Atorvastatin

# Atorvastatin ## Overview - **Classification**: HMG-CoA Reductase Inhibitor (Statin) - **Mechanism**: Competitively inhibits HMG-CoA reductase, the enzyme responsible for cholesterol synthesis in the liver. This leads to increased LDL receptor expression and reduced LDL-C levels. ## Primary Indications 1. **Hyperlipidemia**: Adjunct to diet to reduce elevated total cholesterol (TC), LDL-C, apoB, and triglycerides (TG) in adults and children ≥10 years. 2. **Primary Prevention of Cardiovascular Disease**: Reduce risk of MI, stroke, and revascularization procedures in patients with multiple risk factors. 3. **Secondary Prevention of Cardiovascular Events**: Reduce risk of MI, stroke, angina, and revascularization in patients with established CVD. ## Adult Dosing ### Standard Dosing **Hyperlipidemia / Cardiovascular Risk Reduction** - **Dose**: **10 mg** to **80 mg** - **Frequency**: Once daily - **Route**: Oral - **Special Considerations**: Initiate with **10 mg** or **20 mg** QD. May initiate **40 mg** QD for patients requiring large LDL-C reductions. Adjust dose every 2-4 weeks. ### Dose Adjustments - **Renal Impairment**: No dose adjustment required. - **Hepatic Impairment**: Contraindicated in active liver disease. Use with caution in patients with a history of liver disease. - **Elderly Patients**: No specific dose adjustment needed based solely on age. Start with lowest effective dose. ## Pediatric Dosing ### Neonates (0-28 days) - **Special Notes**: Not typically indicated; safety and efficacy not established. ### Infants (1-12 months) - **Special Notes**: Not typically indicated; safety and efficacy not established. ### Children (1-12 years) **Heterozygous Familial Hypercholesterolemia (HeFH) (Ages 10-17 years)** - **Dose**: Initial **10 mg** once daily - **Frequency**: Once daily - **Maximum**: **20 mg** once daily - **Special Notes**: Dose titration may occur at 4-week intervals. Only for patients aged 10-17 years with HeFH. ### Adolescents (13-18 years) **Heterozygous Familial Hypercholesterolemia (HeFH)** - **Dose**: Initial **10 mg** once daily - **Frequency**: Once daily - **Maximum**: **20 mg** once daily - **Special Notes**: Follows the same dosing as children 10-17 years for HeFH. **Homozygous Familial Hypercholesterolemia (HoFH) (Ages 10-17 years)** - **Dose**: **10 mg** to **80 mg** once daily - **Frequency**: Once daily - **Maximum**: **80 mg** once daily - **Special Notes**: Adult dosing range may be used for HoFH. ## Safety Information ### Contraindications - **Absolute**: Active liver disease, including unexplained persistent elevated serum transaminases. - **Absolute**: Pregnancy (Category X). - **Absolute**: Breastfeeding. - **Absolute**: Concomitant use with glecaprevir/pibrentasvir. ### Common Adverse Effects - **Common (1-10%)**: Myalgia, arthralgia, diarrhea, nasopharyngitis, dyspepsia, nausea. - **Serious but Rare**: Rhabdomyolysis with acute renal failure, hepatic failure, myopathy, immune-mediated necrotizing myopathy. ### Key Drug Interactions - **Strong CYP3A4 Inhibitors (e.g., itraconazole, clarithromycin, HIV PIs)**: Significantly increase atorvastatin levels. Limit atorvastatin dose to **20 mg** daily with clarithromycin; avoid with others. - **Cyclosporine**: Significantly increases atorvastatin exposure. Limit atorvastatin dose to **10 mg** daily. - **Gemfibrozil / Other Fibrates**: Increased risk of myopathy/rhabdomyolysis. Avoid concomitant use if possible. - **Grapefruit Juice**: Large amounts (>1.2 L/day) can increase atorvastatin levels. Avoid excessive consumption. - **Colchicine**: Increased risk of myopathy, especially in elderly or renal impairment. Use with caution. ## Monitoring & Follow-up - **Before Treatment**: Obtain baseline lipid panel (TC, LDL-C, HDL-C, TG) and Liver Function Tests (LFTs). - **During Treatment**: - Lipid panel: 4-12 weeks after initiation or dose change, then every 3-12 months. - LFTs: If clinically indicated (e.g., symptoms of liver injury). - **Clinical Signs**: Monitor for muscle pain, tenderness, weakness (myopathy/rhabdomyolysis); dark urine, jaundice, fatigue (liver injury). ## Clinical Pearls - 💡 **Timing**: Can be taken at any time of day, with or without food, due to its long half-life. - 💡 **Myalgia**: Counsel patients to report unexplained muscle pain or weakness, especially if accompanied by fever or malaise. - 💡 **Lifestyle**: Emphasize that atorvastatin is an adjunct to, not a replacement for, diet and exercise. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.