Cannabis is a flowering plant that has a long history of being used for medicinal purposes across much of the world. In the UK, cannabis is categorised as a class B drug under the Misuse of Drugs Act, and it is illegal to possess, supply or cultivate, with the exception being when used for research or other specific means. This is where producers will have a licence from the UK government Home Office to cultivate cannabis, under strict controls, for medicinal purposes.
In 2018 the UK government announced the legalisation of medicinal cannabis which gave the green light for it to be prescribed to patients by specialist doctors in the UK for certain conditions. In some areas of the world, laws are being reformed which allow cannabis to be used for both recreational and medicinal therapeutic use. These reforms usually have the effect of widening the door of access to cannabis for many and help to regulate the content of what is being consumed. This is a particular problem in places where the cultivation, distribution and possession of cannabis is a criminal offence, unless under licence.
In the second half of the 20th century a group of scientists based at Israel’s Weizmann Institute of Science, led by Professor Raphael Mechoulam, extracted more than 60 different chemicals from cannabis plants. These chemicals are known as cannabinoids and were thought to have the potential for medicinal use. Since that discovery, it is now known that there are many more cannabinoids, all of which possess therapeutic properties.
One notable cannabinoid which Professor Mechoulam and his team discovered is delta-9-tetrahydrocannabinol (THC). This is a compound found in the cannabis plant that produces a psychoactive effect when it is smoked, inhaled via a vaporiser or consumed. THC is the part of the plant that can give a sense of relaxation or pleasure, as well as some unwelcome side effects such as drowsiness and anxiety.
Along with THC, another major constituent part of cannabis is cannabidiol (CBD). CBD is the element of cannabis on which initial research had focused as a potential treatment for spasticity in MS. However, it is now widely acknowledged that using THC and CBD in unison with the many more cannabinoids and chemicals contained in cannabis can enhance its overall medicinal effect. This is known as the entourage effect – more on that in a moment.
Professor Mechoulam and his team also discovered the human endocannabinoid system (ECS), which in very brief terms is the label given to a group of receptors located in the brain and central nervous system that are involved in mediating the effects of cannabis. These receptors are neuromodulators and have great influence over many of our vital physiological processes including appetite, pain-sensation, mood and memory. The cannabinoids found in cannabis plants attach themselves to these receptors, helping to modulate their functions. Research is ongoing into the various medicinal properties of cannabinoids, including their effect on the ECS, with hopefully more positive results to come.
Back to the entourage effect. This was first positioned by Professor Mechoulam and Professor Shimon Ben-Shabat in the late 1990s and provides a further understanding of how the different chemicals found naturally in the cannabis plant complement each other, in the medicinal sense.
The entourage effect is a complex science, however in short, there are over one hundred different cannabinoids in the cannabis plant, including the aforementioned THC and CBD. Other compounds include fatty acids, flavonoids and terpenes, all of which possess their own therapeutic benefits. It is thought that these different compounds work in synergy with each other and the ECS, with the result being enhanced therapeutic benefits.
Cannabis products labelled ‘full spectrum’ do contain a variety of these naturally derived chemicals, in different consistencies. This includes the prescribed drug Sativex (the brand name for the oromucosal spray nabiximols) and some CBD products.
On a cautionary note, studies have returned varying results regarding the existence and impact of the entourage effect, with a recent systematic review stating that more high-quality scientific evidence is required to aid further understanding of its mechanisms and medicinal significance.
Historically, MS-specific research into cannabis-based medicines has shown mixed results, have been on a small scale and often the outcomes suggest further studies are needed to underpin efficacy.
Back in 2003 a study involving 667 people with MS was aimed at determining the efficacy of cannabinoids in managing spasticity and other MS related symptoms. The study results showed beneficial effects on mobility and self-reported improvements in pain versus placebo but did not find any significant effect on spasticity.
