Last Week I Had A Fever And I Took A

Last week I had a fever and I took a course of Azithromycin. When the antibiotic course was over, my fever was gone. Then I started to cough and the phlegm is thick and brownish. I tried Benadryl, Dynadyrl and Mucolix bot not much effect to overcome the cough which disturbed me especially at night and upsetted my sleep. Any suggestions? Should I try Roxithroymycin now?