Efficacy of budesonide Turbuhaler compared with that of beclomethasone dipropionate pMDI in Japanese patients with moderately persistent asthma

OBJECTIVE: The aim of the study was to compare the efficacy and safety of budesonide Turbuhaler with that of beclomethasone dipropionate (BDP) pMDI. METHODOLOGY: Three hundred and fifty adult asthma patients (mean age 52.7 years, mean baseline morning peak expiratory flow (PEF) 294 L/min (< 80% predicted normal)), taking BDP via pressurized metered-dose inhaler (pMDI), 400 microg daily for at least 2 months, were randomized in an open 6 week study to receive daily doses of either budesonide 100 microg or 400 microg twice daily via Turbuhaler or continued treatment with BDP, 100 microg four times daily. The primary efficacy variable was the mean change in morning PEF from baseline to the end of treatment. Outcome was also assessed using symptom scores and investigators' assessments employed in Japanese clinical trials. RESULTS: At the end of the 6 week treatment period, mean morning PEF improved significantly from baseline in both budesonide groups, 16 L/min and 33 L/min in the 200 microg and 800 microg groups, respectively, but not in the BDP group, 5 L/min. There was no significant difference between 200 microg budesonide and 400 microg BDP treatment in the effect on PEF (P = 0.29), but 800 microg budesonide was significantly superior to BDP (P < 0.001). Final assessment of improvement and usefulness ratings showed that both budesonide treatments were significantly superior to BDP (P < 0.001). All treatments were well tolerated. CONCLUSION: Budesonide Turbuhaler (200 microg) was as effective as 400 microg BDP pMDI. The efficacy of budesonide was improved significantly by increasing the dosage to 800 microg daily. The study design shows the importance of including a higher dose treatment group when comparing two formulations of inhaled corticosteroids in order to determine whether the treatments to be compared are on the steep part of the dose-response curve. Without that information, comparative studies are usually inconclusive.