Duration of erection: does it really matter? A randomized, double-blind clinical trial to assess the impact of vardenafil ODT on duration of erection and its correlation with patients' and partners' sexual quality of life and duration of intercourse: the VADEOPEN study.

INTRODUCTION: Stopwatch-assessed duration of erection has been proposed as an objective and reliable efficacy end point for erectile dysfunction (ED) treatments.

AIM: The aim of this study is to assess vardenafil orodispersible tablets' (ODTs) efficacy in terms of duration of erection and (i) its correlation with other efficacy end points and male and female sexual quality of life (QoL) and (ii) its impact on intercourse duration.

METHODS: Randomized, double-blind, placebo-controlled, multicenter study comparing the efficacy and safety of vardenafil ODT 10 mg on-demand over 12 weeks in 127 patients with ED was carried out.

MAIN OUTCOME MEASURES: Primary efficacy end points were stopwatch-assessed duration of erection (min) at any attempt and when leading to successful intercourse, and the erectile function domain of the International Index of Erectile Function (EF-IIEF) score. Secondary end points were sexual encounter profile (SEP) 3 response rate and male sexual QoL. End points in participating women (N = 46) were stopwatch-assessed duration of intercourse and sexual QoL.

RESULTS: At week 12/last observation carried forward, patients taking vardenafil ODT had longer duration of erections (at any attempt or leading to successful intercourse) vs. placebo (least square mean ± standard error 10.2 ± 0.9 minutes vs. 7.9 ± 1.0 minutes, and 10.4 ± 0.8 vs. 8.3 ± 1.0 minutes, respectively), and significant increases in EF-IIEF scores, the SEP-3 response, and all sexual QoL items. An increased duration of intercourse was also observed. Female sexual QoL improved significantly. Both duration end points strongly correlated with EF-IIEF scores, and the three end points correlated well with SEP-3 response. Correlation was good with sexual QoL scores in men and women and with duration of intercourse, with differences between treatment groups only for duration end points. Safety was similar in both groups.

CONCLUSION: This study provides further evidence for the consistency and reliability of the stopwatch-assessed duration of erection as an efficacy end point for ED treatments, with "duration of erection leading to successful intercourse" showing better properties than duration at any attempt.