β-2 agonists in sport: are the anti-doping rules meeting the needs of asthmatic athletes?

(a) To review the methacholine tests performed in our laboratory up until 2008; (b) to compare them with previously reported data in 2006 and (c) to examine if the anti-doping rules are meeting the needs of asthmatic athletes who really need bronchodilator treatment.

Between April 2004 and September 2008, 89 high-level athletes were examined in our laboratory in order to obtain an abbreviated therapeutic use exemption for β-2 agonists. Of these, 50 men (23.31 (7.05) years) and 23 women (20.68 (5.94) years) performed a methacholine inhalation test with increasing concentrations of methacholine (0.025, 0.25, 2.5, 5, 10 and 25 mg/ml) until a fall of 20% in forced expiratory volume in 1 s (FEV(1)) was achieved.

31 candidates (42.5%) had a provocative concentration causing a 20% fall in FEV(1) (PC(20)) <2 mg/ml; 12 (16.4%) were between 2 and 4 mg/ml; 8 (11%) between 4.1 and 8 mg/ml and 22 candidates (30.1%) had a PC(20) >8 mg/ml. Seven of the 73 candidates had an obstructive pattern in the spirometry at rest, demonstrated by a FEV(1)% <70% but with a FEV(1) >70% of the reference value.

The anti-doping regulations with respect to β-2 agonists need to be reviewed, and measures should be adopted to include a fall of 70% in FEV(1)% as an obstruction criterion to indicate a bronchodilation test and to extend the criterion for a positive methacholine test to a PC(20) of 8 mg/ml.