List of products in the National Drug Code with proprietary name . Formoterol is used as a long-term (maintenance) treatment to prevent or decrease breathing problems caused by ongoing lung diseases (chronic obstructive pulmonary disease-COPD, including chronic bronchitis and emphysema). Formoterol belongs to the class of drugs known as long-acting inhaled beta-agonists (LABAs). It works by relaxing the muscles around the airways so that they open up and you can breathe more easily. This effect helps to reduce wheezing, coughing, and shortness of breath. This medication does not work right away and should not be used for sudden attacks of breathing trouble. Your doctor must prescribe a quick-relief inhaler (e.g., albuterol, also called salbutamol in some countries) for sudden shortness of breath while you are using formoterol. You should always have a quick-relief inhaler with you. This form of formoterol is not approved to treat asthma. People with asthma using long-acting inhaled beta agonists (such as formoterol) without also using an inhaled corticosteroid may have an increased risk of serious (sometimes fatal) breathing problems.