Montelukast (Singulair ) is a selective leukotriene-receptor antagonist that inhibits the cysteinyl leukotriene 1 receptor. It is well tolerated and safe even in young children. Montelukast is an effective treatment for asthma (and allergic rhinitis from 1 year of age. Infections with viruses causing URI such as Influenza A, Rhinovirus and respiratory syncitial virus increases leukotriens levels in nasal secretions. Therefore, one may postulate that leukotriens inhibitors may reduce symptoms during URI. However the effect of montelukast as a treatment for non-specific cough was not properly studied and there are no studies on the effect of montelukast as prevention for URI.