Randomized, double-blind, placebo-controlled study of postoperative nightly sildenafil citrate for the prevention of erectile dysfunction after bilateral nerve-sparing radical prostatectomy

Int J Impot Res. 2008 Sep-Oct;20(5):479-86. doi: 10.1038/ijir.2008.33. Epub 2008 Jul 24.


Four weeks after bilateral nerve-sparing radical retropubic prostatectomy, men with normal erectile function before surgery were randomized to double-blind sildenafil (50 or 100 mg) or placebo nightly for 36 weeks, followed by an 8-week drug-free period before assessment of erectile function. Enrollment was prematurely ceased and only 76 men completed because, assuming a placebo response rate similar to the published literature (for example, 34% in meta-analysis), the 25% response at blinded interim review suggested a lack of treatment effect. On the contrary, spontaneous erectile function (a combined score of >or=8 for questions 3 and 4 of the International Index of Erectile Function and a positive response to 'Were erections good enough for satisfactory sexual activity?') occurred in only 4% of the placebo group (n=1 of 25) versus 27% (n=14 of 51, P=0.0156, Fisher's exact test) of the sildenafil group. Nightly sildenafil administration for 36 weeks after surgery markedly increased the return of normal spontaneous erections.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Darkness*
  • Erectile Dysfunction / prevention & control*
  • Humans
  • Male
  • Middle Aged
  • Piperazines / adverse effects
  • Piperazines / pharmacology*
  • Postoperative Care*
  • Prostate / innervation*
  • Prostate / surgery*
  • Prostatectomy / methods*
  • Purines / adverse effects
  • Purines / pharmacology
  • Sildenafil Citrate
  • Sulfones / adverse effects
  • Sulfones / pharmacology*


  • Piperazines
  • Purines
  • Sulfones
  • Sildenafil Citrate