Protease inhibitors like lopinavir and ritonavir have been used in COVID-19 patients. They are substrates of CYP3A4 so it is likely they will be present at high plasma concentrations during infection. In addition, these drugs are known to inhibit CYP3A4 and induce other CYPs which can affect the metabolism of other drugs as well. Furthermore, they are known to cause hepatotoxicity regardless which could add to liver injury during COVID-19 infection.