ABSTRACT
Coughing occurs as a consequence of aspiration, particulate matter, patho-
gens, accumulated secretions, inflammation, and mediators associated with inflammation. The elderly, newborns, lung transplant patients, and patients
with paralysis or neuromuscular disorders have a poorly developed and/or
compromised cough reflex and are rendered highly susceptible to lung
infections and aspiration pneumonia (1-4). Under normal conditions,
therefore, coughing serves an important protective role in the airways and
lungs. In diseases such as asthma, chronic obstructive pulmonary disease,
gastroesophageal reflux disease, and rhinitis, however, cough may become
excessive and nonproductive, and is potentially harmful to the airway mucosa (4). These contrasting consequences of coughing highlight the dif-
ficulty associated with developing therapeutic strategies that prevent exces-
sive and nonproductive cough, while preserving the important innate
defensive role of this respiratory reflex.
