On Apr. 24, 2020, the U.S. Food and Drug Administration (FDA) issued a Drug Safety Communication regarding known side effects of hydroxychloroquine and chloroquine, including serious and potentially life-threatening heart rhythm problems, that were reported with their use for treatment or prevention of COVID-19, for which they are not approved by the FDA.

Hydroxychloroquine and chloroquine are FDA-approved to treat or prevent malaria. Hydroxychloroquine sulfate is also FDA-approved to treat lupus and rheumatoid arthritis. These medicines have not been proven safe or effective for treating COVID-19.