title: Analytical interference of drugs in clinical chemistry: I--Study of twenty drugs on seven different instruments.
abstract: We have investigated the effect of 20 drugs on the accuracy of results obtained from seven instruments now widely used in clinical biochemistry laboratories: Abbott VP, aca II, Cobas Bio, Ektachem 400, Hitachi 705, KDA and SMAC. Eleven to 18 constituents were analysed on each instrument. Our results lead us to the following conclusions: (1) only rarely does drug interference with a method lead to a clinically significant change in a measured value; (2) the magnitude of the change may relate linearly or non-linearly to the drug concentration but is usually independent of the target analyte concentration; (3) interference with a chemical reaction on one instrument does not always mean that the same reaction will be altered in the same way on other instruments; (4) no interferences were found for drugs with therapeutic levels in the low micro-molar range; (5) in most cases the interference could not be predicted from the chemical nature of drug.
mesh_terms: D001322:Autoanalysis / Q000295:instrumentation*; D001774:Blood Chemical Analysis; D001786:Blood Glucose / Q000032:analysis; D003545:Cysteine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D004364:Pharmaceutical Preparations / Q000097:blood*
chemical_list: D001786:Blood Glucose; D004364:Pharmaceutical Preparations; D003545:Cysteine