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Role of mucoactive agents and secretion clearance techniques in COPD

Loutfi Sami Aboussouan, MD
Section Editor
James K Stoller, MD, MS
Deputy Editor
Helen Hollingsworth, MD


Tracheobronchial mucus contributes significantly to the symptoms of chronic obstructive pulmonary disease (COPD). It is a diagnostic criterion for chronic bronchitis and one of the primary causes of airflow obstruction. In addition, chronic mucus hypersecretion is associated with increased mortality, an accelerated decline of forced expiratory volume in one second (FEV1), and an increased risk of hospitalization in COPD [1-3].

The role of mucoactive therapy in the management of COPD will be reviewed here. The role of mucoactive agents in the treatment of cystic fibrosis (CF) lung disease and non-CF bronchiectasis is discussed separately. (See "Cystic fibrosis: Overview of the treatment of lung disease" and "Treatment of bronchiectasis in adults".)


A mucoactive drug is defined as an agent with the capability of modifying mucus production, secretion, its nature and composition, or its interactions with the mucociliary epithelium [4]. Examples of mucoactive drugs include expectorants (induce cough or increase the volume of secretions), mucolytics (reduce the viscosity of mucus), mucokinetic drugs (increase the mobility and transportability of mucus), and mucoregulators (control the process of hypersecretion) [5].


The surface liquid covering the epithelial lining of the airways comprises at least two layers: the mucus layer (gel) and the periciliary watery layer surrounding the cilia (sol) [6,7]. Mucus consists of a mixture of transudative fluid and secretions from surface epithelium and submucosal glands. It is predominantly composed of water (95 percent) and glycoproteins (2 to 3 percent), with smaller components of proteoglycans (0.1 to 0.5 percent), lipids (0.3 to 0.5 percent), proteins, and DNA [8].

The normal volume of mucus secretion is approximately 15 mL/day [9]. Mucus secretion can increase three-fold in chronic obstructive pulmonary disease (COPD) and 10-fold in cystic fibrosis [6]. The composition can also change in disease states. As an example, DNA can contribute up to 10 percent of the dry weight of mucus secretions in cystic fibrosis [10].


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Literature review current through: Sep 2016. | This topic last updated: May 11, 2016.
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