- Treatment with inhaled corticosteroids at a daily dose ≤ 1000 μg of BDP or equivalent. The daily dose of inhaled corticosteroids taken at visit 1 will be assessed taking into account the following ratios between the doses of the different steroids: fluticasone propionate : BDP CFC = 1 : 2; budesonide : BDP CFC = 4 : 5; flunisolide : BDP CFC = 1 : 1. The ratios between inhaled steroids are irrespective of the formulations (i.e. spray aerosol or powder) used. When BDP is given in the new extra-fine HFA-134a formulation (as QVAR®, 3M Healthcare), the ratio with BDP CFC is set as 2 : 5. Therefore, the maximum allowed daily dose of inhaled corticosteroids at study entry will be: budesonide 800 μg, fluticasone propionate 500 μg, flunisolide 1000 μg, BDP 1000 mg, BDP HFA extra-fine 400 μg.