DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B-9052 Gent, Belgium.
Drug Test Anal. 2009 May;1(5):209-13. doi: 10.1002/dta.31.
Until the end of 2003 a urinary concentration of pseudoephedrine exceeding 25 microg/mL was regarded as a doping violation by the World Anti-Doping Agency. Since its removal from the prohibited list in 2004 the number of urine samples in which pseudoephedrine was detected in our laboratory increased substantially. Analysis of 116 in-competition samples containing pseudoephedrine in 2007 and 2008, revealed that 66% of these samples had a concentration of pseudoephedrine above 25 microg/mL. This corresponded to 1.4% of all tested in competition samples in that period. In the period 2001-2003 only 0.18% of all analysed in competition samples contained more than 25 microg/mL. Statistical comparison of the two periods showed that after the removal of pseudoephedrine from the list its use increased significantly. Of the individual sports compared between the two periods, only cycling is shown to yield a significant increase.Analysis of excretion urine samples after administration of a therapeutic daily dose (240 mg pseudoephedrine) in one administration showed that the threshold of 25 microg/mL can be exceeded. The same samples were also analysed for cathine, which has currently a threshold of 5 microg/mL on the prohibited list. The maximum urinary concentration of cathine also exceeded the threshold for some volunteers. Comparison of the measured cathine and pseudoephedrine concentrations only indicated a poor correlation between them. Hence, cathine is not a good indicator to control pseudopehedrine intake. To control the (ab)use of ephedrines in sports it is recommended that WADA reintroduce a threshold for pseudoephedrine.
直到 2003 年底，世界反兴奋剂机构（WADA）将尿液中伪麻黄碱浓度超过 25 微克/毫升视为兴奋剂违规行为。自 2004 年该物质从禁用清单中移除以来，我们实验室检测到尿液中伪麻黄碱的样本数量大幅增加。对 2007 年和 2008 年含有伪麻黄碱的 116 个比赛样本进行分析，结果显示，这些样本中 66%的伪麻黄碱浓度超过 25 微克/毫升，相当于同期所有比赛样本的 1.4%。而在 2001-2003 年期间，所有比赛样本中仅 0.18%的样本中含有超过 25 微克/毫升的伪麻黄碱。对这两个时期进行统计比较后发现，伪麻黄碱从禁用清单中移除后，其使用量明显增加。在所比较的两个时期的个别运动项目中，只有自行车运动显示出显著的增加。对一次给药 240 毫克伪麻黄碱的治疗日剂量后的排泄尿液样本进行分析显示，可超过 25 微克/毫升的阈值。同样的样本也被分析了其目前在禁用清单中阈值为 5 微克/毫升的去甲伪麻黄碱。一些志愿者的尿液中去甲伪麻黄碱浓度也超过了阈值。对测量的去甲伪麻黄碱和伪麻黄碱浓度进行比较，仅表明两者之间相关性较差。因此，去甲伪麻黄碱不是控制伪麻黄碱摄入量的良好指标。为了控制运动中（兴奋剂）麻黄碱的使用，建议 WADA 重新引入伪麻黄碱的阈值。
