麻豆传媒

The FDA rescinded its emergency use authorization (EUA) of hydroxychloroquine (HCQ) to treat COVID-19 patients, citing concerns about efficacy and risks associated with its use, and saying the drug no longer meets the criteria for an EUA, .

"The agency determined that the legal criteria for issuing an EUA are no longer met," according to an FDA statement. Both hydroxychloroquine and a related antimalarial drug, chloroquine (CQ), are "unlikely to be effective at treating COVID-19" for uses described in the EUA, the statement continued.

Moreover, the FDA now says the benefits of the drug "no longer outweigh the potential risks," citing the serious cardiac adverse events associated with the drug.

"This warrants revocation of the EUA for HCQ and CQ for the treatment of COVID-19," the agency said.

A letter from the agency to the Biomedical Advanced Research and Development Authority (BARDA) , including that suggested dosing regimens are "unlikely to produce an antiviral effect," and said "decreased viral shedding" from treatment with these drugs, noted in some observational studies, "has not been consistently replicated."

While current FDA guidelines did not recommend use of the drugs outside of a randomized clinical trial, the FDA also pointed to recent data from a large clinical trial showing no "evidence of benefit" for mortality, effect on hospital length of stay, or need for mechanical ventilation among COVID-19 patients treated with hydroxychloroquine.

The FDA originally granted an EUA to HCQ on March 28, 2020.

This may be the end for the controversial drug as COVID-19 therapy; study after study found no benefit in the drug among hospitalized patients or as post-exposure prophylaxis. It will remain available for its previously approved conditions, which include rheumatoid arthritis and systemic lupus erythematosus as well as malaria, and can still be prescribed off-label at physicians' discretion. Without the EUA, however, third-party reimbursement may become harder to secure for COVID-19 cases, and malpractice litigation easier to win if patients suffer adverse events. Also, access to HCQ and CQ in the National Strategic Stockpile for use in COVID-19 patients will now end.

A noted that patients currently being treated with HCQ can finish their treatment course, "to the extent found necessary by the patient's attending physician." The document added that clinical trials studying HCQ and CQ to see if the drugs can benefit patients with COVID-19 will continue.

And in a separate announcement, the when co-administering either HCQ sulfate or CQ phosphate and the antiviral remdesivir to treat hospitalized COVID-19 patients with severe disease, saying it "may result in reduced antiviral activity of remdesivir."

The agency said it has revised about remdesivir, which received an EUA in May for treating COVID-19 patients, recommending against co-administration of remdesivir and either HCQ sulfate or CQ phosphate in COVID-19 patients.

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