Measurement of posaconazole, itraconazole, and hydroxyitraconazole in plasma/serum by high-performance liquid chromatography with fluorescence detection.

Background: Itraconazole and posaconazole are used in the prevention and treatment of invasive fungal infections. However, the oral bioavailability of both compounds varies widely, and dose-serum concentration relationships are poorly defined for these analytes. The aim of this work was to develop and validate a simple assay that could be implemented in most laboratories for the purpose of therapeutic drug monitoring.