Lipitor belongs to the class of medications known as statins, making it a lipid-altering drug. It is used in conjunction with an appropriate diet to lower levels of cholesterol produced by the liver. It lowers “bad” cholesterol and fats such as LDL and triglycerides (TG) and raises “good” cholesterol like HDL. By controlling lipid levels, Lipitor reduces the risk of heart disease, stroke, and heart attacks. Lipitor is indicated for:
Prevention of Cardiovascular Disease in Adults
Lipitor can be used in individuals with risk factors for coronary heart disease. Risk factors include age, hypertension, smoking, decreased HDL-C, or family history of heart disease. With use, Lipitor can:
- Decrease the risk of myocardial infarction (MI)
- Decrease the risk of stroke
- Decrease the risk of angina and revascularization procedures
Additionally, Lipitor can be used in individuals who have type 2 diabetes and risk factors for coronary heart disease like retinopathy, smoking, hypertension, or albuminuria. For these patients, Lipitor can:
- Decrease the risk of MI
- Decrease the risk of stroke
In adult patients that have existing coronary heart disease, Lipitor can also:
- Decrease the risk of non-fatal MI
- Decrease the risk of fatal and non-fatal stroke
- Decrease the risk of revascularization procedures
- Decrease the risk of CHF hospitalization
- Decrease the risk of angina
Lipitor can be used:
- As an adjunct to diet to decrease high levels of total cholesterol, LDL, apo B, and TG and elevate levels of HDL in individuals with primary hypercholesterolemia and mixed dyslipidemia
- As an adjunct to diet to treat individuals with increased levels of TGs
- Treat individuals with primary dysbetalipoproteinemia that are not responsive to adequate diet
- Decrease total cholesterol and LDL in individuals with homozygous familial hypercholesterolemia (HoFH) in conjunction with other lipid-lowering treatments
- As an adjunct to diet to decrease levels of total cholesterol, LDL, and apo B in children aged 10-17 years with heterozygous familial hypercholesterolemia (HeFH) on an adequate diet and who have an:
- LDL ? 190 mg/dL OR
- LDL ? 160 mg/dL AND a family history of premature cardiovascular disease OR more than 2 CVD risk factors exist
HOW DOES LIPITOR WORK?
Lipitor competitively blocks HMG-CoA reductase, an enzyme that converts substrates into cholesterol precursors. In animal models, Lipitor has been shown to decrease levels of cholesterol and lipoprotein through:
- Inhibition of HMG-CoA reductase and cholesterol production by the liver
- Raising the number of LDL receptors in the liver, thus increasing LDL uptake and catabolism
- Decreasing LDL production and the amount of LDL particles
Lipitor can cause some side effects with the most common ones including:
- Diarrhea or constipation
- Mild muscle pain
- Changes to blood test labs
WARNINGS AND PRECAUTIONS
Rhabdomyolysis and Myopathy
Lipitor can cause muscle pain, weakness, and tenderness with elevated creatine kinase (CK) and rhabdomyolysis. In rare cases, fatality has occurred from statin-induced rhabdomyolysis. Patients are at greater risk for developing myopathy if they are 65 years of age or older, have uncontrolled hypothyroidism, have renal impairment, are on other drugs with myopathy risk, or are on high doses of Lipitor. Patients should be counseled on symptoms, including muscle pain or weakness, malaise, or fever.
Immune-Mediated Necrotizing Myopathy
An autoimmune myopathy known as immune-mediated necrotizing myopathy (IMNM) has occurred in patients using statins. IMNM includes symptoms such as muscle weakness, increased serum CK, positive anti-HMG CoA reductase antibody, and necrotizing antibody. If IMNM occurs, patients should be treated with immunosuppressive agents.
Statins have been shown to increase levels of serum transaminases over 3 times the upper limit of normal (ULN). Therefore, Lipitor should be used with caution in individuals who are heavy alcohol drinkers and/or who have liver disease.
Statins can affect the synthesis of cholesterol and therefore may slow adrenal and/or gonadal steroid production. Lipitor should be used in caution in those who have low levels of endogenous steroid hormone, like ketoconazole or cimetidine.
Cyclosporine or Gemfibrozil
Cyclosporine and gemfibrozil used concomitantly with Lipitor can increase one’s risk of myopathy and rhabdomyolysis. Therefore, cyclosporine and gemfibrozil should not be taken if also on Lipitor.
Many antiviral medications are potent inhibitors of CYP3A4 and transporters. Therefore, concomitant use of antiviral medications and statins has been shown to increase statin plasma concentrations. This can put an individual at risk for rhabdomyolysis and myopathy. Providers and patients should proceed with caution when taking certain antiviral medications along with Lipitor.
Certain Azole Antifungals and Macrolide Antibiotics
Certain azole antifungals and macrolide antibiotics inhibit CYP3A4 and transporters. If on itraconazole and clarithromycin, patients should not exceed more than 20 mg of Lipitor daily. Providers should take into account the risk and benefits of proceeding with simultaneous use of other azole antifungals and macrolide antibiotics with Lipitor. Additionally, patients should be monitored for myopathy symptoms.
Concomitant use of niacin and statins has been shown to cause myopathy and rhabdomyolysis. If simultaneous use is necessary, patients should be monitored for symptoms of myopathy throughout the course of therapy.
Fibrates (besides Gemfibrozil)
Fibrates alone carry the risk of myopathy. Therefore, there is increased risk of rhabdomyolysis and myopathy when fibrates are used with Lipitor. If used together, patients should be monitored for signs of myopathy.
Use of colchicine and Lipitor together have been shown to cause myopathy and rhabdomyolysis. If used together, patients should be monitored for signs of myopathy.
Excessive intake of grapefruit juice (greater than 1.2 liters per day) can cause increased concentrations of Lipitor in the plasma. This can increase an individual’s risk for developing rhabdomyolysis and myopathy. Patients should avoid excessive intake of grapefruit juice when taking Lipitor.
Rifampin is an inducer of CYP3A4 and inhibitor of OATP1B1. When taken with Lipitor, rifampin can cause decreased levels of atorvastatin in the plasma. Separated administration of rifampin and Lipitor can cause significant decreases in atorvastatin plasma concentrations. Therefore, if taking rifampin, Lipitor and rifampin should be given at the same time.
Lipitor has been shown to elevate norethindrone and ethinyl estradiol concentrations in the plasma when taken concomitantly. This interaction should be considered when picking a patient’s mode of contraception.
When used concomitantly, Lipitor can increase concentrations of digoxin. Therefore, patients should be monitored if on both.