The efficacy and safety of udenafil, a new selective phosphodiesterase type 5 inhibitor, in patients with erectile dysfunction

J Sex Med. 2008 Apr;5(4):946-953. doi: 10.1111/j.1743-6109.2007.00723.x. Epub 2008 Jan 21.


Introduction: Udenafil is a potent selective phosphodiesterase type 5 (PDE5) inhibitor newly developed for the treatment of erectile dysfunction (ED).

Aim: This study was performed to evaluate the efficacy and safety of udenafil therapy in patients with ED.

Methods: In this multicenter, double-blind, placebo-controlled, fixed-dose, parallel-group phase III trial, 167 patients with ED of diverse origin and severity were randomized to take placebo or udenafil at fixed doses of 100 or 200 mg as needed for 12 weeks.

Main outcome measures: Primary efficacy variable was change from baseline in erectile function (EF) domain scores of the International Index of Erectile Dysfunction (IIEF) questionnaire. Secondary efficacy variables include change from baseline in scores on the IIEF Questions 3 and 4 (IIEF Q3 and Q4), change from baseline in all domain scores of the IIEF, patients' responses to questions 2 and 3 of the Sexual Encounter Profile (SEP2 and SEP3), and patients' responses to the Global Assessment Question (GAQ). Any adverse events were also recorded during the trial.

Results: After 12 weeks of treatment, the patients treated with udenafil showed significantly greater change from baseline in the IIEF-EF domain score compared with placebo (placebo, 0.20; 100-mg udenafil, 7.52; and 200-mg udenafil, 9.93, respectively) (P < 0.0001). Compared with placebo, udenafil significantly enhanced the rates of successful penetration (SEP Q2) and maintenance of erection (SEP Q3) (P < 0.0001). Furthermore, significantly greater proportions of udenafil treatment groups responded positively to the GAQ compared with the placebo group (GAQ: placebo, 25.9%; 100-mg udenafil, 81.5%; and 200-mg udenafil, 88.5%, respectively) (P < 0.0001). Treatment-related adverse events were generally mild to moderate with facial flushing and headache being the most common.

Conclusions: Udenafil is an effective and well-tolerated therapy for ED of broad-spectrum etiology and severity.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Administration Schedule
  • Erectile Dysfunction / drug therapy*
  • Humans
  • Male
  • Middle Aged
  • Patient Satisfaction
  • Penile Erection / drug effects*
  • Phosphodiesterase Inhibitors / administration & dosage*
  • Pyrimidines / administration & dosage*
  • Quality of Life
  • Research Design
  • Severity of Illness Index*
  • Sexual Behavior / drug effects
  • Sulfonamides
  • Treatment Outcome


  • Phosphodiesterase Inhibitors
  • Pyrimidines
  • Sulfonamides
  • udenafil