Objective: To assess the efficacy and safety of daily tadalafil, a potent selective phosphodiesterase 5 inhibitor, for the treatment of erectile dysfunction (ED) in men previously unresponsive to on-demand tadalafil.
Materials and methods: A total of 112 men with a mean age of 63 (range 21-79) and moderate to severe ED of various aetiologies were treated with tadalafil, taken on a daily basis at flexible daily doses of 10 and 20 mg for 12 weeks. The three primary outcomes were changes from the pretreatment and on-demand tadalafil baseline in the erectile function domain of the International Index of Erectile Function and the proportion of yes responses to questions 2 and 3 of the Sexual Encounter Profile. Additional efficacy instruments included a Global Assessment Question administered at completion of the study.
Results: Compared with pretreatment and on-demand tadalafil baseline, daily dosed tadalafil significantly enhanced all efficacy outcome variables. Patients receiving daily tadalafil (10 mg) experienced a significant mean improvement of 12.8 and 8.2 in the International Index of Erectile Function erectile function domain score from baseline (P < 0.001) and from on-demand tadalafil, respectively (P < 0.001). Fifty-eight percent of intercourse attempts (Sexual Encounter Profile question 3) were successfully completed (P < 0.001 vs. pretreatment baseline, P < 0.001 vs. on-demand tadalafil). Improved erections at end point were reported by 69% of men compared with 42% of men with on-demand tadalafil. Daily tadalafil was well tolerated with headache, dyspepsia, and facial flushing as the most frequent adverse events.
Conclusion: Daily tadalafil (10/20 mg) was effective and well tolerated in this study population and is an effective salvage for previous on-demand tadalafil nonresponders.