Relation between intracavernosal dose of prostaglandin Pge 1 and mean duration of erection in men with different underlying causes of erectile dysfunction.

AIM To analyze differences in effect of intracavernosally applied alprostadil (prostaglandin PGE 1) on men with different underlying causes of erectile dysfunction. METHODS Forty eight men with erectile dysfunction lasting for at least six months were stratified according to the etiology of erectile dysfunction into one of 4 groups comprising 12 patients. The groups were the following: psychogenic, arteriogenic, veno-occlusive, and neurological erectile dysfunction group. All men filled out International Index of Erectile Function (IIEF)-5 questionnaire, which is a 5-question version of International Index of Erectile Function Questionnaire, underwent clinical examination including neurological assessment, were tested for nocturnal penile tumescence, and had Doppler color sonography of penile arteries. Intracavernosal alprostadil was then applied to the patients, starting with a 5 mug dose and then increased in 5 microg increments until the final dose of 20 microg was reached. We measured the time from the moment of application until the start of erection and time of erection duration. For statistical analysis, non-parametric Friedman test for significant differences between repeated measurements in small groups and Wilcoxon test for differences between doses were used. RESULTS Significant relation was found between the applied dose of intracavernosal alprostadil and the duration of erection in all 4 groups of men with erectile dysfunction. In patients with arteriogenic erectile dysfunction, mean (+/-standard deviation) duration of erection for consecutive doses of alprostadil 5 microg, 10 microg, 15 microg, and 20 microg were 40.0+/-20.6, 54.6+/-23.6, 65.0+/-29.6, and 82.1+/-35.4 minutes, respectively, with significant increase for each dose. In patients with veno-occlusive dysfunction, mean durations of erection significantly increased from 8.2+/-7.8 minutes at 10 microg to 17.3+/-9.5 minutes at 20 microg. In patients with neurogenic erectile dysfunction, mean durations of erection were 40.4+/-16.6, 61.7+/-24.7, 82.5+/-34.4, and 101.0+/-28.5 minutes respectively, with significant increase for each dose. In patients with psychogenic erectile dysfunction, mean durations of erection were 32.4+/-15.4, 45.8+/-15.1, 69.9+/-23.5, and 98.3+/-37.9 minutes respectively, with a significant increase for each dose. CONCLUSION Men with different underlying cause of erectile dysfunction show different response to the intracavernosally applied alprostadil. In order to achieve the optimal result, the treatment should be started with the smallest doses which are gradually increased until the maximum effect is reached.