The study, led by researchers in Brazil, included 504 patients with confirmed Covid-19 who either needed no supplemental oxygen, or were receiving up to 4 liters per minute of oxygen. The study was conducted across 55 hospitals in Brazil.
The patients were randomly assigned to receive either standard of care; hydroxychloroquine at a dose of 400mg twice daily; or hydroxychloroquine at a dose of 400mg twice daily, plus azithromycin at a dose of 500mg once daily for seven days. The researchers then assessed how the patients were doing 15 days later.
Neither hydroxychloroquine alone nor hydroxychloroquine plus azithromycin appeared to affect the condition of the patients at the 15-day mark, the study showed.
Additionally, unusual heart rhythms and elevated liver-enzyme levels were more frequent in patients receiving hydroxychloroquine alone or with azithromycin, according to the study.
Overall, the researchers wrote that “among patients hospitalized with mild-to-moderate Covid-19, the use of hydroxychloroquine, alone or with azithromycin, did not improve clinical status at 15 days as compared with standard of care.”
The study was funded by the Coalition Covid-19 Brazil and EMS Pharma, a pharmaceutical company in Brazil.
The National Institutes of Health announced last month it was halting its clinical trial of hydroxychloroquine for coronavirus patients.
One study published this month by researchers at Henry Ford Health System in Southeast Michigan found hydroxychloroquine increased hospitalized patients’ chances of survival. However, researchers not involved with the study were critical of it, saying it wasn’t of the same quality of the previous studies that showed hydroxychloroquine did not help patients.