Risk factors for papaverine-induced priapism.

Intracorporeal administration of papaverine hydrochloride is frequently used in the diagnosis and treatment of impotence. Priapism is the most serious potential complication of its use. The historical characteristics of 400 consecutive men receiving a standardized dose of papaverine were reviewed in an effort to determine the risk factors for prolonged erections. Younger men (p less than 0.0001) with better baseline erectile function (p less than 0.023) were more likely to have priapism. Despite use of a significantly lower dose, patients with overt neurological disease also had an increased rate of priapism. Patients with a history of coronary artery disease had a significantly lower risk of priapism (p less than 0.05). Patients with a final diagnosis of either psychogenic or neurogenic impotence had a much greater risk of priapism than those with vasculogenic impotence (p less than 0.001). The initial dosage in pharmacological erection therapy may be adjusted according to these risk factors. However, not all patients with psychogenic or neurogenic impotence had priapism and some patients with vascular disease did have priapism. Therefore, all impotent patients are potentially at risk for pharmacologically induced priapism.