Introduction. Data from head-to-head clinical trials of phosphodiesterase type 5 (PDE5) inhibitors are scarce, making it difficult for clinicians to differentiate among these agents to select the most appropriate treatment for their patients with erectile dysfunction (ED).
Aim. This randomized, double-blind, crossover head-to-head clinical trial compared patient preference, efficacy, and safety of vardenafil and sildenafil in men with ED and diabetes, hypertension, and/or hyperlipidemia.
Methods. Prospective analysis was performed on two studies in which 1,057 men were randomized to vardenafil 20 mg (N = 530) or sildenafil 100 mg (2 × 50 mg encapsulated tablets) (N = 527) for 4 weeks. Following a 1-week washout, patients switched treatment for 4 weeks.
Main Outcome Measures. Patients were asked about overall preference: “Overall, which medication do you prefer?”, plus 11 other preference questions relating to their ED treatment. Efficacy assessments after each treatment period included the erectile function (EF) domain score of the International Index of Erectile Function (IIEF); Sexual Encounter Profile (SEP) diary questions SEP2 and SEP3; Global Assessment Question (GAQ); and Treatment Satisfaction Scale (TSS). Data regarding adverse events were collected throughout the study.
Results. A total of 931 men (mean age 57.9 years) were included in the intent-to-treat (ITT) population. Non-inferiority of vardenafil over sildenafil was achieved for overall preference (vardenafil 38.9%; sildenafil 34.5%; and no preference 26.6%). Additionally, the change from baseline in the EF domain score of the IIEF achieved nominal significance for vardenafil over sildenafil (10.00 vs. 9.40; P = 0.0052). Patients also had a higher percentage of positive responses for vardenafil for SEP2, SEP3, GAQ, and 12 of 19 questions on the TSS. Both drugs were well tolerated.
Conclusions. This randomized, double-blind, head-to-head trial in ED patients with cardiovascular risk factors demonstrated noninferiority of vardenafil for overall preference. Vardenafil achieved nominal statistical superiority over sildenafil for several frequently used efficacy measures. Both drugs were well tolerated. Rubio-Aurioles E, Porst H, Eardley I, and Goldstein I for the Vardenafil–Sildenafil Comparator Study Group. Comparing vardenafil and sildenafil in the treatment of men with erectile dysfunction and risk factors for cardiovascular disease: A randomized, double-blind, pooled crossover study. J Sex Med 2006;3:1037–1049.