Today’s AM report was an excellent presentation on Statin induced autoimmune myopathy in a patient presenting with symmetric proximal muscle weakness.

Key learning points:

• For a majority of patients, Statin medications are well tolerated and have an acceptable side-effect profile.
• Statin associated myopathy is extremely rare, but keep this on your differential in a patient presenting with symmetric proximal muscle weakness. 
• The degree of myotoxicity can be dose dependent, but adverse-effects can arise at any time while a patient is on therapy.
• CK level is usually very elevated, sometimes up to 10x the upper limit of normal, and is more sensitive than Aldolase.
• Look for active myopathy on EMG, evidence of muscle inflammation/edema on MRI, and muscle necrosis on biopsy. 

High Yield: Test for HMG-CoA Reductase antibodies to confirm the diagnosis