Expectorants thin mucus so it’s cleared more easily out of the air-ways. They also soothe mucous membranes in the respiratory tract. The result is a more productive cough.
The most commonly used expectorant is guaifenesin.
Guaifenesin is absorbed through the GI tract, metabolized by the liver, and excreted primarily by the kidneys.
By increasing production of respiratory tract fluids, expectorants reduce the thickness, adhesiveness, and surface tension of mucus, making it easier to clear from the airways. Expectorants also pro-vide a soothing effect on the mucous membranes of the respirato-ry tract.
Guaifenesin is used to relieve symptoms due to ineffective, pro-ductive coughs from many disorders, such as:
· bronchial asthma
· minor bronchial irritation
Guaifenesin isn’t known to have specific drug interactions; howev-er, it does cause some adverse reactions. (See Adverse reactionsto guaifenesin.)