Involuntary Movements Following Administration of Hydroxychloroquine for COVID-19 Pneumonia.

Hydroxychloroquine (HCQ) has been used as an investigational drug for patients with moderate to severe coronavirus disease 2019 (COVID-19). There have been concerns of potential harms from side effects of the drug. We present a case of a 38-year-old male who was started on HCQ for COVID-19 pneumonia. He was referred for evaluation of myoclonus of all extremities, which resolved after discontinuation of HCQ. The involuntary movements were first reported after the initiation of HCQ, persisted despite improvement in inflammatory and radiologic parameters and eventually resolved after HCQ discontinuation. This supports a possible causality related to adverse drug reactions from HCQ that have not been commonly reported.