Lefebvre R A, Surmont F, Bouckaert J, Moerman E
Heymans Institute of Pharmacology, University of Gent Medical School, Belgium.
J Pharm Pharmacol. 1992 Aug;44(8):672-5. doi: 10.1111/j.2042-7158.1992.tb05492.x.
The urinary excretion of ephedrine after intranasal administration of the drug was studied in 8 healthy volunteers. Ephedrine (6 drops of a commercial 0.75% nasal ephedrine solution in each nasal cavity) was administered 4 times at intervals of 2 h (total amount applied equivalent to approximately 14 mg ephedrine), and urine was collected each hour for 10 h; the volunteers exercised on a bicycle ergometer at 50% of their VO2max for 2 h after the last ephedrine application. Ephedrine was detected in all urine samples. The urinary ephedrine concentration ranged from 0.9 to 16.5 micrograms mL-1; the number of urine samples with an ephedrine concentration exceeding 5 micrograms mL-1 ranged from 1/10 (volunteer 2) to 9/10 (volunteers 1 and 3). The mean percentage of dose recovered within 10 h was 33% (range 23-50%). There was a weak but significant negative correlation between urinary pH and amount of ephedrine in the urine; exercise did not consistently influence the urinary amount. These results illustrate the systemic availability of ephedrine upon intranasal administration and show that the therapeutic use of a nasal ephedrine formulation by an athlete on the day of a competition can lead to a urinary ephedrine concentration above 5 micrograms mL-1, which is considered positive in current doping regulations of the International Union of Cyclists.
在8名健康志愿者中研究了经鼻给药后麻黄碱的尿排泄情况。麻黄碱（每个鼻腔滴入6滴市售0.75%的麻黄碱滴鼻液）每隔2小时给药1次，共给药4次（给药总量约相当于14mg麻黄碱），每小时收集尿液，共收集10小时；在最后一次给予麻黄碱后，志愿者在自行车测力计上以其最大摄氧量（VO2max）的50%进行2小时运动。所有尿液样本中均检测到麻黄碱。尿中麻黄碱浓度范围为0.9至16.5微克/毫升；麻黄碱浓度超过5微克/毫升的尿液样本数量范围为1/10（志愿者2）至9/10（志愿者1和3）。10小时内回收剂量的平均百分比为33%（范围为23 - 50%）。尿pH值与尿中麻黄碱量之间存在弱但显著的负相关；运动并未始终如一地影响尿中麻黄碱量。这些结果说明了经鼻给药后麻黄碱的全身可用性，并表明运动员在比赛当天使用麻黄碱滴鼻剂进行治疗可能导致尿中麻黄碱浓度高于5微克/毫升，这在国际自行车联盟当前的反兴奋剂规定中被视为阳性。
