10 Mar Cholesterol Management: Statin Associated Muscle Pain?

Musculoskeletal side effects are the commonest cause of statin cessation. They occur much more frequently in everyday practice than in clinical trials.  There is a tendency to blame all musculoskeletal problems on statins. It is essential to determine if it is really the statin that is responsible. Lipophilic statins (simvastatin, atorvastatin) more commonly cause problems than hydrophilic drugs (rosuvastatin, pravastatin). And muscle side effects are dose related.

Simple reassurance may suffice for mildly affected individuals. When symptoms are more troublesome your initial workup should include measurement of CK, renal and thyroid function and probably Vitamin D levels. A very high CK (>10 X normal) is uncommon but potentially serious. Statins should be permanently discontinued. More modest elevations of CK need monitoring, but are not an absolute contraindication to statin use.  Thyroid disease and Vitamin D deficiency amplify the tendency to statin myalgia.

Also, look for drug interactions. Ask about grapefruit consumption, and try and minimise concomitant use of calcium channel blockers, SSR’s (e.g. Prozac), SNRI’s (e.g., Venlafaxine). For example, in a hypertensive patient, you may switch them away from calcium channel blockers. Other drugs also interact but they are usually agents that are used more short term e.g. macrolide antibiotic such as roxithromycin.

For patients on high dose statins, a simple dose reduction may work.

Where this is unsuccessful try a drug holiday for at least a month. If there is no improvement, you will have the patient’s confidence that the statin is not the cause.

Reintroduction of the same statin at a lower dose is often well tolerated. Alternatively switch to a modest dose of a hydrophilic drug such as pravastatin 20g or Rosuvastatin 5mg. Ezetimibe may be added if target LDL is not reached. For patients who do not tolerate this, 2 or 3 times weekly dosing can be successful. Rosuvastatin 5mg may be most effective, especially if combined with ezetimibe.

Finally, in statin-intolerant patients, who do not have clinical disease (primary prevention) consider whether they really need the drug. A calcium score may be very helpful is these situations as if 0 or very low, prognosis is excellent and all lipid therapy can sometimes be avoided.

If you have further queries about this or any other cardiology subject please do email me at jaffe@ascotcardiology.co.nz