It is quite common for children of this age to get repeated attacks of cold, cough
. Gradually the immune system matures and the frequency of attacks comes down. Give him vegetables and fruits daily. You can also give him a spoon of honey daily or if available in your area gooseberry soaked in honey which will boost his immunity. Premature babies
are prone to develop anemia
. Make sure he is not anemic. It will not be necessary to give that drug for life.