My Husband Has Had A Cough For Several Months. It

My husband has had a cough for several months. It is productive, and the phlem is relatively clear. He does not have cold or sinus symptoms, is not having breathing issues. He went to our regular doc, who ordered a chest xray, put him on a course of prednisone, a cough suppressant, an antibiotic and omeprazole to be taken once a day in the am. He went back about 10 days later, xray showed no issues. Doc then prescribed another antiacid med, famotidine, to be taken at night. I am at a loss as to these antacisd meds s my hubby does not have heartburn issues( he does have s large belly).