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

•Invasive fungal infections are life threatening in immunocompromised population.•Proper treatment with azole antifungal agents may be lifesaving.•Therapeutic drug monitoring of azole is helpful for dosing strategies.•LC-MS/MS is the method of choice due to its high specificity and sensitivity.•This LC-MS/MS method includes 5 azoles and 1 active metabolite.

BackgroundAzole 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.MethodsTo 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.ResultsThe validated method solely required a protein precipitation step before subsequent dilution and injection onto the LC-MS/MS system. Furthermore, the analysis time was < 2 min per sample.ConclusionsThis method enables measurement of all 6 of these analytes into a single LC-MS/MS assay.