The Food and Drug Administration authorized a second at-home antiviral pill to treat COVID-19 on Thursday. The clearance for the drug, called molnupiravir, came a day after the agency signed off on Pfizer’s COVID-19 antiviral, called Paxlovid. Both drugs reduce the risk of hospitalization and death in people diagnosed with COVID-19 and at risk of having a severe case of the disease.
Molnupiravir, made by pharmaceutical company Merck, is authorized for people 18 years of age and older who are at a high risk of getting seriously ill if they contract the coronavirus. It’s a higher age cutoff than Paxlovid, which is cleared for people 12 and up, because molnupiravir might affect bone and cartilage growth, the FDA said in a statement.
Like Paxlovid, patients have to start taking Merck’s drug within a few days of developing symptoms in order for it to be the most effective. That might be difficult in the United States, where testing to confirm someone has COVID-19 is often slow and limited — particularly during surges in case numbers when treatments are most needed.
Molnupiravir initially appeared to cut the risk of hospitalization and death by about half in a clinical trial. Additional evaluation, though, found that it was only around 30 percent effective. That’s far less effective than Paxlovid, which reduced hospitalizations and deaths for high-risk groups by 89 percent in a clinical trial.
Despite its lower efficacy, the US may be reliant on molnupiravir in the near future — the Biden administration expects to have 3 million courses of the Merck drug available by the end of January but only 265,000 courses of Paxlovid. The federal government started allocating courses of Paxlovid to states after its authorization yesterday.