A double-blind, placebo-controlled, efficacy and safety study of topical gel formulation of 1% alprostadil (Topiglan) for the in-office treatment of erectile dysfunction

Abstract

Objectives. To asses the efficacy and safety of Topiglan (1% alprostadil in a formulation with 5% SEPA [soft enhancer of percutaneous absorption]) or placebo gel (0.25 mL) applied to the glans penis only in 60 patients with moderate to severe erectile dysfunction in a two-visit, in-office clinical trial. Methods. During the first visit, open-label placebo gel was applied. At the second visit, blind, random allocation to Topiglan (n = 31) or placebo gel (n = 29) occurred. Thirty minutes after application, an erotic movie showing heterosexual sex began; at 45 minutes, a penile vibrator was used. Audiovisual and tactile stimulation were discontinued at 65 minutes, and the patient was observed until 90 minutes after application. At the scheduled time points, the erection response was assessed by both the investigator and the patient and signs and symptoms of tolerance were evaluated. Results. Topiglan produced a greater angle of erection ( P = 0.003) and maximum rigidity ( P = 0.033) compared with the placebo gel. The responses to Topiglan were greater than to placebo gel at all time points after application, with the greatest differences observed at 45 and 60 minutes. Of the 31 patients treated with Topiglan, 12 (38.9%) achieved an erection judged sufficient for vaginal penetration ( P = 0.005); 2 (6.9%) of the 29 patients who received placebo gel did so. Penile erythema was more common with Topiglan; symptoms of minor to mild warmth or burning and, less commonly, tingling and coolness were reported by most patients after both Topiglan and placebo gel application. No significant changes in vital signs were noted. Conclusions. Topiglan applied to the glans penis increased penile rigidity and expectations regarding vaginal penetration in patients with erectile dysfunction.