Cannabis and cannabinoid analgesia were reviewed in a study, involving the endocannabinoid system we mention on this website. In addition, non receptor processes and random clinical trials were conducted for the treatment of pain. THC, Marinol and nabilone, Cesamet, are currently approved in the US and in other countries, but not for pain management. There is another one, only in development as of now, called ajulemic acid. There is also herbal cannabis that remains in an illegal status, but it is also being studied.
Sativex is a cannabis derived oral spray that contains equal parts of THC, partially a CB1 receptor agonist, and cannabidiol, which is a CB1 receptor antagonist. They influence the brain and central nervous system.going back to Sativex, it was approved in Canada in 2005 for the treatment of central neuropathic, or nerve pain, in multiple sclerosis. Then in 2007, it was approved for severe cancer pain. Many clinical trials have demonstrated the safety and efficacy of Sativex for central and peripheral nerve pain rheumatoid arthritis and cancer pain. In addition, a new drug application to conduct clinical trials for cancer pain was approved by the FDA in January 2006. These cannabinoid analgesics have been well tolerated overall in clinical trials, and they show promise to help treat cancer pain.