Enrex-A Syrup is a combination medication which promotes the secretion of sputum (phlegm) by the airways (bronchi), used to treat coughs. It treats respiratory conditions, including chronic obstructive pulmonary diseases (COPD) like bronchitis (inflammation of bronchial tubes), emphysema (shortness of breath), and upper respiratory tract infections. COPD is a chronic inflammatory lung disease caused by obstructed airflow in the lungs.