Suggest Treatment For Cough In A Child

sir,my 4 yrs old daughter is suffering from chronic cough since last 6 to 8 months, paed has recommended antibiotic like Augmentine syp,azithromycie syp,sobutamole syp and nebulisation with normal saline, she got relief for 2 to 3 days and again she got same problem,Kindly advice what to do for quick relief.