In 1955, Hydroxychloroquine (HCQ) was approved for medical use in the U.S. in 1955. Chloroquine was discovered in 1934 by Hans Andersag and coleagues at the Bayer labs. The drug fell into American hands during WWII, and was introduced into clinical practice in 1947 for prophylactic treatment of malaria.

HCQ is a derivative of chloroquine that has both antimalarial and antiinflammatory activities. HCQ is sold as Plaquenil and is indicated by the U.S. Food and Drug Administration (FDA) for treatment of uncomplicated malaria, and is used to treat systemic lupus erythematosus, and rheumatic disorders.

HCQ is taken by mouth in tablet form. HCQ is manufactured by several companies, including: Activias/Teva, Dr. Reddy’s, Sandoz/Norvatis, Zydus,/Cdila and others with an estimated 50% manufactured in India. In 2020, the FDA approved the drug combination for the clinical trial in patients infected with Covid-19.