Evaluating erectile dysfunction: oral sildenafil versus intracavernosal injection of papaverine

Intracavernosal injection of vasoactive drugs is an established method of evaluating erectile dysfunction. However, it is invasive and may be associated with pain and priapism. We investigated the use of oral sildenafil as a possible substitute for intracavernosal agents.

Men with erectile dysfunction were randomized into two groups of 25 each. One group of 25 men received injection papaverine initially followed by oral sildenafil, and another 25 received oral sildenafil followed by injection papaverine. Genital self-stimulation was used in both the groups. Penile length and circumference as well as angle of erection, before and after each medication, were recorded. Two days later, the intervention arms were crossed over. Subjective responses were obtained. The effect of medication on each outcome variable was studied by using analysis of variance models in relation to patient, period and medication.

There was statistically significant improvement from the baseline value in both the arms, i.e injection papaverine and oral sildenafil (p<0.001, p<0.001, respectively) for both penile length and circumference. No significant difference was observed between the two medications in the outcome measures. CONCLCUSION: Oral sildenafil was as effective as injection papaverine in evaluating erectile dysfunction.