Studies of the metabolism of Nirmatrelvir revealed that it doesn't last for long in the body. The liver enzymes are actively working fast with it. As a result, plasma concentrations of it decrease too rapidly. 2 possible solutions to maintaining sufficient presence to have an inhibitory effect on viral replication via the target Mpro are: 1) use higher and more frequent doses, 2) add an inhibitor to the garbage collection process by blocking the action of the CYP enzymes, in particular 3A4. Both have drawbacks: 1) unwanted interactions with other proteins, 2) blocking the liver enzymes from normal function could result in increased levels of other medications to the point of toxicity. Dose changes for either purpose obviously means more interactions with a variety proteins, not only Mpro.