Objective: To evaluate the efficacy of vardenafil in patients previously unresponsive to sildenafil.
Patients and methods: A multicentre, double-blind, 12-week, flexible-dose, placebo-controlled trial was conducted, involving 463 men aged > or = 18 years with moderate-to-severe erectile dysfunction (ED) and who were unresponsive to sildenafil (by history). After a 4-week treatment-free run-in, patients received placebo or vardenafil 10 mg with the option to maintain current dose or to titrate by one dose level (5, 10 or 20 mg) based on efficacy and tolerability at 4 and 8 weeks. Outcome measures were the erectile function (EF) domain score of the International Index of Erectile Function, two Sexual Encounter Profile diary questions (vaginal penetration and maintenance of erection until successful completion of intercourse), and the Global Assessment Question (GAQ).
Results: There was significantly better EF with vardenafil than with placebo throughout the study. The least-square mean EF domain scores increased from 9.3 at baseline to 17.6 at the 'last' observation carried forward (LOCF) analysis with vardenafil (P < 0.001). Overall least-square mean per-patient success rates more than doubled for penetration (30.3% to 62.3%) and quadrupled for successful intercourse (10.5% to 46.1%) with vardenafil. Improved erections (positive response to the GAQ) were reported by 61.8% of patients receiving vardenafil and 14.7% of those receiving placebo at LOCF (P < 0.001). Normal EF (domain score > or = 26) was achieved by 30% of patients receiving vardenafil and 6% receiving placebo at LOCF (P < 0.001). Adverse events were infrequent and representative of the phosphodiesterase-5 inhibitor profile.
Conclusion: Vardenafil is an effective and generally safe treatment for ED, even in men unresponsive to sildenafil (by history).