Asthmatic bronchitis and taking advair?

About 3 months ago..I was suffering from sever coughing, irritation and pain in the throat. I went to see the doctor and he diagnosed my symptoms as asthmatic bronchitis. He gave me this medication called singulair adn this inhaler(powdered) called advair. I took these medications for about a month and my symptoms slowly went away, but I still have acute irritation on the throat and alittle cough due to the irritation on the throat. I went to see the the doctor again and he prescribed me some more singlair for the cough and another advair(spray type this time) for throat irritation. When I read the instructions for advair...it says that you should only take advair if you have already used other asthma medications and did not work because advair is strong and may have side effects. Also it says that advair is to prevent or decrease the symptoms of wheezing or trouble breathing caused by asthma. But I do not have symptoms of wheezing or trouble breathing. My symptoms are just coughing and throat irritation. So I do not understand why the doctor told me that the advair is for the irritation of the throat when that is not what it says on the instructions. Is there any one taking advair who can give me some info of it? Also is there anyone with asthmatic bronchitis?? Does anyone know a best cure for asthmatic bronchitis??