Elimination of ephedrines in urine following administration of a Sho-seiryu-to preparation.

Sho-seiryu-to is one of the most common Traditional Chinese Medicine preparations for the attenuation of colds. Ephedrae Herba is one of the prescriptions of Sho-seiryu-to. The major ingredients of Ephedrae Herba, ephedrines, are banned substances on the World Anti-Doping Agency (WADA) list. The purpose of this study was to investigate the elimination of urinary ephedrines after administering Sho-seiryu-to preparation and to determine the possibility of positive ephedrines test results in urine. Six healthy volunteers took a single 2.5-g dose of concentrated Sho-seiryu-to preparation. All urine was collected for 48 h. The concentrations of urinary ephedrines were analyzed by high-performance liquid chromatography and the elimination half-life of the ephedrines was estimated. The results show that ephedrine and cathine (norpseudoephedrine), the prohibited substances of the WADA, were excreted in the urine after taking a single dose of Sho-seiryuto preparation. The peak concentration of ephedrine was 3.88 +/- 1.87 mg/mL (mean +/- SD), which was lower than the WADA permitted value (10 mg/mL). The estimated elimination half-lives of ephedrine, norephedrine, pseudoephedrine, and norpseudoephedrine following administration of this preparation were 5.3 +/- 1.2, 4.9 +/- 0.9, 4.4 +/- 1.0, and 5.4 +/- 1.8 h, respectively. This study concluded that the urine would not violate the antidoping rules after administering a single dose of Sho-seiryu-to preparation. Nevertheless, an applied multiple-dose study upon administering the preparation for three times per day for three days showed a positive urine ephedrine result (13.7 mg/mL). Athletes should be careful when taking more than a single dose of Sho-seiryu-to preparation.