A patient asks the nurse to explain the medications they are taking. Which medication would be considered an angiotensin converting enzyme inhibitor?

A) Simvastatin:
Simvastatin is a medication used to lower cholesterol levels by inhibiting HMG-CoA reductase, an enzyme involved in the production of cholesterol in the liver. It is not an angiotensin-converting enzyme (ACE) inhibitor. Therefore, it does not have a direct effect on blood pressure or the renin-angiotensin system.

B) Losartan:
Losartan is an angiotensin II receptor blocker (ARB), not an ACE inhibitor. Like ACE inhibitors, ARBs are used to treat conditions like hypertension and heart failure, but they work differently by blocking the receptors that angiotensin II binds to, rather than inhibiting the enzyme that converts angiotensin I to angiotensin II.

C) Quinapril:
Quinapril is an ACE inhibitor. ACE inhibitors block the enzyme angiotensin-converting enzyme, which converts angiotensin I into angiotensin II, a potent vasoconstrictor. By inhibiting this conversion, ACE inhibitors like quinapril help lower blood pressure, reduce strain on the heart, and treat conditions like hypertension and heart failure.

D) Metoprolol:
Metoprolol is a beta-blocker, not an ACE inhibitor. It works by blocking beta-adrenergic receptors in the heart, which helps to lower heart rate and blood pressure. It is often used in the management of hypertension, heart failure, and to prevent heart attacks, but it does not affect the renin-angiotensin system like ACE inhibitors.