Is the Sulfonamide Group of Tamsulosin the Main Factor in the Pathophysiology of Floppy Iris Syndrome?

The 2018 study investigated the pathophysiology of Intraoperative Floppy Iris Syndrome (IFIS), a condition first described in 2005 in patients using alpha-blockers. The drug tamsulosin, a selective alpha-adrenergic receptor antagonist commonly prescribed for benign hyperplasia of the prostate, was found to have the strongest association with IFIS. Other drugs that could lead to IFIS included alfuzosin, doxazosin, terazosin, finasteride, labetalol, mianserin, chlorpromazine, donepezil, and other antipsychotic agents. The researchers analyzed the chemical composition of these drugs and hypothesized that the sulfonamide group in tamsulosin might be a causative factor in IFIS. However, the pathophysiological evaluation of IFIS did not yield clear-cut results.