Part of a senior doctor holding pill bottle with scale and marijuana, isolated on white background Photo: istock
CANNABIS has been used therapeutically throughout human history and was itself a mainstream medicine in Western societies until the Prohibition movements of the 20th century relegated it to the sidelines.
In the past 25 years, science has come to understand that this complex botanical medicine works via the endocannabinoid system (ECS), an innate promoter of homeostasis (balance) in our various physiological systems.
Although tetrahydro-cannabinol (THC), the main psychoactive component of cannabis receives the most attention or notoriety, it is only one of many phyto-cannabinoids in the plant, which also harbours essential oil terpenoids that give cannabis its aroma, as well as the ability to synergise or boost the therapeutic effects, among them pain relief, reduction of inflammation and benefits on mood. It is this synergy that makes cannabis potentially much more than the sum of its parts.
This is particularly noteworthy in cannabis varieties that contain cannabidiol (CBD), a non-intoxicating component of cannabis that boosts analgesic and anti-inflammatory effects, but counteracts THC intoxication and reduces side effects of anxiety and even psychosis.
One must consider the question of why so many people turn to cannabis as an alternative to “conventional medicine”.
In truth, this rarely has anything to do with a desire by patients to get high, but rather is motivated by the fact that cannabis often is of substantial benefit for myriad conditions where standard approaches have fallen dramatically short.
Cannabis is actually among the most studied drugs of all time, largely as a result of US-sponsored research on its harms.
Yes, there can be too much of a good thing, but in reality, there is no known lethal dose of THC or cannabis.
This contrasts to opiates, which in overdose depress the respiratory drive in the brain, and are responsible for thousands of overdose deaths each year.
" The proper approach to cannabis is to remove legal penalties, regulate its production and distribution so that those who need it have access, physicians and consumers can be assured of its composition, freedom from pesticide contamination, and to educate the population properly on both its benefits and liabilities. "
In truth, the adverse event profile of cannabis is far more benign than that of many approved drugs for which it can effectively substitute.
We actually know a great deal about the composition and dosing of standardised cannabis preparations. Sativex oromucosal cannabis-based medicine contains roughly equal amounts of THC and CBD along with other components, and is a regulatory-approved pharmaceutical for spasticity in multiple sclerosis in 29 countries, including Australia.
In the course of its development, it proved superior to an extract containing THC without CBD in a study of cancer pain unresponsive to optimised opioids — an indication also approved in Canada.
Despite an explosion in cannabis usage over the past several decades, there has been no corresponding increase in schizophrenia in epidemiological studies, but rather a reduction. Cannabis does not induce psychosis de novo; rather, it may unmask it earlier in those with a prior predisposition.
While it remains the best advice that people with a family history of psychosis should avoid recreational cannabis, it may surprise people to know that cannabidiol (CBD) has itself proven safe and efficacious for its treatment in two separate Phase II clinical trials.
Let us be clear: Neither I nor anyone else is saying that cannabis is totally harmless and that we should not be concerned about its chronic daily use by teenagers who should be engaging in more salutary pursuits.
One should be reassured however, that even in such chronic cannabis use, associated memory and other cognitive deficits seem to clear completely after one month of abstinence.
Such misuse is worlds apart from the therapeutic application of standardised cannabis products in a non-smoked form in the much lower doses necessary to allay symptoms of disease without intoxication.
The proper approach to cannabis is to remove legal penalties, regulate its production and distribution so that those who need it have access, physicians and consumers can be assured of its composition, freedom from pesticide contamination, and to educate the population properly on both its benefits and liabilities.
Dr Ethan Russo is a board-certified American child and adult neurologist, former senior medical adviser to GW Pharmaceuticals, and study physician/medical monitor for numerous clinical trials of cannabis-based medicines. He is also medical director of PHYTECS, a research and development company investigating therapeutic approaches to the endocannabinoid system. He is the author of more than 50 peer-reviewed publications on cannabis, cannabinoids and the endocannabinoid system.