Preclinical assessment of novel therapeutics on the cough reflex: cannabinoid agonists as potential antitussives.

Cough, a reflex defense mechanism, is a common symptom of many airway inflammatory diseases. At present there are no satisfactory treatments for cough that have an acceptable side effect profile. Recent data have described the inhibitory effect of selective cannabinoid CB(2) receptor agonists on sensory nerve activity in vitro and the cough reflex in a guinea pig model. CB(2) receptor expression is limited in the central nervous system (CNS) and hence the development of selective agonists may provide a new therapeutic strategy for treatment of cough devoid of the CNS-mediated side effects that are normally associated with nonselective cannabinoid agonists.