Whether it’s smoked, eaten or vaporized, marijuana consumption in humans leads to some fairly predictable outcomes: euphoria, hunger, relaxation, introspection, nervousness and even paranoia. Increasingly, however, people are consuming the plant for another reason – chronic pain relief. While marijuana has been a legalized treatment option in Canada for certain medical conditions since 2001, medical marijuana use among Canadians has soared over the last five years. As of September 2017, there are more than 235,000 registered pot users in Canada, up from 7,900 as of June 2014.
Yet, this upsurge in medicinal marijuana use among Canadians has not staggered the use of other pain-relieving drugs in the country, namely opiates. This past year saw the most opiate-related deaths on record nationally, a number estimated to be greater than 4,000 by the Public Health Agency of Canada. Undoubtedly, the opioid overdose epidemic has roots in the illicit drug supply, but the crisis also stems from the over-prescription of high potency painkillers. The slated legalization of marijuana in Canada this fall has thrust the plant firmly into the spotlight, sparking (up) debate as to whether it can serve as a viable solution to the opioid crisis raging the nation.
Marijuana is the dried form of the cannabis sativa plant and is a natural and powerful drug. Cannabis is made up of over 560 different substances, more than 100 of which have active properties. These constituents are collectively known as cannabinoids. The human body naturally produces its own repertoire of cannabinoids, and these molecules bind to cannabinoid receptors found widely throughout the brain. This entire natural complex of cannabinoids and their receptors has been dubbed the endocannabinoid system (ECS), pointing to the endogenous nature of the signalling network. Although not identified until 1988, the ECS has been proven crucial to regulating and maintaining proper brain health.
Exogenous cannabinoids, like those found in cannabis, interfere with the proper workings of the ECS. Two of the best-studied ones are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the main active ingredient in cannabis – the more THC found within the strain of cannabis, the stronger the psychoactive effect. In other words, THC is the substance responsible for making you feel high. THC announces itself in the brain by disrupting the ECS, snugly fitting within a cannabinoid receptor and overtaking the site. CBD, on the other hand, is non-euphoric. Like THC, it’s a psychoactive constituent of cannabis because it crosses the blood-brain barrier but does not affect the same receptors as its cannabinol cousin. How CBD exerts its function in the brain is still a matter of scientific investigation, but the compound can be administered at relatively high doses without the unwanted psychological side effects.
Inquiry into the medicinal properties of cannabis has been the subject of much research in Canada. Dr. Mark Ware, a world-renowned pain specialist and medical cannabis researcher, has been embedded in the field for over twenty years. Most recently, he pioneered the largest national, multicentre study examining the safety of cannabis use among sufferers of chronic pain to date, Cannabis for the Management of Pain: Assessment of Safety Study (COMPASS). This year-long study followed 431 adult patients with chronic, non-cancer pain, 215 of whom used cannabis for chronic pain management. All subjects were put through testing throughout the study, including cognitive assessments, blood tests, and self-reported questionnaires related to pain. The results demonstrated that cannabis did not impact cognitive function nor immune cell subsets among its users, but it did positively affect pain management and overall quality of life. Dr. Ware is transparent regarding the study’s overall limitations, saying “[p]atients were self-selected, not randomized, and most were experienced users. So what we are seeing is that it appears to be a relatively safe drug when used by people who have already determined that it helps them. We cannot draw conclusions about safety issues of new cannabis users.”
Implicit in Dr. Ware’s reaction to the success of the COMPASS trial is that indeed, many chronic pain sufferers are gravitating towards cannabis to manage their symptoms. Canadian seniors, for instance, are readily consuming CBD-based products in place of pharmaceutical drugs to mitigate chronic pain. While confronting their own personal “stereotypes about grizzled hippie stoners”, patients like 80-year old Hope Bobowski are finding pain-free solace using CBD oils, and are electing “to use [cannabis] ahead of opioids” to combat their pain.
Studies of the US Medicare system are confirming this profound switch in pain management among its citizens. Two separate papers recently published in Journal of American Medical Association Internal Medicine examine medical cannabis use and its correlation with opiate use from Medicare D subscribers. Medicare D is an optional prescription drug plan that covers more than 42 million Americans, including seniors. The first study found that when a state had a medical cannabis law in place, its daily rate of opiate prescriptions filled decreased from 23.08 million doses to 20.97 million doses, an 8.5% decrease, relative to states without medical cannabis laws. Interestingly, reductions were even more profound for states that allow cannabis dispensaries, amounting to nearly 15%. The second study investigated both medical and adult recreational use of marijuana in Medicare D participants, finding that passing recreational marijuana laws saw an overall reduction in opiate prescriptions by close to 7%. These authors conclude, “[M]arijuana liberalization may serve as a component of a comprehensive package to tackle the opioid epidemic.”
Not all researchers, however, are convinced of marijuana’s absolute potential to alleviate opiate addiction. Senior scientist at Toronto’s Centre for Addiction and Mental Health (CAMH) Dr. Benedikt Fischer cautions that while both Canada and the US are enduring similar opiate crises, the US-based studies cannot directly inform the Canadian healthcare system, saying “[a] lot of the effects that are being observed in the US over the last years may already have been materializing [in Canada] because we have that sort of broad legal availability for quite some time. For us to even begin to think that those kinds of effects might be happening here in Canada as well, we need Canadian data for this.” Phillipe Lucas, head of the Canadian Medical Cannabis Council, adds: “I’d be the last person to suggest that cannabis was entirely safe or entirely appropriate for every individual.” Sean Mackey, pain specialist at Stanford University, offers medical marijuana as one of many non-opiate treatments to manage pain, saying, “there’s over 200 medications I can [prescribe, and] 90 percent of them are non-opioids.”
It’s hard to deny the growing body of evidence that points to cannabis having a role in treating chronic pain. But before reefer madness begins, it’s important to note that the data highlighting marijuana’s role in managing pain has been largely anecdotal and correlative. There is a paucity of long-term randomized clinical trial data monitoring how medical marijuana stacks up against opiates to manage pain. Hopefully, the imminent legalization of marijuana in Canada eases the manner in which marijuana-based clinical trials can be conducted, and also brings with it standards for dosing, THC:CBD ratios, and routes of administration to mitigate pain. And if along the way, cannabis outperforms opiates in pain management, that would be pretty dope.
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