Hydroxychloroquine (HCQ) is a medication used to prevent and treat malaria in areas where malaria remains sensitive to chloroquine. Other uses of Hydroxychloroquine include treatment of rheumatoid arthritis, lupus, and porphyria cutanea tarda.

Hydroxychloroquine (HCQ) is also being studied as an experimental treatment for Novel Coronavirus Disease 2019 (COVID-19).