Simultaneous quantitation of azole antifungals, antibiotics, imatinib, and raltegravir in human plasma by two-dimensional high-performance liquid chromatography-tandem mass spectrometry.

High-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a standard analytical technique for therapeutic drug monitoring (TDM). A rapid LC-MS/MS method was developed for simultaneous quantitation of 3 antifungals and one active metabolite (posaconazole, voriconazole, itraconazole, and hydroxy-itraconazole), 5 antibiotics (daptomycin, ciprofloxacin, oxacillin, levofloxacin, and rifampicin), an antineoplastic agent (imatinib), and an antiretroviral (raltegravir) in human plasma. Protein precipitation of 10 μL of plasma with acetonitrile was used as a single-extraction procedure. After 2-dimensional LC, all drugs were quantified by electrospray ionization-triple quadrupole mass spectrometry by selected reaction monitoring detection in the positive mode. The method was validated per FDA recommendations including the study of extraction recovery (from 79.3% to 105.9%) and matrix effect via ion suppression/enhancement phenomenon. This method is precise (intra- and inter-assay coefficients of variation of 1.95-12.77%, 2.56-8.16% and 2.12-11.38% for low, medium and high levels of internal quality controls respectively) and accurate (intra- and inter-assay biases of 0.19-12.67%, 0.04 to -12.17% and 0.22-12.98% respectively). This method is an efficient tool for routine TDM and optimization of laboratory resource utilization.