The efficacy and safety of tadalafil in United States and Puerto Rican men with erectile dysfunction.

PURPOSE: We evaluate the efficacy and safety of tadalafil, taken as needed, in men with mild to severe erectile dysfunction (ED) and assess sexual intercourse attempt patterns.

MATERIALS AND METHODS: In this multicenter, double-blind, placebo controlled, parallel study conducted in the United States and Puerto Rico 207 men with ED were randomized to placebo or 20 mg tadalafil for 12 weeks. The primary efficacy variables were changes from baseline in the mean International Index of Erectile Function erectile function domain score and mean per patient percentage of "yes" responses to Sexual Encounter Profile (SEP) diary questions 2 (successful penetration) and 3 (successful intercourse). The Global Assessment Question was a secondary end point and post hoc analyses on sexual intercourse attempt patterns were conducted.

RESULTS: Men treated with tadalafil compared with placebo reported greater mean changes from baseline on the erectile function domain score (9.3 vs 0.3 with placebo, p <0.001) and on the mean per patient percentage of successful penetration (SEP question 2, 31.6% vs 2.3% with placebo, p <0.001) and successful intercourse attempts (SEP question 3, 43.6% vs 3.5% with placebo, p <0.001). The per treatment group percentage of successful intercourse attempts during treatment was higher for tadalafil than placebo (67.6% vs 24.1%, respectively, p <0.001) and most successful intercourse attempts occurred between 4 and 36 hours after taking tadalafil. Of the men treated with tadalafil 82.8% reported improved erections versus 19.6% taking placebo (Global Assessment Question, p <0.001). The most common treatment emergent adverse events were headache (15.7% vs 6.3% with placebo), back pain (8.8% vs 0%), and dyspepsia (7.5% vs 0%).

CONCLUSIONS: Tadalafil (20 mg) significantly improved erectile function and patients did not closely temporally link sexual intercourse attempts with taking tadalafil. Tadalafil was also well tolerated in both groups of men with mild to severe ED.