Conclusions
The current case presents an unexpected interaction between voriconazole
and atazanavir/ritonavir due to impaired CYP2C19 activity and
concomitant CYP3A4 inhibitors, which reminded us to consider the effect
of gene polymorphisms on the drug interaction and the time of CYP450
recovery after inhibition, which was easily overlooked because the
suspected drug was already stopped. Otherwise, regular dose adjustment
would have resulted in severe adverse events or unsatisfactory
therapeutic effects.