Introduction
As COVID-19-infected patients are immunocompromised and highly
susceptible to serious opportunistic fungal
infections,1 there is a need to understand and manage
drug–drug interactions between antiretroviral and antifungal agents,
particularly broad-spectrum voriconazole.2,3
The antiretroviral drug lopinavir/ritonavir is widely used for the
treatment of HIV and is a potential candidate for the treatment of
COVID-19. Ritonavir induces the hepatic activity of cytochrome P450
enzymes, namely CYP2C9, CYP2C19, and CYP1A2, but it inhibits the hepatic
and intestinal activity of CYP3A4-6. Voriconazole is
extensively metabolized by CYP2C19 and, to a lesser extent, by CYP2C9
and CYP3A. Therefore, concominant of voriconazole and
lopinavir/ritonavir is not recommended as the AUC and Cmax of
voriconazole have been shown to decrease 39% and 24% respectively, due
to possible induction of CYP450 by ritonavir7.
However, in this study, the voriconazole concentration was unexpectedly
increased in the context of lopinavir/ritonavir coadministration in a
COVID-19 patient.