Approach to Statin-Induced Myopathy

Initial Assessment and Diagnosis

When a patient reports muscle symptoms on statin therapy, immediately obtain a CK measurement and compare it to baseline, then check TSH to rule out hypothyroidism as a contributing factor, as recommended by the American College of Cardiology and the American Heart Association 1, 2
Recent exercise or strenuous physical activity should be considered as a potential cause of muscle symptoms in patients on statin therapy, according to the American College of Cardiology 1
Hypothyroidism, which can be diagnosed with a TSH test, should be ruled out as a contributing factor to muscle symptoms in patients on statin therapy, as recommended by the American College of Cardiology 2
Other medications that may cause myopathy, such as fibrates or niacin, should be considered as potential causes of muscle symptoms in patients on statin therapy, as reported by the American Heart Association 3

Discontinue the statin immediately in symptomatic patients with CK >10× ULN, as recommended by the American College of Cardiology and the American Heart Association 1, 4
Wait for symptoms to resolve and CK levels to normalize before considering reinitiation of statin therapy in patients who have discontinued due to myopathy, as recommended by the American College of Cardiology 4, 2
Use a lower dose or consider an alternative statin when restarting therapy in patients who have experienced myopathy, as recommended by the American College of Cardiology 4

Switch to pravastatin or fluvastatin, which have fewer drug interactions and lower myopathy risk, as an alternative for statin-intolerant patients, according to the American College of Cardiology 5
Consider once-weekly rosuvastatin 5-10 mg as a second-line alternative for statin-intolerant patients, as reported by the American Heart Association 5
Use the lowest effective statin dose to achieve cholesterol goals, as myopathy risk is dose-dependent, as recommended by the American College of Cardiology 4, 5

Identify patients at increased risk for statin myopathy, including those with age >80 years, small body frame and frailty, chronic renal insufficiency, multiple medications or polypharmacy, and perioperative periods, as recommended by the American College of Cardiology and the American Heart Association 1, 3, 4
Withhold statins during hospitalization for major surgery, as myopathy risk increases significantly in this setting, as recommended by the American College of Cardiology and the American Heart Association 1, 3, 4

Do not combine statins with high-risk medications, including gemfibrozil, cyclosporine, azole antifungals, macrolide antibiotics, HIV protease inhibitors, nefazodone, verapamil and amiodarone, and large quantities of grapefruit juice, as recommended by the American College of Cardiology and the American Heart Association 1, 3, 5
Note that statin-fibrate combinations carry higher myopathy risk than statin-niacin combinations, as reported by the American Heart Association 1, 5

Obtain baseline lipid panel, liver enzymes, CK, and TSH, and follow-up monitoring, including evaluation of muscle symptoms at 6-12 weeks after starting therapy and at every follow-up visit, as recommended by the American College of Cardiology and the American Heart Association 1, 2, 3, 5
Check liver enzymes at 12 weeks, then annually, and obtain CK measurement whenever patients report muscle soreness, tenderness, or pain, as recommended by the American College of Cardiology and the American Heart Association 1, 5