The U.S. Food and Drug Administration issued an Emergency Use Authorisation (EUA), for Merck's molnupiravir for the treatment of mild-to-moderate coronavirus disease (Covid-19) in adults with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe Covid-19, including hospitalization or death, and for whom alternative Covid-19 treatment options authorized by the FDA are not accessible or clinically appropriate. Molnupiravir is available by prescription only and should be initiated as soon as possible after diagnosis of Covid-19 and within five days of symptom onset.

Molnupiravir is not authorized for use in patients younger than 18 years of age because molnupiravir may affect bone and cartilage growth. It is not authorized for the pre-exposure or post-exposure prevention of Covid-19 or for initiation of treatment in patients hospitalized due to Covid-19 because benefit of treatment has not been observed in people when treatment started after hospitalization due to Covid-19.  

"Today's authorization provides an additional treatment option against the Covid-19 virus in the form of a pill that can be taken orally. Molnupiravir is limited to situations where other FDA-authorized treatments for Covid-19 are inaccessible or are not clinically appropriate and will be a useful treatment option for some patients with Covid-19 at high risk of hospitalization or death," said Patrizia Cavazzoni, M.D., director of the FDA's Center for Drug Evaluation and Research. "As new variants of the virus continue to emerge, it is crucial to expand the country's arsenal of Covid-19 therapies using emergency use authorization, while continuing to generate additional data on their safety and effectiveness."

Molnupiravir is a medication that works by introducing errors into the SARS-CoV-2 virus' genetic code, which prevents the virus from further replicating. Molnupiravir is administered as four 200 milligram capsules taken orally every 12 hours for five days, for a total of 40 capsules. Molnupiravir is not authorized for use for longer than five consecutive days.

The issuance of an EUA is different than an FDA approval. In determining whether to issue an EUA, the FDA evaluates the totality of the scientific evidence available and carefully balances any known or potential risks with any known or potential benefits of the product. Based on the FDA's review of the totality of the scientific evidence available, the agency has determined that it is reasonable to believe that molnupiravir may be effective for use as treatment of mild-to-moderate COVID-19 in certain adults when alternative Covid-19 treatment options authorized by the FDA are not accessible or clinically appropriate. The agency has also determined that the known and potential benefits of molnupiravir, when used consistent with the terms and conditions of the authorization, outweigh the known and potential risks of the product. There are no adequate, approved and available alternatives to molnupiravir for the treatment of Covid-19.