Introduction: Vardenafil, a potent and selective oral PDE5 inhibitor, is efficacious and generally well-tolerated in men with erectile dysfunction (ED). Of considerable interest to patients and physicians is an understanding of the time required after dosing to attain penile erection sufficient for successful sexual intercourse.
Aim: To determine the earliest time to onset of action of vardenafil 10 and 20 mg leading to successful intercourse compared to placebo in men with ED.
Methods: A prospective, randomized, double-blind, parallel-group, at-home study of 732 men with ED (mean age 55.5 years) was conducted at 64 sites in North America and Europe. Following a 4-week run-in period, patients were randomized to either vardenafil 10 (N = 237) or 20 mg (N = 248) or placebo (N = 247) to be taken on demand over 4 weeks. Using a stopwatch, patients recorded the elapsed time from dosing to attainment of an erection perceived to be adequate for penetration that led to intercourse completion. Earliest time of onset was defined as the fastest time among the first four doses for each patient. Time points from 25 to 5 minutes were tested for significance (alpha = 0.025) using a backward stepping procedure.
Results: Mean baseline erectile function domain score (13.4) indicated moderate ED. Within 25 minutes after dosing, 50%/53% of men on vardenafil 10/20 mg had at least one erection in the first four doses perceived to be sufficient for penetration with subsequent intercourse completion compared to 26% on placebo (P < 0.0001). A statistically superior response to vardenafil vs. placebo was observed in these responders at all times >or= 10 and >or= 11 minutes (P < 0.025) in the 10 and 20 mg groups, respectively. In a retrospective analysis using time intervals of <or= 15, <or= 20, <or= 25 and <or= 30 minutes between dosing and erection adequate for penetration, 75-77% of these intercourse attempts were successful (SEP3 positive) by patients receiving vardenafil 10/20 mg, compared to 45-47% of attempts by those who received placebo. Vardenafil 10/20 mg was generally well-tolerated with headache (7%/12% vs. 1%) and flushing (6%/9% vs. < 1%) reported more frequently than with placebo. No patient discontinued vardenafil therapy due to adverse events.
Conclusion: In this large, at-home study, the onset of action of vardenafil with subsequent intercourse completion was recognized as early as 10 minutes after dosing.