Priapism is specifically listed in trazodone's FDA prescribing information as a risk. The label instructs that any erection lasting longer than four hours — painful or not — should prompt immediate discontinuation of the drug and emergency medical attention, because delayed treatment can cause permanent damage to erectile tissue.
Priapism
A prolonged, and often painful, erection unrelated to sexual arousal. It is a rare but medically documented risk of trazodone use in men and is considered a medical emergency if it lasts more than four hours.