The drug hydroxychloroquine, pushed by US President Donald Trump and others in recent months as a possible treatment to people infected with the coronavirus disease (COVID-19), is displayed by a pharmacist at the Rock Canyon Pharmacy in Provo, Utah, US, May 27, 2020. (Photo: Agencies)
The US Food and Drug Administration on Monday revoked the emergency use authorization (EUA) for chloroquine and hydroxychloroquine, the anti-malaria drugs backed by President Donald Trump to combat COVID-19, saying that their potential benefits do not outweigh the risks.
In addition, the agency warned health care providers about a newly discovered potential drug interaction related to remdesivir, the only remaining drug with FDA authorization against COVID-19.
After reviewing new information from large clinical trials, the FDA believed the suggested dosing regimens "are unlikely to produce an antiviral effect", the agency's chief scientist Denise Hinton said in a letter announcing the decision.
The FDA issued the emergency use authorization for the drugs on March 28, the day when the US COVID-19 death toll exceeded 2,000. The authorization would allow doctors to use them on hospitalized patients with COVID-19, though they had not yet been formally approved by the agency.
The letter cited a large, randomized study that it said showed "no evidence of benefit for mortality or other outcomes such as hospital length of stay or need for mechanical ventilation".
"FDA has determined that CQ and HCQ are unlikely to be effective in treating COVID-19 for the authorized uses in the EUA," the agency said.
"Additionally, in light of ongoing serious cardiac adverse events and other serious side effects, the known and potential benefits of CQ and HCQ no longer outweigh the known and potential risks for the authorized use," it said in the letter.
The revoking of EUA came after a request from Gary Disbrow, acting director of the Biomedical Advanced Research and Development Authority.
President Trump has suggested many times that the malaria medicine is an effective treatment for the coronavirus. At one point, he hailed hydroxychloroquine as a potential "game-changer" in the fight against the coronavirus.
The president said last month that he was taking hydroxychloroquine.
"It certainly didn't hurt me," Trump replied Monday when asked by the media about the FDA's withdrawing the emergency authorization for hydroxychloroquine use.
Following the authorization for hydroxychloroquine use, the FDA also granted emergency use authorization to remdesivir on May 1.
Remdesivir is an antiviral drug developed by California-based Gilead Sciences Inc. Researchers found that the drug reduced patients' recovery time by 31 percent, from 15 days to 11 on average and may have also an improved or reduced mortality.
But on Monday, the FDA cautioned, "Co-administration of remdesivir and chloroquine phosphate or hydroxychloroquine sulfate is not recommended as it may result in reduced antiviral activity of remdesivir."
The World Health Organization has said that until there is sufficient evidence, it cautions against physicians and medical associations recommending or administering the treatments to patients with COVID-19 or people self-medicating with them.
Out of safety concerns about the medication, health authorities in Britain have ordered Oxford University to suspend a trial of hydroxychloroquine as a treatment for COVID-19 and those in France have also ceased the use of hydroxychloroquine in COVID-19 patients recently.
"I am pleased to see this FDA action in the face of what may have been political pressure to do otherwise," said William A. Haseltine, chair and president of ACCESS Health International in New York.
"We all count on our regulatory agencies to keep us safe. Last week France took similar measures. Hopefully countries like India & Brazil will follow," Haseltine said in a Twitter post.
Eugene Gu, founder and CEO of CoolQuit.com, said that months before the FDA issued its EUA for hydroxychloroquine, he had warned the medical community "not to use human beings as guinea pigs" with untested drugs without evidence.
"Many doctors did so anyway, and they must face consequences," Gu tweeted Monday.