The same researchers looked at the data they had gathered and conducted a further study, which was published in 2006, relating to cannabinoids and their effect on MS related bladder continence and urgency. This study consisted of 630 people with MS and compared the impact of orally ingested cannabis extract to placebo. They found that there was a clinically significant effect of using cannabis to manage incontinence episodes in patients with MS.
Moving forwards to 2012, a clinical trial titled ‘Multiple sclerosis and extract of cannabis’ (MUSEC) recruited 279 people with MS and found that the relief of pain and muscle stiffness after using cannabis extract was consistently higher than in the placebo group.
As is usually the case in the medical science world, over time more information unfolds, leading to a better understanding of the efficacy and safety of certain medications. It can be argued that this is the case regarding the use of cannabis for managing MS symptoms.
An example of this occurred in 2014 when NICE first licenced Sativex to help people with MS manage chronic spasms and spasticity. This was for patients in Wales only at the time, however it has since been approved for use throughout the UK. The decision by NICE to approve Sativex for this purpose was underpinned by robust scientific evidence of its efficacy and safety, when used in controlled doses, for managing these common MS symptoms. Then in 2018 came the reform of medical cannabis use in the UK, which we mentioned earlier.
More recently, a review of previous studies published in 2022, which looked at the efficacy of medicinal cannabis found that nabiximols is effective in the management of MS related spasticity, neuropathic pain and improved sleep quality. In late 2023 it was also reported that two clinical trials have shown nabiximols to be instrumental in relieving muscle stiffness and spasms in people with MS.
It is also thought that cannabis has neuroprotective qualities, which means that it may protect nerve cells against damage or degeneration. The way this works and the full potential of cannabinoids as a therapy in neurodegenerative disorders is not currently completely understood. However, a systematic review of previous studies, published in late 2022, outlines the role which cannabinoids may play in managing the impact of neurodegenerative conditions. The authors conclude that this is likely due to the antioxidant and anti-inflammatory properties that they possess.
There is also a wealth of anecdotal evidence available from the MS community which underpins how medical cannabis has helped them to manage MS symptoms, particularly regarding spasms and spasticity, pain, bladder problems and tremor.
We mentioned nabiximols earlier and referred to its brand name of Sativex. This is a medical cannabis medication which may be available to you via the NHS. Sativex is an orumucosal spray which means that it is sprayed into the mouth and absorbed into the blood stream via its mucous surfaces. It is currently only prescribed for the treatment of moderate to severe spasticity and is licenced in the UK only for people who have not responded sufficiently to first line and other anti-spasticity medication.
Medical cannabis can also be accessed privately via specialist clinics, prescribed by authorised doctors who have experience in this area. The dosage and type of product prescribed will be decided according to your condition and wider health concerns, ranging from oils, topical creams and dried flower which is suitable to be administered via a vape.
It is also worth being aware of T21, part of Drug Science, which is spearheaded by Professor David Nutt in the UK. Professor Nutt founded Drug Science in 2010, which is an organisation that works to provide an evidence base free from political or commercial influence to help implement drug classification and legislation change.
T21 provides access to medical cannabis, via specialist clinics, at a reduced cost. In return, data is requested from participants in the form of questionnaires sent to them every quarter. This data is used as a basis for Drug Science’s research, which is then published with the aim being to influence policy change.
It will be interesting to see how scientific research into the benefits of cannabis for managing conditions such as MS unfolds over the coming years. Equally as interesting will be the impact that this further knowledge will have upon access to this potentially groundbreaking medication in the UK and beyond.
As always, MS-UK will continue to share any significant outcomes with the MS community on the news section of our website.
Our Choices Spasms and spasticity and Complementary and other therapies booklets provide more information about the use of medical cannabis for people affected by MS.
The Medical Cannabis Patients Association (MCPA) is a community interest company set up by a group of medical cannabis users in the UK. Their aim is to inform people of the benefits of medical cannabis by raising awareness and in turn normalising its use. Their website provides information about medical cannabis, including how to access it in the UK, and they hold regular online group meetings.
