What Is The Best Treatment For Persistent Coughing With Phlegm In An Asthmatic Patient?

I am asthmatic and regularly taking medicines AB Flow SR 200 in the morning and montelukas in night, use inhaler foracort 400 and duolin 200 and nebuliser once a day , my age is 68 years, weight 70 kg, BP 95/145 average, these days my coughing not dry is too much in the morning and night and phelgom is there., I also take zedex to stop coughing., Seems there is throat problem.pl.suggestva good medicine , how many times a day and how many days I have to take. Thanks Pl.suggest solution.