Pilot study of the transdermal application of testosterone gel to the penile skin for the treatment of hypogonadotropic men with erectile dysfunction

Abstract

Androgens influence important central and peripheral mechanisms of the erectile system. The relevance of a moderate decrease of serum testosterone level for erectile dysfunction (ED) has not been clarified so far. The aim of our study was to offer an easy transcutaneous method of androgen application. A previous study on the pharmacokinetic profile of the testosterone gel applied, showed marked elevation of the serum levels of testosterone. In our study, 46 hypogonadal patients with ED and total lack of vaginal penetration applied testosterone gel (4 mg/day; supplied by Azupharma, Germany) to the penile skin twice a day over 6-8 weeks, after a run-in period with placebo gel of 2 weeks. All patients showed decreased testosterone serum levels (<3 ng/ml) in at least two morning samples over a period of 3 weeks before treatment. Psychogenic etiology was excluded by a sexual psychologist. Patient age was 37-69 years (mean 53.5). Three patients (6.5%) responded to placebo in the run-in phase and were withdrawn from further treatment. Fifteen patients (32.6%) showed improved erection, allowing penetration and sexual intercourse. Twenty-eight patients (60.9%) did not respond to therapy. Local genital skin irritation was not observed. Elevation of peripheral testosterone was not correlated to a positive therapy response. A success-rate of 32.6% in this group of patients after exclusion of psychogenic patients and placebo-responders seems to justify further investigations. A medication period of 6-8 weeks is most probably too short to induce imaginable regenerative effects of testosterone on the erectile system. We therefore suggest that future double-blind and placebo-controlled studies should be designed for a minimum of 3 months. Testosterone gel may be a cost effective form of androgen administration.

Transdermal testosterone gel increases serum testosterone levels in hypogonadal men in Taiwan with improvements in sexual function

“…To date, other such studies have been performed on American 1,2,5,7,8,11 and German men. 15 In the United States, the Testosterone Gel Study Group 5,7,8 evaluated 163 American hypogonadal men for up to 42 months; for the first 6 months, the study was a randomized, parallel trial of two doses of TTG and a transdermal patch; this was followed by 36 months of open-label study of TTG. Sexual function improved rapidly with TTG treatment, and changes were maintained throughout the 42-month study period.…”

“…Compared with placebo, the gel significantly improved spontaneous erections, sexual desire and sexual motivation. In Germany, Schultheiss et al 15 performed a pilot study of 46 hypogonadal men with ED for 6-8 weeks and reported a 32.6% success rate with improved erection.…”

“…However, there was no placebo control in this study. The German pilot study 15 had neither a placebo control group nor used IIEF scores to measure sexual function.…”

“…8,15 However, most of the events were short-term potentially drug-related and were transient with spontaneous recovery. No drug-related AEs was found in the TTG group.…”

“…14 Applied over a large area of skin in an open system, TTG is associated with minimal (B5.5%) skin irritation. 1,2,7,8,11,[13][14][15] The purpose of the present study was to evaluate the efficacy and safety of 50 mg/day of TTG, applied on non-scrotal skin, for hypogonadal men in Taiwan. Although TTG has been shown to be effective in Caucasian men, there are little data regarding its efficacy in Asian population.…”