title: Efficacy and safety of oral sildenafil (Viagra) in men with erectile dysfunction caused by spinal cord injury.
abstract: OBJECTIVE
  To evaluate the efficacy and safety of 50-mg doses of sildenafil during a 28-day period in patients with erectile dysfunction caused by spinal cord injury (cord level range, T6 through L5).
  
  
  BACKGROUND
  Sildenafil is an orally active, potent, and selective inhibitor of phosphodiesterase type 5, an important regulator of cyclic guanosine monophosphate in the human corpus cavernosum.
  
  
  METHODS
  To be included in this double-blind, placebo-controlled study, all patients had to be able to achieve at least a partial reflexogenic erectile response to penile vibratory stimulation. The study utilized a single triangular sequential trial design. A total of 27 patients were randomized to receive 50 mg of sildenafil or placebo, taken orally as required (not more than once daily) approximately 1 hour before sexual activity.
  
  
  RESULTS
  After 28 days of treatment, nine of 12 patients (75%) on sildenafil and one of 14 patients (7%) on placebo reported that treatment had improved their erections (p=0.0043). Furthermore, eight of 12 patients (67%) on sildenafil and two of 13 patients (15%) on placebo indicated that they wished to continue treatment (p=0.018). A significant improvement in satisfaction with their sex life was reported by patients taking sildenafil (p=0.012). No patients discontinued treatment due to adverse events.
  
  
  CONCLUSIONS
  Oral sildenafil, taken as required (not more than once daily), significantly improves the quality of erections and satisfaction with sex life in men with erectile dysfunction caused by a spinal cord injury between T6 and L5.
authors.affiliation: National Spinal Injury Centre, Stoke Mandeville, UK.
authors.forename: F A
authors.initials: FA
authors.lastname: Derry
authors.forename: W W
authors.initials: WW
authors.lastname: Dinsmore
authors.forename: M
authors.initials: M
authors.lastname: Fraser
authors.forename: B P
authors.initials: BP
authors.lastname: Gardner
authors.forename: C A
authors.initials: CA
authors.lastname: Glass
authors.forename: M C
authors.initials: MC
authors.lastname: Maytom
authors.forename: M D
authors.initials: MD
authors.lastname: Smith
mesh_terms: D000284:Administration, Oral; D000328:Adult; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000009:adverse effects*; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects*; D011687:Purines; D012018:Reflex / Q000187:drug effects; D019529:Sexuality; D000068677:Sildenafil Citrate; D013119:Spinal Cord Injuries / Q000150:complications*; D013450:Sulfones
chemical_list: D004791:Enzyme Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate