This medication is typically used to help clear the mucus in the airways. Its effects can be felt within 1 hour. This medication is typically used every 6 hours. However, your doctor or pharmacist may have suggested a different schedule that is more appropriate for you. Generally, it is used only as needed. This medication works by suppressing dry, hacking coughs. It is usually used for a short term to control coughing associated with the flu, a cold, or due to inhaled irritants.