chloroquine UK /ˈklɔː.ɹə(ʊ).kwiːn/US /ˈklɔɹ.əˌkwɪn/ noun1 •A 4-aminoquinoline drug used to treat and prevent malaria, having the chemical formula C₁₈H₂₆ClN₃.Perhaps the most egregious example of shifting the standards of evidence comes when the report discusses the off-label use of drugs such as chloroquine and ivermectin. — 2024 formschloroquines