What is the mechanism of action of Valsartan in Valsartan/Sacubitril?

Valsartan is classified as an angiotensin II receptor blocker (ARB). Its primary mechanism of action involves competitively antagonizing the angiotensin II receptor, specifically the type 1 receptor (AT1). By blocking angiotensin II, Valsartan effectively prevents the hormone from exerting its vasoconstrictive effects, leading to vasodilation, reduced blood pressure, and decreased workload on the heart.

The role of angiotensin II in the body is significant, as it contributes to increased blood pressure and fluid retention. By antagonizing this receptor, Valsartan helps to mitigate these effects, making it particularly useful in treating conditions such as hypertension and heart failure.

In the combination of Valsartan with Sacubitril, the latter inhibits neprilysin, an enzyme that breaks down several peptides including natriuretic peptides that help to manage blood volume and pressure. While this combination leverages both mechanisms to provide a more comprehensive approach to treating heart failure, the action of Valsartan itself centers on its role as a competitive antagonist of the angiotensin II receptor. This is what makes the correct choice significant in understanding the function of Valsartan in the combination therapy.