A placebo-controlled, multicenter, randomized, double-blind, flexible-dose, two-way crossover study to evaluate the efficacy and safety of sildenafil in men with traumatic spinal cord injury and erectile dysfunction

J Spinal Cord Med. 2008;31(5):522-31. doi: 10.1080/10790268.2008.11753647.


Background/objective: To show the efficacy, safety, and tolerability of sildenafil in men with erectile dysfunction (ED) associated with complete or incomplete spinal cord injury (SCI) and to assess its effects on quality of life (QoL) using the Life-Satisfaction Check List.

Methods: This was a placebo-controlled, multicenter, randomized, double-blind, flexible-dose, 2-way crossover study with a 2-week washout period between each phase. Patients with ED attributable to SCI (Sexual Health Inventory-Male score < or =21) received 50 to 100 mg sildenafil (n = 24) or placebo (n = 26).

Results: Compared with placebo, sildenafil produced higher levels of successful sexual stimulation, intercourse success, satisfaction with sexual life and sexual relationship, erectile function, overall sexual satisfaction, and an improved Erectile Dysfunction Inventory of Treatment Satisfaction score, with no clinically relevant effects on vital signs. Sildenafil seemed more effective in patients with incomplete SCI than in those with complete SCI, producing significant improvements, compared with placebo, in a number of measures only in patients with incomplete SCI. All patients who expressed a preference selected sildenafil over placebo, although the drug had no effect on patient QoL. Sildenafil was well tolerated, with a profile comparable to that of placebo.

Conclusions: Compared with placebo, treatment with oral sildenafil safely and effectively improved erectile function in patients with ED attributable to SCI, especially in those with incomplete injury, and was the agent of choice in those who expressed a preference.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Analysis of Variance
  • Cross-Over Studies
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Erectile Dysfunction / drug therapy*
  • Erectile Dysfunction / etiology
  • Evaluation Studies as Topic*
  • Humans
  • Male
  • Middle Aged
  • Phosphodiesterase Inhibitors / therapeutic use*
  • Piperazines / therapeutic use*
  • Purines / therapeutic use
  • Severity of Illness Index
  • Sildenafil Citrate
  • Spinal Cord Injuries / complications
  • Spinal Cord Injuries / drug therapy*
  • Sulfones / therapeutic use*
  • Time Factors


  • Phosphodiesterase Inhibitors
  • Piperazines
  • Purines
  • Sulfones
  • Sildenafil Citrate