Overview Assess the Effect of Daily Treatment of Vardenafil 20mg or Sildenafil 100mg and Placebo on Sperm Function Status: Completed Trial end date: 2006-06-01 Target enrollment: Participant gender: Summary Assess the effect of daily treatment of vardenafil 20mg or sildenafil 100mg and placebo on sperm function Phase: Phase 4 Details Lead Sponsor: BayerTreatments: Sildenafil CitrateVardenafil Dihydrochloride