Objectives: In the treatment of stable mild to moderate asthma, twice-daily administration of inhaled steroids may allow adequate control of the asthma; however, comparisons of the efficacy of once- or twice-daily administration brought contradictory results. This study is a randomized, double-blind crossover trial, set to determine if inhaled beclomethasone dipropionate given once daily in the late afternoon or at bedtime can be as effective as a twice-daily regimen in the treatment of moderate asthma.
Design: Subjects were randomly assigned to 3 different dosing regimens of inhaled beclomethasone: (1) regimen A, a twice-daily dose of 500 micrograms in the morning and at bedtime; (2) regimen B, a single dose of 1,000 micrograms in the late afternoon; and (3) regimen C, a single dose of 1,000 micrograms at bedtime.
Patients and participants: Enrolled in the study were 42 subjects who required 500 micrograms of inhaled beclomethasone dipropionate twice daily to control symptoms of asthma and to minimize use of beta 2-adrenergic agonists, according to criteria suggested in a recent international consensus on asthma therapy. Prior to receiving therapy with inhaled steroids, all of these patients either had chronic symptoms of asthma that required administration of a short-acting beta 2-agonist at least twice per day, or had nocturnal asthma symptoms at least once per week.
Therapy: After a 2-week baseline evaluation, each subject was given the 3 treatment regimens in randomized order, each for a period of 4 weeks. Subjects were asked to record daily symptoms of asthma and peak expiratory flows in the morning and evening. At the end of each treatment period, spirometric data and airway responsiveness to methacholine were measured.
Measurements and results: Thirty-seven subjects completed the study. No significant difference was found among the 3 treatment regimens for asthma symptoms, FEV1, the provocative concentration of methacholine causing a 20 percent decrease in the FEV1 (PC20) (geometric means, 1.41, 1.09, and 1.09 mg/ml), and mean morning and evening peak expiratory flow rates (PEFR). The plasma cortisol level and the adrenocorticotropic hormone (ACTH) response were not significantly different among treatments, nor were side effects, which were minimal.
Conclusion: In moderate asthma controlled with a twice-daily dose of inhaled beclomethasone, a single total daily dose administered in the late afternoon or in the evening provides as good control of asthma for 2 months.