Association of Priapism in Phenothiazine Therapy

Abstract

Four patients seen in the last 5 yr who had taken thioridazine (Mellaril) prior to development of priapism are presented. One of the 4 patients suffered penile trauma while taking the phenothiazine drug and this is another possible etiologic factor in that case. No underlying urologic or hematologic disorders were present. All patients were treated by corporeal aspiration and corpus cavernosum-corpus spongiosum shunts. The mechanism of phenothiazine-induced priapism is hypothesized as being related to its peripheral adrenergic blockade, perhaps directly blocking the sympathetic impulse for detumescence, although a CNS effect must be considered as well. The possibility of coincidence also exists, since phenothiazine treatment is becoming more common and was unrelated to the condition in an additional 6 patients with priapism seen during the same period.