Evaluation of the Interference of 49 Commonly Used Clinical Drugs on 60 Biochemical Tests

Objective This study aimed to systematically evaluate the interference of 49 commonly used clinical drugs on 60 routine biochemical tests, providing a foundation for clinical laboratories to establish drug-interference alert systems and support more accurate result interpretation. Method We tested 49 drugs at three concentrations (baseline, therapeutic C1, supra-therapeutic C2) on 60 biochemical assays following CLSI EP07. For each drug-test combination, a single patient serum/plasma pool was split into three aliquots: baseline, C1-spiked, and C2-spiked. All samples were analyzed using a Mindray BS-2800M fully automated biochemical analyzer. Results at C1 and C2 were compared with baseline (zero concentration) to characterize drug-induced interference with each biochemical test. Results At concentration C1, 23 drugs exhibited no interference across all 60 biochemical tests. Among the 2940 drug-test combinations evaluated, C1 generated 27 cases (0.9%) of strong interference, mainly within liver function assays, and 40 cases (1.4%) of weak interference. The majority (97.7%) exhibited no detectable effect. At concentration C2, a total of 2820 drug-test combinations were included in the analysis. Strong interference was detected in 103 cases (3.7%), primarily affecting liver and lipid profiles, alongside 117 cases (4.1%) of weak interference. Nonetheless, 92.2% of combinations still showed no interference. Conclusion This study provides a comprehensive profile of drug-induced interference across 60 routinely performed biochemical tests. These findings could support the accurate interpretation and interference identification of laboratory results.