Udenafil is a novel PDE5-inhibitor approved for treatment of ED in Korea. It has an onset of action of 1-1.5 hours and a half-life of 11-13 hours, suitable for both on-demand and daily use. It has been tested across various levels of trials (through Phase III studies) in subjects with ED and concomitant diabetes mellitus, hypertension, and BPH. It appears to be safe and well-tolerated, resulting in significant improvements in men with ED according to IIEF parameters.
Commonly reported adverse effects include headache, facial flushing, and febrile sensation, and none were considered to be of moderate or severe intensity. In a multiple-dose study, a color discrimination abnormality was reported that affected the blue-green region of the visual spectrum, yet this adverse effect spontaneously resolved upon successive testing defined as 1.5 hours after the fourth dose. There were no clinically significant findings in routine laboratory parameters including platelet aggregation tests, bleeding time, or semen analysis.
Udenafil appears to have a longer onset time compared with vardenafil and a shorter duration compared to tadalafil. Larger cohort, multi-ethnic trials will be required to more accurately assess its efficacy for worldwide use.
Reference: Kang SG, Kim JJ. Udenafil: efficacy and tolerability in the management of erectile dysfunction. Ther Adv Urol 2013;5(2):101-110.