At its core, the primary action of an expectorant is to enhance the clearance of mucus from the respiratory tract. This is accomplished by increasing the volume of respiratory tract secretions, making mucus less viscous and therefore easier to expel. Commonly used expectorants, such as guaifenesin, are found in many over-the-counter cold and cough medications. They are often recommended for individuals suffering from conditions such as bronchitis, pneumonia, and allergic reactions that cause excessive mucus production.
