evidence: There's been widespread interest in hydroxychloroquine as both a preventative measure and for treating patients with coronavirus. [...] It concluded that "there is no beneficial effect of hydroxychloroquine in patients hospitalised with Covid-19" and the drug has now been pulled from the trial. There's been some hope that hydroxychloroquine could be effective if used early on when a person gets the virus, before there's a need for them to be hospitalised.