probably your child is having bronchial asthma
The best medication for your child will be inhaler with spacer.
They contain reliever medication for temporary relief and preventer medication which will reduce the inflammation in the air-pipes of your child.
The quantity of drug in these are very low as it is given directly to lungs
Montair Lc tablet contains levocetrizine - a purer form of cetrizine( present in cetzene) and monteleukast.
Monteleukast can prevent asthmatic inflammation but whether it will be sufficient for your child can be decided by examining your child. Consult nearby peadiatrician or pulmonologist.
Monteleukast is generally tolerated with minimal side effects.
The duration of therapy will depend on response to treatment .
Dont be under the impression that giving the tablet for a specific period guarantees a permanent cure.