A comparison of HFA-BDP Autohaler with budesonide Turbuhaler in asthma control of adult patients with mild to moderately severe disease.

Hydrofluoroalkane-134a (HFA) beclomethasone dipropionate (BDP) extrafine aerosol is a pressurized metered dose inhaler (pMD1) available for the treatment of asthma. Unlike most pMDIs, HFA-BDP is a solution, rather than a suspension, of BDP in HFA propellant. This reforrnulation, combined with improvements in inhaler technology, results in the production of aerosol particles of smaller mean mass aerodynamic diameter (MMAD) than produced from chlorofluorocarbon (CFC)-BDP inhalers, I.1 pm vs. 3.5-4 pm, respectively (1,2). Inhaled corticosteroids are increasingly recommended for first-line therapy in the management of asthma (3,4) with pMDIs the most commonly prescribed method of delivery. However, a significant proportion of patients fail to use pMDIs correctly, even with appropriate training. It has been reported that 50% of patients revert to their previous incorrect press and breathe inhaler technique following proper training (5). HFA-BDP as the AutohalerTM (AH) inhalation device has been shown to be of clinical benefit to patients with problems handling a press and breathe pMD1 (6). Drypowder inhalers (DPIs) such as the budesonide Turbuhaler@ (BUD TH), have also been designed to limit the handling difficulties encountered with traditional pMDIs. However, in contrast to HFA-BDP AH, DPIs remain breath dependent (i.e. drug delivery from the inhaler is dependent on inspiratory flow) (Fig. I) (7). While comparative dosing strategies for HFA-BDP AH and BUD, TH have,‘not yet been investigated, it is recognized that CFC-BDP and budesonide have similar therapeutic efficacy and safety profiles. In the past, these agents have been considered to be equipotent (9,10), but recently budesonide has been recognized to be somewhat more potent, especially if administered via the Turbuhaler@ (3,1 I). Given this, and the fact that HFA-BDP produces equivalent efficacy to CFC-BDP at approximately 2.5-times the daily steroid dose (12) it can be hypothesized that half the daily dose of HFA-BDP AH would provide equivalent control of asthma symptoms to the BUD TH. The