Efficacy and Safety of Udenafil Once Daily in Patients with Erectile Dysfunction after Bilateral Nerve-Sparing Robot-Assisted Laparoscopic Radical Prostatectomy: A Randomized, Double-Blind, Placebo-Controlled Study

Purpose To evaluate the efficacy and safety of udenafil 75 mg once daily in patients with erectile dysfunction following bilateral nerve-sparing robot-assisted laparoscopic radical prostatectomy (BNS-RALP). Materials and Methods A multi-center, prospective, randomized, controlled, double-blind study was conducted. Among patients with localized prostate cancer with international index of erectile function-erectile function domain (IIEF-EF) score of 18 or higher before BNS-RALP, those who developed postoperative erectile dysfunction (IIEF-EF score 14 or less at 4 weeks after BNS-RALP) were enrolled. Enrolled patients were randomly assigned to the udenafil 75 mg daily group or the placebo group in a 2:1 ratio. Each subject was followed up at 8 weeks (V2), 20 weeks (V3), and 32 weeks (V4) to evaluate the efficacy and safety of udenafil. Results In all, 101 patients were screened, of whom 99 were enrolled. Of the 99 patients, 67 were assigned to the experimental group and 32 to the control group. Ten (14.93%) patients in the experimental group and 10 (31.25%) in the control group dropped out of the study. After 32 weeks of treatment, IIEF-EF score of 22 or higher was seen in 36.51% (23/63) of patients in the experimental group and 13.04% (3/23) patients in the control group (p=0.021). The proportion of patients with IIEF-EF improvement of 25% or more compared to the baseline was 82.54% (52/63) in the experimental group and 62.96% (17/27) in the control group (p=0.058). Conclusions Udenafil 75 mg once daily after BNS-RALP improved the erectile function without any severe adverse effects.