Two new studies are the latest in a series to show that a drug touted by US President Donald Trump as a potential game changer against Covid-19 doesn't work.
Hydroxychloroquine reduces inflammation, pain and swelling, and is widely used to treat rheumatic diseases and malaria.
Laboratory tests of the drug against Covid-19 yielded promising results, but mounting evidence from clinical and observational studies suggest that it doesn't provide any meaningful benefits for Covid-19 patients.
In the first of the two new studies published May 14 in the BMJ, researchers in France assessed the effectiveness and safety of hydroxychloroquine compared with standard care in 181 adults hospitalised with pneumonia due to Covid-19 who needed oxygen.
Of those patients, 84 received hydroxychloroquine within 48 hours of admission and 97 did not. Treatment with the drug did not significantly reduce admission to intensive care or death within seven days, or the development of acute respiratory distress syndrome within 10 days.
The findings do not support the use of hydroxychloroquine in patients hospitalised with Covid-19 pneumonia, said the team led by Matthieu Mahevas, from the department of internal medicine at Henri-Mondor Hospital, Assistance Publique-Hopitaux de Paris.
The second study, led by Qing Xie, from the department of infectious disease at the Shanghai Jiao Tong University School of Medicine, was conducted in China and included 150 adults hospitalised with mainly mild or moderate Covid-19. Half received hydroxychloroquine in addition to standard care and the others received standard care only.
Both groups had similar rates of Covid-19 recovery after 28 days, but those who received hydroxychloroquine experienced more adverse events. There was little difference in reduction of symptoms and time to relief of symptoms between the two groups of patients.
The findings do not support the use of hydroxychloroquine to treat patients with persistent mild to moderate Covid-19, the study authors said in a journal news release.
The US Food and Drug Administration now warns against use of the drug outside clinical trials or hospital settings due to the risk of heart rhythm problems.READ | The chloroquine debate: Two experts weigh in
READ | Covid-19: The problems caused by the chloroquine and hydroxychloroquine hype
READ | No apparent harm or benefit from hydroxychloroquine - study
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