Side Effects of Quitting Flomax

Flomax (tamsulosin hydrochloride) is an oral medication for treating symptoms of benign prostatic hyperplasia (BPH), also known as an enlarged prostate. It is taken once daily, and is available in 0.4 mg or 0.8 mg tablets. Flomax commonly causes a drop in blood pressure upon standing, dizziness and headaches.

These symptoms can occur at any time during treatment but particularly at the beginning of treatment, when the dose is changed or when the medication is stopped abruptly. The dose of Flomax should always be adjusted slowly, under the advice of a health care provider.

Reasons to Stop Flomax

The use of Flomax may cause a condition known as intraoperative floppy iris syndrome, and can increase the risk of serious postoperative events following cataract surgery. Surgeons may recommend discontinuing Flomax for up to two weeks prior to cataract surgery or may modify the surgical technique to minimise this risk. Some men obtain effective relief from BPH symptoms and choose to discontinue Flomax due to the potential for drug interactions, lifestyle considerations or personal choice. Other men may not be able to tolerate the side effects of Flomax, regardless of symptom relief.

How to Stop Flomax

Flomax should be discontinued slowly, over several days to weeks. The dose should be gradually decreased to avoid side effects, and blood pressure should be monitored closely during the period of discontinuation.

Return of BPH Symptoms

Stopping Flomax may cause the return of symptoms of BPH. These include urinary urgency and frequency, incomplete bladder emptying and a weak urine stream. These symptoms can cause a significant decrease in quality of life. Untreated BPH can also lead to chronic renal failure, recurrent urinary tract infections and bladder stones, as well as other kidney damage.

Cardiovascular Side Effects

Flomax may also cause changes in blood pressure, dizziness or fainting with any change in dose, including discontinuation. Blood pressure should be monitored closely as the dose is discontinued, and care should be taken to avoid activities such as driving, operating machinery or other potentially hazardous activities while the dose is being adjusted.


Flomax is not approved for use in women or children, and the drug should not be used to treat high blood pressure. Do not stop taking Flomax or change the dose unless under the care and supervision of a health care provider.