Analgesic Properties of THC and Its Synthetic Derivatives

Abstract

Cannabis has been used for thousands of years for the treatment of pain resulting from a wide range of disorders. Although clinical evaluations of Cannabis and its psychoactive constituent THC have not led to a general consensus regarding their analgesic effectiveness, THC and other synthetic cannabinoid analogs elicit antinociception in a variety of pain tests in laboratory animals. These antinociceptive effects are mediated through cannabinoid receptors in the central nervous system which, in turn, modulate the perception of painful stimuli. The endogenous ligand, arachinodyl-ethanolamine (anandamide), is also an effective antinociceptive agent in experimental models. The extent to which the endogenous cannabinoid system is involved in the modulation of pain is currently unknown. Coadministration of opioids and THC by the intrathecal route produces an additive antalgic effect. Recent work indicates that coadministration of opioids and cannabinoids produces at least an additive effect. The possibility exists that the analgesic effects can be optimized and untoward effects be minimized if agents from these two classes of drugs were coadministered for the treatment of painful conditions.