Background: Chlorofluorocarbon-propelled metered dose inhalers are facing a worldwide ban. Dry powder inhalers have been developed for the agents used in treatment of asthma.
Objective: Our objective was to compare the effects of two inhaled glucocorticosteroids in dry power inhalers: budesonide (delivered via Turbuhaler) and beclomethasone dipropionate (delivered via Rotahaler).
Methods: A randomized, crossover study with two steroid-treatment periods of 8 weeks. At the end of the study, the treatment with the inhaled steroid was stopped for 4 weeks. Sixteen adult patients with moderately severe asthma participated. Before the study all patients were treated with an inhaled steroid in a median dose of 0.60 mg/day (range 0.15-0.80); during the study they received 0.20 mg twice daily. Peak expiratory flow rate was measured twice daily at home throughout the study, lung function was assessed every fourth week and airway responsiveness was measured before and after each period. Preference concerning efficacy and inhaler type was assessed at the end of the study.
Results: Twelve patients completed the study. Lung function, airway responsiveness, and symptoms deteriorated significantly in the steroid-free washout period; this period had to be shortened in 5/12 patients. Mean morning peak expiratory flow was significantly higher during budesonide treatment than during beclomethasone dipropionate treatment, the difference being 17 L/min (95% C.I.: 2-32 L/min, P = .026). Airway responsiveness improved 1.1 doubling concentrations after budesonide treatment, but decreased 0.3 doubling concentrations after beclomethasone dipropionate treatment. The difference between the values after budesonide and beclomethasone dipropionate treatment was 1.4 doubling concentrations (95% C.I.: 0.4-2.4 doubling concentrations, P = .033). Forced expiratory flow in one second improved slightly more during budesonide than during beclomethasone treatment. The difference was 4.3% predicted (95% C.I.: -0.7-9.3%). Most patients reported budesonide Turbuhaler to be more effective (10 versus 0) and easier to use (11 versus 1) than beclomethasone dipropionate Rotahaler.
Conclusions: As a consequence of the difference in local potency of the steroids and the fact that Turbuhaler deposits more drug particles in the lung than Rotahaler, budesonide inhaled via Turbuhaler appeared to be a more effective steroid formulation than beclomethasone dipropionate inhaled via Rotahaler.