ABSTRACT
M ucoactive Drugs In patients with chronic bronchitis, hypertropy of mucous glands and goblet cells leads to excessive production of mucus. This, in turn, contributes to airflow obstruction by occluding the small airways and reducing the clearance of inflammatory cells and media tors. Therapy directed at enhancing the mobilization of mucus from the peripheral airways would, therefore, appear to be beneficial. In the United States, two drugs guaifenasin and potassium iodide, have been approved for use as expectorants, and both are believed to reduce sputum viscosity by increasing the transport of water into the airway lumen. Studies
examining these and other mucoactive drugs, however, have reported conflicting results. Although some have noted a decrease in dyspnea as well as cough frequency and severity, others have found no symptomatic improvement. A trial of a mucoactive agent is reason able in patients who complain of difficulty expectorating sputum, but the drug should be discontinued in the absence of a subjective response.
