Question

Sildenafil, vardenafil, and tadalafil all improve erectile dysfunction by which one of the following mechanisms?

A. Phosphodiesterase 5 inhibition
B. Calcium channel antagonism
C. Nitric oxide antagonism
D. α1 Adrenergic antagonism
E. Carbonic anhydrase inhibition

Answer 1

Sildenafil, vardenafil, and tadalafil improve erectile dysfunction by inhibiting phosphodiesterase 5.

Step-by-step explanation:

Sildenafil, vardenafil, and tadalafil all improve erectile dysfunction through phosphodiesterase 5 inhibition. These drugs work by blocking the enzyme called phosphodiesterase type 5 (PDE5), which degrades cGMP, a key component in the nitric oxide (NO) signaling pathway that induces relaxation of the smooth muscles surrounding the penile arteries, leading to vasodilation necessary for an erection.