title: Bioassay of teicoplanin in serum containing rifampin or a beta-lactam antibiotic.
abstract: The purpose of this study was to develop bioassays for the measurement of teicoplanin in serum containing rifampin or a beta-lactam antibiotic. Use of rifampin-resistant Bacillus subtilis as indicator organism or pretreatment of the serum sample with Bacillus cereus penicillinase Type I (nafcillin, ticarcillin, mezlocillin) or Type II (cefazolin, cefuroxime, ceftazidime, ceftriaxone) effectively eliminated assay interference. Validation bioassays performed on two separate days utilizing triplicate coded serum samples containing 0 to 200 micrograms teicoplanin in combination with 40 micrograms/ml rifampin or 200 to 500 micrograms/ml beta-lactam showed no significant differences (p greater than 0.05, two-way analysis of variance) in analyte recovery between assay days. Regression analysis of each teicoplanin/rifampin or teicoplanin/beta-lactam data set yielded slope values of 0.92 to 1.01, intercept values of -0.45 to 0.84 and correlation coefficients of 0.9925 to 0.9990. Thus, serum teicoplanin can be quantitated accurately, precisely, and reproducibly in patients receiving concomitant rifampin or beta-lactam chemotherapy.
authors.affiliation: Merrell Dow Research Institute, Indianapolis, IN 46268.
authors.forename: M T
authors.initials: MT
authors.lastname: Kenny
authors.forename: J K
authors.initials: JK
authors.lastname: Dulworth
authors.forename: M A
authors.initials: MA
authors.lastname: Brackman
authors.forename: H L
authors.initials: HL
authors.lastname: Torney
authors.forename: C B
authors.initials: CB
authors.lastname: Gibson
authors.forename: A R
authors.initials: AR
authors.lastname: Hildebrand
authors.forename: L S
authors.initials: LS
authors.lastname: Weckbach
authors.forename: J L
authors.initials: JL
authors.lastname: Staneck
mesh_terms: D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000097:blood*; D001681:Biological Assay; D006020:Glycopeptides / Q000097:blood; D006801:Humans; D012044:Regression Analysis; D012293:Rifampin / Q000097:blood*; D017334:Teicoplanin; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D047090:beta-Lactams; D017334:Teicoplanin; D012293:Rifampin