Toxic Myopathies

AbstractPurpose of reviewThe goal of this paper is to review the clinical, electrophysiologic, and histopathologic features of toxic myopathy related to prescribed medications, highlighting new understanding. This paper is organized by treatment class to allow providers to easily prioritize learning about the potential myotoxic side effects of the medications they prescribe most frequently. Pathogenesis of toxicity is also discussed.Recent findingsMild muscle-related symptoms are common among statin users, but rarely statins can cause weakness due to either a toxic necrotizing myopathy or an immune-mediated necrotizing myopathy (IMNM). The latter can be diagnosed with the aid of serum autoantibodies to 3-hydroxy-3-methylglutarylcoenzyme A reductase (HMGCR) and uniquely requires immunotherapy for symptomatic control. We review recent data on the clinical spectrum of chloroquine and hydroxychloroquine myopathy. We also cover newer classes of medications that have been associated with a toxic myopathy, most notably immune checkpoint inhibitors (ICI) now used for the treatment of many cancers.SummaryThere are many medications that have the potential to induce muscle damage. Early recognition of a toxic myopathy is essential because stopping the use of the offending agent can lead to improvement of symptoms, or in the rare cases of statin-associated IMNM or ICI-associated myopathy, appropriate treatment can be initiated.
Source: Current Treatment Options in Neurology - Category: Neurology Source Type: research