NEW YORK (Reuters Health) – Montelukast (Singulair), a leukotriene receptor antagonist, can help prevent recurrent wheezing episodes after respiratory syncytial virus (RSV) bronchiolitis, new research shows.
From earlier work, the researchers knew that airway levels of cysteinyl leukotriene correlated with eosinophil numbers in RSV bronchiolitis. The goal of the present study was to see if reduction of leukotriene levels with montelukast might reduce eosinophil degranulation, which in turn would help reduce recurrent wheezing.
To this end, Dr. Chang-Keun Kim, from Inje University Sanggye Paik Hospital in Seoul, Korea, and colleagues conducted a randomized trial in 200 infants, 6 to 24 months of age, who were hospitalized with a first episode of acute RSV bronchiolitis. Daily for three months, the babies received either oral montelukast 4 mg or placebo. Eosinophil degranulation was assessed by serum levels of eosinophil-derived neurotoxin.
The researchers report their findings in the February 22nd online issue of the Journal of Pediatrics.
At the end of the treatment period, eosinophil-derived neurotoxin levels had decreased significantly in the montelukast group (p < 0.01) and increased significantly in the placebo group (p < 0.0001), the researchers report. Neurotoxin levels remained significantly lower in the montelukast group at 12 months. (Twelve-month data was available for 79 babies in the treatment group and 71 in the placebo group.)
Infants in the montelukast group had significantly fewer recurrent wheezing episodes (p = 0.039), but the significant difference between the groups only emerged after 9 to 12 months. Although this may not seem like strong supporting evidence for montelukast, the authors note this is likely because of the short observation period.
The results “suggest that eosinophil degranulation is important in the pathogenesis of severe RSV disease and that therapies that inhibit degranulation of eosinophils warrant further investigation,” the authors said.
Also, they point out, infants with high levels of eosinophil-derived neurotoxin at 3 months seems to be at increased risk for recurrent wheezing. “Although subsequent wheezing may also be caused by other acute viral infections, we suggest 3-month eosinophil-derived neurotoxin levels may be a useful biomarker for predicting recurrent wheezing in children with post-RSV bronchiolitis,” the researchers conclude.
The study was funded, in part, by Merck, the maker of Singulair.
J Pediatr 2010.