estsWith Laboratory TDrug Interference

Prepared by

abweeny -Clinical Pharmacist: Eshraq Al

Supervisor of DIC/KAUH

EXT: 41417

A common source of diagnostic error is the lack of knowledge of the presence of drug-laboratory test

interactions (DLTIs). Misinterpretation of test results may lead to an erroneous diagnosis, unnecessary extra

diagnostic tests, therapy or follow-up.

There are two main categories of DLTIs: physiological and analytical interactions.

Physiological interactions are in vivo processes, in which drugs affect patients’ laboratory test results. Test

results may reveal an intended or unintended effect of a drug. Intended effects of drugs will generally not

result in diagnostic misinterpretation. However, unintended effect of drugs often can lead to diagnostic

confusion.

Analytical interactions are in vitro processes. In these cases, the interactions between drugs and laboratory

tests disturb the analytical process, which may have an important negative clinical impact, as affected

laboratory test results may not reflect the clinical situation of the patient. These analytical interactions

should be avoided by using an alternative assay, or erroneous test interpretations should be eliminated by

warning systems.

ACE: angiotensin-converting enzyme

INR: international normalized ratio

PAM: pralidoxime

PT : prothrombin time

TIBC: total iron-binding capacity

TSH: thyroid stimulating hormone

UBT: C-urea breath test

References:

1- Jasmijn A van Balveren , Wilhelmine P H G Verboeket-van de Venne

, Lale Erdem-Eraslan

, Albert J de Graaf

, Annemarieke E Loot

,et

al. Diagnostic error as a result of drug-laboratory test interactions. Diagnosis (Berl) . 2019 Mar 26;6(1):69-71

2- Hui Yao , Elizabeth R Rayburn

, Qiang Shi

, Liang Gao

, Wenjie Hu

, Haibo Li

. FDA-approved drugs that interfere with laboratory tests:

A systematic search of US drug labels . Crit Rev Clin Lab Sci. 2017 Jan;54(1):1-17.

3- Santos S, Borges R, Barros K. Drugs that interfere with the results of laboratory tests: an integrative review of the literature. Rev

Bras Anal Clin.2018 Nov 23;50(2) :105-110.

4- ASCLS. Laboratory Patient Safety Tips: Drug -related Laboratory Test Interference For Providers.2018