Guaifenesin

guaifenesin is an expectorant that also has some muscle relaxing action. it is used in many cough preparations.
guaifenesin is a glyceryl guaiacolate with expectorant effects. guaifenesin increases respiratory tract mucus secretions, acts as an irritant to gastric vagal receptors and recruits efferent parasym- pathetic reflexes that cause glandular exocytosis. this agent reduces the viscosity of mucus secretion by reducing adhesiveness and surface tension as well as increasing hydration of mucus.guaifenesin promotes the efficiency of the mucociliary mechanism important in removing accumulated secretions from the upper and lower airway.