Codeine: A Relook at the Old Antitussive.

Cough is the most frequent complaint of patients seeking medical attention in general and hospital practice. Cough is controlled by treating the cause, however, when no cause can be found, symptomatic relief of cough must be considered. Treatment of dry cough resulting from increased sensitivity of the cough reflex remains a challenge in some subjects. Codeine in combination with other medicines has been a mainstay for the effective short-term symptomatic relief of dry or nonproductive cough in clinical practice. This article focuses on the current status of codeine as an antitussive formulation in the treatment of dry cough. Codeine is one of the centrally acting narcotic opioids approved for use as an antitussive, a prodrug that is bioactivated by CYP2D6 into morphine in the liver. The opioid effects of codeine are related to plasma morphine concentrations. Codeine is one of the most frequently used antitussive in clinical practice and has been widely regarded as the standard cough suppressant against which newer drugs are being evaluated. Codeine has an advantage as an antitussive because of its multifaceted effect as an analgesic and sedative along with cough suppression. However, codeine may have efficacy to suppress cough in humans only in specific situations. Caution is also needed to limit its use only when and as long as it is clinically necessary, particularly in children.