Effect of oral administration of prostaglandin E1 on erectile dysfunction

To investigate the effect of limaprost, an oral prostaglandin E1 (PGE1) derivative, on erectile dysfunction and to compare the effects of limaprost with a Chinese herbal drug, gosyajinki-gan.

The study comprised 50 consecutive patients with mild erectile dysfunction who showed a good erectile response to intracavernosal injection with 20 micrograms of PGE1. Limaprost was administered to the first 25 patients (30 micrograms three times daily) and gosyajinki-gan (7.5 g three times daily) to the next 25 patients, for 8 consecutive weeks. Patients were evaluated by their ability to achieve vaginal penetration and by a subjective assessment of erectile function (penile rigidity and maintenance of erection) before and after the treatment, using a self-administered questionnaire. Objective measurements (nocturnal penile tumescence, NPT, values) were also evaluated.

Eleven of the 24 patients who received limaprost without interruption and four of the 24 taking gosyajinki-gan succeeded in vaginal penetration; the difference in the positive response rate was significant. The mean increment of NPT was significantly higher with limaprost treatment. However, all positive responders in both groups did not experience a full erection. There were no side-effects in any patient except one in the limaprost group who developed a facial flush. Thus the treatment was mild enough to be tolerated.

Limaprost was more effective for mild erectile dysfunction than was gosyajinki-gan.