Neprilysin inhibitor is:
**Core Concept**
Neprilysin is a metalloprotease enzyme involved in the degradation of various peptides, including natriuretic peptides, bradykinin, and substance P. Inhibiting neprilysin increases the levels of these peptides, which can lead to vasodilation, natriuresis, and diuresis.
**Why the Correct Answer is Right**
A neprilysin inhibitor, such as sacubitril, works by blocking the action of neprilysin, leading to an increase in the levels of natriuretic peptides. This results in vasodilation and a decrease in blood pressure. Sacubitril is often used in combination with an angiotensin-converting enzyme (ACE) inhibitor, such as valsartan, to treat heart failure. The combination of sacubitril and valsartan is known as sacubitril/valsartan.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a neprilysin inhibitor. While ACE inhibitors do have some effects on neprilysin, they are not neprilysin inhibitors themselves.
**Option B:** This option is incorrect because it does not correctly identify a neprilysin inhibitor. Lisinopril is an ACE inhibitor, not a neprilysin inhibitor.
**Option C:** This option is incorrect because it does not correctly identify a neprilysin inhibitor. Losartan is an angiotensin II receptor antagonist, not a neprilysin inhibitor.
**Clinical Pearl / High-Yield Fact**
When treating heart failure, it is essential to combine a neprilysin inhibitor with an ACE inhibitor to maximize the benefits of vasodilation and natriuresis. This combination has been shown to improve symptoms and reduce hospitalizations in patients with heart failure.
**Correct Answer:** C. Sacubitril.