Hello Doctor, My 8 Months Old Son Is Having Cough

Hello doctor, my 8 months old son is having cough and cold since few days.due to cold he feels discomfort during feed.my doctor suggested to give maxtra drops 0.4ml 3 times a day, ambrodil S syrup 3ml 3 times a day...and nebulizer with levolin 0.31mg..plz tell me is this ok..bcoz i think ambrodil S is quiet strong...plz suggest me if he needs any antibiotic? As he is not becoming well after 2 days medication..