Antitussive activity of some naturally occurring cannabinoids in anesthetized cats.

Experimental cough was elicited in pentobarbital-anesthetized cats by either electrical stimulation of the superior laryngeal nerve or by mechanical stimulation of the tracheal mucosa. Intravenous administration of delta9-tetrahydrocannabinol (THC) effectively reduced the amplitude of the cough response in both these models of experimentally induced cough with ED50 values (AtD50) of 1.84 and 0.78 mg/kg, respectively. This cough suppressant activity of THC was more similar to codeine-PO4 than dextromethorphan-HBr. On the other hand, both cannabinol (CBN) and cannabidiol (CBD) were devoid of antitussive activity at doses as high as 10.0 mg/kg.