Statins (e.g., atorvastatin, simvastatin) work by inhibiting which enzyme?

Correct answer: C. HMG-CoA reductase (the rate-limiting enzyme in cholesterol synthesis)

• A. ACE inhibition is the mechanism of lisinopril, captopril — not statins.
• B. COX inhibition is the mechanism of NSAIDs — not statins.
• C. Correct. Statins are HMG-CoA REDUCTASE INHIBITORS. HMG-CoA reductase is the rate-limiting enzyme in the mevalonate pathway for cholesterol biosynthesis in the liver. Inhibiting it: (1) reduces intracellular cholesterol, (2) upregulates LDL receptors → increases LDL uptake and clearance from blood, (3) reduces VLDL and triglycerides. DENTAL RELEVANCE: statins may cause calcification within the pulp chamber (a notable Day 2 recall finding).
• D. Lipoprotein lipase breaks down triglycerides in chylomicrons — not a statin target.