In all primary studies, recording of the symptoms and initiating of the intervention in the intermittent montelukast studies were carried out by parents/caregivers. Although in all the trials, the parents were contacted either through telephone or visits, only one study provided an educational program to the parents on recognising symptoms which were more likely to represent respiratory tract infection and followed by wheezing . It is possible that the initiation of treatment was too long after the onset of symptoms, causing stimulation of the immune response by the virus and thus failure of the montelukast therapy .