Efficacy and Safety of Udenafil for the Treatment of Pulmonary Arterial Hypertension: a Placebo-controlled, Double-blind, Phase IIb Clinical Trial

Purpose Udenafil is an oral phosphodiesterase-5 inhibitor approved for the treatment of erectile dysfunction. In a multicenter, placebo-controlled, randomized Phase IIa study, the reduction of pulmonary vascular resistance index was greater with a 50-mg baseline dose of udenafil than with the 100-mg dose, the cardiac index did not decrease at most points, and the safety was excellent, suggesting that 50-mg udenafil could be used in a Phase IIb...