Which of the following best describes the mechanism of action of Sildenafil?

Sildenafil primarily works by inhibiting phosphodiesterase type 5 (PDE5), which is an enzyme that breaks down cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. By inhibiting PDE5, sildenafil increases the levels of cGMP, leading to enhanced vasodilation and increased blood flow to the penis when sexual stimulation occurs. This mechanism is critical for its use in treating erectile dysfunction, as it allows for the physiological processes related to erection to occur more effectively.

The other mechanisms listed do not accurately describe how sildenafil functions. While blood pressure may be influenced indirectly through the vasodilation it causes, inhibiting blood pressure is not its primary action. Additionally, sildenafil does not have a role in blocking glucose absorption or stimulating serotonin release. Understanding the specific mechanism of action is essential for comprehending how sildenafil can effectively facilitate the physiological response necessary for achieving and maintaining an erection.