Immune‐mediated necrotizing myopathy associated with statins

TLDR

Patients were identified by proximal muscle weakness during or after statin use, elevated creatine kinase, persistent symptoms after drug discontinuation, improvement with immunosuppressive therapy, and muscle biopsy showing necrotizing myopathy without significant inflammation. Of 25 patients, 24 required multiple immunosuppressive agents, 15 relapsed after tapering, and statin exposure was markedly higher than in dermatomyositis, polymyositis, or inclusion‑body myositis, supporting an immune‑mediated etiology. Muscle Nerve, 2010.

Abstract

Abstract We report patients from two neuromuscular centers who were evaluated between the years 2000 and 2008 and met the following criteria: (1) proximal muscle weakness occurring during or after treatment with statins; (2) elevated serum creatine kinase (CK); (3) persistence of weakness and elevated CK despite discontinuation of the statin; (4) improvement with immunosuppressive agents; and (5) muscle biopsy showing necrotizing myopathy without significant inflammation. Twenty‐five patients fulfilled our inclusion criteria. Twenty‐four patients required multiple immunosuppressive agents. Fifteen patients relapsed after being tapered off immunosuppressive therapy. Exposure to statins prior to onset was significantly higher in patients with necrotizing myopathy (82%) as compared to those with dermatomyositis (18%), polymyositis (24%), and inclusion‐body myositis (38%) seen in the same time period. The lack of improvement following discontinuation of statins, the need for immunosuppressive therapy, and frequent relapse when treatment was tapered suggest an immune‐mediated etiology for this rare, statin‐associated necrotizing myopathy. Muscle Nerve, 2010