Comparison of the Efficacy, Safety and Patient Preference of the Phosphodiesterase Type 5 Inhibitors for the Patients with Erectile Dysfunction

Abstract

Purpose: To compare the clinical efficacy and safety of three phosphodiesterase type 5 (PDE5) inhibitors in the treatment of mele erectile dysfunction according to patient preference. Materials and Methods: Between January 2004 and August 2005, 113 male erectile dysfunctional patients were enrolled to this randomized, prospective, comparative, open-label, triple-crossover study of three PDE5 inhibitors. Patients were assigned to one of six medication schedules, and were prescribed a full dose of the drugs for 8 weeks, with a week of washout period prior to the next drug cycle. The International Index of Erectile Function (IIEF) scores and side effects related with each medication were obtained at the end of study. 48 patients finished all the medications, and completed the study with a global assessment questionnaire on their drug preference and reasons for that preference. Results: The mean age of the patients was 54.6 (33-73) years. The mean pre-treatment IIEF and EF domain scores (±S.D.) were 28.2±14.7 and 10.6 ±6.6, respectively. The scores were significantly improved, to 47.9±14.6 and 19.9±6.6 with sildenafil, to 49.7±12.3 and 21.3±5.8 with vardenafil, and to 47.9±14.9 and 19.8±7.2 with tadalafil (p<0.01). There were no significant differences in the scores or frequencies of side effects between the drugs. The preference percentages were 29.2, 29.2 and 35.4% for sildenafil, vardenafil and tadalafil, respectively. Patient preference was mainly due to improvement in erectile function (70.9%), such as rigid erection, prolonged erection and fast erection, and not to the infrequent rate of side effects (20.8%). Conclusions: There were no significant differences of the efficacy and safety among the three PDE5 inhibitors. The preference for a drug for the treatment of erectile dysfunction was mainly related to the efficacy on the improvement of erectile function rather than the less frequent side effects. (Korean J Urol 2007;48:219-225)