Falsely low vancomycin results using the Abbott TDx

Sources of Erroneous Results in Therapeutic Drug Monitoring Due to Preanalytical Errors, High Bilirubin, Hemolysis, and Lipids

“…The authors concluded that although the assay on the AxSYM analyzer somehow was not affected by high direct bilirubin, the assay on the TDx analyzer demonstrated false -negative results for such samples (49) . Her liver enzymes and bilirubin were elevated despite a history of liver disease.…”