• Erectile Dysfunction;
  • PDE5;
  • Long-Acting PDE5 Inhibitor;
  • Udenafil;
  • Clinical Trial


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

Aim.  To evaluate the efficacy of udenafil in treating ED for up to 12 hours after dosing.

Methods.  This was a randomized, double-blind, placebo-controlled, parallel-group, fixed dose design, multicenter study. Following a 4-week nondrug baseline period, 104 men with ED of broad etiology and severity were randomized to one of two treatment groups: udenafil 100 mg or placebo. Participants were requested to attempt sexual intercourse at 12 hours after udenafil or placebo dosing during a 4-week treatment period.

Main Outcome Measures.  The primary efficacy variable was the response of patients to question 3 of the Sexual Encounter Profile (SEP Q3). The secondary efficacy measures were the response of patients to question 2 of the Sexual Encounter Profile (SEP Q2). Additional secondary efficacy measures included changes from baseline in the erectile function (EF) domain scores of the International Index of Erectile Function (IIEF) questionnaire.

Results.  Of the 104 patients, 103 (50 in the udenafil group, 53 in the placebo group) completed the study. Udenafil significantly enhanced the rate of maintenance of erection (SEP Q3; placebo, 28.3% vs. udenafil, 54.7%; P < 0.0001). Significant change from baseline in the IIEF-EF domain was observed in the udenafil group (placebo, –0.58 ± 0.67; udenafil, 4.40 ± 0.84; P < 0.0001). For SEP Q2, there was no difference from baseline and no difference between the two groups. The overall adverse events rate was 11.3%. Most adverse events were mild or moderate in severity, and no serious adverse events were reported during the study and the follow-up period.

Conclusions.  Udenafil at 100 mg was effective for relieving ED for up to 12 hours after dosing. This duration of effectiveness could allow for flexibility and spontaneity in the sexual lives of patients. Park HJ, Park JK, Park K, Min K, and Park NC. Efficacy of udenafil for the treatment of erectile dysfunction up to 12 hours after dosing: A randomized placebo-controlled trial. J Sex Med 2010;7:2209–2216.