Montelukast pharmacokinetics and molecular data

Pharmacokinetics
Mechanism Effect on eosinophils in peripheral blood

Mechanism
Montelukast causes inhibition of airway cysteinyl leukotriene receptors as demonstrated by the ability to inhibit bronchoconstriction due to inhaled LTD4 in asthmatics. Doses as low as 5 mg cause substantial blockage of LTD4-induced bronchoconstriction. In a placebo-controlled, crossover study (n=12), Montelukast inhibited early- and late-phase bronchoconstriction due to antigen challenge by 75% and 57%, respectively. Return to top

Effect on eosinophils in peripheral blood
The effect of Montelukast on eosinophils in the peripheral blood was examined in clinical trials. In patients with asthma aged 2 years and older who received Montelukast, a decrease in mean peripheral blood eosinophil counts ranging from 9% to 15% was noted, compared with placebo, over the double-blind treatment periods. In patients with seasonal allergic rhinitis aged 15 years and older who received Montelukast, a mean increase of 0.2% in peripheral blood eosinophil counts was noted, compared with a mean increase of 12.5% in placebo-treated patients, over the double-blind treatment periods; this reflects a mean difference of 12.3% in favor of Montelukast. The relationship between these observations and the clinical benefits of montelukast noted in the clinical trials is not known. Return to top