Udenafil: efficacy and tolerability in the management of erectile dysfunction.

Udenafil is a potent novel phosphodiesterase-5 inhibitor approved for use in Korea. Udenafil has unique properties, with a T max of 1.0-1.5 h and a T 1/2 of 11-13 h (a relatively rapid onset and a long duration of action). Therefore, both on-demand and once-daily use of udenafil have been reported. Udenafil's efficacy and tolerability have been evaluated in several studies, and recent and continuing studies have demonstrated udenafil's promise in both dosing regimens. Presently, tadalafil is the only FDA-approved drug for daily dosing, but udenafil can be used as a once-daily dose for erectile dysfunction patients who cannot tolerate tadalafil due to phosphodiesterase subtype selectivity. Udenafil as an on-demand or once-daily dose is effective and tolerable, but more studies are needed in patients of other ethnicities and with comorbid conditions such as diabetes mellitus, hypertension, and benign prostate hyperplasia.