Antifungal therapeutic drug monitoring

A growing body of evidence suggests that patient-to-patient variability in the pharmacokinetics of some antifungals, particularly the mold-active triazoles (itraconazole, voriconazole, and posaconazole) may contribute to therapeutic failure or unexpected toxicity. As a result, many clinicians have recognized a need for therapeutic drug monitoring (TDM) to individualize drug dosing in select patients with suspected or documented invasive fungal infections. However, approaches for performing and interpreting plasma concentrations are not well standardized, and logistical issues such as the turnaround time of test results can limit the clinical usefulness of testing in acutely ill patients. This article summarizes the pharmacologic rationale for TDM of antifungal agents, with a particular focus on recently published data for the newer triazoles, voriconazole and posaconazole. Practical recommendations for TDM-guided dosing are also provided, based on a critical evaluation of literature published over the past 5 years. © 2010 Springer Science+Business Media, LLC.