Simvastatin vs. Atorvastatin

Simvastatin vs. Atorvastatin: What You Should Know


Simvastatin and atorvastatin are both cholesterol-lowering drugs called statins. They block an enzyme in the body to prevent your body from making cholesterol. 

Cholesterol is naturally produced in your body. Your diet has sources of cholesterol too. Cholesterol or plaque can accumulate in your blood vessels and can start to impact circulation. If these plaques break off, they can block a vessel or travel to your brain. If so, you could have a heart attack or a stroke.

Diabetes, high blood pressure, or heart disease can cause inflammation, which can also increase your risk of forming plaques in your vessels. Statins can help prevent plaque formation and may even reduce it.

What are statins?

Statins are often prescribed to help lower your cholesterol. According to the American College of Cardiology statins can help, if you:

  • have a buildup of cholesterol inside your blood vessels
  • have high LDL, also known as bad cholesterol, which is greater than 190 mg/dL
  • have diabetes, are between 40 and 75 years old, and have LDL between 70 to 189 mg/dL, even without buildup of cholesterol inside your blood vessels
  • have LDL between 70 to 189 mg/dL, are between 40 and 75 years old, and have at least a 7.5 percent risk that cholesterol could build up in your blood vessels

What are the differences between simvastatin and atorvastatin?

Both drugs are taken orally and available in generic form. You can also find both drugs available in a range of doses and dispensed in every pharmacy.

Cost • less expensive; may cost $10-$15 a month
• brand name Zocor may cost between $200-$250 a month
• more expensive; may cost $25-$40 a month
• brand name Lipitor may cost between $150-$200 a month
Interactions • several drug interactions, which can increase side effects
• interacts with grapefruit juice
• several drug interactions, which can increase side effects
• interacts with grapefruit juice
Side Effects • slightly more likely to cause muscle pain
• may cause fatigue
• may increase blood sugar and risk of developing diabetes
• more likely to cause upset stomach or diarrhea
• higher doses are associated with higher risk of stroke if you’ve had a stroke or transient ischemic attack (TIA) in the last six months
• may increase blood sugar and risk of developing diabetes
• may cause fatigue
Effectiveness • may reduce LDL level by 30 to 50 percent • more potent; could reduce LDL level by more than 50 percent

Drug interactions

Both drugs have a number of drug interactions, which can raise the level of the drug in your body and increase your risk of side effects. 

antibiotics and antifungals, like erythromycin, clarithromycin, itraconazole, and ketoconazoleantibiotics and antifungals, like erythromycin, clarithromycin, itraconazole, and rifampin
colchicine (Colcrys)colchicine (Colcrys)
heart disease drugs, like amiodaroneheart disease and blood pressure drugs, including digoxin, diltiazem, and verapamil
blood pressure drugs, including verapamil, diltiazem, and amlodipineoral contraceptives (drug levels of some of these hormones may increase if you take atorvastatin)
HIV drugs, including protease inhibitorsHIV drugs, including protease inhibitors such as atazanavir/ritonavir and lopinavir/ritonavir and others for HIV
cholesterol lowering drugs like gemfibrozil, niacin, and fibratescholesterol lowering drugs like gemfibrozil, fenofibrate, and niacin
anti-rejection drugs, like cyclosporinetipranavir used to treat HIV
warfarin (your doctor may have to adjust your dose)grapefruit juice
grapefruit juice

Muscle pain and fatigue

All statins can cause muscle pain. Simvastatin is more likely to cause this pain than atorvastatin. Muscle pain may develop gradually and can feel like a pulled muscle or fatigue from exercise. Call your doctor about any new pain you experience when you start a statin. This pain can lead to kidney problems or even damage.

A related side effect is fatigue. A study funded by the National Institutes of Health compared fatigue in patients who took small doses of simvastatin and pravastatin. Women in particular have a substantial risk of fatigue from statins, which was greater from simvastatin. 

Upset stomach and diarrhea

Both drugs can also cause stomach upset and diarrhea. Atorvastatin has more intense versions of these side effects. Usually this resolves over a few weeks. 

Liver and kidney disease

If you experience darkened urine or pain in your side, call your doctor immediately. A few people who take statins develop liver disease. 

If you have severe kidney disease, atorvastatin could be the better choice for you, since there is no need to adjust the dose. When simvastatin is given to those with severe kidney disease at the highest dose (80 mg per day) it may slow the kidneys. If you take it for an extended period of time, the amount of the drug in your system can add up. Talk to your doctor before taking any new drug, if you have severe kidney disease.

In 2014, the American Heart Association published two large, randomized controlled studies with more than 8,000 patients. Patients with no kidney disease, as well as many patients with mild to moderate kidney disease were included in these studies. Both studied whether high-dose simvastatin or atorvastatin were likely to cause kidney injury. Researchers found no increased risk of kidney injury within the two studies. 


A high dose of atorvastatin (80 mg per day) is associated with a higher risk of stroke if you’ve had a stroke or TIA in the last six months. This and other statins could also increase your blood sugar and hemoglobin A1C, which is a measure of long-term blood sugar. 

The takeaway

If you need low to moderate intensity treatment to reduce cholesterol, simvastatin may be the right choice. If your LDL is very high, your doctor may put you on a higher intensity treatment like atorvastatin. This statin can lower your bad cholesterol, LDL, by more than 50 percent.

If you currently take simvastatin or atorvastatin, ask your doctor the following:

  • Why am I taking this drug?
  • How well is this drug working for me?

Your individual health risks help your doctor determine which drug is right for you.

Don’t stop taking your statin without talking to your doctor. Statins only work if they are taken every day.

If you’re having side effects, like muscle pain, dark urine, or you worry about kidney disease, your doctor can check your lab work to help prevent these problems.

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