Hydroxychloroquine-induced autophagic vacuolar myopathy with mitochondrial abnormalities.

Hydroxychloroquine (HCQ) and chloroquine are used worldwide for malaria as well as connective and rheumatological disorders. They have been reported to be linked to myopathy in patients. We report four patients who were receiving HCQ as part of treatment for connective tissue disorder and who presented with myopathy. The muscle biopsy in these patients was consistent with findings of HCQ toxicity. HCQ muscle toxicity is usually self-limiting after discontinuation of the drug. It also usually tends to be under-reported due to presence of various confounding factors. This warrants close monitoring and consideration of muscle biopsy as part of initial work up of patients who present with myopathy while receiving HCQ.