Purpose: Phosphodiesterase type 5 inhibitors are the first choice therapy in the treatment of erectile dysfunction. Many men in their reproductive years are now using phosphodiesterase type 5 inhibitors. The purpose of this study was to determine the effects of 6 months of treatment with 20 mg vardenafil, compared with 100 mg sildenafil and placebo, on semen characteristics and reproductive hormones in men with and without erectile dysfunction.
Materials and methods: This was a randomized, double-blind, placebo controlled, parallel group, multicenter study. A total of 200 men with or without erectile dysfunction, able to produce semen samples without erectile dysfunction therapy, 25 to 64 years old, were randomized to daily treatment with vardenafil, sildenafil or placebo for 6 months. The primary variable was the percentage of vardenafil treated individuals with a 50% or greater decrease in mean sperm concentration from baseline to 6-month last observation carried forward, compared with placebo treated individuals.
Results: The between group difference (vardenafil minus placebo) in the percentage of patients with 50% or greater decrease in sperm concentration (baseline to 6 months last observation carried forward) was 0.07% (95% CI, -8.53% to 8.39%). Vardenafil also had no clinically significant effects on any other semen parameters, or on levels of reproductive hormones, when compared with placebo. Similar data were observed with sildenafil.
Conclusions: This study demonstrated that vardenafil had no adverse effects on sperm concentration, compared with sildenafil and placebo, when administered daily at the maximum recommended dose for 6 months. Specifically, use of vardenafil for 6 months does not impair sperm concentration, total sperm count per ejaculate, or sperm morphology and motility. Levels of reproductive hormones were also unaffected.