Atorvastatin
HMG-CoA reductase inhibitor; lipid-lowering statin
Mechanism of Action
Atorvastatin is a selective, competitive inhibitor of HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol biosynthesis (mevalonate pathway). By inhibiting HMG-CoA reductase, atorvastatin reduces intracellular cholesterol, upregulating LDL receptor expression and increasing hepatic LDL clearance from circulation. Beyond LDL reduction, atorvastatin has pleiotropic effects: improved endothelial function, reduced inflammation (lowered CRP), decreased oxidative stress, and plaque stabilization. It is metabolized by CYP3A4 and has a long duration of action due to active metabolites.
Evidence Level
Clinical Trial - Human
6 studies published
Pharmacology
Molecular Weight
558.6 g/mol (calcium salt)
Half-Life
Approximately 14 hours (parent); 20-30 hours (active metabolites)
Bioavailability
Approximately 14% oral bioavailability (extensive first-pass metabolism)