What is the evidence that hydroxychloroquine is effective for the treatment, or prophylaxis, of SARS-CoV-2 infection?
In an observational study of 1,446 COVID-19 patients, 811 received hydroxychloroquine treatment, which did not change the risk of intubation or death.196 Furthermore, in a Brazilian randomized control study evaluating 2 different doses of chloroquine in COVID-19 patients with severe respiratory symptoms, mortality was 2.5 times higher in the high-dose chloroquine arm.197 A recent study of 96,032 hospitalized patients with COVID-19 was unable to confirm a benefit of hydroxychloroquine or chloroquine, when used alone or with a macrolide, on in-hospital outcomes for COVID-19.182 Importantly, each of these drug regimens was associated with decreased in-hospital survival and an increased frequency of ventricular arrhythmias when used for treatment of COVID-19.182 Moreover, pre-published results from US Veterans Health Administration Hospitals did not support any advantages of hydroxychloroquine administered alone or with azithromycin.198