When Should a Patient with Statin-Induced Myopathy Be Re-challenged? A Case of Necrotizing Autoimmune Myopathy

Abstract

Statins are notorious for causing myalgia and sometimes mild elevation of CPK (creatine phosphokinase). Herein, we present a case of necrotizing autoimmune myopathy induced by statins. The patient was on therapy with atorvastatin for about six years before she started developing myalgia and mild elevation in CPK that resolved after discontinuation of therapy. Since her cardiovascular risk was high and she had hypercholesterolemia, three months after CPK levels normalization, she was re-challenged with pravastatin. Few months later, she again presented severe myalgia, weakness, and elevated CPK levels. Hence, medication was discontinued, and she undergone an extensive workup for possible causes of inflammatory myopathies that revealed necrotizing autoimmune myopathy. Our case report offers an excellent source of “identification patterns” of muscular autoimmune disease which can be easily mistaken as common side effect of a drug.

Anti-HMGCR myopathy presenting with acute systolic heart failure

“…However, these findings were not stratified according to the specific NAM subtype 7. Multiple recent case reports of anti-HMGCR myopathy do not describe significant cardiac involvement 2–6. A recent case report does describe the rapid progression of heart failure in a patient with pre-existing idiopathic inflammatory myopathy, but does not further specify a specific diagnosis 16.…”

“…Anti-HMCGR myopathy is a form of NAM and is a rare side effect of statin use, which is estimated to occur in 2–3 out of every 100 000 statin users 1. Multiple recent case reports, including the aforementioned case, describe atorvastatin-induced NAM, although pravastatin, rosuvastatin and simvastatin have also been implicated 2–7 12. However, no studies have been done investigating the relative risk of developing NAM with different statins (such as hydrophobic vs hydrophilic statins), and the preponderance of atorvastatin-induced cases likely represents prescribing practices as opposed to a specific drug effect 13.…”

“…Necrotising autoimmune myopathy (NAM) is a rare but increasingly recognised side effect of statin use 1. Multiple recent case reports describe cases of anti-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) myopathy induced by statins, although none of them describes significant cardiac involvement 2–6. It is being increasingly shown that early recognition and treatment with immunosuppression improves outcomes in NAM 7.…”