Treatment for pneumonia. Coughing.

Hi, My father is undergoing dialysis since 10yrs. Recently he was having high fever and was admitted to hospital. Upon admission it was found that his left lung was highly infected and treatment was started for the same.  But the antibiotics (merotac, mucinac, maclar) were not working. Sputum culture was sent to hinduja hospital and upon finding a type of bacteria, treatment was changed and discharged after 15 days. He was administered Mikacin 500mg and zonamax es for 8 days. Zonomax is discontinued and tab altipod cv 200 is started. Attached are discharge report and after 8 days of discharge. Also the latest xray. Currently he is feeling better but his coughing is same as before. Also he is taking oxygen intermittently since he feels exhausted after walking few rounds at home. Would be really helpful to know, if the treatment is correct and what could be done to reduce coughing.