Effect of nightly versus on-demand vardenafil on recovery of erectile function in men following bilateral nerve-sparing radical prostatectomy.

BACKGROUND To date, no data have been available from large, well-designed trials comparing on demand and nightly dosing of phosphodiesterase type 5 (PDE5) inhibitors on recovery of erectile function in postprostatectomy patients with erectile dysfunction (ED). OBJECTIVE To investigate the effect of early postoperative dosing with vardenafil, administered either nightly or on demand, compared with placebo on recovery of erectile function in men with ED following bilateral nerve-sparing radical prostatectomy (NSRP) surgery. DESIGN, SETTING, AND PARTICIPANTS A randomised, double-blind, double-dummy, multicentre, parallel group study conducted at 87 centres across Europe, Canada, South Africa, and the United States. For inclusion, patients had to be scheduled to undergo bilateral NSRP within 1 mo of screening and have a normal International Index of Erectile Function erectile function domain (IIEF-EF) score of > or =26 at screening. A total of 628 men, aged 18-64 yr, were randomised to treatment. Study design consisted of a 9-mo double-blind treatment period, a 2-mo single-blind washout period, and an optional 2-mo open-label period. INTERVENTION Patients received placebo, nightly vardenafil, or on demand vardenafil. MEASUREMENTS Primary outcome measure was the percentage of subjects with an IIEF-EF score of > or =22 after the 2-mo washout period. Secondary variables included mean per-patient success rates for Sexual Encounter Profile (SEP) questions 2 and 3. RESULTS AND LIMITATIONS No statistically significant differences were observed among treatment groups in the proportion of patients with an IIEF-EF score of > or =22 or in SEP3 success rates after the washout period. On-demand vardenafil treatment resulted in significantly greater IIEF-EF scores and better SEP3 response rates than placebo over the entire treatment period. CONCLUSIONS In this study of men with ED following bilateral NSRP, vardenafil was efficacious when used on demand, supporting a paradigm shift towards on demand dosing with PDE5 inhibitors in this patient group. TRIAL REGISTRATION European clinical trials database (EudraCT; available at http://eudract.emea.europa.eu/). TRIAL REGISTRATION NUMBER 11336.