Lipitor (atorvastatin) vs. Zetia (ezetimibe)

• Lipitor (atorvastatin) and Zetia (ezetimibe) are used to lower cholesterol levels in the blood.
• Lipitor and Zetia belong to different drug classes. Lipitor is an HMG-CoA reductase inhibitor (a “statin” drug) and Zetia is a cholesterol-lowering drug.
• Side effects of Lipitor and Zetia that are similar include diarrhea and joint pain.
• Side effects of Lipitor that are different from Zetia include constipation, fatigue, gas, heartburn, headache, common cold, pain in the extremities, and urinary tract infection (UTI).
• Side effects of Zetia that are different from Lipitor include abdominal pain, back pain, muscle aches, and sinusitis.

Lipitor (atorvastatin) is a “statin” drug (an HMG-CoA reductase inhibitor) used to lower cholesterol levels in the blood. Lipitor reduces total cholesterol along with LDL (“bad”) cholesterol, which is chiefly responsible for coronary artery disease development. Reducing LDL cholesterol slows the progression and can reverse coronary artery disease. Lipitor also raises HDL ("good") cholesterol that protects against coronary artery disease and reduces the concentration of triglycerides in the blood, which are also associated with coronary artery disease. Lipitor prevents angina, stroke, heart attack, hospitalization for congestive heart failure, and revascularization procedures in individuals with coronary artery disease.

Zetia (ezetimibe) is used to treat elevated blood cholesterol. The most commonly used class of drugs for lowering cholesterol levels, statins, acts by preventing the production of cholesterol by the liver. Zetia has a different mechanism of action and lowers blood cholesterol by reducing the absorption of cholesterol from the intestine. It does not affect the absorption of triglycerides or fat-soluble vitamins.

Lipitor

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

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

Inflammation of the muscles caused by statins can lead to 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 health-care 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.

Zetia

The most common side effects of ezetimibe are:

• diarrhea,
• abdominal pain,
• back pain,
• joint pain,
• muscle aches, and
• sinusitis.

Hypersensitivity reactions, including angioedema (swelling of the skin and underlying tissues of the head and neck that can be life-threatening) and skin rash rarely occur.

Other important side effects include:

• Nausea,
• pancreatitis,
• muscle damage (myopathy or rhabdomyolysis) and
• hepatitis

Lipitor

• 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.

Zetia

• The recommended dose of ezetimibe is 10 mg daily. Ezetimibe can be taken with or without food and at the same time as statin drugs.

Lipitor

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 includes:

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

Zetia

Cholestyramine (Questran), colestipol (Colestid) and colesevelam (WelChol), bile acid-binding drugs that may be used to treat elevated levels of cholesterol, bind to ezetimibe and reduce its absorption from the intestine by about 50%. Therefore, ezetimibe should be taken at least two hours before or 4 hours after administration of these drugs. Cyclosporine (Gengraf, Neoral) increases the levels of ezetimibe while ezetimibe increases levels of cyclosporine. Combining both drugs may increase side effects of either drug.

Lipitor

• Lipitor should not be taken during pregnancy because the developing fetus requires cholesterol for development, and Lipitor reduces the production of cholesterol. 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.

Zetia

• There are no adequate studies of ezetimibe in pregnant women. Therefore, physicians must weight the benefit of prescribing ezetimibe during pregnancy against potential but unknown risks.
• There are no adequate studies of ezetimibe in women who are breastfeeding. Therefore, physicians must weight the benefit of prescribing ezetimibe to nursing women against potential but unknown risks.