My 9 month old son, who weighs 9 kgs, has been suffering from cold , running nose and cough for over a month now. It started off after a viral fever in the family. As adviced by the doctor, we have given him Fluzet, Droxyl, Amoxcillin, Tacof etc.. but cold still persists. He has cough but only while he is asleep. Kindly advise