title: Falsely elevated aminoglycoside serum levels in jaundiced patients.
abstract: Two cases in which hyperbilirubinemia produced falsely elevated aminoglycoside concentrations, using the Emit assay, are described. Patients' sera were analyzed by both the Emit and a microbiologic assay. The first patient had a 26-percent greater tobramycin concentration with the Emit assay, as compared with the microbiologic assay, when the total bilirubin was 20.1 mg%. For the same patient, there was essentially no difference between the two assays when the total bilirubin was 4 mg%. The Emit concentrations in the other patient were 34-percent elevated with a total bilirubin of 9.7 mg%. Pharmacokinetic analysis also was performed on serum levels reported by each method. Calculated kinetic parameters and dosage regimens varied greatly. Patients with total bilirubin concentrations greater than 4 mg% may need to have aminoglycoside serum levels assayed by a method other than the Emit assay.
mesh_terms: D000368:Aged; D000617:Aminoglycosides / Q000097:blood; D000900:Anti-Bacterial Agents / Q000097:blood*; D001663:Bilirubin / Q000097:blood; D001681:Biological Assay; D005260:Female; D006207:Half-Life; D006801:Humans; D007124:Immunoenzyme Techniques; D007565:Jaundice / Q000097:blood*; D008297:Male; D008875:Middle Aged
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001663:Bilirubin