The FDA has issued a new warning about the cholesterol drug simvastatin (Zocor). It recommends that doctors “sharply curtail” prescriptions of 80 mg simvastatin, given to an estimated 2.1 million Americans last year, due to the risk of muscle injury. It’s well established that cholesterol-lowering statin drugs can cause myopathy, or muscle damage in up to 20% of those who use them. Symptoms that can go with myopathy include muscle pain and weakness, fatigue and depression. The damage done to muscles by statin-induced muscle myopathy can be permanent. The higher 80 mg dose of Zocor is more likely to cause myopathy.
If you’re taking a statin drug and experience muscle pain or weakness, even months or years after you start taking them, you should immediately suspect the drug. This is particularly true of seniors, who may assume that muscle weakness is simply caused by aging. (There’s no evidence that statins save lives in women over age 55 or men over 70.) Research suggests that the creatinine phosphokinase (CK) tests doctors use to determine muscle damage by statins may not be accurate because the damage can go on at a microscopic level not picked up by the test.
The journal article listed below by Fernandez et al, is an excellent review of statin-induced myopathy and is a free download.
For more information read:
Fernandez G, Spatz ES, Jablecki C, Phillips PS, “Statin myopathy: a common dilemma not reflected in clinical trials,” Cleve Clin J Med. 2011 Jun;78(6):393-403. Available at: http://www.ccjm.org/content/78/6/393.long
Mohaupt MG, Karas RH, Babiychuk EB, et al. Association between statin-associated myopathy and skeletal muscle damage. CMAJ 2009; 181:E11-E18. Available at: http://www.cmaj.ca.