Hydroxychloroquine (HCQ), sold under the brand name Plaquenil among others, is a medication used to prevent and treat malaria in areas where malaria remains sensitive to chloroquine.[2] Other uses include treatment of rheumatoid arthritis, lupus, and porphyria cutanea tarda.[2] It is taken by mouth.[2] HCQ is being studied to prevent and treat coronavirus disease 2019 (COVID?19).[3] High-quality evidence of benefit for such use is lacking, with concerns of potential harms from side effects.[3][4][5]

Common side effects may include vomiting, headache, changes in vision, and muscle weakness.[2] Severe side effects may include allergic reactions, vision problems, and heart problems.[2][6] Although all risk cannot be excluded, it remains a treatment for rheumatic disease during pregnancy.[7] Hydroxychloroquine is in the antimalarial and 4-aminoquinoline families of medication.[2]

Hydroxychloroquine was approved for medical use in the United States in 1955.[2] It is on the World Health Organization's List of Essential Medicines.[8] In 2017, it was the 128th most commonly prescribed medication in the United States, with more than five million prescriptions.[9][10] The speculative use of hydroxychloroquine for COVID?19 threatens its availability for people with established indications.[4]

In June 2020, the World Health Organization (WHO) discontinued use of hydroxychloroquine in the international Solidarity trial, as did the United Kingdom RECOVERY Trial, when hydroxychloroquine was shown to provide no benefit for hospitalized people severely infected with COVID-19.[11][12] The FDA revoked the emergency use authorization for hydroxychloroquine, stating that oral hydroxychloroquine was not effective in treating COVID?19, and that potential risks remained for people using the drug.[13]

Medical uses

Hydroxychloroquine treats rheumatic disorders such as systemic lupus erythematosus, rheumatoid arthritis, and porphyria cutanea tarda, and certain infections such as Q fever and certain types of malaria.[2] It is considered the first-line treatment for systemic lupus erythematosus.[14] Certain types of malaria, resistant strains, and complicated cases require different or additional medication.[2]

It is widely used to treat primary Sjögren syndrome but does not appear to be effective.[15] Hydroxychloroquine is widely used in the treatment of post-Lyme arthritis. It may have both an anti-spirochete activity and an anti-inflammatory activity, similar to the treatment of rheumatoid arthritis.[16]

Contraindications

The drug label advises that hydroxychloroquine should not be prescribed to individuals with known hypersensitivity to 4-aminoquinoline compounds.[17] There are several other contraindications,[18][19] and caution is required if the person considered for treatment has certain heart conditions, diabetes, or psoriasis.