Medications used to thin mucus in chronic obstructive pulmonary disease patients include expectorants such as guiafenesin and mucolytics such as N-acetylcysteine, which aid in clearing lungs and air passages for easier breathing, according to the American Thoracic Society. Drinking water, juice and other nondehydrating liquids thins mucus naturally.
COPD patients producing mucus or sputum need to drink 64 ounces or more of liquid each day, notes the American Thoracic Society. Guiafenesin is a common expectorant and N-acetylcysteine is a common mucolytic, which breaks up mucus molecules. Doctors prescribe N-acetylcysteine in an inhaled form with a nebulizer to administer it. Patients in European counties use it more frequently than patients in the United States, as of 2015. Experts disagree about the effectiveness of the medications.