Rationale Excessive airway narrowing in response to broncho-active stimuli is a predictor for severe exacerbations in asthma. Leukotriene receptor antagonists (LTRAs) have complementary properties to inhaled corticosteroids (ICS) on asthma control.
Objectives The LTRA montelukast may provide an additional protection against excessive airway narrowing. We tested the add-on effects of montelukast on the maximal response plateau and PD20 to inhaled methacholine in asthmatics on a stable dose of ICS.
Methods Thirty-one patients with allergic asthma [14M/17F, 19–50 years, forced expiratory volume in 1 s (FEV1) >70% pred., PD20 <3.9 μmol methacholine], with a twice documented response plateau to methacholine, were randomized in a double-blind (montelukast 10 mg or matching placebo once daily), 12-week parallel study. Bronchoprovocation tests with methacholine (0.03–256 μmol or 40% decline in FEV1) were repeated every 4 weeks and after wash-out. The main study objectives were changes from baseline in maximal FEV1 decline at the response plateau (i.e. >2 post-dose FEV1 values within 5%) and PD20 to methacholine after 12 weeks' treatment.
Results Neither treatment affected baseline FEV1 (P=0.62). Compared with placebo, montelukast significantly decreased the maximal response plateau to methacholine (mean difference 9.4%; 95% confidence interval 3.9–15.7; P<0.005), improved the FEV1 decline (mean change in FEV1 decline was 2.1% [montelukast] and −0.8% [placebo], respectively, P<0.05), and increased PD20 methacholine (mean change in PD20 of 5.3 [montelukast] and 1.4 [placebo] doubling doses, respectively, P<0.001).
Conclusion Add-on montelukast to ICS has disease-modifying effects in adults with persistent asthma, and hence reduces the risk of excessive airway narrowing (NCT 00913328).
Cite this as: C. S. Ulrik and Z. Diamant, Clinical & Experimental Allergy, 2010 (40) 576–581.