1. Introduction:

Statins are a class of lipid-lowering drugs that are primarily used to reduce cardiovascular risk by lowering LDL cholesterol (low-density lipoprotein). They work by inhibiting the enzyme HMG-CoA reductase, which is the rate-limiting step in cholesterol biosynthesis in the liver.

2. Mechanism of Action:
Statins competitively inhibit HMG-CoA reductase, the enzyme that converts HMG-CoA to mevalonate, a precursor in the cholesterol biosynthesis pathway.

• ↓ Mevalonate → ↓ Cholesterol synthesis in hepatocytes

• ↓ Intracellular cholesterol → ↑ LDL receptors on liver cells

• ↑ LDL receptors → ↑ clearance of LDL from blood

3. Pharmacokinetics:

4. Common Statins:

5. Therapeutic Uses:

• Hyperlipidemia (especially high LDL)

• Primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD)

• Stabilization of atherosclerotic plaques

• Anti-inflammatory and pleiotropic effects (beyond lipid-lowering)

6. Adverse Effects:

• Myopathy, myalgia, rhabdomyolysis (rare but serious)

• Elevated liver enzymes (monitor LFTs)

• Gastrointestinal disturbances

• Rare: cognitive effects, new-onset diabetes

7. Drug Interactions:

• CYP3A4 inhibitors (e.g., erythromycin, azole antifungals, grapefruit juice) → ↑ statin levels → ↑ toxicity

• Fibrates (e.g., gemfibrozil) → ↑ risk of myopathy

• Warfarin → ↑ anticoagulant effect with some statins

8. Contraindications:

• Pregnancy and lactation

• Active liver disease

• Hypersensitivity to statins