A multinational registry analysis (Mehra et al) of the use of hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19 comprised data from 671 hospitals in six continents.
The included patients were hospitalised between Dec 20, 2019, and April 14, 2020, with a positive laboratory finding for SARS-CoV-2.
Patients who received one of the treatments of interest within 48 h of diagnosis were included in one of four treatment groups (chloroquine alone, chloroquine with a macrolide, hydroxychloroquine alone, or hydroxychloroquine with a macrolide), and patients who received none of these treatments formed the control group.
96 032 patients with COVID-19 were hospitalised during the study period and met the inclusion criteria. Of these, 14 888 patients were in the treatment groups
10 698 (11·1%) patients died in hospital.
After controlling for multiple confounding factors (age, sex, race or ethnicity, body-mass index, underlying cardiovascular disease and its risk factors, diabetes, underlying lung disease, smoking, immunosuppressed condition, and baseline disease severity), when compared with mortality in the control group (9·3%), hydroxychloroquine (18·0%), hydroxychloroquine with a macrolide (23·8%), chloroquine (16·4%), and chloroquine with a macrolide (22·2%) were each independently associated with an increased risk of in-hospital mortality.
The researchers were unable to confirm a benefit of hydroxychloroquine or chloroquine, when used alone or with a macrolide, on in-hospital outcomes for COVID-19.
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.
Monday May 25 the Guardian announces that WHO halts hydroxycloroquine for coronavirus aid safety fears. The other arms of the trial are continuing.