Effect of azelastine, montelukast, and their combination on allergen-induced bronchoconstriction in asthma

Histamine and cysteinyl leukotrienes play an important role in early (EAR) and late (LAR) allergen reactions. Although protection by anti-histamines and anti-leukotrienes has been studied extensively, little is known about the effect of their combination. We, therefore, assessed the effect of clinically recommended doses of azelastine and montelukast alone and in combination on EAR and LAR.

Seventeen patients (mean age 31 years, 14 m/3 f) with asthma and proven EAR and LAR received an oral dose of 4 mg azelastine twice daily, or 10mg montelukast once daily, or both for 1 week, in a double-blind, double-dummy, cross-over fashion. FEV(1) was measured after single-dose allergen challenges during EAR (0-2h) and LAR (2-9h).

Azelastine, montelukast and their combination protected against both EAR and LAR (p<0.004, each) by 46% and 43%, 76% and 59%, and 89% and 78%, respectively. Azelastine was not as effective during EAR but equally effective to montelukast during LAR. The combination was superior to each drug alone during both EAR and LAR (p<0.05, each).

The combination of azelastine and montelukast in clinically recommended doses has a greater effect in suppressing early and late allergen reactions than each drug alone.