Development and validation of a liquid chromatography-tandem mass spectrometry assay for the simultaneous quantitation of 5 azole antifungals and 1 active metabolite.

BACKGROUND: Azole antifungal medications are often administered to prevent or treat invasive fungal infections. These infections are deadly in the immunocompromised population. Therapeutic drug monitoring of the azole antifungal medications may potentially decrease morbidity and mortality in patients undergoing azole treatment.

METHODS: To assist with azole therapeutic drug monitoring, a liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated for 6 azole analytes: fluconazole, voriconazole, posaconazole, isavuconazole, itraconazole, and its active metabolite hydroxyitraconazole.

RESULTS: The validated method solely required a protein precipitation step before subsequent dilution and injection onto the LC-MS/MS system. Furthermore, the analysis time was <2min per sample.

CONCLUSIONS: This method enables measurement of all 6 of these analytes into a single LC-MS/MS assay.