Introduction

Cough is a protective reflex that serves to prevent the entry of foreign material into the respiratory tract, as well as to promote the expulsion of mucus from the airways. Often, however, persistent cough appears to serve no useful purpose, and results in significant morbidity, especially in terms of quality of life, among afflicted individuals. Cough is the most common complaint for which outpatient medical attention is sought in the United States.

Acute cough, most commonly associated with an upper respiratory tract infection, is usually self limited. However, since the acute onset of cough may also indicate more serious underlying conditions such as pneumonia, malignancy, pulmonary embolism, congestive heart failure, or endobronchial foreign body, clinical judgment must dictate the extent of initial evaluation. Chronic cough, defined as cough present for greater than 3 weeks, is more likely to stimulate a patient to seek medical evaluation, and may present the clinician with a difficult diagnostic challenge. Fortunately, studies have confirmed that with the use of a systematic, diagnostic protocol, the etiology of cough can be established in the vast majority of patients.

Pharmacological therapy for cough can be most broadly categorized as antitussive or protussive.