The estimated glomerular filtration rate is a rather important measurement for patients under intensive care, since they often receive several drugs, and impaired renal function may result in misleading dosing. The estimated glomerular filtration is derived from mathematical models using serum creatinine, a measurement that suffers interference of some drugs, such as metamizole. The study intented to evaluate the impact on patient stratification for dose adjustment of two antimicrobials (meropenem and vancomycin) caused by metamizole interference in creatinine measurement by dry chemistry. A cross-sectional study was conducted with a group of 108 hospitalized patients under metamizole prescriptions at fixed intervals. Serum creatinine levels were determined by enzymatic dry chemistry and Jaffé assays and the estimated glomerular filtration rate was calculated through the CKD-EPI equation. Patients were stratified in groups according to their estimated glomerular filtration rate for drug dosing of vancomycin and meropenem. As expected, creatinine values were significantly lower in measurements performed by the dry chemistry method in comparison to Jaffé assay (p<0.0001) when patients are under metamizole treatment. A significant bias (-40.3%) was observed between those two methods, leading to a significant difference (p<0.0001) in patient classification according to renal function using the CKD-EPI equation for dosing adjustment. Thus, during the validity of metamizole treatment, the stratification for drug dosing by the estimated glomerular filtration rate is not reliable if the creatinine measurement is done through dry chemistry. Clinical and laboratory staff must be aware of these limitations and cooperate to optimize pharmacotherapy.

对于重症监护患者来说，估计的肾小球滤过率是一项相当重要的指标，因为他们经常服用几种药物，并且肾功能受损可能会导致误导性用药。估计的肾小球滤过率是从使用血清肌酐的数学模型得出的，血清肌酐是一种受某些药物（例如间咪唑）干扰的测量方法。该研究旨在通过干化学法检测肌酐干扰中咪唑对两种抗菌药物（美罗培南和万古霉素）的剂量调整，以评估对患者分层的影响。一组横断面研究是按固定间隔按照metamizole处方对一组108名住院患者进行的。血清肌酐水平通过酶促干化学和Jaffé测定确定，并通过CKD-EPI方程计算估计的肾小球滤过率。根据对万古霉素和美罗培南给药的估计肾小球滤过率，将患者分组。不出所料，当患者接受metamizole治疗时，与Jaffé分析法相比，干化学法测量的肌酐值显着降低（p <0.0001）。在这两种方法之间观察到显着的偏倚（-40.3％），根据使用CKD-EPI方程进行剂量调整的肾功能，导致患者分类的显着差异（p <0.0001）。因此，在metamizole治疗的有效性期间，如果肌酐的测定是通过干化学法进行的，则通过估计的肾小球滤过率进行给药的分层是不可靠的。临床和实验室工作人员必须意识到这些局限性，并进行合作以优化药物治疗。