Off-label prescribing in the midst of a pandemic: The case of hydroxychloroquine

In the middle ages, the deadly, feverish illness endemic throughout most of the world was known as ague. The term ‘mal’aria’ was unknown in English until the 18th century, but the alleged cure, derived from the South American cinchona tree, had already been in use for 100 years.1 In the treatment of malaria, quinine (the active ingredient in cinchona bark) and its chemical successors chloroquine and hydroxychloroquine have largely been superseded by more effective, less toxic medications; hydroxychloroquine is reserved for still significant but less common conditions.