Objective: To determine the efficacy and safety of tadalafil when taken on demand by men with erectile dysfunction (ED) secondary to traumatic spinal cord injury (SCI).
Design and setting: Multicenter, randomized, double-blind, placebo-controlled, flexible dose-titration, parallel-group study in clinical practices in Europe. Patients Enrolled patients had ED secondary to SCI (all spinal levels) and sustained 6 months or longer before visit 1.
Interventions: After a 4-week run-in period, patients were randomly assigned to tadalafil, 10 mg, (n = 142) or placebo (n = 44) for a 12-week, on-demand treatment period with assessments at 4-week intervals. The dose of tadalafil was maintained or titrated (10 or 20 mg) at 4 and 8 weeks.
Main outcome measures: Efficacy was measured using the International Index of Erectile Function (IIEF), Sexual Encounter Profile (SEP), and Global Assessment Question (GAQ). Treatment-emergent adverse events and vital signs were collected at each visit.
Results: Mean age was 38 years. Mean baseline IIEF erectile function domain score was 13.4, and following 12 weeks of treatment, 22.6 for tadalafil and 13.6 for placebo (P < .001). After treatment, the tadalafil group compared with the placebo group was significantly greater (P < .001) in mean per-patient percentage of successful penetration attempts (SEP question 2; 75.4% vs 41.1%) and intercourse attempts (SEP question 3; 47.6% vs 16.8%); percentage of improved erections (GAQ question 1; 84.6% vs 19.5%); and ejaculatory frequency (IIEF question 9; P = .03). The 2 most common treatment-emergent adverse events in the tadalafil group compared with placebo were headache (8.5% vs 4.5%) and urinary tract infection (7.7% vs 6.8%).
Conclusions: Tadalafil (10 mg and 20 mg) improved erectile function and was well tolerated by men with ED secondary to traumatic SCI.