An attempt to standardize the pharmacological diagnostic screening of vasculogenic impotence with prostaglandin E1.

The response to the intracavernosal injection of differing doses of prostaglandin E1 (PGE1)(10, 20 and 30 micrograms) was compared in a randomized prospective manner in 283 men with chronic impotence, in an attempt to identify the optimal drug dose for pharmacological diagnosis. The mean age of patients studied was 63.1 years, and comprised 90 men with arteriogenic impotence, 133 men with either pure venogenic impotence or venous leakage associated with arteriogenic impotence, and 60 men with psychogenic impotence. Erectile responses were quantified using real-time RigiScan monitoring and were compared to a diagnosis based on the patient history, examination findings and all subsequent investigations. In patients with arteriogenic impotence, correct pharmacological diagnosis with doses of 10, 20 and 30 micrograms of PGE1, was made in 71, 89 and 90% of patients respectively. In patients with venous leakage, correct pharmacological diagnosis with doses of 10, 20 and 30 micrograms of PGE1 was made in 95, 95 and 93% of patients respectively. In patients with psychogenic impotence, correct pharmacological diagnosis with doses of 10, 20 and 30 micrograms of PGE1 was made in 72, 95 and 98% of patients respectively. This study indicates that pharmacological diagnosis with PGE1, is a useful screening test to differentiate penile vascular disease from psychogenic impotence and arteriogenic impotence from cavernosal venous leakage, achieves optimal sensitivity and specificity with doses of 20 micrograms or greater, but is associated with a high false diagnosis rate of diagnosis of penile vascular disease if doses of less than 20 micrograms are used.