Child Prescribed Medicines For Cough With Phlegm Which Helps Temporarily. Should The Inhaler Also Be Given As Prescribed?

my son is 13 years old. he is suffering from cough with phlegum for last six months. the doctor advised for pft, chest x-ray, blood test and sputum examination. from pft thereport says fev predicted %=56. chest x-ray shows cx12 and referred more cardiological diagnosis . from blood test wbc=11.6, eo= 0.87+, aec=870/cmm.the sputum exam report is negative. the doctor prescribed ODIMONT FOR 30 days, p2ID for 30 days , lupitus syrup for 15 days and formonide forte with turbospin for 30 days. is the prescription over dose? i gave him all the medicines except the inhaler as i thought that if someone takes inhaler it will be of a lifelong use. Now if his cough is cured for one day , the next day it returns. what should i do? should give the prescribed inhaler?????????