Erectile Dysfunction

Erectile dysfunction is defined as the inability to achieve and maintain an erection sufficient to permit satisfactory sexual intercourse.1 It has been estimated to affect 20 million to 30 million men in the United States.2,3 It may result from psychological, neurologic, hormonal, arterial, or cavernosal impairment or from a combination of these factors. In this article we provide a brief overview of the physiology of erection and the pathophysiology of erectile dysfunction, followed by a discussion of drug treatment for the disorder.Physiology of Penile ErectionPenile erection is a neurovascular event modulated by psychological factors and hormonal status. . . .