Efficacy and safety of flexible-dose oral sildenafil citrate (Viagra) in the treatment of erectile dysfunction in Brazilian and Mexican men

Int J Impot Res. 2002 Aug:14 Suppl 2:S27-32. doi: 10.1038/sj.ijir.3900895.


A 12-week, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of flexible-dose sildenafil citrate (Viagra) treatment (25, 50 or 100 mg) in Brazilian and Mexican men with erectile dysfunction (ED) of broad-spectrum etiology. Efficacy was assessed on the basis of responses to the 15-item International Index of Erectile Function (IIEF) questionnaire, completed at baseline and after 12 weeks of treatment. At end point, mean scores for all IIEF domains of sexual function (erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction) were significantly (P<0.0001) higher in the sildenafil group (n=109) than in the placebo group (n=105). These findings confirm the significant increases in frequency of penetration and frequency of maintained erections reported previously. Sildenafil treatment was well tolerated. The most common adverse events were headache and flushing. In conclusion, sildenafil is a well-tolerated and effective treatment for ED of broad-spectrum etiology in Latin American men.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Aged, 80 and over
  • Brazil
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Erectile Dysfunction / drug therapy*
  • Humans
  • Libido / drug effects
  • Male
  • Mexico
  • Middle Aged
  • Orgasm / drug effects
  • Patient Satisfaction
  • Piperazines / administration & dosage*
  • Piperazines / adverse effects
  • Piperazines / therapeutic use
  • Purines
  • Safety
  • Sildenafil Citrate
  • Sulfones
  • Treatment Outcome
  • Vasodilator Agents / administration & dosage*
  • Vasodilator Agents / adverse effects
  • Vasodilator Agents / therapeutic use


  • Piperazines
  • Purines
  • Sulfones
  • Vasodilator Agents
  • Sildenafil Citrate