Statins (HMG-CoA Reductase Inhibitors)

What is cholesterol?

Cholesterol (also called a lipid) is a fat-like substance present in cell walls or membranes everywhere in the body, including the brain, nerves, muscles, skin, liver, intestines, and heart. The body needs cholesterol to produce many hormones, vitamin D, the bile acids, build the walls of cells. The body makes cholesterol and gets it from food.

There are two types of cholesterol: a "good" cholesterol called high-density lipoprotein (HDL) and a "bad" cholesterol called low-density lipoprotein (LDL). HDL cholesterol carries cholesterol back to the liver, where it is removed from the body. The liver can excrete excess cholesterol as bile acids. LDL transports cholesterol from the liver to the tissues of the body, therefore it is considered the "bad" cholesterol.

Cholesterol levels rise slightly with age. Women generally have a higher HDL cholesterol level than men.

Dangers of high cholesterol levels

Having high blood cholesterol is a risk factor for several diseases:

Atherosclerosis is a build-up of plaque on the inner walls of arteries. If the LDL levels are too high, the excess can accumulate on the arterial walls. This build-up of plaque can narrow the artery and lead to arteriosclerosis, which turns the normally flexible tissue into more brittle.
Alzheimer's disease - people with high cholesterol levels are at increased risk for developing Alzheimer's disease or vascular dementia
Cardiovascular disease - high cholesterol is a direct contributor to cardiovascular disease, which can lead to stroke and heart attack. The World Health Organization estimates that about 20% of all strokes and over 50% of all heart attacks can be linked to high cholesterol.

Statins (HMG-CoA reductase inhibitors)

Statin drugs (HMG-CoA reductase inhibitors) are lipid-lowering medications. Statins lower the blood level of LDL cholesterol. These agents also slightly raise levels of HDL cholesterol.

Commonly prescribed statins include:

Atorvastatin (Lipitor)
Fluvastatin (Lescol, Lescol XL)
Lovastatin (Mevacor, Altocor)
Pravastatin (Pravachol)
Rosuvastatin (Crestor)
Simvastatin (Zocor)

Baycol (cerivastatin) was removed from the market in 2001 because of serious side effects.

Statins inhibit the enzyme HMG-CoA reductase, which controls the rate of cholesterol production in the body. These drugs lower cholesterol by slowing the production of cholesterol and by increasing the liver's ability to remove the "bad" cholesterol (low-density lipoprotein) already in the blood.

Statins provide the greatest benefit to people with coronary heart disease, diabetes, high cholesterol levels, and other risk factors for heart disease.

Effectiveness of Statins

Statins are considered to be the most effective drugs for lowering LDL. All statins have the ability to reduce LDL cholesterol by 30% or more. Atorvastatin, lovastatin and simvastatin can reduce LDL cholesterol in excess of 40%. Atorvastatin has demonstrated the ability to reduce LDL by 50% or greater.

Lovastatin, pravastatin and simvastatin have been demonstrated in high quality clinical trials to reduce cardiovascular health problems. Atorvastatin and fluvastatin reduced some cardiovascular diseases in fair quality studies.

Statins side effects

Statin side effects have been the subject of controversy over the past years. Research is revealing new serious side effects associated with statin medications use.

Muscle pain, Statin induced myopathy
The most common statin side effects are muscle pain and muscle weakness. Many people on statins develop muscle weakness and pain. New research1 shows that in some people statins cause serious structural muscle damage.

Liver dysfunction
All statin drugs have been shown to elevate liver enzymes. There is evidence that the statins may cause liver damage in high doses. Although most cases of liver damage from statins are minor and reversible, some can be severe or even potentially fatal.

Statin-induced CoQ10 depletion
Statins have been found to decrease Coenzyme Q10 production as a side effect of their action. CoQ10 plays a key role in the mitochondria, the energy-producing center of the cell. Statins can lower CoQ10 plasma levels by as much as 40%2.

Memory problems
Some people taking statin medications develop memory problems, confusion, and transient amnesia.

Other side effects
A large variety of other side effects have been reported with statins, including (but not limited to) gastrointestinal side effects, neurological effects, psychiatric problems, immune effects, sexual dysfunction, rash and skin problems, and sleep problems.

References

1. Mohaupt MG, Karas RH, Babiychuk EB, Sanchez-Freire V, Monastyrskaya K, Iyer L, Hoppeler H, Breil F, Draeger A. Association between statin-associated myopathy and skeletal muscle damage. CMAJ. 2009 Jul 7;181(1-2):E11-8.
2. Ghirlanda G, Oradei A, Manto A, Lippa S, Uccioli L, Caputo S, Greco AV, Littarru GP. Evidence of plasma CoQ10-lowering effect by HMG-CoA reductase inhibitors: a double-blind, placebo-controlled study. J Clin Pharmacol. 1993 Mar;33(3):226-9.

Last updated: September, 2009