"Whilst not a placebo controlled trial, an observational study on this scale undertaken with stringent and meticulous analysis is powerful indeed". Significant numbers of doctors have been prescribing it without evidence.
The woman, who asked to only be referred to as Kim, said she had felt safer knowing that the anti-malaria drug, which she has taken for 19 years to help with her lupus, was gaining worldwide attention as a possible treatment for warding off COVID-19, news station WISH reported. It found that those treated with hydroxychloroquine, or the closely related drug chloroquine, were more likely to develop an irregular heart rhythm that could lead to sudden cardiac death.
US President Donald Trump has been criticised after he said he had nothing to lose by taking hydroxychloroquine, which is used to treat malaria and arthritis, despite warnings it could be unsafe.
Because the drugs have demonstrated antiviral effects in laboratory studies, chloroquine and hydroxychloroquine are still worth studying, the researchers noted, and said the need for randomized clinical trials is urgent. The drugs are used to prevent and treat malaria and can reduce fever and inflammation.
Of those treated with hydroxychloroquine or chloroquine alone, 18 per cent and 16.4 per cent respectively had died.More news: Tributes for White House veteran who served 11 presidents
The study is a double-blind, randomised, placebo-controlled trial that will enrol more than 40,000 people who work with confirmed or suspected coronavirus patients from Europe, Africa, Asia and South America, MORU co-principal investigator Professor Sir Nicholas White said in a statement.
Kim was left stunned at her diagnosis, saying she thought she was safe because of what Trump has said about the drug. And for those who received hydroxychloroquine and an antibiotic, there was a 45% increased risk of death and a 411% increased risk of serious heart arrhythmias.
The drugs should only be used for Covid treatment as part of robust studies that will definitively show their impact, the researchers said.
Friday's report in the journal Lancet is not a rigorous test of hydroxychloroquine or chloroquine, but it is by far the largest look at their use in real world settings, spanning 671 hospitals on six continents.
Dr Stephen Griffin, associate professor in the school of medicine, University of Leeds, said the paper was "potentially a landmark study for Covid-19 therapy". A study of 368 USA veterans also showed that the drugs might be potentially harmful. The other 81,144 patients served as a control group.More news: Toronto to reopen more than 850 park amenities this week
This week, Trump said he has been taking hydroxychloroquine as a preventative medicine, despite a lack of scientific evidence.
"Furthermore, it is clear that high-profile endorsements of taking these drugs without clinical oversight are both misguided and irresponsible".
Earlier this week it was announced that a trial to see whether the drugs could prevent Covid-19 had begun in Brighton and Oxford.
"It might even be said that to go on giving them, other than in a trial, is unethical, given this evidence that is not yet contradicted by other available evidence".More news: Renewable energy will show "resilience" to coronavirus pandemic