Lnhaled salbutamol and doping control: Effects of dose on urine concentrations

Objective: The present study was designed to examine the dose-response relationship of inhaled salbutamol and its concentration in the urine while resting at various times after inhalation, and to compare these values against the current World Anti-Doping Code limits. Design: An interventional, repeated-measures design. Setting: Sport Medicine Clinic, University of British Columbia (Vancouver, Canada). Participants: Eight healthy, nonasthmatic males participated in this study (age = 28 +/- 6 years, height = 179.4 +/- 5.1 cm, and weight = 77.4 +/- 5.4 kg). Intervention: Administration of three different doses of inhaled salbutamol (800, 400, and 200 mu g) in a randomized fashion separated by at least 72 hours. Main Outcome Measurement: Urine concentration of non-sulphated salbutamol Results: Urine concentrations were highly variable between subjects and increased as dose increased, with a significant difference noted between 800 and 200 mu g at 30, 60, and 120 minutes after inhalation. Urine concentrations of salbutamol peaked at 60 minutes for all doses. No samples exceeded the doping criterion of 1000 ng/mL, and the maximum value observed was 904 ng/mL. Conclusion: These results indicate that after inhalation of doses up to 800 mu g, urinary concentrations of salbutamol are well below the limits used in doping control.