Prescription drug · Used for an enlarged prostate

Tamsulosin (Flomax) side effects

This side effect is printed on the FDA label for Tamsulosin. It was a question in our daily quiz, where you pick the real side effect from four choices.

A floppy iris during eye surgery

It can happen even if you've stopped taking it. The iris goes limp, which makes cataract surgery harder.

From the FDA label

“During cataract or glaucoma surgery, a condition called intraoperative floppy iris syndrome (IFIS) can happen if you take or have taken tamsulosin hydrochloride capsules.”

Tamsulosin label, updated Sep 1, 2026 · Read the full label on DailyMed

What to watch for

Tell your eye surgeon if you take or have ever taken it. Get help for an erection that lasts more than 4 hours.

8 reports to the FDA's adverse event system mention floppy iris syndrome. A report is not proof the drug caused it. See the query

From quiz No. 8 · October 2, 2026 · Play that quiz →

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Not medical advice. Don't stop or start a medication because of a quiz. Talk to your doctor or pharmacist. Label text and report counts from openFDA. Not affiliated with any drug maker.