udenafil + bosentan

Udenafil + bosentan is a combination of two small molecule drugs with distinct mechanisms of action. Udenafil is a phosphodiesterase type 5 (PDE5) inhibitor used primarily for the treatment of erectile dysfunction. It works by inhibiting the cGMP-specific phosphodiesterase type 5 enzyme, leading to increased levels of cGMP and promoting smooth muscle relaxation and vasodilation in the corpus cavernosum[4]. Bosentan is an endothelin receptor antagonist indicated for pulmonary arterial hypertension (PAH). It acts as a competitive antagonist at both endothelin-A (ET-A) and endothelin-B (ET-B) receptors, blocking the effects of endothelin-1—a potent vasoconstrictor—thereby reducing pulmonary vascular resistance and improving exercise capacity in PAH patients[1][2][6]. The combination may be considered in clinical scenarios where both PDE5 inhibition and endothelin receptor antagonism are desired.