Hi, My Son Has Been Suffering From Upper Respiratory Tract

Hi, My son has been suffering from upper respiratory tract infection since he was 9 months old. He does get wheezing about 4 times a year n at times results in severe cough, i'm forced to give omnocortil forte for 2 to 3 days. My Dr strictly recommends to use omnacortil as a last resort n increase giving the asthalin inhaler every 2hours as its still better than taking omnocortil as it has steroids. Though I don't use it for Morethan 5 days in a course, want to know if it still have sideeffects n upto what stage / how many doses I can use to avoid these side effects. Dosage that I currently give is 4ml for a max of 5 days with once a day n my son is now 3.6yrs old.