COVID antiviral pills: what scientists still want to know

December 18, 2021

Molnupiravir acts by introducing mutations into the viral genome during viral replication. A metabolite of the drug is picked up by a viral enzyme called RNA-dependent RNA polymerase and incorporated into the viral genome, eventually causing so many errors that the virus can no longer survive.

Paxlovid acts by inhibiting an enzyme that’s needed to process some viral proteins into their final, functional form. But the drug is a combination of an antiviral and another drug, called ritonavir, which helps to prevent enzymes in the liver from breaking down the antiviral before it has a chance to disable the coronavirus. Ritonavir, a component of some HIV treatment cocktails, can affect how some other medications are metabolized by the body.
Molnupiravir & Paxlovid