¹Department of Urology, Massachusetts General Hospital, Boston, MA, USA

Correspondence: P Gomery, Department of Urology, Massachusetts General Hospital, 55 Fruit Street, GRB 1102, Boston, MA 02114, USA. E-mail: pgomery@partners.org

Received 1 December 2005; Revised 7 March 2006; Accepted 22 March 2006; Published online 18 May 2006.

Abstract

To show that tadalafil is efficacious in Black American and Hispanic men with erectile dysfunction (ED) and efficacy is noninferior to that in Caucasian men. Multiple observations in men with ED in national tadalafil study in the US, a multicenter, open-label study, assessed the efficacy of tadalafil 20 mg taken as needed (maximum one dose/day before sexual activity) for 12 weeks by patients with ED in various populations. This analysis focuses on three groups: Caucasian (Reference group), Black American, and Hispanic men. Primary measurement of efficacy was change from baseline in erectile function (EF) domain of the International Index of Erectile Function (IIEF) and the primary analysis was whether efficacy in Black American and Hispanic groups was noninferior to efficacy in the Caucasian group. Secondary efficacy measures included sexual encounter profile (SEP), IIEF intercourse satisfaction (IS) and overall satisfaction (OS) domains, Global Assessment Question (GAQ), and Psychological and Interpersonal Relationship Scale (PAIRS). Safety was assessed from adverse events (AEs) reported by all enrolled patients. The increase in IIEF EF domain score (9.5) from baseline for each group was statistically significant (P<0.001) and clinically relevant. Efficacy of tadalafil in Black American and Hispanic patients was noninferior to the Caucasian group. IS and OS domains of IIEF had a statistically significant increase from baseline (P<0.001). Change from baseline in positive responses to SEP questions for each group was significant (P<0.001). At least 77% of intercourse attempts were successful over various time intervals up to 36 h postdose. At least 88% of patients in the various groups had a positive response to GAQ1. Improvement from baseline in Sexual Self-Confidence and Spontaneity domains of PAIRS was statistically significant (P<0.001). A low number of AEs and a low AE-related discontinuation rate (2.3%) were reported in all groups. Tadalafil 20 mg was as efficacious in Black American and Hispanic men with ED as in Caucasian patients and was well tolerated.