Comparison of extrafine and non-extrafine inhaled corticosteroids/long-acting β2-agonists as maintenance and reliever therapy in asthma: a randomized open-label crossover trial.

Background/aims: Asthma is characterized by chronic inflammation. Inhaled corticosteroids (ICS) remain the cornerstone of anti-inflammatory therapy, targeting both the large and small airways.

Methods: This randomized open-label crossover trial included 30 patients receiving step 3 inhaled medication according to the Global Initiative for Asthma (GINA). Patients received beclomethasone/formoterol (BDP/F) for maintenance and reliever therapy for 6 weeks, followed by budesonide/formoterol (BUD/F) for 6 weeks, or vice versa, with a 4-week washout period in between. Assessments at each visit included the Asthma Control Test (ACT), Asthma Control Questionnaire, Quality of Life Questionnaire for Adult Korean Asthmatics, and pulmonary function test. The primary endpoint was the change in forced expiratory flow between 25% and 75% of vital capacity (FEF25-75% pred).

Results: Twenty-four patients (15 females, mean age 39.3 years) completed the study. The changes in FEF25-75% pred were comparable between BDP/F and BUD/F (5.79 ± 38.34 vs. -1.36 ± 14.93, p = 0.399). No significant differences were observed between the BDP/F and BUD/F groups in terms of improvement in asthma control or quality of life. However, in the subgroup of patients with positive methacholine bronchial provocation tests, BDP/F significantly improved ACT scores compared to BUD/F (0.92 ± 2.25 vs. -1.31 ± 3.04, p = 0.044).

Conclusion: Our study demonstrated that extrafine ICS treatment provided no significant advantage over non-extrafine ICS in improving small airway obstruction or overall asthma control in moderate asthma. This suggests that factors other than particle size may contribute to treatment outcomes.