Efficacy and tolerability of budesonide Clickhaler and Turbuhaler in adult asthma.

New dry powder inhalers should be clinically comparable with established devices to ensure the continuity of effective therapy for asthma patients. This randomized, open, parallel group study compared the clinical efficacy and tolerability of budesonide delivered via Clickhaler or Turbuhaler dry powder inhalers in adults with mild to moderate stable asthma. Following a 4-week stabilizing period using budesonide Turbuhaler adults aged 18 years or older, who had been treated with inhaled corticosteroids for at least the previous 12 weeks, were randomized to receive budesonide twice daily (<or=1600 microg/day) via either Clickhaler (n=110) or Turbuhaler (n=112) for 12 weeks. Morning peak expiratory flow (PEF), evening PEF, asthma symptoms, and use of inhaled short-acting beta2-agonist were recorded daily by the patients on diary cards. Lung function and tolerability data were recorded at clinic visits following 4, 8, and 12 weeks' treatment. Efficacy was measured primarily by mean change from the run-in baseline in weekly morning PEF. Of the 222 patients randomized to treatment, 167 completed the study according to the protocol. Repeated-measures analysis of covariance indicated that the devices were clinically equivalent; a treatment difference of--2.3 L/min separated the group mean changes in weekly morning PEF (95% confidence interval--7.9 to 3.3). Secondary analyses also supported clinical comparability. This study demonstrates the comparable clinical efficacy and tolerability of budesonide Clickhaler and Turbuhaler devices in adult patients with stable asthma.