Effectiveness of beclomethasone dipropionate aerosolized through different nebulizers to asthmatic patients

The aim of our study was to verify if the type of nebulizer used could influence the results of aerosol therapy with beclomethasone dipropionate (BDP) in mild allergic asthma. We assigned 27 asthmatics allergic to grasses to 3 groups and treated them from May to July 1998 with aerosol therapy with BDP (800 microg) b. i. d. via nebulizer + pMDI salbutamol (200 microg) if necessary. Each group used a different type of nebulizer: jet nebulizer with glass ampoule (group JG); jet nebulizer with polycarbonate ampoule (group JP); ultrasonic nebulizer (group US). During the study patients underwent periodic lung function tests and methacholine bronchial challenges, recorded twice a day self-monitoring PEF and filled out a daily diary for the presence and intensity of asthmatic symptoms. At the end of the study the provocative dose of methacholine causing a 20% fall in FEV1 (PD20), the self-monitoring PEF and the clinical scores were all greatly improved, but without any statistically significant difference among the three groups. On the contrary, the variations during the study of basal spirometric parameters (specifically FEV1, PEF, FEF25) were significantly better in jet nebulizer groups than in group US. The results coming from the aerosol characterization that we carried out for each of the three nebulizers confirmed the clinical findings, since jet nebulizers showed greatly lower MMAD than the ultrasonic nebulizer (2.9 and 3.7 vs 5.8). Our data suggest that jet nebulizers are more appropriate than ultrasonic nebulizers for delivering BDP in aerosol therapy.