A randomized, double-blind, double-dummy, parallel-group, multicenter, dose-reduction trial of the minimal effective doses of budesonide and fluticasone dry-powder inhalers in adults with mild to moderate asthma.

BACKGROUND: Inhaled corticosteroids are established first-line anti-inflammatory treatment for asthma. Clinical trials comparing inhaled corticosteroids must take into consideration that because of their excellent effect at low doses, they typically induce a near-maximal response in asthma patients.

OBJECTIVE: The aim of the present dose-response study was to estimate the minimal effective doses (MEDs) of budesonide and of fluticasone propionate via dry-powder inhaler in adults with mild to moderate asthma.

METHODS: This was a randomized, double-blind, double-dummy, parallel-group, multicenter, dose-reduction trial performed in adults to compare these 2 inhaled corticosteroids. After a 4- to 6-week run-in period with beclomethasone dipropionate 2000 pg/d, patients fulfilling defined criteria for asthma control were randomly allocated to treatment with budesonide or fluticasone, both administered BID at a total of 800 pg/d. At 5-week intervals, the dose was reduced to 400 and then 200 pg/d (200 and 100 pg BID) if asthma control was maintained according to further defined criteria. The MED was defined as the last dose level before deterioration of asthma control.

RESULTS: Subjects were 197 asthmatic patients with a mean age of 40.6 years in the budesonide group and 41.5 years in the fluticasone group. In both groups, baseline mean forced expiratory volume in 1 second (FEV(1)) was 79.4% of the predicted normal volume and baseline mean FEV(1) reversibility was 22.3%. The median MED for both groups was 400 microg/d, with no detectable difference in dis-tributions. The budesonide-to-fluticasone ratio for the geometric mean MED was 123% (95% CI, 99-153 [not significant]). No statistically significant differences regarding lung function, symptom scores, or rescue medication usage were found between the treatment groups during the first treatment period. Adverse-event profiles were similar in both groups, and no unexpected adverse events were considered to be caused by the study drugs.

CONCLUSION: This effect-controlled study did not detect a statistically significant difference between the MEDs for budesonide and fluticasone via dry-powder inhaler in adults with mild to moderate asthma.