The US Food and Drug Administration (FDA) has revoked emergency use authorisation (EUA) for chloroquine and hydroxychloroquine drugs in treating certain patients hospitalised with Covid-19.

The regulatory body determined the legal criteria for issuing the EUA is no longer met, adding that the two drugs are unlikely to be an effective treatment for the coronavirus under the authorised uses that were previously outlined.

Having initially granted an EUA for chloroquine phosphate and hydroxychloroquine sulfate on 28 March, the FDA also said the authorised use is no longer warranted due to evidence of serious cardiac adverse events, and other potential serious side-effects associated with the drugs.

The potential side-effects caused by these drugs mean their known and potential benefits no longer outweigh their known and potential associated risks, according to the regulator.

Dr Patrizia Cavazzoni, acting director of the FDA’s Center for Drug Evaluation and Research, said: “While additional clinical trials continue to evaluate the potential benefit of these drugs in treating or preventing Covid-19, we determined the emergency use authorisation was no longer appropriate.

“This action was taken following a rigorous assessment by scientists in our Center for Drug Evaluation and Research.

“We remain committed to using every tool at our disposal in collaboration with innovators and researchers to provide sick patients timely access to appropriate new therapies.

“Our decisions will always be based on objective and rigorous evaluation of the scientific data. This will never change.”


FDA use authorisation of chloroquine drugs for Covid-19

On 28 March, when the number of domestic Covid-19 cases in the US stood at about 125,000, and there had been fewer than 2,800 coronavirus-related deaths, the FDA granted an EUA for chloroquine phosphate and hydroxychloroquine sulfate drugs.

This allowed them to be donated to the American Strategic National Stockpile (SNS) — the country’s repository of antibiotics, vaccines and other critical medical supplies — and used to treat hospitalised Covid-19 patients when administering them as part of a clinical trial was impossible, or participation in a clinical trial wasn’t feasible.

Hydroxychloroquine, in particular, has received increased media coverage ever since US president Donald Trump announced on 18 March that he was taking the antimalarial drug to lessen symptoms of Covid-19 if he was infected.

But, on 15 June, after receiving a letter from the US Department of Health and Human Services office BARDA (Biomedical Advanced Research and Development Authority) — which also requested the original EUA — the FDA revoked this emergency use authorisation.


The regulator also cited recent results from a large, randomised clinical trial in hospitalised patients, which demonstrated that hydroxychloroquine showed no benefit with regard to mortality or in speeding up recovery from the novel coronavirus.

The FDA referenced other new data that this trial was consistent with as well — including data showing that the suggested dosing regimens for chloroquine and hydroxychloroquine are unlikely to kill, or inhibit, the SARS-CoV-2 virus that causes Covid-19.

Dr Anand Shah, FDA Deputy Commissioner for Medical and Scientific Affairs, said: “We’ve made clear throughout the public health emergency that our actions will be guided by science, and that our decisions may evolve as we learn more about the SARS-CoV-2 virus, review the latest data, and consider the balance of risks versus benefits of treatments for Covid-19.

“The FDA always underpins its decision-making with the most trustworthy, high-quality, up-to-date evidence available.

“We will continue to examine all of the emergency use authorisations the FDA has issued and make changes, as appropriate, based on emerging evidence.”