Abstract: AIM: To observe the effects of montelukast on the level of urine LTE4 in children with bronchiolitis. METHODS: Sixty-nine cases of children with bronchiolitis were divided into two groups randomly, a group with montelukast treatment and a group with regular treatment. The treatment effects and the urine LTE 4 level of the two groups were compared. At the same time, 48 cases of children with bronchiolitis in remission were given montelukast or fluticason inhalation, the changes of level on urine LTE4 of the two groups were observed. RESULTS: The period to the disappearance of breath shortness, the disappearance of physical symptoms and the length of stay in hospital of montelukast group were shorter than those in the group with regular treatment(P<0.01).Before the therapy, there was no significant difference of urine LTE4 between the groups of montelukast treatment and regular treatment(P>0.05),the level of urine LTE4 in both group were increased compared with the control group(P<0.01).After therapy, the urine LTE4 level of the montelukast treatment group was decreased obviously compared with those of the regular treatment group(P<0.01). There was no significant difference compared with the comparison group(P>0.05);while the urine LTE4 level of group with regular treatment was higher than those of control group(P<0.01).After the remission of bronchiolitis, the children were given with montelukast or fluticasone propionate inhalation for a month and there was obviously lower level urine LTE4 in the group montelukast treatment than the group with hormone treatment. CONCLUSION: Montelukast can effectively decrease the levels of urine LTE4 in the acute phrase and remission and improve the clinical symptoms of children with bronchiolitis.

Key words: Montelukast, Bronchiolitis, Cysteinyl leukotriene