Extrafine compared to non-extrafine particle inhaled corticosteroids in smokers and ex-smokers with asthma

•Extrafine and non-extrafine particle inhalation corticosteroids were compared.•Smokers and ex-smokers with asthma were included.•QVAR, Clenil and Flixotide were compared with adenosine provocation and IOS.•ΔPD20 adenosine and ΔR5-R20 at PD20 adenosine is comparable for the treatments.•Extrafine and non-extrafine particle ICS equally improve small airways function.

BackgroundSmoking is as prevalent in asthmatics as in the general population. Asthmatic smokers benefit less from inhaled corticosteroids (ICS) than non-smoking asthmatics, possibly due to more smoking-induced small airways disease. Thus targeting small airways may be important in treating asthmatic (ex-)smokers. We hypothesized that extrafine particle ICS improve small airways function more than non-extrafine particle ICS in asthmatic (ex-)smokers.MethodsWe performed an open-label, randomized, three-way cross-over study comparing extrafine beclomethasone (HFA-QVAR) to non-extrafine beclomethasone (HFA-Clenil) and fluticasone (HFA-Flixotide) in 22 smokers and 21 ex-smokers with asthma (≥5 packyears).ResultsImprovement from baseline in PD20 adenosine after using QVAR, Clenil or Flixotide was 1.04 ± 1.71, 1.09 ± 2.12 and 0.94 ± 1.97 doubling doses, mean ± standard deviation (SD), respectively. The change from baseline in R5-R20 at PD20 adenosine after using QVAR, Clenil or Flixotide was −0.02 ± 0.27, 0.02 ± 0.21, and −0.02 ± 0.31 kPa sL−1, mean ± SD, respectively. The change in PD20 adenosine and R5-R20 at PD20 adenosine were neither statistically significant different between QVAR and Clenil (p = 0.86 and p = 0.82) nor between QVAR and Flixotide (p = 0.50 and p = 0.96).ConclusionSimilar effectiveness in improving small airways function was found for extrafine and non-extrafine particle ICS treatment for asthmatic smokers and ex-smokers.