Study objective: To test the hypothesis that patients with asthma who develop cough and wheezing after the use of beclomethasone aerosol would have a better tolerance for triamcinolone aerosol.
Design: Randomized, double-blinded, crossover trial.
Setting: Pulmonary function laboratory.
Patients: Volunteer sample of 24 patients attending an asthma clinic who had developed cough, with or without wheezing, after inhaling beclomethasone aerosol. All patients completed the study.
Interventions: Aerosols were used in habitual manufacturers' preparations and canisters, but both were administered in three puffs through the delivery system used for triamcinolone. The preparations differed in drug (beclomethasone dipropionate or triamcinolone acetonide), propellant (trichloromonofluoromethane and dichlorodifluoromethane, or dichlorodifluoromethane alone, respectively) and dispersant (oleic acid or dehydrated alcohol, respectively). PATIENTS inhaled three puffs of one aerosol on one day and three of the other on the next.
Measurements and main results: Forced expiratory volume in one second (FEV1) was measured before and after each aerosol application. The FEV1 decreased a mean of 17.7% from baseline after inhalation of beclomethasone, and 0.8% after triamcinolone (difference, 16.9; 95% confidence limits, 12.36 to 21.34; p less than 0.001). Coughs were counted after each puff. The mean number of coughs after beclomethasone aerosol inhalation was 35.8, and after triamcinolone, 0.5 (difference, 35.3; 95% confidence limits, 22.62 to 47.98, p less than 0.001).
Conclusions: Asthmatic patients who are unable to inhale beclomethasone aerosol due to cough or wheezing can inhale triamcinolone aerosol without difficulty. Our investigation does not determine the exact cause of the coughing and wheezing with the beclomethasone aerosol, but we suspect the dispersant as the source.