An article published in The Journal of the Association of Physicians in India observed that wide range of disease processes may present with cough and definitive treatment depends on identifying the cause and diagnosis. Usually, specific treatment of the cause controls the cough; however, this may not occur in all cases and in a sizeable proportion of patients, no associated cause can be found. In patients with dry cough, an increased sensitivity of the cough reflex can be observed.

Symptomatic relief should be sought when cough interferes with the patients daily activities and this is effectively treated with antitussive preparations which are available as combinations of codeine ordextro methorphan with antihistamines, decongestants and expectorants. Antitussives are efficacious in symptomatic relief of dry or non-productive cough.

The authors further stated that first generation antihistamines like chlorpheniramine and centrally acting opioid derivatives like codeine are often used alone or in combination in the management of nonspecific cough. Sedation caused by these is valuable, particularly, if cough is disturbing the sleep.

Cough is one of the commonest symptoms of respiratory tract infections and is a frequent problem encountered in general practice as well as in hospital practice. 

Source: The Journal of the Association of Physicians in India. 2013 May;61(5Suppl):9-13.