Extracorporeal Membrane Oxygenation Can Affect Posaconazole Exposure in Critically Ill Patients

Posaconazole is an antifungal agent used to prevent or treat invasive fungal infections (IFIs) in critically ill patients, including those receiving extracorporeal membrane oxygenation (ECMO). However, in vitro data suggest that posaconazole is extensively sequestered in ECMO circuits. The aim of this study was to determine the impact of ECMO on posaconazole concentrations in critically ill patients.

The authors conducted a retrospective cohort study involving patients receiving intravenous posaconazole in the intensive care unit from January 2014 to July 2024. Posaconazole concentrations at the first sampling and the proportion of patients achieving target concentrations for prophylaxis (>0.7 mg/L) and treatment (>1 mg/L) of IFI were assessed. Patients receiving ECMO were compared with non-ECMO patients. In addition, the impact of ECMO initiation or decannulation on posaconazole concentrations was examined.

In total, 19 patients (8 ECMO and 11 non-ECMO) were included. ECMO patients had lower posaconazole concentrations (median [interquartile range], 0.7 [0.5-0.7] mg/L versus 1.2 [0.7-1.4] mg/L, P = 0.04) and were less likely to reach therapeutic concentrations (13% versus 64%, P = 0.04). Fewer ECMO patients achieved concentrations required for prophylaxis, although this difference was not statistically significant (50% versus 82%, P = 0.17). ECMO initiation was associated with a reduction in posaconazole concentration (n = 1), whereas decannulation was associated with an increase (n = 3).

ECMO patients may be at an increased risk of subtherapeutic posaconazole concentrations for treating IFI, and ECMO decannulation may increase concentrations. Close therapeutic drug monitoring is recommended, especially during ECMO initiation and decannulation, to ensure posaconazole concentrations are appropriate for treating or preventing IFI.