Can a single dose response predict the effect of montelukast on exercise-induced bronchoconstriction?

RationaleExercise-induced bronchoconstriction (EIB) can be prevented by a single dose of montelukast (MLK). The effect is variable, similar to the variable responsiveness observed after daily treatment with MLK. We hypothesized that the effect of a single MLK-dose (5 or 10mg) on EIB could predict the clinical effectiveness of longer term once daily treatment.MethodsThis was a prospective, open-label study. Twenty-four asthmatic adolescents (12-17 years) suboptimally controlled by low-dose inhaled corticosteroids, with 10% post-exercise fall in FEV1, were included. They performed an exercise test at baseline, 20hr after a single MLK-dose and 40-44hr after the last dose of 4 weeks once daily treatment. The correlations between the effect of a single dose and 4 weeks treatment on area under the curve (AUC) and maximum % fall in FEV1 were calculated.ResultsAUC(0-20min) decreased significantly after a single MLK-dose (P=0.001, CI: 64.9-218.2), but not after 4 weeks of treatment (P=0.080, CI: -12.2 to 200.4). There was a moderate correlation between the effect of a single MLK-dose and 4 weeks treatment on AUC(0-20min), r=0.49 (P=0.011), and maximum % fall in FEV1, r=0.40 (P=0.035).ConclusionThe protection provided by a single MLK-dose against EIB only modestly predicts the effect of regular treatment against EIB in adolescent asthmatics on low-dose inhaled corticosteroids. If used on a daily base, MLK offered clinically significant protection against EIB in two thirds of adolescents suboptimally controlled by low-dose ICS. Pediatr Pulmonol. 2016;51:470-477. (c) 2015 Wiley Periodicals, Inc.