A double blind, placebo controlled study of intracavernosal vasoactive intestinal polypeptide and phenotolamine mesylate in a novel auto-injector forthe treatment of non-psychogenic erectile dysfunction

Three hundred and four patients with non-psychogenic erectile dysfunction ( ED) completed a dose assessment phase with intracavernosal injection utiliz ing 25 mu g vasoactive intestinal polypeptide (VIP) combined with phentolam ine mesylate 1.0 mg (VIP/P-1) or 2.0 mg (VIP/P-2) in an auto-injector for a response rate of 83.9%. In a sub-group of 183 patients who withdrew from o ne or more previous ED therapies, 82% responded with an erection suitable f or intercourse. One hundred and ninety-five patients were subsequently trea ted in a placebo controlled phase. 75.1% responded to VIP/P-1, 12% to place bo (P < 0.001); 66.5% responded to VIP/P-2, 10.3% to placebo (P<0.001), wit h the median duration of erection of 54 min. The principal adverse event wa s transient facial flushing in 2770 injections (33.9%). There was no pain p ost injection and two episodes of priapism (0.05%). Only nine patients with drew because of adverse events. Over 85% and 95% of patients were satisfied with the drug and auto-injector, respectively. Over 81% of patients and 76 % of partners reported an improved quality of life.