hello welcome to HCM
as per the symptoms you told the boy is suffering form URTI (upper respiratory tract
infection) , but even after trying with antibiotic , there is no releif . so i suggest you to take the child to a pediatrician
to check the complete blood picture , and the chest x-ray , becoz we should rule out the hidden infection if any... after physical examination and going through the reports , doctor can come to conclusion .
so dont wait with trying all those medicines
take care bye