Abstract
Once-daily tadalafil administration has been well established; however, studies about tadalafil once-daily treatment in the Chinese population are lacking. In this phase 4, postmarketing study, we ascertained the long-term safety and effectiveness of tadalafil 2.5 mg and 5.0 mg once daily in Chinese men with erectile dysfunction (n = 635). The primary endpoint of the study was safety at 12 months as assessed by the proportion of patients experiencing at least one treatment-emergent adverse event (serious or nonserious). The secondary endpoints included safety and effectiveness, measured by the International Index of Erectile Function-Erectile Function (IIEF-EF) domain scores. Similar adverse events to the known safety profile of tadalafil, such as nasopharyngitis, upper respiratory tract infection, headache, and dizziness, were detected. No new cardiovascular safety concerns were observed. After 3 months of treatment, significant increases in IIEF-EF domain scores were detected for both 2.5-mg (least squares [LS] mean change: 6.3; 95% confidence interval [CI]: 5.4-7.1; P < 0.001) and 5.0-mg (LS mean change: 7.4; 95% CI: 6.8-7.9; P < 0.001) tadalafil doses, and significance was maintained up to 12 months. In addition, approximately 40% of patients regained normal erectile function (IIEF-EF ≥26) following 1 year of tadalafil once-daily treatment. The findings in this study provide evidence for the extended effectiveness and tolerability of tadalafil, demonstrating no new safety concerns, in a Chinese population and make once-daily tadalafil administration a viable option for improving sexual performance and satisfaction in Chinese men with erectile dysfunction.