Tadalafil 2.5 or 5 mg administered once daily for 12 weeks in men with both erectile dysfunction and signs and symptoms of benign prostatic hyperplasia: results of a randomized, placebo-controlled, double-blind study

Introduction: Erectile dysfunction (ED) and lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH-LUTS) commonly coexist in aging men. Tadalafil, a phosphodiesterase type 5 inhibitor approved for treating ED, is currently being evaluated for treating BPH-LUTS.

Aims: This multinational Phase 3 study assessed effects of tadalafil 2.5 or 5 mg once daily on ED and BPH-LUTS in men with both conditions during 12 weeks of double-blinded therapy.

Methods: Men were ≥ 45 years old, sexually active, and experiencing ED for ≥ 3 months and BPH-LUTS for >6 months. Randomization (baseline) followed a 4-week placebo lead-in; changes from baseline were assessed via analysis of covariance and compared to placebo. A gatekeeping procedure controlled for multiple comparisons of co-primary and key secondary measures at end point (last post-baseline observation).

Main outcome measures: The co-primary measures were the International Index of Erectile Function-erectile function (IIEF-EF) domain and International Prostate Symptom Score (IPSS) score; key secondary measures were the Sexual Encounter Profile Question 3 (SEP Q3) and BPH Impact Index (BII). Treatment-emergent adverse events, serious adverse events, orthostatic vital signs, clinical laboratory and uroflowmetry parameters, and postvoid residual volume were assessed.

Results: Tadalafil 2.5 mg (N = 198) and 5 mg (N = 208) significantly improved IIEF-EF domain scores (both P < 0.001) vs. placebo (N = 200) at end point. For IPSS, improvements were significant with tadalafil 5 mg (P < 0.001), but not 2.5 mg, for observations from 2 weeks through end point (least-squares mean ± standard error change from baseline at end point, placebo -3.8 ± 0.5, tadalafil 2.5 mg -4.6 ± 0.4, and 5 mg -6.1 ± 0.4). Tadalafil 5 mg significantly improved SEP Q3 and BII (P < 0.001). Overall, tadalafil was well tolerated with no clinically adverse changes in orthostatic vital signs or uroflowmetry parameters.

Conclusions: Tadalafil 5 mg significantly improved both ED and BPH-related outcomes through 12 weeks and was well tolerated.