Atorvastatin
Lipitor
Overview
Atorvastatin is an HMG-CoA reductase inhibitor (statin) used to lower cholesterol and reduce cardiovascular disease risk. One of the most prescribed medications worldwide.
Indications
- Hyperlipidemia
- Primary prevention of cardiovascular disease
- Secondary prevention post-MI
Contraindications
- Active liver disease
- Unexplained persistent transaminase elevation
- Pregnancy
- Breastfeeding
Mechanism of Action
Competitively inhibits HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis, leading to upregulation of LDL receptors and increased clearance of LDL from blood.
Pharmacodynamics
Reduces LDL-C by 39-60%, increases HDL-C by 5-9%, and reduces triglycerides by 19-37% depending on dose.
Pharmacokinetics
- Absorption
- Rapidly absorbed. Low absolute bioavailability (14%) due to first-pass metabolism.
- Distribution
- Highly protein bound (≥98%).
- Metabolism
- Extensively metabolized by CYP3A4 to active metabolites.
- Excretion
- Primarily biliary/fecal.
- Half-life
- 14 hours (20-30 hours for active metabolites)
- Bioavailability
- 14%
- Protein Binding
- ≥98%
Dosage
Typical dosage: 10-80 mg once daily
Available Forms
- Tablet
Side Effects
Common
- Myalgia
- Arthralgia
- Diarrhea
- Nasopharyngitis
Serious
- Rhabdomyolysis
- Hepatotoxicity
- New-onset diabetes
Rare
- Immune-mediated necrotizing myopathy
Drug Interactions
CYP3A4 inhibition increases atorvastatin levels and myopathy risk.
Increases atorvastatin levels. Avoid large quantities.
Warnings
Pregnancy
Category X
Toxicity
Myopathy and rhabdomyolysis. Discontinue if CK significantly elevated.
Overdose
No specific antidote. Supportive care.
References
Looking for patient-friendly information? Visit RemedyDoor for easy-to-read guides about this medication.