Breaking down statin myopathy: understanding the self-limited and autoimmune subtypes

Statins are widely used crucial drugs for the primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD). Although generally well tolerated, statin intolerance can unfortunately limit statin use, with statin-associated muscle symptoms (SAMS) being the most common side effect associated with its discontinuation. Statin intolerance is an inability to tolerate a dose of statin required to sufficiently reduce an individual's cardiovascular risk, limiting the effective treatment of patients at risk of or with cardiovascular disease (CVD). Statin myopathy is a broad entity encompassing self-limited/toxic and autoimmune aetiologies. As statins are a mainstay of therapy in those with or at risk for CVD and offer a mortality benefit, it is critical to determine whether one's symptoms are truly statin-associated before discontinuing the drug. This review article aims to provide an update on the epidemiology, pathophysiology, clinical features, diagnosis, evaluation and management of statin myopathy and to elucidate key differences between autoimmune and self-limited types.