Side-effects of Statin Drugs

Statin drugs are popular cholesterol lowering drugs these days. We call them statin drugs because the generic names of these drugs end up with "statin."

These drugs include simvastatin ( Zocor), atorvastatin ( Lipitor), rosuvastatin (Crestor), pravastatin ( Pravachol), fluvastatin ( Lescol) and lovastatin (Mevacor).

A lot of people suffer from the side-effects of these drugs.These side-effects include:

Muscle Aches and Pains.

Muscle aches and pains are common side-effects from these drugs. Often physicians blame it on something else, such as fibromyalgia, chronic fatigue, physical inactivity etc. In the USA, physicians may even run a number of expensive tests and send their patients to a number of specialists, who may even put them on a number of pain killers, but will often keep them on a statin drug.

A conscientious physician may even order a blood test to see if muscle aches and pains are due to a statin drug. This test is called CK (or CPK).CK is an enzyme that is present in the muscle cells. If muscle cells die, then this enzyme gets released into blood circulation.Even if CK is elevated, many physician in the USA may keep their patients on a statin drug because they are under this misconception that for a statin drug to cause any problem, the CK level has to be pretty high, at least three times the upper limit of normal. Why? Because this is the level drug companies arbitrarily chose as  acut-off point. For this reason, the reported incidence by the drug companies of the side-effect of muscle aches and pains due to a statin drug was not terribly high in the clinical trials that led to their approval by the FDA ( Food and Drug Administration).  But when these drugs got into the real every-day medical practice, a lot of physcians were amazed how frequently patients experienced muscle aches and pains due to statin drugs.

How does a statin drug cause muscle aches and pains? To understand this side-effect, you need to understand the mechanism of action of a statin drug, which works by inhibiting an enzyme called HMG-CoA reductase, in the liver cells and that's how it lowers the level of LDL cholesterol. As it turns out, HMG-CoA reductase is also present in the muscle cells. And a statin drug inhibits this enzyme in the muscle cells as well. In doing so, a statin drug unfortunately may also interfere with the normal functioning of the  mitochondria inside the muscle cells. These mitochondria are the "energy power houses" inside the muscle cells. Isn't it pretty obvious how a statin drug may jeopardize the health of a muscle cell.

Rhabdomyolsis and Acute Kidney Falire

Sometimes, statin drugs can cause severe muscle pains, weakness and an acute kidney failure. This happens if mild muscle damage due to a statin drug is not diagnosed and a statin drug is continued. This can lead to severe muscle necrosis.Technically we call it Rhabdomyolysis.

Patient may experince severe muscle pain. CK is markedly elevated. The breakdown products of muscle necrosis can cause life-threatening condition of acute renal failure. 

Liver Failure

Liver injury is another well known side-effect of statin drugs. As a statin drug lowers LDL cholesterol by interfering with the normal functioning of the liver cells, in some individuals, it can lead to liver injury.

This side-effect is often diagnosed on a blood test, called, ALT( or SGPT), which gets elevated. Usually patients have no symptoms.

Increased risk for the Development of Diabetes

Statin drugs are linked to increased risk for the development of Diabetes. A recent, large clinical study clearly linked major statin drugs to a statistically significant increased risk for developing diabetes. In this study (1), researchers performed a meta-analysis of 13 statin studies and found a statistically significant, overall 9% increase in the risk for developing diabetes. The risks of developing diabetes associated with individual statin were as follows:

Atorvastatin (Lipitor) = 14% Simvastatin (Zocor) = 11% Rosuvastatin (Crestor) = 18% Pravastatin (Pravachol) = 3%

Also, in an earlier study, researchers were surprised to find an increased risk for developing diabetes. This study was called JUPITER (Use of Statins in Primary Prevention: An intervention Trial Evaluating Rosuvastatin). This trial was aimed at seeking more people to go on a statin, rosuvastatin (Crestor).


References: 1. Sattar N, Preiss D, Murray HM, et al.Statins and risk of incidental diabetes: a collaborative meta-analysis of randomized statin trials.Lancet 2010DOI:10,1016/S0140-6736(09)61965-6


This article was written by Sarfraz Zaidi, MD, FACE. Dr. Zaidi specializes in Diabetes, photoEndocrinology and Metabolism.

Dr. Zaidi is a former assistant Clinical Professor of Medicine at UCLA and Director of the Jamila Diabetes and Endocrine Medical Center in Thousand Oaks, California.


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