Is there a connection between Flomax and cataracts?

I take Flomax (tamsulosin) to administer my BPH. Advertisements say something about cataract surgery. What is the connection between drugs and cataracts? If I'm taking Flomax, do I actually have to stop having my cataracts removed?

Kevin R. Loughlin, MD, MBA, director of urologic research at Brigham and Women's Hospital, says:

Flomax works by blocking certain cellular receptors, which cause the sleek muscles within the bladder neck and urethra to loosen up. As a result, urine flow improves. Although they should not particularly abundant, these same receptors are present elsewhere within the body, including the iris in your eye. The iris opens and closes to regulate the quantity of sunshine entering the pupil. When the receptors that control the iris are blocked, the pupil constricts.

During cataract surgery, the ophthalmologist removes the cloudy lens, which sits under the iris throughout the lens capsule (see photo). When the pupil is small, the relatively large iris obscures the cataract. The iris also can slip out of its normal position during surgery, making it harder for the ophthalmologist to remove the old lens and insert a brand new one. This condition, called floppy iris syndrome, increases the possibility of complications, including vision loss.

Some researchers recommend that patients on Flomax temporarily stop taking it several days before cataract surgery. However, the good thing about discontinuing the drug has not been proven. Instead, tell your eye surgeon that you simply take this medication. He or she may modify the surgery to scale back the danger of any problems.

Cataracts and Flomax Flomax (tamsulosin) can affect the opening and shutting of the iris, causing the pupil to constrict. If this happens during surgery, or if the iris slips out of position, the surgeon can have a difficult time removing and replacing the lens, which sits underneath it.

Source: Chang DF, Osher RH, Wang L, Koch DD. A prospective multicenter evaluation of cataract surgery in patients receiving tamsulosin (Flomax). Eye diseases 2007; 114:957–64. PMID: 17467530.

Originally published on April 1, 2008; Last reviewed on April 18, 2011.