Prospective, randomized, crossover comparison of sublingual apomorphine (3 mg) with oral sildenafil (50 mg) for male erectile dysfunction.

Purpose: We established the efficacy and safety of sublingual apomorphine compared with oral sildenafil in comparable groups of patients with erectile dysfunction (ED).

Materials And Methods: This prospective, randomized, crossover study included 77 heterosexual men with ED of various etiologies and severities. A total of 62 men were randomized but only 34 were evaluable for efficacy and tolerability. The study started with a run-in period of 2 to 4 weeks. The first 4 weeks of treatment were followed by a washout period of 4 weeks, after which patients changed to the alternate treatment for an additional 4-week period. The sequence of the 2 treatments was established by a randomization list in blocks in closed packets. The primary efficacy end point was the percent of attempts resulting in erection firm enough for intercourse. Additional variables were the percent of attempts resulting in intercourse and improvement in ED, as evaluated by the erectile function domain score of the International Index of Erectile Function questionnaire.

Results: Sildenafil was significantly more effective than apomorphine in regard to the percent of attempts resulting in erection firm enough for intercourse (85% vs 44%, p <0.0001) and actually resulting in intercourse (81% vs 43%, p <0.0001) as well as erectile function evaluated by the erectile function domain score of the International Index of Erectile Function (p <0.001). The incidence of adverse events was not significantly different for the 2 drugs. Although the number of patients was small, this study had strong statistical power due to the striking difference in results.

Conclusions: Sildenafil was significantly more effective than apomorphine for ED. No statistical difference in adverse events was noted.