The US Food and Drug Administration has revoked its emergency use authorization for the drugs hydroxychloroquine and chloroquine for the treatment of Covid-19.
After reviewing the current research available on the drugs, the FDA determined that the drugs do not meet "the statutory criteria" for emergency use authorization as they are unlikely to be effective in treating Covid-19 based on the latest scientific evidence, the agency noted on its website on Monday.
"FDA has concluded that, based on this new information and other information discussed in the attached memorandum, it is no longer reasonable to believe that oral formulations of HCQ and CQ may be effective in treating COVID-19, nor is it reasonable to believe that the known and potential benefits of these products outweigh their known and potential risks," FDA chief scientist Denise Hinton wrote in a letter to Gary Disbrow of the Biomedical Advanced Research and Development Authority (BARDA) on Monday.
"Accordingly, FDA revokes the EUA for emergency use of HCQ and CQ to treat COVID-19," Hinton wrote in the letter. "As of the date of this letter, the oral formulations of HCQ and CQ are no longer authorized by FDA to treat COVID-19."
The FDA's emergency use authorization for hydroxychloroquine and chloroquine was narrow in scope, applying only to hospitalized Covid-19 patients and only to drugs donated to the Strategic National Stockpile.
In an open letter published late last month, FDA commissioner Dr. Stephen Hahn appeared to defend the agency's decision to issue the authorization.
"This decision was based on evaluation of the EUA criteria and the scientific evidence available at that time. We continue to look at the data on hydroxychloroquine and chloroquine and we will make future determinations on these products based on available evidence including ongoing clinical studies," Hahn said in the letter last month.
The emergency use authorization, or EUA, made it easier for pills donated to the national stockpile to be distributed to coronavirus patients.
Hahn added in the letter that "we also knew it was important to help ensure a stable supply of the drugs for patients with lupus and rheumatoid arthritis given the increased demand."
In an interview with CNN last month, Hahn also defended his agency's handling of hydroxychloroquine. He acknowledged the political climate surrounding the drug, but said, "I stand by our decisions because I think they are rooted in science and data, and we'll continue to reevaluate."