To avoid the side effects associated with long-term administration of high doses of inhaled glucocorticosteroids, they should be used at the lowest effective dose. This study compared the clinical efficacy of budesonide given via a dry-powder, inspiratory flow-driven device (Turbuhaler), at a daily dose of 800 micrograms, with beclomethasone dipropionate (BDP) 1500 to 2000 micrograms given via pressurized metered-dose inhaler (pMDI) with spacer to adults requiring the latter dose of BDP to control their asthma. The study was performed as a 2-week run-in, 8-week open, randomized, multicenter, parallel-group design. Adult asthmatics with a forced expiratory volume in 1 second 55% or more of predicted normal and receiving BDP 1500 to 2000 micrograms daily entered the study. After a 2-week run-in, one group continued with BDP and the other was switched to budesonide through the Turbuhaler. After 8 weeks, morning peak expiratory flow (PEF) had increased by 5.9 L/min from a mean of 390 L/min in the budesonide group and by 1.9 L/min from a mean of 402 L/min in the BDP group. No clinically or statistically significant differences between groups were evident with regard to the change in this primary variable. Similarly, only small changes in evening PEF and secondary variables of lung function were seen, with no statistically significant difference between groups. The authors concluded that both treatments were equivalent in managing asthma in adult patients with stable asthma.