“…Low troughs are associated with therapeutic failure among patients with IFIs, and dose adjustments for undetectable concentrations are reported to improve treatment efficacy (10,13,21,24,28,32,36,37,39). In some studies, elevated troughs are linked to increased toxicity, including central nervous system (CNS) events and elevated liver function tests (5,10,16,19,21,24,28,34). In general, a target trough range of 1 to 4 g/ml is recommended for treatment of IFIs (2, 7).…”