Statins' Adverse Effects Documented

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Statins' Adverse Effects Documented

http://medicalnewscenter.com/out/out.cgi?

http://www.sciencedaily.com/releases/2009/01/090127090735.htm

A paper co-authored by Beatrice Golomb, MD, PhD, associate professor

of medicine at the University of California, San Diego School of

Medicine and director of UC San Diego's Statin Study group cites

nearly 900 studies on the adverse effects of HMG-CoA reductase

inhibitors (statins), a class of drugs widely used to treat high

cholesterol.

The result is a review paper, currently published in the online

edition of American Journal of Cardiovascular Drugs, that provides

the most complete picture to date of reported side effects of

statins, showing the state of evidence for each. The paper also helps

explain why certain individuals have an increased risk for such

adverse effects.

" Muscle problems are the best known of statin drugs' adverse side

effects, " said Golomb. " But cognitive problems and peripheral

neuropathy, or pain or numbness in the extremities like fingers and

toes, are also widely reported. " A spectrum of other problems,

ranging from blood glucose elevations to tendon problems, can also

occur as side effects from statins.

The paper cites clear evidence that higher statin doses or more

powerful statins – those with a stronger ability to lower

cholesterol – as well as certain genetic conditions, are linked to

greater risk of developing side effects.

" Physician awareness of such side effects is reportedly low, " Golomb

said. " Being vigilant for adverse effects in their patients is

necessary in order for doctors to provide informed treatment

decisions and improved patient care. "

The paper also summarizes powerful evidence that statin-induced

injury to the function of the body's energy-producing cells, called

mitochondria, underlies many of the adverse effects that occur to

patients taking statin drugs.

Mitochondria produce most of the oxygen free radicals in the body,

harmful compounds that " antioxidants " seek to protect against. When

mitochondrial function is impaired, the body produces less energy and

more " free radicals " are produced. Coenzyme Q10 ( " Q10 " ) is a compound

central to the process of making energy within mitochondria and

quenching free radicals. However, statins lower Q10 levels because

they work by blocking the pathway involved in cholesterol production –

the same pathway by which Q10 is produced. Statins also reduce the

blood cholesterol that transports Q10 and other fat-soluble

antioxidants.

" The loss of Q10 leads to loss of cell energy and increased free

radicals which, in turn, can further damage mitochondrial DNA, " said

Golomb, who explained that loss of Q10 may lead to a greater

likelihood of symptoms arising from statins in patients with existing

mitochondrial damage – since these people especially rely on ample

Q10 to help bypass this damage. Because statins may cause more

mitochondrial problems over time – and as these energy powerhouses

tend to weaken with age—new adverse effects can also develop the

longer a patient takes statin drugs.

" The risk of adverse effects goes up as age goes up, and this helps

explain why, " said Golomb. " This also helps explain why statins'

benefits have not been found to exceed their risks in those over 70

or 75 years old, even those with heart disease. " High blood pressure

and diabetes are linked to higher rates of mitochondrial problems, so

these conditions are also clearly linked to a higher risk of statin

complications, according to Golomb and co-author Marcella A. ,

of UC San Diego and UC Irvine Schools of Medicine.

The connection between statins' antioxidant properties and

mitochondrial risk helps explain a complicated finding that statins

can protect against the very same problems, in some people, to which

they may predispose others – problems such as muscle and kidney

function or heart arrhythmia.

This paper was funded in part by a Wood Generalist

Physician Faculty Scholar award to Dr Golomb.

Adapted from materials provided by University of California - San

Diego