Suddenly losing your hearing with no warning is a terrifying prospect, and that’s been a known side effect of erectile dysfunction drugs Viagra and Levitra for almpst a decade, with the Food and Drug Administration publishing a warning about a possible link back in 2007. A new analysis by the Institute for Safe Medication Practices shows that while hearing loss is a very rare side effect, it is much more likely to happen when taking either of these medications.

While the best-known use of phosphodiesterase 5 (PDE5) inhibitors is as a treatment for erectile dysfunction, they’re also used to treat pulmonary hypertension. The ISMP combed through incident reports in the FDA’s Medwatch database, and found that out of 50,879 cases reporting issues with the drugs, there were 214 reports of sudden hearing loss.

That’s a tiny fraction, but the number of people taking PDE5 inhibitors who reported hearing loss was 21.5 times higher than the number of people reporting sudden hearing loss who were otherwise comparable to the PDE5 inhibitor patients.

According to the 2007 report, by the way, patients who reported hearing loss almost all said that it was only one-sided, and at least one-third of cases resolved on their own.

QuarterWatch – April 6, 2016 — Data from 2015 Quarter 3 [ISMP]