D. Breilh, C. Pobel, P. Rispal, MC. Saux
Laboratory of Clinical Pharmacokinetic, Bordeaux II University, France
Analysing concentration of vancomycine individually showed that pharmacokinetic parameters show a marked inter-and intra-individual variability and more particulary on the apparent volume of distribution (Vc) and the elimination constant (Kel). In this study, 161 neutropenic patients with a cocci gram positive infection were admitted in a hospital blood disease department, receiving 1*2g of vancomycine per 24 hours in continuous infusion via an electric syringe over 9 days that may be repeated. Blood sampling is done by FPIA (TDx FLx ABBOTT). Results (initial estimaes are similar for each analysis):
Neutropenic patients show a decrease in plasma concentrations that can be explained versus reference, by an increase in Vc for P-PHARM, a portion of renal excretion Ks, Cl similar or higher for P-PHARM, NONMEM and finally a Kcp higher for NONMEM and NPEM2. The various approaches give interesting results that are to be taken into account but are nevertheless questionable.