Atorvastatin vs. simvastatin comparison

Atorvastatin (Lipitor) and simvastatin (Zocor) are parts of a group of drugs called statins that revolutionized cholesterol management and heart disease prevention.

Atorvastatin and simvastatin both target the same chemical in the body to reduce drastically the bloodstream levels of LDL (low-density lipoprotein, or "bad cholesterol"), which lowers the risk it will clog up arteries, a central cause of cardiovascular problems.

These drugs also modestly raise levels of "good cholesterol" (HDL or high-density lipoprotein).

Both Lipitor and Zocor are good for lowering LDL, but Zocor is better at increasing HDL and tends to have fewer gastrointestinal side effects, according to one study.

Both atorvastatin and simvastatin share some possible side effects, including:

Lipitor and Zocor differ on a number of other less serious side effects.

A large number of drugs interact with both atorvastatin and simvastatin, so be sure to tell your doctor about all your other medications if they prescribe you either of these cholesterol drugs.

What are atorvastatin and simvastatin?

Atorvastatin and simvastatin are both chemicals that interfere with liver cells' cholesterol production. They are in a family of statins which also includes:

The molecules of the medications target an enzyme called HMG-CoA reductase, one step in the chemical process cells use to fabricate cholesterol from simpler types of molecules. Because of this, statins are called "HMG-CoA reductase inhibitors."

Cholesterol is essential for many body functions, including hormone production, cell structure, lining of nerve cells, digestion, and more. The body can make all the cholesterol it needs, but foods also contain cholesterol the body can use.

A healthy liver can balance cholesterol levels, but too much cholesterol in the bloodstream in LDL form leads to a host of cardiovascular diseases. The excess LDL forms plaques on artery walls, narrowing blood vessels to cause clots and blockages that can lead to coronary heart disease, stroke, heart attack, and other debilitating or fatal problems.

Lipitor and Zocor, as well as other statins, stop the cholesterol-making process in the liver cells by grabbing onto and binding up HMG-CoA reductase before it becomes cholesterol, sabotaging the cell's cholesterol factory.

When the liver cells can't make enough of their own cholesterol anymore because of the statin treatment, the body's cholesterol balancing impulse kicks into action, causing liver cells to suck up more LDL from the bloodstream. The cells break down the LDL into cholesterol to make up for the shortfall in production. As a consequence, less LDL is floating around in the bloodstream to add to arterial plaque deposits, thus substantially reducing cardiovascular disease risk.

Statins like atorvastatin and simvastatin also modestly increase HDL (high-density lipoproteins) in the bloodstream, which is the so-called "good cholesterol." Good levels of HDL molecules are healthy because they act as scavenger molecules, grabbing LDL from the bloodstream and taking it to the liver for processing and removal.

Researchers don't yet understand exactly how statins increase HDL.


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What are the uses for atorvastatin and simvastatin?

Lipitor and Zocor are used for the treatment of elevated total cholesterol, LDL, and triglycerides and to elevate HDL cholesterol. Both atorvastatin and simvastatin can help prevent:

Lipitor and Zocor reduce the risk of heart attack, stroke, angina and revascularization procedures in adults with multiple risk factors for coronary artery disease. Atorvastatin and simvastatin also prevent heart attacks and strokes in patients with type 2 diabetes with multiple risk factors for coronary artery disease.

What are the side effects of atorvastatin and simvastatin?

Side effects common to both Lipitor and Zocor include:

Common side effects unique to atorvastatin include constipation, fatigue, gas, heartburn, common cold, urinary tract infection and joint pain.

Simvastatin, on the other hand, can cause nausea, vomiting, gas, and allergic reactions.

The most serious possible side effect of both Lipitor and Zocor is liver damage. Statins will usually affect the results of liver tests soon after treatment starts, but then return to normal. Doctors should stop administering atorvastatin or simvastatin if liver tests for certain chemical markers remain three times normal concentrations for an extended period.

Muscle inflammation caused by Lipitor and Zocor can cause serious damage if muscle protein (myoglobin) leeches into the bloodstream. This can cause rhabdomyolysis, a potentially fatal condition that can cause kidney failure because those organs cannot filter myoglobin.

Anonther concern with both atorvastatin and simvastatin is they can raise blood sugar and HbA1c levels, mimicking conditions seen in diabetes.


In the U.S., 1 in every 4 deaths is caused by heart disease. See Answer

How should atorvastatin and simvastatin be taken (dosage)?

atorvastatin (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.

simvastatin (Zocor)

  • The recommended dose range of simvastatin is 10 mg to 40 mg, and it is administered once daily in the evening with or without food. People usually start with 10 or 20 mg daily, but those with high heart disease risk can start with 40 mg daily.
  • Simvastatin 80 mg is restricted to patients who have been taking simvastatin 40 mg long-term (for example, for a year or more) without evidence of muscle toxicity. The 80 mg dose is associated with increased risk of muscle toxicity, including rhabdomyolysis. Patients who are currently tolerating the 40 mg dose of simvastatin who need to start an interacting drug that should not be taken with simvastatin or is associated with a dose cap for simvastatin should be switched to an alternative statin or statin-based regimen with less potential for the drug-drug interaction.
  • Patients that require more than the 80 mg dose should be switched to an alternative drug.

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Which drugs interact with atorvastatin and simvastatin?

A number of drugs reduce the body's ability to get rid of both Lipitor and Zocor. They include, but aren't limited to:

Large quantities of grape fruit juice (more than 1.2 liters daily) also will increase blood levels of atorvastatin and simvastatin, so drink it sparingly.

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

A number of other drugs have reactions with Liptor and Zocor. This is not a complete list of drugs dangerous to combine with these statins, so make sure to tell your doctor about all the medications you are taking if they prescribe you atorvastatin or simvastatin.

Are atorvastatin and simvastatin safe to take during pregnancy or while breastfeeding?

Because cholesterol is vital to the formation of the fetus and the growth of infants, pregnant and nursing mothers should never take atorvastatin, simvastatin, or any other statin. The risk is so great, doctors won't prescribe statins to women of childbearing age unless they are unlikely to become pregnant.

Lipitor and Zocor are passed on in breast milk, so either feed your infant with formula or don't take any statins.


Atorvastatin (Lipitor) and simvastatin (Zocor) are both statins that lower cholesterol levels in the bloodstream. These drugs, part of a family called statins, are prescribed to treat a large number of cardiovascular disease, including to prevent heart failure. Learn dosage, side effects, and pregnancy safety information before taking this drug.

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FDA Prescribing Information

"A Comparison of Simvastatin and Atorvastatin up to Maximal Recommended Doses in Large Multicenter Randomized Clinical Trial"
D. Roger Illingworth et. al
Current Medical Research and Opinion, 2001

"The 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductases"
Jon A Friesen and Victor W Rodwell
Genome Biology, 2004

"Drug Class Review: HMG-CoA Reductase Inhibitors (Statins) and Fixed-dose Combination Products Containing a Statin: Final Report Update 5"
National Center for Biotechnology information

"Low-density lipoprotein receptor--its structure, function, and mutations"
JC Defesche
Seminars in Vascular Medicine, 2004

"Statin inhibition of HMG-CoA reductase: a 3-dimensional view."
E. Istvan
Atherosclerosis Supplements, 2003

"Effect of statins on HDL-C: a complex process unrelated to changes in LDL-C: analysis of the VOYAGER Database"
Philip J. Barter et. al
Journal of Lipid Research

"Good vs. Bad Cholesterol"
The American Heart Association