A new bronchodilating agent, procaterol, in preventing exercise-induced asthma.

The aim of the present study was to verify the effectiveness of procaterol, a recent and specific beta-2-adrenoceptor stimulant, in preventing exercise-induced asthma (EIA). Twelve asthmatic patients were selected aged 18.6 +/- 5.6 years with a positive response to EIA and a basal forced expiratory volume of the first second (FEV1) better than 80% of predicted. The patients underwent four bronchoprovocation challenges on four consecutive days. On the first day they performed an inclusion test, and, on the three subsequent days, they were submitted, to three identical standardized challenges according to a randomized design. Fifteen minutes before, procaterol (20 mcg), salbutamol (200 mcg) and a placebo were administered as metered aerosol. No pharmacological treatment was given for 24 h (48 h for antihistamines) before each challenge. The test was carried out running on treadmill (10% grade) for 7 min. Room temperature (20-25 degrees C) and relative humidity (40-55%) were maintained constant. At baseline, 15 min before, 5, 10, 15, 30 and 60 min after the exercise, lung function was assessed. Basal mean values of FEV1 were 94.7, 94.9, 90.7 and 91.5% of predicted for the inclusion and the three protected tests, respectively, without significant differences. The FEV1 mean values showed a mild bronchodilation 15 min after salbutamol (+13.2%, p less than 0.006) and procaterol (+8%, NS). At every considered time all indices showed a significant gap (p less than 0.01) between drugs and the placebo with no appreciable differences between procaterol and salbutamol.