A male, 65 yrs old, non-smoker c/o frequent bouts of cough in day with very sticky, frothy white sputum after several times forceful coughing; no other symptoms. This happens anytime and apparently has no relation to outdoor air exposure. Inhalers (steroids) are of some help only.

History of pulmonary TB some 50 yrs back. What could be cause and line of treatment?