From the University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice Zagreb, Zagreb, Croatia. Dr Brencic is now with the Department of Laboratory Diagnostics, General Hospital Pula, Pula, Croatia.
Arch Pathol Lab Med. 2019 Jun;143(6):738-747. doi: 10.5858/arpa.2017-0462-OA. Epub 2019 Jan 15.
CONTEXT.—: Gentamicin and vancomycin are nephrotoxic antibiotics. Little is known about the influence of drug concentrations on results of clinical chemistry tests.
OBJECTIVE.—: To investigate gentamicin and vancomycin interference on results of 33 commonly measured biochemistry tests.
DESIGN.—: The study was carried out in the University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice (Zagreb, Croatia). For each drug, 10 aliquots of pooled serum were prepared. In order to cover toxic concentrations, pool serum samples were spiked with drugs to obtain 0 to 50 μg/mL of gentamicin and 0 to 200 μg/mL of vancomycin. Biochemistry tests were measured in duplicate on the Architect c8000 analyzer, and drug concentrations were measured on Architect i2000 SR (both Abbott Laboratories, Abbott Park, Illinois). For each tested concentration, bias was calculated against the initial measurement. Acceptance criteria were defined as measurement uncertainty of the commercial control with the value close to the measured range of the pool sample.
RESULTS.—: For gentamicin, all bias values were below established criteria. For vancomycin, significant changes were observed for potassium, direct bilirubin, and immunoglobulin A. Significant bias was already detected at low vancomycin concentration (2.98 μg/mL) for direct bilirubin (bias = 9.7%; acceptable = 8%). Potassium bias at the highest vancomycin concentration (204.4 μg/mL) exceeded acceptance criteria (bias = 4.5%; acceptable = 4%). For immunoglobulin A, no apparent trend was observed, and bias is attributed to increased method imprecision.
CONCLUSIONS.—: Gentamicin did not interfere with the results of clinical chemistry tests. Direct bilirubin concentration is falsely increased in the presence of vancomycin, and potassium is affected at high concentrations.
庆大霉素和万古霉素是具有肾毒性的抗生素。关于药物浓度对临床化学检验结果的影响知之甚少。
研究庆大霉素和万古霉素对 33 项常用生化检验结果的干扰。
该研究在萨格勒布西梅罗维采大学医院医学系化学系（克罗地亚）进行。对于每种药物，均制备 10 份混合血清的等分试样。为了涵盖毒性浓度，将药物添加到混合血清样品中，使庆大霉素的浓度达到 0 至 50μg/ml，万古霉素的浓度达到 0 至 200μg/ml。在 Architect c8000 分析仪上重复测量两次生化检验，在 Architect i2000 SR 上测量药物浓度（均为雅培实验室，伊利诺伊州雅培公园）。对于每个测试浓度，均根据初始测量值计算偏差。接受标准定义为接近混合样品测量范围的商业对照品的测量不确定度。
对于庆大霉素，所有偏差值均低于既定标准。对于万古霉素，钾、直接胆红素和免疫球蛋白 A 的检测结果发生了显著变化。当万古霉素浓度较低（2.98μg/ml）时，直接胆红素的偏差已经显著（偏差=9.7%；可接受=8%）。在最高万古霉素浓度（204.4μg/ml）时，钾的偏差超过了可接受标准（偏差=4.5%；可接受=4%）。对于免疫球蛋白 A，未观察到明显趋势，偏差归因于方法精密度增加。
庆大霉素不会干扰临床化学检验结果。在存在万古霉素的情况下，直接胆红素浓度被错误地升高，而在高浓度时，钾会受到影响。
