[Risperidone-induced priapism].

Priapism or pathological, prolonged erection, is a rare adverse effect sometimes associated with psychotropic medication and is due to alpha adrenergic receptor blockade. Priapism in a 44-year-old mental patient receiving risperidone is described. Urinary retention was relieved by catheterization, followed by saline irrigations. Priapism was relieved when a hematoma was evacuated from his penis. This may be the first description of priapism following risperidone alone, since a previous report included a patient receiving risperidone together with 2 other psychotropic medications. Priapism should be looked for in men receiving risperidone, a novel antipsychotic medication.