What is the primary action of statins?

What is the primary action of statins?

• A. They inhibit HMG-CoA reductase, reducing cholesterol synthesis and lowering LDL.
• B. They inhibit platelet aggregation
• C. They inhibit intestinal cholesterol absorption
• D. They increase cholesterol synthesis

Answer: (A)

The primary action of statins is to inhibit HMG-CoA reductase, the enzyme that drives the rate-limiting step of cholesterol synthesis in the liver. By blocking this step, the liver makes less cholesterol, which leads to upregulation of LDL receptors on liver cells. Those receptors pull more LDL cholesterol out of the bloodstream, resulting in a lower circulating LDL level. Clinically, this LDL reduction is the hallmark of statin therapy, and they can also modestly lower triglycerides and raise HDL slightly. This differs from inhibiting platelet aggregation, which is what antiplatelet drugs do, and from blocking intestinal cholesterol absorption, which is the mechanism of drugs like ezetimibe. It’s also opposite to increasing cholesterol synthesis, which statins do not do—they decrease it.

The primary action of statins is to inhibit HMG-CoA reductase, the enzyme that drives the rate-limiting step of cholesterol synthesis in the liver. By blocking this step, the liver makes less cholesterol, which leads to upregulation of LDL receptors on liver cells. Those receptors pull more LDL cholesterol out of the bloodstream, resulting in a lower circulating LDL level. Clinically, this LDL reduction is the hallmark of statin therapy, and they can also modestly lower triglycerides and raise HDL slightly.

This differs from inhibiting platelet aggregation, which is what antiplatelet drugs do, and from blocking intestinal cholesterol absorption, which is the mechanism of drugs like ezetimibe. It’s also opposite to increasing cholesterol synthesis, which statins do not do—they decrease it.