Isavuconazole Concentration in Real-World Practice: Consistency with Results from Clinical Trials.

Clinical use of voriconazole, posaconazole, and itraconazole revealed the need for therapeutic drug monitoring (TDM) of plasma concentrations of these antifungal agents. This need for TDM was not evident from clinical trials. In order to establish whether this requirement also applies to isavuconazole, we examined the plasma concentrations of 283 samples from patients receiving isavuconazole in clinical practice and compared the values with those from clinical trials. The concentration distributions from real-world use and clinical trials were nearly identical (>1 μg/ml in 90% of patients). These findings suggest that routine TDM may not be necessary for isavuconazole in most instances.