Switching from intracavernous prostaglandin E1 injections to oral sildenafil citrate in patients with erectile dysfunction: Results of a multicenter European study

Purpose: Intracavernous injection is a well established medical therapy for erectile dysfunction. We assessed the rate of success when patients with erectile dysfunction who were effectively treated with intracavernous injections of prostaglandin E1 were changed to oral therapy with sildenafil citrate. Materials and Methods: Only patients effectively managing erectile dysfunction by the intracavernous injection of 20 mu g. or less prostaglandin E1 for more than 6 months were eligible for study enrollment. After a 4-week run-in phase while intracavernous prostaglandin E1 therapy continued and a 48-hour washout period 176 patients with erectile dysfunction received open label sildenafil orally for 12 weeks. Satisfaction with treatment was evaluated by the 11-item erectile dysfunction index of treatment satisfaction questionnaire. A successful change to sildenafil was prospectively defined as a questionnaire score of 0 to 100 after sildenafil that was greater than or equal to the score after intracavernous prostaglandin E1. Results: Of the 176 patients 69% (95% confidence limit 62 to 76) successfully changed from intracavernous prostaglandin E1 injections to oral sildenafil and elected to continue oral treatment. Mean satisfaction score after sildenafil and prostaglandin E1 was 73.8 and 63.9, respectively (p <0.001). Only 3 patients (1.7%) discontinued therapy because of treatment related adverse events. Conclusions: More than two-thirds of the men with erectile dysfunction who were stable on intracavernous injections of 20 mu g. or less prostaglandin E1 successfully changed to oral sildenafil, as determined by maintained or enhanced treatment satisfaction.