Statin-induced necrotizing autoimmune myopathy.

Statins are the most widely used class of drug in the United States. They lower blood cholesterol levels by inhibiting 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase. Common side effects include myalgias and a mild increase in liver function tests. Statin-induced necrotizing autoimmune myopathy (SINAM) is a very rare side effect that is independent of the type and duration of statin use. Treatment involves high-dose steroids and immunosuppressants such as azathioprine, methotrexate, or mycophenolate mofetil. Nonresponders and patients with severe weakness can be treated with intravenous immunoglobulin or rituximab. We present a case of SINAM that was successfully treated with intravenous immunoglobulin.