The World Health Organization is pausing the use of hydroxychloroquine in its global study of COVID-19 treatments amid a review of safety data, officials announced Monday.

The move follows findings from a large observational study, published Friday, that found increased risk of heart problems and death in COVID-19 patients who used chloroquine and hydroxychloroquine.

It’s a scientific decision nonetheless fraught with politics: U.S. President Donald Trump is a champion of hydroxychloroquine, revealing last week that he’s taking it to prevent COVID-19. He has threatened to cut off U.S. funding to the WHO within a month absent unspecified reforms.

The executive committee of the WHO’s Solidarity trial met last Saturday, said WHO Chief Scientist Soumya Swaminathan, and decided “in the light of this uncertainty that we should be proactive, err on the side of caution and suspend enrollment temporarily into the hydroxychloroquine arm.” (Chloroquine is not part of the trial.)
世界卫生组织首席科学家Soumya Swaminathan说,世界卫生组织的SOLIDARITY临床试验执行委员会上周召开会议,决定“鉴于这种不确定性,我们要有前瞻性,谨慎行事,暂停使用羟氯喹”。(氯喹并不是此次试验用药。)

The meeting came a day after the Lancet published the largest observational study of the malaria drugs to date, and as some national regulators began expressing concern about using the drug.

WHO officials estimated the pause would last a week or two as the trial’s data safety monitoring board considers information already collected from the Solidarity trial and other ongoing studies to determine whether it’s safe to continue with hydroxychloroquine.

The study, a randomized trial, has enrolled 3,500 patients in at least 17 countries since March to study four medicines, including hydroxychloroquine.