Testosterone and erectile function in hypogonadal men unresponsive to tadalafil: results from an open-label...

The study was aimed at investigating the efficacy of tadalafil (Cialis) in combination with transdermal testosterone (Testogel) for the treatment of tadalafil-refractory erectile dysfunction in hypogonadal patients. In an open-label, retrospective trial, 69 hypogonadal nonresponders to tadalafil monotherapy (mean age: 59 years, total testosterone < or =3.4 ng ml(-1)) were randomly divided into two homogeneous groups. Group I (n = 35) received Testogel (5 g containing 50 mg testosterone, daily) for 4 weeks, followed by concurrent therapy with tadalafil (20 mg, twice a week). Group II (n = 34) was assigned to treatment with Testogel (5 g containing 50 mg testosterone, daily) for a duration of 10 weeks before adjunctive therapy with tadalafil was initiated. Total testosterone levels were measured at baseline, week 4 and week 10. Sexual function was assessed employing the International Index of Erectile Function (IIEF). As an additional measure of efficacy, a questionnaire completed by the patients' partner was used. Mean testosterone levels were observed to increase from baseline to study end. Following 4 weeks of therapy, an improvement in Erectile Function (EF) from baseline was observed, which was greater in group I than in group II. The assessment after week 10 showed that EF had further increased and was quite similar now in both groups. Partners found that erectile capacity had greatly improved from baseline to study end. No adverse effects have been observed. These data suggest that combination therapy with testosterone and tadalafil is an effective means in a subset of hypogonadal patients who did not respond to tadalafil alone. We assume that testosterone-induced remodelling of penile tissue structure is one underlying reason for the observed improvement of erectile function. The results imply that this process may require a longer period of testosterone administration than 4 weeks.