Exposure to intravenous posaconazole in critically ill patients with influenza: A pharmacokinetic analysis of the POSA‐FLU study

Abstract Background Data on posaconazole in the critically ill are scarce. In the POSA‐FLU study, we examined the prevention of influenza‐associated pulmonary aspergillosis with posaconazole in this population. Methods In this observational sub‐study, we performed a pharmacokinetic analysis, including protein binding and target attainment (TA). Blood samples were collected over a 24 h‐dosing interval on both an early (Day 2 or 3) and a later (≥Day 4) treatment day. Results Target attainment was shown for AUC 0‐24 and C min prophylaxis but not for C min treatment. Moreover, a saturable protein binding with a significant, positive relationship between albumin concentrations and the maximum binding capacity was observed. Conclusions Our analysis indicates that posaconazole may be a suitable drug to further investigate for prophylaxis, as TA for prophylaxis was reached. Exposure targets for treatment were insufficiently attained in this population.