Muscle injury with statin therapy can range from myalgias to myositis to rhabdomyolysis. Muscle symptoms usually begin within weeks to months after starting statins and usually return to normal over days to weeks after drug discontinuation.
You should warn your patients about new onset muscle pain and weakness when you start a statin. A CK level should be obtained at baseline, but routine monitoring of serum CK levels is not recommended.
Patients with acute or chronic renal failure, liver disease, and hypothyroidism are at higher risk of developing muscle injury. Clinical symptoms or a CK level >10X the upper limit of normal should prompt a drug discontinuation.
Pravastatin and fluvastatin appear to have much less intrinsic muscle toxicity than other statins. After the CK has returned to baseline, patients may be tried on a statin less likely to cause muscle toxicity with careful monitoring.
Here is review on the topic.
An assessment of statin safety by muscle experts. Thompson PD, Clarkson PM, Rosenson RS, National Lipid Association Statin Safety Task Force Muscle Safety Expert Panel. Am J Cardiol. 2006;97(8A):69C.
