Fluctuating Voriconazole Concentrations during Extracorporeal Membrane Oxygenation

Abstract

BackgroundPatients requiring extracorporeal membrane oxygenation (ECMO) demonstrate complex drug pharmacokinetics due to alterations in clearance and volume of distribution, necessitating close therapeutic drug monitoring. Case Report: A 19-year-old Caucasian female with no past medical history was transferred from an outside hospital and admitted to the intensive care unit for acute respiratory distress syndrome secondary to a fresh water drowning event. The patient decompensated, requiring veno-arterial ECMO, which was subsequently changed to veno-venous ECMO. She was diagnosed with a Scedosporium apiospermum fungal pneumonia and was started on voriconazole. Throughout the course of antifungal therapy, the patient's voriconazole concentrations were labile, ranging from subtherapeutic, requiring dose increases to twice the labeled therapeutic dose, followed by subsequent supratherapeutic concentrations, requiring dose reductions. Conclusion: Our findings demonstrate how voriconazole drug concentrations can be unpredictable when administered during ECMO and the importance of close monitoring of drug concentrations. More studies are needed to provide sufficient guidance on administering voriconazole in critically ill patients receiving ECMO.

Keywords: antifungals; extracorporeal membrane oxygenation; plasma concentrations; voriconazole.