Which medication is associated with intraoperative floppy iris syndrome during cataract surgery?

Tamsulosin, commonly known by the brand name Flomax, is associated with intraoperative floppy iris syndrome (IFIS) during cataract surgery. This phenomenon occurs because tamsulosin is an alpha-1 adrenergic antagonist that selectively blocks alpha-1A receptors in the smooth muscle of the prostate and bladder neck, but also affects the iris dilator muscle in the eye.

When patients taking tamsulosin undergo cataract surgery, the irritation caused by the medication can lead to characteristics such as a floppy iris that does not fully dilate, making the procedure more challenging. Surgeons may encounter greater difficulty controlling the iris during surgery, which can increase the risk of complications.

The other medications listed do not have a similar association with IFIS. Doxazosin, another alpha-1 blocker, is less likely to cause this syndrome. Atenolol and propranolol, which are beta-blockers, do not influence the iris muscle in the same way that drugs targeting alpha receptors do. Therefore, the effect observed during cataract surgery is specifically linked to tamsulosin.