Objectives: 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.
Patients and methods: 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.
Results: 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.
Conclusion: Limaprost was more effective for mild erectile dysfunction than was gosyajinki-gan.