Pharmacological Reviews, Vol 6, 521-542, Copyright © 1954 by the American Society for Pharmacology and Experimental Therapeutics

EXPECTORANTS AND RESPIRATORY TRACT FLUID

¹ Department of Pharmacology, Queen's University, Kingston, Ontario, Canada

Expectorants may be defined as drugs which augment the output of respiratory tract fluid and are available for use in the therapy of cough due to irritation from lack of sufficient demulcent respiratory tract fluid below the epiglottis.

Respiratory tract fluid may be collected quantitatively through a cannula ligated into the trachea under certain standardized conditions. Published data upon the method of collection, source, volume, composition, autonomic control, functions, excretion and disposal of, and effect of anaesthetics upon, respiratory tract fluid have been reviewed.

Evidence that the following drugs may affect the output and composition of respiratory tract fluid and the mechanism of their action have been reviewed; ammonium chloride and carbonate, potassium citrate, potassium iodide and certain organic iodides, parasympathomimetic agents, aminophylline, ipecacuanha, various saponins and glycosides, volatile oils, terebene, terpin hydrate, tolu balsam, creosote, certain guaiacols, paregoric, chloroform and certain sulphonamides.

The following drugs have no expectorant effect: syrup, morphine, methadone, codeine, dihydrocodeinone, racemorphan, dextromethorphan, diphenhydramine, chlorprophenpyridamine and bromazine.