Atorvastatin: Uses, Dosage, Side Effects, and More
1. Drug Name
Generic Name: Atorvastatin
Brand Name(s):
- Pakistan: Atorlip, Atorva, Sortis
- India: Atorva, Lipicure, Atorlip
- United States: Lipitor
- United Kingdom: Atorvastatin
2. Pharmacological Class
Class: HMG-CoA reductase inhibitor (statin)
Subclass: Lipid-lowering agent
3. Mechanism of Action
Atorvastatin is a competitive inhibitor of HMG-CoA reductase, the enzyme that catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. By inhibiting this enzyme, atorvastatin decreases cholesterol synthesis in the liver, leading to increased uptake of LDL cholesterol and reduced plasma cholesterol levels.
4. Indications
Primary Indications:
- Hyperlipidemia (elevated cholesterol levels)
- Prevention of cardiovascular disease
- Reduction of the risk of stroke
Off-label Uses:
- Adjunct therapy in patients with homozygous familial hypercholesterolemia
- Reduction of inflammation in certain conditions
5. Dosage and Administration
Standard Dosage:
- Hyperlipidemia: Initial dose of 10-20 mg once daily; usual dose range 10-80 mg once daily.
- Prevention of Cardiovascular Disease: Initial dose of 10 mg once daily; usual dose range 10-80 mg once daily.
- Reduction of Stroke Risk: 80 mg once daily, or as directed by a healthcare provider.
Route of Administration: Oral (tablets).
Special Populations:
- Pediatric: Safety and effectiveness in pediatric patients have not been established.
- Geriatric: Consider lower starting doses due to increased risk of adverse effects.
6. Pharmacokinetics
Absorption: Rapidly absorbed from the gastrointestinal tract.
Distribution: Extensively distributed into tissues.
Metabolism: Metabolized by cytochrome P450 3A4 to active metabolites.
Excretion: Primarily excreted in the bile.
Half-life: Approximately 14 hours.
7. Contraindications
Atorvastatin is contraindicated in patients who are hypersensitive to this product or any of its components. It is also contraindicated in patients with active liver disease or unexplained persistent elevations of serum transaminases, in pregnancy, and in breastfeeding mothers.
8. Warnings and Precautions
Use with caution in patients with a history of liver disease or heavy alcohol use. Monitor for signs of liver dysfunction and myopathy. Avoid excessive alcohol consumption.
9. Side Effects
Common Side Effects: Headache, muscle pain, diarrhea, and nausea.
Serious Side Effects: Rhabdomyolysis, liver dysfunction, and diabetes mellitus. Discontinue use and notify a healthcare provider immediately if these occur.
10. Drug Interactions
Major Interactions: Gemfibrozil, cyclosporine, and certain protease inhibitors may increase the risk of myopathy or rhabdomyolysis.
Moderate Interactions: Clarithromycin, diltiazem, and certain antifungal agents.
Minor Interactions: Grapefruit juice and warfarin.
11. Pregnancy and Lactation
Pregnancy Category: Category X - Atorvastatin should not be used during pregnancy because of the potential for fetal harm. Discontinue use as soon as pregnancy is recognized.
Breastfeeding Considerations: Atorvastatin is contraindicated in breastfeeding women because of the potential for serious adverse reactions in nursing infants.
12. Patient Counseling Information
Key Points for Patients:
- Take atorvastatin exactly as directed. Do not exceed the recommended dose.
- Report any unexplained muscle pain, tenderness, or weakness to your healthcare provider immediately.
- Follow a cholesterol-lowering diet plan and exercise program while taking atorvastatin.
Administration Tips:
- Take atorvastatin at the same time each day, with or without food.
- If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Do not double the dose to catch up.