<unk> , 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. Other uses include treatment of rheumatoid arthritis, lupus, and porphyria cutanea tarda. It is taken by mouth, often in the form of<unk>  sulfate. Common side effects may include vomiting, headache, changes in vision, and muscle weakness. Severe side effects may include allergic reactions, vision problems, and heart problems. Although all risk cannot be excluded, it remains a treatment for rheumatic disease during pregnancy.<unk>  is in the antimalarial and 4-aminoquinoline families of medication.<unk>  was approved for medical use in the United States in 1955. It is on the World Health Organization's List of Essential Medicines. In 2019, it was the 122nd most commonly prescribed medication in the United States, with more than 5million prescriptions.<unk>  has been studied for an ability to prevent and treat coronavirus disease 2019 (COVID‑19), but clinical trials found it ineffective for this purpose and a possible risk of dangerous side effects. Among studies that deemed<unk>  intake to cause harmful side effects, a publication by The Lancet was retracted due to data flaws. The speculative use of<unk>  for COVID‑19 threatens its availability for people with established indications.
Hydroxychloroquine
Azathioprine
Teriflunomide
Leflunomide
Tofacitinib
Etanercept
Cyclizine
Prednisolone