Normalization of Urinary Drug Concentrations with Specific Gravity and Creatinine
Normalization of Urinary Drug Concentrations with Specific Gravity and Creatinine
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DOI：
10.1093/jat/33.1.1
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发表时间：
2009-01-01
影响因子：
2.5
通讯作者：
Black, David L.
中科院分区：
文献类型：
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作者：
Cone, Edward J.;Caplan, Yale H.;Black, David L.
过量的液体摄入可大大稀释尿中药物浓度，并导致吸毒者的假阴性报告。纠正尿液中药物/代谢物浓度的方法（“正常化”）已被反兴奋剂实验室、疼痛监测项目和环境监测项目用于补偿过度水合作用，但此类程序尚未在工作场所、法律和治疗环境中常规使用。我们评估了两种基于比重和肌酐的药物正常化程序。这些修正应用于从三个不同的组（疼痛患者、海洛因使用者和大麻/可卡因使用者）收集的尿液样本。每个组在特征、研究设计和给药条件上都是独一无二的。两种归一化方法的结果高度相关（r= 0.94，范围0.78-0.99）。海洛因使用者（正常水合状态）的比重和肌酐正常化阳性百分比增加很小（分别为0.3%和- 1.0%），疼痛患者（水合状态未知）的百分比增加不大（4.2-9.8%），大麻/可卡因使用者（过度水合状态）的百分比增加很大（2- 38倍）。尽管有一些限制，这些标准化程序提供了处理高度稀释、稀释和浓缩尿液标本的替代方法。通过这些程序使药物/代谢物浓度正常化被推荐用于尿液检测程序，特别是作为处理稀释标本的一种手段。
Excessive fluid intake can substantially dilute urinary drug concentrations and result in false-negative reports for drug users. Methods for correction (“normalization”) of drug/metabolite concentrations in urine have been utilized by anti-doping laboratories, pain monitoring programs, and in environmental monitoring programs to compensate for excessive hydration, but such procedures have not been used routinely in workplace, legal, and treatment settings. We evaluated two drug normalization procedures based on specific gravity and creatinine. These corrections were applied to urine specimens collected from three distinct groups (pain patients, heroin users, and marijuana/ cocaine users). Each group was unique in characteristics, study design, and dosing conditions. The results of the two normalization procedures were highly correlated (r= 0.94; range, 0.78–0.99). Increases in percent positives by specific gravity and creatinine normalization were small (0.3% and −1.0%, respectively) for heroin users (normally hydrated subjects), modest (4.2–9.8%) for pain patients (unknown hydration state), and substantial (2- to 38-fold increases) for marijuana/cocaine users (excessively hydrated subjects). Despite some limitations, these normalization procedures provide alternative means of dealing with highly dilute, dilute, and concentrated urine specimens. Drug/metabolite concentration normalization by these procedures is recommended for urine testing programs, especially as a means of coping with dilute specimens.