Very Interesting

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Myositis (Muscle Inflammation)…Check The Meds!

I am a rheumatologist – an internal medicine specialist who is trained

to evaluate, diagnose, and treat diseases that involve the muscles and

joints. Because rheumatologists have a keen interest in undiagnosed

conditions, I see a number of patients every week who are seeking a

first diagnosis.

It is commonplace for doctors to refer patients to a rheumatologist for

the evaluation of painful muscles. There are many diseases that are

associated with inflammation of muscles. Furthermore, many conditions

may appear to involve muscles, but may actually be a result of disease

of the tendons, joints, or bones.

By way of illustration, I want to call viewers' attention to a patient

that I just saw in the office this week. I feel that this patient is

very representative of a muscle condition that is underappreciated

nowadays. I also know that patients and doctors should have a heightened

awareness of this condition since it is easily managed when discovered

early. When discovered late, it can lead to serious injury - not only to

the muscles, but also potentially to the kidneys and heart.

Mr. is a 75 year old man who was referred by a cardiologist

because of pains and stiffness in the muscles of his arms, shoulders,

thighs, and buttocks. He has been taking Lipitor (atorvastatin) for six

months to control elevated cholesterol levels in his blood. Mr.

reported muscle aching for the past eight weeks. He was also weak in the

locations of pain. Blood testing for the muscle enzyme, CPK, was mildly

elevated

Now, here's my point:

Lipitor is a member of a class of cholesterol-lowering drugs called

statins. The statins include lovastatin (brand name: Mevacor),

simvastatin (Zocor), pravastatin (Pravachol), fluvastatin (Lescol),

atorvastatin (Lipitor), and cerivastatin (Baycol). Statin drugs are

known to cause muscle pains and inflammation around the muscle cells

(myositis). It should also be noted that the risk of muscle injury is

greater when a statin is combined with other drugs that also cause

muscle damage by themselves. For example, when lovastatin (Mevacor) is

used alone to lower cholesterol, muscle damage occurs on the average in

one person out of about every 500. However, if lovastatin (Mevacor) is

used in combination with other drugs such as niacin, gemfibrozil (Lopid)

or fenofibrate (Tricor) to further reduce cholesterol levels, the risk

of muscle injury skyrockets to one person out of every 20 to 100 who

receive the combination. The risk of muscle damage is thus multiplied 5

to 25-fold by using a combination of a statin and another

cholesterol-lowering drug rather than by just using statin alone.

In fact, the manufacturers of statins recommend that any patient taking

a statin " should be advised to report promptly any unexplained muscle

pain, tenderness or weakness….  When a muscle disease is suggested,

the doctor stops the statin drug.

You see, statin drugs cause three types of muscle conditions. First,

they can cause muscle aching. This condition generally reverses itself

within weeks of discontinuing the drugs. Second, they can cause muscle

pains and mild muscle inflammation that may also be accompanied by minor

weakness. Blood testing for the muscle enzyme, CPK, is mildly elevated.

This condition also generally reverses, but it may take several months

to resolve. Third, statins can cause severe muscle inflammation and

damage so that not only are the muscles painful all over the body, they

also become severely weakened. Heart muscle can even (rarely) become

affected. Blood testing for the muscle enzyme, CPK, is markedly

elevated. When the muscles are severely damaged, the muscle cells

release proteins into the blood that collect in and can damage the

kidneys. This can lead to kidney failure and require dialysis.

In each of the above three forms of muscle conditions that result from

statin drugs, the outcome is always much better when the condition is

detected early.

My patient is expected to do well. I have discontinued his Lipitor and

his muscle pain and stiffness will resolve in the upcoming weeks. He

will follow-up with me in a month for a progress report.

There are many other medications (aside from statins) and diseases that

can cause muscle aching. Of all causes, however, statin drugs are what I

see as the most common culprits. If you or someone you know has muscle

pains, check the medications being taken first!

Finally, please understand that the statin drugs have been shown to be

the most effective (and widely prescribed) medications to optimally

lower cholesterol and prevent heart attacks and stroke. This perspective

article is intended to highlight the fact that even the best drugs

require monitoring and can have side effects.

For an excellent review of statin drugs and their common side effects,

see MedicineNet.com's Doctors' Views for Drugs to Lower Cholesterol –

Warning.

C. Shiel Jr., M.D., F.A.C.P., F.A.C.R.

 

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