['Airway inflammation is a hallmark of asthma, therefore current treatment recommendations include the use of inhaled glucocorticosteroids (GCS). However, there is little evidence that the effects of inhaled GCS are dose dependent.', 'The objective of this study was to assess the efficacy and safety of a second-generation GCS, budesonide, delivered by Turbuhaler, in adults with chronic asthma.', 'In a 12-week, randomized, double-blind, multicenter, parallel-group study, 473 subjects 18 to 70 years of age received either placebo or budesonide (200, 400, 800, or 1600 microg total daily dose) administered twice daily. Primary efficacy end points were mean change from baseline for FEV1 and morning peak expiratory flow. Safety was assessed by reported adverse events and by a cosyntropin-stimulation test.', 'The mean baseline FEV1 was 63% to 66% of predicted normal value between groups. All doses of budesonide were more effective than placebo (p < 0.001). The mean changes in morning peak expiratory flow were 12, 22, 27, and 30 L/min in the 200, 400, 800, and 1600 microg budesonide total daily dose groups, respectively, and -27 L/min for the placebo group. A statistically significant dose-response effect for the mean change from baseline over the 12-week study was seen for both morning peak expiratory flow and FEV1. Budesonide-treated subjects also demonstrated significant reduction in asthma symptoms and bronchodilator use compared with placebo. There were no clinically significant differences in treatment-related adverse experiences among groups.'] Is budesonide delivered by Turbuhaler effective in a dose-dependent fashion when used in the treatment of adult patients with chronic asthma?