US revokes virus use of malaria medication

US regulators have revoked emergency authorisation for malaria drugs promoted by Donald Trump for treating Covid-19 amid growing evidence they do not work and could cause serious side-effects.

The Food and Drug Administration said hydroxychloroquine and chloroquine are unlikely to be effective in treating coronavirus. Citing reports of heart complications, the FDA said the drugs’ unproven benefits “do not outweigh the known and potential risks”.

The decades-old drugs, also prescribed for lupus and rheumatoid arthritis, can cause heart rhythm problems, severely low blood pressure and muscle or nerve damage.

The move means that shipments of the drugs obtained by the federal government will no longer be distributed to state and local health authorities for use against coronavirus. The drugs are still available for other uses, so doctors could still prescribe them for Covid-19 – a practice known as off-label prescribing.

Steven Nissen, a Cleveland Clinic researcher who has been a frequent FDA adviser, agreed with the decision and said he would not have granted emergency access in the first place.

“There has never been any high-quality evidence suggesting that hyrdoxychloroquine is effective” for treating or preventing coronavirus infection, he said, but there is evidence of serious side-effects.

On Thursday, a National Institutes of Health panel of experts revised its recommendations to specifically recommend against the drug’s use except in formal studies, and “that, I’m sure, had influence on the FDA”, Dr Nissen said.

The actions by the FDA and the NIH send a clear signal to health professionals against prescribing the drugs for coronavirus.

The president aggressively pushed the drug in the first weeks of the outbreak and stunned medical professionals when he revealed he took the drug pre-emptively against infection.

No large, rigorous studies have found the drugs safe or effective for preventing or treating Covid19, and a string of recent studies made clear they could do more harm than good.

The FDA granted emergency use of the drugs for coronavirus patients in late March at the same time the US government accepted 30 million doses of hydroxychloroquine and chloroquine that had been donated by two foreign drug manufacturers.