Comparison between montelukast and tiotropium as add-on therapy to inhaled corticosteroids plus a long-acting β-agonist in for patients with asthma.

: Asthma often remains uncontrolled despite treatment with inhaled corticosteroids (ICS) alone or with ICS plus a long-acting β-agonist (LABA). The recommended alternative is the addition of either montelukast or tiotropium. The aim of this study was to compare the effects of montelukast and tiotropium on airway inflammation and remodeling in persistent asthma. : Eighty-seven patients with asthma were treated with budesonide and formoterol (640/18 μg); then, the patients were randomly allocated to three groups to receive oral montelukast (10 mg/day), inhaled tiotropium (5 μg/day), or no add-on to the maintenance therapy for 48 weeks. Fractional exhaled nitric oxide (FeNO) and pulmonary function were measured, and quantitative computed tomography was performed. : Compared to the maintenance therapy, add-on montelukast significantly decreased FeNO ( < 0.05) and improved airflow obstruction ( < 0.05), whereas airway dimensions remained unchanged. Changes in FeNO were significantly correlated with changes in FEV ( = -0.71,  < 0.001). In contrast, the addition of tiotropium significantly decreased airway wall area corrected for body surface area (WA/BSA) ( < 0.05), decreased wall thickness (T/√BSA) ( < 0.05) and improved airflow obstruction ( < 0.05) with no change in FeNO. Changes in WA/BSA and T/√BSA were significantly correlated with the change in percentage predicted FEV ( = -0.84,  < 0.001 and  = -0.59,  < 0.01, respectively). :Adding either montelukast or tiotropium to ICS/LABA may provide additive benefits with respect to the pulmonary function and airway inflammation or remodeling in patients with asthma.