A Rapidly Debilitating Myopathy: A Rare Case of Statin-Induced Necrotizing Myositis

Statins are well tolerated in general but can be associated with myopathies. Statin-induced myopathies can range widely from mild myalgias to necrotizing autoimmune myopathies. We present a case of an 81-year-old man on statins for five years with no complications, who developed progressive muscle weakness, rhabdomyolysis, and dysphagia. His laboratory workup revealed elevated inflammatory markers with creatine kinase (CK) levels above 2000 U/L. The myositis panel was negative, and the anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody was positive. His muscle biopsy showed randomly scattered necrotic fibers with minimal perivascular inflammation confirming statin-induced necrotizing autoimmune myopathy (SINAM). Statins were discontinued immediately after initial suspicion. The patient was started on intravenous immunoglobulin followed by hydrocortisone and mycophenolate mofetil. The patient continued to have muscle weakness and progressive dysphagia to the point that he could not handle his secretions. His disease course was complicated by recurrent aspiration pneumonia. Percutaneous endoscopic gastrostomy tube placement was considered, but his family decided on hospice care given his overall comorbidities. Physicians should note that SINAM can occur after a few months to several years of statin use. This disease can be rapidly debilitating and progress even after discontinuation of statins, and treatment requires immunosuppressants, including steroids and steroid-sparing agents.