The US Food and Drug Administration (FDA) first became aware of this bizarre potential side effect back in April, when a 44-year-old man suffered sudden and profound hearing loss in both ears after taking Viagra (sildenafil citrate) for just over two weeks.
Fast forward six months and the FDA has now uncovered 29 reports of sudden hearing loss associated with phosphodiesterase type 5 (PDE5) inhibitors, the class of drugs to which Viagra belongs.
Although no one has proved that the drugs directly cause hearing loss, the association is strong enough to have prompted the FDA to insist the drugs’ labels should be changed to warn of the potential risk “more prominently”.