What is the mechanism of statins and a key lab to monitor?

• A. Inhibit HMG-CoA reductase reducing cholesterol synthesis; monitor liver enzymes ALT/AST and check for myopathy.
• B. Increase cholesterol synthesis; monitor blood glucose.
• C. Inhibit the absorption of cholesterol in the intestine; monitor lipid panel.
• D. Block LDL receptors; monitor renal function.

Answer: (A)

Statins work by inhibiting HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis. This decreases cholesterol production in the liver, which in turn upregulates LDL receptors on hepatocytes and increases clearance of LDL from the blood, ultimately lowering plasma LDL cholesterol. A key lab to monitor is liver function tests (ALT and AST) because statins can cause hepatotoxicity; baseline and periodic monitoring are important, and CK monitoring is considered if patients develop muscle symptoms to watch for myopathy.