The French government on Wednesday revoked a decree authorising hospitals to prescribe the controversial drug for Covid-19 patients after France’s public health watchdog warned against its use to treat the disease. The drug has been the subject of much debate in France, where “maverick” Professor Didier Raoult claimed in March to have successfully treated Covid-19 patients using a combination of hydroxychloroquine and azithromycin. However, doctors have questioned the value of Professor Raoult’s study, saying it was poorly designed and based on too small a sample to offer hard evidence of benefit.