Return of spontaneous erection during long-term intracavernosal alprostadil (Caverject) treatment

To investigate the effect of long-term intracavernosal self-injection of alprostadil (Caverject) on the penile circulation and return of spontaneous erection in men with arteriogenic erectile dysfunction.

Seventy men with a stable heterosexual partner entered the titration phase of this open-label, flexible-dose study. The effective alprostadil dose (ie, the dose producing penile rigidity adequate for intercourse and lasting up to 60 minutes) was determined before entry into the 12-month self-treatment home phase. Duplex ultrasonography was used to measure the peak systolic velocity and diameter of the cavernosal arteries at the end of the titration phase and after 4, 8, and 12 months of the home phase. The efficacy, tolerability, and return of spontaneous erections were assessed from the patients' diaries and by interview at each clinic visit. Sixty-three men entered the home phase; 49 of them filled out the diaries and 42 completed the study.

An effective dose was established for 67 (96%) of the 70 men (median dose 15 microg). During the home phase, 94% of men responded to alprostadil, and the median dose remained unchanged. Complete duplex ultrasound data were obtained in 38 men and showed significant increases in postinjection peak systolic velocity in both cavernosal arteries (P <0.001 at 12 months) and between the preinjection and postinjection cavernosal arterial diameters (P = 0.0001) compared with baseline. Reports of a return of spontaneous erections increased throughout the study compared with baseline (37%, 26 of 70) and were confirmed by interview for 46 (85%) of 54 men with available data overall. Treatment was generally well accepted, with low incidences of penile pain (23%), prolonged erection, which resolved spontaneously (6%), and fibrosis (1%).

Intracavernosal alprostadil was effective, acceptable, and generally well tolerated in men with arteriogenic erectile dysfunction. Long-term treatment improved the penile circulation, and most men reported an increase in return of spontaneous erections.