Chan K M, Matthews W S, Saxena S, Wong E T
Department of Pathology, University of Southern California School of Medicine, Los Angeles.
J Anal Toxicol. 1993 Sep;17(5):299-303. doi: 10.1093/jat/17.5.299.
To assess the value of the current NIDA cutoff concentrations for screening assays that detect urinary cocaine metabolites and phencyclidine (PCP), we collected data on concentrations of these drugs in newborns and patients admitted to the Los Angeles County + University of Southern California Medical Center from July 1, 1991, to December 31, 1991. Less than 2% of the patients were positive for PCP. However, 16.5% of the newborns and 25.1% of the remaining age groups tested positive for cocaine metabolites. Among specimens that tested negative with the screening assays, approximately 3% (182 specimens, with 15 from newborns) clearly contained detectable amounts (between 50 and less than 300 ng/mL) of benzoylecgonine by GC/MS, while less than 0.6% had detectable amounts (10-25 ng/mL) of PCP. The mothers of 7 of the 15 newborns also had detectable benzoylecgonine at various concentrations. This indicates that a lower screening cutoff concentration may be desirable for cocaine metabolites in hospitalized patients. Among those patients positive for cocaine metabolites or PCP, most were males between 20 and 39 years old. The urine drug concentrations in this population were 4-300 times greater than the cutoff concentrations for the screening assays.
为评估美国国立药物滥用研究所（NIDA）当前用于检测尿中可卡因代谢物和苯环己哌啶（PCP）的筛查检测的临界浓度值，我们收集了1991年7月1日至1991年12月31日期间洛杉矶县+南加州大学医学中心收治的新生儿和患者体内这些药物浓度的数据。PCP检测呈阳性的患者不到2%。然而，16.5%的新生儿和25.1%的其他年龄组可卡因代谢物检测呈阳性。在筛查检测呈阴性的标本中，约3%（182份标本，其中15份来自新生儿）通过气相色谱/质谱联用仪（GC/MS）明确含有可检测量（50至不足300 ng/mL）的苯甲酰爱康宁，而PCP可检测量（10 - 25 ng/mL）的标本不到0.6%。15名新生儿中的7名母亲体内也有不同浓度的可检测到的苯甲酰爱康宁。这表明住院患者中可卡因代谢物的筛查临界浓度可能需要降低。在可卡因代谢物或PCP检测呈阳性的患者中，大多数是20至39岁的男性。该人群中的尿药浓度比筛查检测的临界浓度高4至300倍。
