Merck’s antiviral pill, molnupiravir, has become the second oral drug authorized for use against COVID-19.
Earlier this week, the U.S. Food and Drug Administration (FDA) authorized Pfizer’s antiviral pill, Paxlovid. Now, just a day later, another drug has received the go-ahead from the regulatory body: Merck’s antiviral pill, molnupiravir. The oral drug had earlier received approval from the British government,
On Thursday, the FDA issued an emergency use authorization (EUA) to molnupiravir for the treatment of mild-to-moderate COVID-19. According to Dr. Patrizia Cavazzoni at the FDA’s Center for Drug Evaluation and Research, it is a promising option for patients at high risk of severe disease, hospitalization, or death. Furthermore, the drug can play a major role in situations where other FDA-authorized COVID-19 treatments are not available or clinically appropriate.
Molnupiravir prevents viral replication by introducing errors into the coronavirus’ genetic code. Treatment consists of four 200mg capsules taken twice daily for five days, for a total of 40 capsules. However, its use should not exceed more than five consecutive days.
Merck vs Pfizer
The authorization of two oral antiviral pills puts forward the question: which is better? While both the drugs have many similarities, they also possess a few qualities that put them on top of each other.
Both Pfizer’s and Merck’s pills work by preventing replication of the SARS-CoV-2 virus. They are only authorized for treatment of mild-to-moderate COVID-19, but not hospitalized patients. However, unlike Paxlovid, molnupiravir is only for patients older than 18 years. This is due to the drug’s possible effect on bone cartilage and growth.
Pfizer’s Paxlovid is a two-dose regimen consisting of the antivirals ritonavir and nirmatrelvir. Although ritonavir plays a role in boosting the efficacy of nirmatrelvir, it also reacts with several other drugs. Additionally, the drug is contraindicated in people with liver and kidney issues. However, Merck’s pill does not pose any of these concerns.
Furthermore, while Pfizer’s pill showed an 89% reduction in hospitalizations and deaths, molnupiravir only caused a 30% reduction in trials. Nevertheless, authorization of two antivirals will greatly help in the fight against evolving coronavirus variants such as the Omicron.