ABSTRACT
The herb cannabis is derived from the Old World species Cannabis sativa L. It is generally conceived that cannabis is a monotypic species (Merzouki, 2001), but C. afghanica may also merit species status (Clarke, 1998). Cannabis has a history as an analgesic agent that spans at least 4,000 years, including a century of usage in mainstream Western medicine. Quality control issues and, ultimately, political fiat eliminated this agent from the modern pharmacopoeia, but it is now resurgent. The reasons lie in the remarkable pharmacological properties of the herb, and new scientific research that reveals the inextricable link that cannabinoids possess with our own internal biochemistry. In essence, the cannabinoids form a system in parallel with that of the endogenous opioids (endorphins/enkephalins) in modulating pain. More importantly, cannabis, and its endogenous and synthetic counterparts, may be uniquely effective in pain syndromes such as neuropathic pain and migraine where opiates and other analgesics fail.
