[Single dose of montelukast as an effective prevention of post exercise bronchospasm in children with bronchial asthma]

Abstract

Post exercise bronchospasm is a well-known phenomenon, particularly affecting children with asthma. In our own study post exercise bronchospasm occurred in 25-66% of children with asthma. The aim of the study was to evaluate the usefulness of cysteinyl leukotriene receptor antagonist -- montelukast (Mnt) in the prevention of post exercise bronchospasm.

Material and methods: We studied 72 children 7-14 years old (22 girls, 50 boys) mean age -- 10.8+/- 2.4 (SD), who were suffering from asthma. All children with forced expiratory volume in one second (FEV1) >70% of the predicted value and a reproducible fall in FEV1 after exercise of at least 15% were enrolled. After a screening test was performed the children were divided in 2 subgroups: 40 children for active treatment -- montelukast, 32 for placebo group. Placebo or montelukast (5 mg) was given once in the evening, randomised, double blind. Next day 3 bronchial provocation tests at 8 a.m., 12 a.m. and 3 p.m. were performed. Data from 72 patients were available for complete analysis of the following parameters: forced expiratory volume in one second (FEV1), peak expiratory flow (PEF) forced expiratory flow at 25 and 75 of forced vital capacity (FEF 25-75%).

Results: Analysis showed a significant total protective effect 12 h after giving montelukast in 25/40 (62.5%) children, but only in 4/32 (12.5%) in the placebo group, (OR=1.87). Partial protection was detected in 3/40 (7.5%) children in montelukast group and in 1/32 (3.3%) child in placebo group. Lack of protection was observed in 12/40 (30%) in montelukast group and in 27/42 (84.4%) in the placebo group.

Conclusions: l. The clinically recommended dose of montelukast protects against post exercise induced bronchospasm. 2. The time of duration of montelukast as protective treatment of post exercise bronchospasm was at least 21 hours. 3. Our study may suggest the participation of leukotrienes in the pathogenesis of exercise-induced broncho-constriction.