As part of its series of evening discussions, the Edinburgh Science Festival hosted an evening of talks on the properties of medicinal cannabis and barriers to its use in the United Kingdom. Panellists included pharmacologist and co-founder of the International Cannabinoid Research Society Professor Roger Pertwee, neurologist Professor Mike Barnes and medicinal cannabis advocate Karen Gray. The panel was chaired by journalist and former health correspondent for BBC Scotland Pennie Taylor.
Each of the three smaller talks given by the panellists approached the topic of medicinal cannabis in a different way. Prof Pertwee began with a breakdown of the biochemical components of cannabis. Cannabis contains an estimated 120 cannabinoid compounds, or chemicals that react with specific receptors (cannabinoid receptors) in the human brain. These receptors, along with chemicals our bodies produce naturally (endocannabinoids) form the endocannabinoid system.
Of the cannabinoids in cannabis, tetrahydrocannabinol (THC) is the most psychoactive. It is the high from THC that recreational cannabis users seek. THC is balanced and counteracted by the other main chemical component of cannabis, cannabidiol (CBD). THC has numerous benefits to health including pain and nausea relief, appetite stimulus and anti-inflammatory properties. CBD is a potent pain reliever, has anti-anxiety properties, can help prevent seizures, and may even help fight cancer. However, Professor Pewtree pointed out that these chemicals are merely the two that have been most well documented. The health benefits of the many other compounds found in cannabis are being illuminated as they are researched more thoroughly.
Cannabis contains an estimated 120 cannabinoid compounds, or chemicals that react with specific receptors (cannabinoid receptors) in the human brain
Professor Barnes discussed the topic from a more clinical point of view. He discussed the barriers to use of cannabis-based products by doctors in the United Kingdom despite the recent change in legislation that allows it to be prescribed in any form except smoking. Many doctors do not understand the evidence for use of cannabis in medicine. Additionally, cultural and moral attitudes around the plant are still very much negative. There are also economic barriers to be considered; the medical cannabis industry is small in the United Kingdom, so medicines must be imported from other countries at tremendous financial and time costs. Barnes stated that despite it being legal to prescribe cannabis since late 2018, that there have been no NHS prescriptions written for any cannabis-based medicine.
While Barnes and Pewtree delivered the bulk of the science, Karen Gray’s talk brought the topic into a real-world context. Gray’s son Murray suffers from myoclonic-astatic epilepsy, also known as Doose Syndrome, a type of early childhood epilepsy that is often resistant to medication and thus very difficult to treat. Murray can suffer as many as twelve seizures a day; Gray reported that during a particularly harrowing episode he suffered twenty in the course of a few hours. Murray’s condition is highly resistant to even the strongest of medications. At one point he was even given ketamine, which is so strong that it is used to tranquilize large animals like horses. Murray showed improvement on Epidolex, a pharmaceutical grade CBD oil, the improvement was not permanent. In other parts of the world with fewer barriers to medicinal cannabis, patients like Murray have shown improvement on medication that includes a proportion of THC in addition to CBD, but Gray has been unable to secure a prescription for Murray despite its legality. The barriers to the use of cannabis-based medicine are still proving problematic for Murray and others like him in the UK. Caregivers are forced to either make do with other treatments, or risk criminalizing themselves to secure cannabis on the black market, something Gray says she is not comfortable doing for an unregulated product.
Professor Pewtree pointed out that [THC and CBD] are merely the two [chemicals] that have been most well documented. The health benefits of the many other compounds found in cannabis are being illuminated as they are researched more thoroughly
After the series of three talks there was a question and answer period, well-orchestrated by Pennie Taylor, who actively engaged the audience and helped synthesize their ideas as opposed to just calling upon people in turn. The conversation focused on the need to educate and engage both established doctors and young people. Additionally, the group identified a need to re-evaluate the ways in which clinical trials are run for cannabis-based medicines, as important anecdotal evidence is too often never considered because of the current legal status of cannabis. Broadly, the evening illuminated the need to continue dialogues on the use of cannabis in medicine because its uses are far beyond mere pain relief. During one exchange, professor Pertwee stated “It’s not one drug,” and Professor Barnes replied, “It’s a family of medicines.” However, until the United Kingdom sees some large changes in attitude, that family of medicines may tragically go to waste.
This post was written by Miles Martin and edited by Karolina Zieba.
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