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