American politicians and doctors are debating whether to use the drug hydroxychloroquine against the new coronavirus. The drug has been used to treat some COVID 19 patients in the United States. But doctors ordering its use have no idea whether it is working. The medicine is among several drugs they experiment with on those infected. The patients differ in severity of sickness, age, sex, pre-existing health condition and other ways. As a result, it is unclear what treatment has helped those who improve or if they would have improved without any treatment at all. The drug has been around for many years and is a popular treatment for the diseases malaria and lupus.