The influence of anesthesia on the evaluation of antitussive effect.

Studies on the antitussive agents have been advanced with the development of bio assay for them. At the present time, a large number of non-narcotic synthetic antitussives are employed in the management of cough instead of narcotic antitussives. The evaluation method for antitussive activity was first reported by Ernst in 1938 (1), that is, coughing was induced by pinching the trachea of a cat which had previously been made to sero-fibrinous pleurisy by means of intrapleural injection of Lugol solution. Two years later, Eichler and Smiatek (2) reported that coughing could be induced in the guinea pig by an inhalation of aerosolized sulfuric acid. However, these two methods have not been accepted widely for the evaluation of antitussive agents because of uncertainty of cough