<s>[INST] My father is suffering from dry cough since past 1 month.He is 64 years old weighing 70 kg ,he is heart patient.8 years back he was hospitalised due to cardiac arrest, One and half years back he was again hospitalised since water got accumlated in his lungs.Doctor now suggested dry cough is due to allergy.He is on antibiotic since past one month.his condition improves but after 2 days same symtoms is seen.Please guide me whether to continue with antibiotic. [/INST] Hello, thanks for using Healthcaremagic. i had gone through all the data you have posted. As you father was a cardiac patient and h/o pulmonary edema (water in lungs) he might be on ACEinhibitor (Angiotensin convertase enzyme) whcih can cause persistent dry cough. Allergic cough starting at 64 yrs and persisting for 1 month is rare. we need more details like cbp report or chest x ray  if it was done.take tab.montelukast +fexofenidine 1-0-0 for 3 days and syp. corex 2 tsp two times a day. if cough persists, discuss with your doctor and try to change ACE inhibitor to ARB. Hopr this helps.. </s>