Hydroxychloroquine # The antimalarial drug chloroquine and its safer derivative hydroxychloroquine are commonly prescribed medication in the treatment of uncomplicated malaria, rheumatoid arthritis, chronic discoid lupus erythematosus, and systemic lupus erythematosus. These drugs have also attracted attention over the past few decades as a potential antiviral agent, currently as a possible treatment for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19. Reports found that chloroquine could inhibit SARS-CoV-2 in vitro, and showed apparent efficacy in treating COVID-19 in humans. The US Food and Drug Administration has designated hydroxychloroquine for off-label, compassionate use for treating COVID-19, and WHO added the drug to its large global solidarity trial to test a variety of potential treatments.