OUTLINE FOR GENTAMICIN AND VANCOMYCIN INTERFERENCE…..
Interference in medical tests
some type of interference exists.
Yadav S, Sanjaya KC Interference of drugs on clinical
chemistry—shall we start thinking?
Analytical interference defined.
Nikolac N. Ispitivanje interferencija. In: Simundic AM, ed. Upravljanje
kvalitetom laboratorijskog rada. Zagreb, Croatia: Medicinska naklada;
2013:51– 64. 3.
Dodig S. Interferences in quantitative immunochemical methods. Biochem
Incorrect test results.
Lippi G, Becan-McBride K, Beh´ulova´ D, et al. Preanalytical quality
improvement: in quality we trust. Clin Chem Lab Med. 2013;51(1):229–241.
Kailajarci M, Takala T, Gr ¨ onroos P, et al. Reminders of drug effects on ¨
laboratory test results. Clin Chem. 2000;46(9):1395–1400.
Nikolac N, Simundic AM, Miksa M, et al. Heterogeneity of manufacturers’ declarations for lipemia interference—an urgent call for standardization.
Clin Chem Acta. 2013;426(1):33–40.
Also, the knowledge of laboratory staff and clinicians about possible drug interferences is often overlooked or unknown.
Sonntag O. Quality in the analytical phase. Biochem Med.
Classification of interferences
Interferences are classified as endogenous or exogenous.
An endogenous interference originates from the substance found naturally in the
patient’s sample, like bilirubin, hemoglobin, glucose, antibodies, or proteins,
with hemolysis, icterus, and lipemia as the most common interferences.
An exogenous interference results from substances not naturally found in a patient’s
specimen, like drugs, their metabolites and additives, herbal products, or other
Interference effect depends on the concentration of an interfering substance, but not necessarily in a proportional way.
Drugs can interfere with laboratory measurements via several mechanisms.
Biological interferences occur when a drug activates one of the mechanisms, like
induction of hepatic microsomal enzymes, enzyme inhibition, or drug
displacement from protein-binding site.
However, these changes reflect a true state in the human body and thus are not
considered analytical errors. Analytical (or chemical) interference is present when
a drug causes falsely decreased or increased results of laboratory parameters.
Mechanisms of interference often include structural similarity of the drug to the
tested analyte, drug inhibition of the reaction used in the analyte measurement,
or changes in the structural integrity of the matrix (ie, viscosity or turbidity).
However, these effects can often go unrecognized in the laboratory because of
the lack of relevant information about patient drug therapy or unavailability of
methods for drug concentration measurement.
Kroll HM, Elin JR. Interference with clinical laboratory analytes. Clin Chem. 1994;40(11):1996–2005. 16.
Forman TD, Young SD. Drug interference in laboratory testing. Ann Clin Lab Sci. 1976;6(3):263–271. 17.
Benet LZ, Sheiner LB. Pharmacokinetics: The Dynamics of Drug Absorption, Distribution and Elimination. New York, NY: Macmillan; 1985:13– 22. 18.
Caraway WT, Kammeyer CW. Chemical interference of drugs and other substances with clinical laboratory test procedures. Clin Chim Acta. 1972;41(1): 395–434. 19. Kroll MH, Ruddel KW, Blank DW. A model for assessing interference. Clin Chem. 1987;33(7):1121–1123.
Seems these references cover the whole paragraph
Introduce objects of interest
Introduce function of objects
. Review of vancomycin-induced renal toxicity: an update
Factors impacting unbound vancomycin concentrations in different patient
We hypothesized that high drug concentrations might affect results of clinical