What Enzyme Does Lipitor Target?
Lipitor (atorvastatin) primarily targets HMG-CoA reductase, the enzyme that controls the rate-limiting step in cholesterol biosynthesis in the liver.[1]
How Does It Work Exactly?
HMG-CoA reductase converts HMG-CoA to mevalonate, a precursor for cholesterol. Lipitor competitively inhibits this enzyme, reducing cholesterol production and increasing LDL receptor expression to clear LDL from blood.[1][2]
Why Is This Enzyme Key for Cholesterol Drugs?
Statins like Lipitor mimic HMG-CoA's structure, binding the enzyme's active site and blocking it. This lowers LDL cholesterol by 20-60% in patients, depending on dose.[2]
What Happens If the Enzyme Isn't Fully Inhibited?
Partial inhibition still cuts cholesterol synthesis but may require higher doses or combination therapy. Genetic variations in HMGCR can affect Lipitor response, with some patients needing alternatives.[3]
How Does Lipitor Compare to Other Statins?
All statins target HMG-CoA reductase but differ in potency and lipophilicity. Lipitor is more potent than simvastatin (Zocor) at equivalent doses, leading to stronger LDL reductions.[2][4]
[1]: FDA Label for Lipitor
[2]: PubMed: Mechanism of Statins
[3]: Nature Reviews Drug Discovery: Statin Variability
[4]: DrugPatentWatch.com: Atorvastatin vs Competitors