INTRACELLULAR CONCENTRATIONS OF AZOLES AND ECHINOCANDINS IN DIFFERENT COMPARTMENTS OF THE PERIPHERAL BLOOD

F. Farowski1*, C. Müller2, M. Rüping1, J. Vehreschild1, O. Cornely1,3

Author address: 

1Klinik I für Innere Medizin, Uniklinik Köln 2Institut für Pharmakologie, Uniklinik Köln 3Universität zu Köln, Zentrum für Klinische Studien (ZKS, BMBF 01KN0706)

Abstract: 

Purpose: Therapeutic drug monitoring (TDM) aims at optimizing the benefits and risks of pharmacotherapy, specifically for drugs exhibiting significant pharmacokinetic variability (Smith, TDM 2008). A rapid turn-around time is a pre-requisite to conduct TDM in a sensible way. While TDM usually is performed by measurement of serum or plasma concentrations, little is known about the concentrations in other compartments of the peripheral blood, i.e. peripheral blood mononuclear cells (PBMCs), polymorphonuclear leucocytes (PMNs), and red blood cells (RBCs). Interactions with these cells might well influence the efficacy of antifungal drugs. We therefore developed a method to quantitate most clinically relevant antifungal drugs in different compartments of the peripheral blood; Based on this method we determined, are determining the intracellular concentrations of anidulafungin, caspofungin, micafungin, posaconazole, and voriconazole. Methods: LC-MS/MS: We developed a liquid chromatography tandem mass spectroscopy (LC-MS/MS) assay allowing the quantitation of anidulafungin (ANF), caspofungin (CSF), isavuconazole (ISC), micafungin (MCF), posaconazole (PSC), and voriconazole (VRC) in different compartments of the peripheral blood. All calibration curves were linear and fitted using least squares with a weighting factor of the reciprocal concentration. Limits of detection [ng/mL] were: ANF 8.3, CSF 31.5, ISC 1.5, MCF 97.7, PSC 3.3, and VRC 1.4. The lower limits of quantitation [ng/mL] were: ANF 64, CSF 108, ISC 4.5, MCF 160, PSC 10, and VRC 4.2. Samples: Whole blood from patients receiving antifungal treatment was collected in two EDTA salt containing tubes (2x8 mL). The blood was separated by double discontinuous Ficoll Hypaque density gradient (Histopaque 1077 and 1119; Sigma Aldrich, Munich, Germany) centrifugation. The cells were extracted with acetonitrile containing internal standard by sonication, vortexing and centrifugation. Results: Up to now, twenty-three samples of fourteen subjects receiving posaconazole for prophylaxis of fungal infections were analyzed. While posaconazole concentrations within the PBMCs and PMNs were significantly increased compared to the plasma concentration (P
2010

abstract No: 

91

Full conference title: 

4th Advances Against Aspergillosis
    • AAA 4th (2010)