atorvastatin

Atorvastatin (Lipitor) is a type of statin that lowers the level of cholesterol in the blood. All statins, including atorvastatin, prevent the production of cholesterol in the liver by blocking HMG-CoA reductase, an enzyme that makes cholesterol. Statins reduce total cholesterol as well as LDL cholesterol in the blood.

LDL cholesterol is believed to be the "bad" cholesterol that is primarily responsible for the development of coronary artery disease. Reducing LDL cholesterol levels retards progression and may even reverse coronary artery disease. Atorvastatin also raises the concentrations of HDL ("good") cholesterol that protects against coronary artery disease and reduces the concentration of triglycerides in the blood. (High blood concentrations of triglycerides also have been associated with coronary artery disease.)

Examples of other statins include:

• lovastatin (Mevacor, discontinued),
• simvastatin (Zocor, discontinued),
• fluvastatin (Lescol, Lescol XL — discontinued),
• pravastatin (Pravachol, discontinued)
• pitavastatin (Livalo, Zypitamag), and
• rosuvastatin (Crestor)

Atorvastatin (Lipitor) uses

Lipitor is used for the treatment of elevated total cholesterol, LDL, and triglycerides, and to elevate HDL cholesterol. The effectiveness of Lipitor in lowering cholesterol is dose-related, meaning that higher doses reduce cholesterol more.

In individuals with coronary artery disease Lipitor prevents:

• angina,
• stroke,
• heart attack,
• hospitalization for congestive heart failure, and
• revascularization procedures.

Lipitor reduces the risk of heart attack, stroke, angina, and revascularization procedures in adults without evidence of coronary heart disease, but with multiple risk factors for coronary artery disease, for example:

• Smoking
• Hypertension
• Family history of coronary heart disease
• Lipitor also prevents heart attacks and strokes in patients with type 2 diabetes without evidence of heart disease, but with multiple risk factors for coronary artery disease.

Atorvastatin (Lipitor) is generally well tolerated. Minor side effects include:

• Constipation
• Diarrhea
• Fatigue
• Gas
• Heartburn
• Headache

Other commonly reported side effects include:

• Common cold (nasopharyngitis)
• Joint pain (arthralgia)
• Pain in the extremities
• Urinary tract infection

Atorvastatin may cause liver and muscle damage. Serious liver damage caused by statins is rare. Liver tests should be performed at the beginning of treatment and then as needed thereafter.

Inflammation of the muscles caused by statins can lead to a serious breakdown of muscle cells called rhabdomyolysis. Rhabdomyolysis causes the release of muscle protein (myoglobin) into the blood, and myoglobin can cause kidney failure and even death. When used alone, statins cause rhabdomyolysis in less than one percent of patients. To prevent the development of serious rhabdomyolysis, patients taking atorvastatin should contact their healthcare professional immediately if they develop unexplained muscle pain, weakness, or muscle tenderness.

Statins have been associated with increases in HbA1c and fasting serum glucose levels as seen in diabetes.

Post-marketing reports for atorvastatin of adverse events include:

• Memory loss
• Forgetfulness
• Amnesia
• Confusion
• Memory impairment

Symptoms may start one day to years after starting treatment and resolve within a median of three weeks after stopping the statin.

• Lipitor is prescribed once daily.
• The usual starting dose for adults is 10-20 mg per day, and the maximum dose is 80 mg per day. Adults who need more than a 45% reduction in LDL cholesterol may be started at 40 mg daily.
• Pediatric patients should receive 10 mg once daily up to a maximum dose of 20 mg daily.
• Lipitor may be taken with or without food and at any time of day.

Decreased elimination of Lipitor could increase levels of Lipitor in the body and increase the risk of muscle toxicity from Lipitor. Therefore, Lipitor should not be combined with drugs that decrease its elimination. Examples of such drugs include:

• erythromycin (E-Mycin),
• ketoconazole (Nizoral),
• itraconazole (Sporanox),
• clarithromycin (Biaxin),
• telithromycin (Ketek),
• cyclosporine (Sandimmune),
• nefazodone (Serzone), and
• HIV protease inhibitors such as indinavir (Crixivan) and ritonavir (Norvir).

Large quantities of grapefruit juice (>1.2 liters daily) also will increase blood levels of Lipitor and should not be taken.

The following drugs also may increase the risk of muscle toxicity when combined with Lipitor.

• amiodarone (Cordarone)
• verapamil (Calan Verelan, Isoptin)
• cyclosporine (Sandimmune)
• niacin (Niacor, Niaspan, Slo-Niacin)
• gemfibrozil (Lopid)
• fenofibrate (Tricor)

Lipitor increases the effect of warfarin and the concentration in the blood of digoxin (Lanoxin). Patients taking Lipitor and warfarin or digoxin should be monitored carefully. Cholestyramine decreases the absorption of Lipitor. Lipitor should be given at least two hours before and at least four hours after cholestyramine.

Rifampin increases the breakdown of Lipitor. To reduce the likelihood of this interaction both drugs should be given at the same time. Lipitor should not be given after rifampin.

• Lipitor may cause fetal harm when administered to a pregnant woman. Lipitor should be discontinued as soon as pregnancy is recognized. Lipitor should only be administered to women of childbearing age if they are not likely to become pregnant.
• It is not known if Lipitor is secreted in breast milk. Because of the potential risk of adverse events, breastfeeding mothers should not use Lipitor.