerosis who suffer from bladder dysfunction.

Bladder disturbances are common in people with MS, and usually include urgency, frequency, incomplete emptying of the bladder, and, sometimes, incontinence. A urinary tract infection should always be excluded, before starting any medication for these symptoms.

Tamsulosin is an alpha-1A-adrenoceptor blocker that selectively blocks nervous stimulation of the receptor, resulting in relaxation of the muscles of the prostate, prostatic urethra, and bladder neck in order to improve the urine flow and reduce symptoms of benign prostatic hyperplasia.2

Because its mechanism of action primarily affects the prostate, tamsulosin is only approved for use in men with MS to promote the flow of urine.1 Tamsulosin is not approved for use in women or children.3

Tamsulosin capsules are to be taken by mouth, initially at a 0.4 mg daily dose, increasing to 0.8 mg once daily if there is no response. Tamsulosin should be taken 30 minutes after the same meal each day.2

Common tamsulosin side effects may include dizziness, drowsiness, weakness, nausea and diarrhea, headache, chest pain, decreased amount of semen, back pain, blurred vision, tooth problems, flu symptoms, runny or stuffy nose, sinus pain, sore throat and cough, insomnia and/or decreased interest in sex.3

There are also generic versions available of tamsulosin.4

Read the latest news on bladder dysfunction.

Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.


  1. http://www.nationalmssociety.org/Treating-MS/Medications/Flomax
  2. https://online.epocrates.com/drugs/755/Flomax
  3. http://www.drugs.com/flomax.html
  4. http://www.drugs.com/availability/generic-flomax.html