Courtesy of Ethan Russo – Geoffrey W. Guy
This study examines the current knowledge of physiological and clinical effects of tetrahydrocannabinol
(THC) and cannabidiol (CBD) and presents a rationale for their combination in pharmaceutical preparations.
Cannabinoid and vanilloid receptor effects as well as non-receptor mechanisms are explored, such as the capability of
THC and CBD to act as anti-inflammatory substances independent of cyclo-oxygenase (COX) inhibition. CBD is
demonstrated to antagonise some undesirable effects of THC including intoxication, sedation and tachycardia, while
contributing analgesic, anti-emetic, and anti-carcinogenic properties in its own right. In modern clinical trials, this has
permitted the administration of higher doses of THC, providing evidence for clinical efficacy and safety for cannabis
based extracts in treatment of spasticity, central pain and lower urinary tract symptoms in multiple sclerosis, as well
as sleep disturbances, peripheral neuropathic pain, brachial plexus avulsion symptoms, rheumatoid arthritis and
intractable cancer pain. Prospects for future application of whole cannabis extracts in neuroprotection, drug
dependency, and neoplastic disorders are further examined. The hypothesis that the combination of THC and CBD
increases clinical efficacy while reducing adverse events is supported.