Molnupiravir works by inserting errors into the genetic code of the SARS-CoV-2 virus, preventing it from replicating.
The Food and Drug Administration (FDA) approved Merck's antiviral pill to treat COVID-19 for emergency use last week, giving the country another tool to fight the virus. The FDA's action came just one day after it approved Pfizer's antiviral drug. Merck's treatment, molnupiravir, was developed in collaboration with Ridgeback Biotherapeutics and is approved for use in adults with mild to moderate COVID-19 who are at risk of developing severe disease, according to the FDA. Pfizer's pill was approved for people as young as 12 years old. The use of molnupiravir will be limited to situations where other authorized treatments are inaccessible or not “clinically appropriate,” Dr. Patrizia Cavazzoni, director of the FDA’s Center for Drug Evaluation and Research, said in a statement.
She added, “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.” The FDA's emergency approval is accompanied by a list of conditions. First, patients should begin taking the antiviral "as soon as possible" after receiving a COVID-19 diagnosis, and at most within five days following the onset of symptoms. Because the drug's efficacy hasn't been observed in hospitalized patients, it hasn't been cleared for pre- or post-exposure prophylaxis or treatment initiation. A full course of Merck’s treatment is a total of 40 pills, taken as four 200-milligram pills, twice a day for five days.