Sometimes, statin drugs interfere with the generation of proteins necessary for proper muscle functioning. This can cause symptoms of vague muscle aches and weakness throughout your body. Contact your doctor if this happens to you. Symptoms usually go away if you discontinue the medication.
If you continue taking the medication, the problem may become worse. Muscle cells and tissue may begin to break down, releasing huge quantities of the protein myoglobin into the bloodstream.
The result can overwhelm the kidney's filtering capacity, resulting in severe kidney damage. This may be followed by a life-threatening complication -- disseminated intravascular coagulation -- that affects your blood's ability to clot. Fortunately, this condition is rare in patients taking statins.
To test for rhabdomyolysis, your doctor may check your blood levels of creatinine kinase, a part of normal muscle tissue that increases in your blood when muscle cells are damaged or die.
Treatment of rhabdomyolysis starts with stopping the cholesterol-lowering drug. Other treatment includes ensuring adequate hydration, giving medications that make urine more alkaline, and giving diuretic medications to increase urine flow through kidneys. In severe cases, kidney dialysis may be required to clean the blood and relieve the strain on the kidneys.
Rhabdomyolysis is more likely if you are:
- Taking particularly high doses of statin medications (atorvastatin 40 or 80 mg/day, fluvastatin 80 mg/day, pravastatin 40 mg/day, or simvastatin 40 or 80 mg/day)
- Combining a statin drug with one or more of these:
- Gemfibrozil
- Cyclosporine
- Nicotinic acid
- An azole antifungal agent
- A macrolide antibiotic
- Erythromycin
- Clarithromycin
- Nefazodone
- Verapamil
- Amiodarone
- More than 80 years old
- A woman
- Slight in frame and/or frail
- Diabetic
- Suffering from high blood pressure; high triglycerides; or thyroid, liver or kidney disease
- Recuperating from a recent surgery
- Drinking large quantities of grapefruit juice (more than a quart a day)
- Exercising heavily on a regular basis
Here's more on the statin drugs.
Sources:
Antons, Kenneth A. "Clinical Perspectives of Statin-Induced Rhabdomyolysis." American Journal of Medicine 119(2006): 400-9. 3 Nov 2008 <http://linkinghub.elsevier.com/retrieve/pii/S0002934306001847> (subscription required).
Jones, Peter H. and Michael H. Davidson. "Reporting Rate of Rhabdomyolysis with Fenofibrate + Statin Versus Gemfibrozil + Any Statin." The American Journal of Cardiology 95(2005): 120-2. 3 Nov 2008 <http://linkinghub.elsevier.com/retrieve/pii/S0002914904014602> (subscription required).
Schwartz, Janice B. "Cardiovascular Disease in the Elderly." Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 2007.

