Efficacy and Tolerability of Beclomethasone Dipropionate 100 µg + Formoterol 6 µg pMDI Via HFA-134a Vs. Budesonide 160 µg + Formoterol 4,5 µg Dry Powder Via Turbuhaler®. (Symbicort®)

Inclusion Criteria: * Clinical diagnosis of moderate to severe persistent asthma for at least 6 months, according to GINA revised version 2002 guidelines: * Forced expiratory volume (FEV1) or peak expiratory flow rate (PEFR) \> 50% and \< 80% of the predicted normal; * Asthma not adequately controlled with the current therapies, defined as presence of daily asthma symptoms \> once a week and night-time asthma symptoms \> twice a month, and daily use of short-acting β2-agonists. These findings are to be based on recent medical history and are to be confirmed in the 2-week run-in period. * 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 mcg, BDP HFA extra-fine 400 μg. * Positive response to the reversibility test in the screening visit, defined as an increase of…