An open-label, randomized, flexible-dose, crossover study to assess the comparative efficacy and safety of sildenafil citrate and apomorphine hydrochloride in men with erectile dysfunction.

Objective: To compare the efficacy and safety of sildenafil and apomorphine in the treatment of men with erectile dysfunction (ED).

Patients And Methods: In all, 139 men with ED who were naïve to treatment were entered into an open-label crossover trial with two treatment periods, each of 8 weeks, separated by a 2-week washout period. Men were randomized to receive either sildenafil then apomorphine or apomorphine then sildenafil, and were allowed to titrate the dose on both drugs. The primary endpoint was the erectile function (EF) domain of the International Index of Erectile Function (IIEF), and other endpoints included diary data, the other domains of the IIEF, overall assessment questions and the Erectile Dysfunction Index of Treatment Satisfaction (EDITS) questionnaire.

Results: The EF domain score after treatment was 25.2 for sildenafil and 15.9 for apomorphine. The treatment difference of the adjusted means was 9.3 points (95% confidence interval 7.6-11.1; P < 0.001). After sildenafil the successful intercourse rate was 75%, vs 35% for apomorphine (P < 0.001), and the EDITS scores were 82.5 for sildenafil and 46.8 for apomorphine (P < 0.001). Of the men, 96% expressed a preference for sildenafil as a treatment for their ED. The side-effect profiles for both drugs were in keeping with published data.

Conclusion: By all measurable endpoints sildenafil was superior to apomorphine in this open-label crossover study of men with ED who were naïve to therapy