Medicinal cannabis was legalised in the UK for the first time in November 2018 but many NHS doctors still are reluctant to prescribe it to patients.
Campaign groups have claimed that the current system in place means patients who can afford private health have gained greater access to medicinal marijuana since the rules were changed but many of those relying on the NHS are being turned away.
What are the rules?
The revised rules mean specialist doctors can prescribe medicinal cannabis, including products containing low levels of tetrahydrocannabinol (THC) – the psychoactive cannabinoid that gets a user “high”.
The regulatory change followed an outcry over the cases of two children who were denied access to cannabis oil to control their severe epilepsy.
The parents of Alfie Dingley and Billy Caldwell said their seizures stopped after taking a THC-based medication.
That sparked a review by England's Chief Medical Officer, Prof Dame Sally Davies, who concluded there were some clinical benefits to medicinal cannabis.
However, the rules surrounding THC remain strict.
Specialist doctors can only prescribe cannabis products containing THC in extreme circumstances such as cases of children with severe forms of epilepsy, adults with vomiting caused by chemotherapy and adults with muscle stiffness caused by multiple sclerosis.
What is the difference between THC and CBD?
Cannabis is made up of 483 compounds, the most dominant of which are cannabinoids known as THC and cannabidiol (CBD).
The medicinal cannabis prescribed by specialist doctors will contain CBD and low levels of THC.
THC produces the high people feel when smoking or ingesting marijuana.
Most of the cannabis being sold illegally in the UK contains a higher percentage of THC than some other types of the drug.
Cannabis with high levels of THC has been linked to psychiatric issues, particularly among adolescents who take large amounts.
CBD, on the other hand, is nonpsychoactive and can be well tolerated.
For this reason, the substance is not restricted in the UK and is widely available at retailers as an oil, spray or food supplement.
CBD products can be sold without a licence so long as claims are not made about their medical benefits.
The products available at stores contain a low percentage of CBD and are mixed with other substances.
For instance, CBD oil is mixed with a carrier oil, often hemp seed or coconut.
But it has been argued that increasing the amount of CBD used in products would be pointless.
The entourage effect
Geremy Thomas, chief executive of the UK’s first medicinal cannabis investment vehicle, Sativa Investments, said it’s the “entourage effect” of all the compounds in a cannabis plant working together that help treat medical conditions.
Pointing to the cases of Alfie Dingley and Billy Caldwell, Thomas said if they were given a product containing pure CBD it has been doubted their seizures would stop.
“It’s the fact that there was a small amount of THC present, which really activated the medicinal effect,” he said.
Scientists are still researching CBD and THC but the combination of the two has been used to help treat seizures, inflammation, muscle spasticity and glaucoma.
Thomas said the ideal percentages of THC and CBD used in medicinal cannabis depends on ailment being treated and more research needs to be done into the effect of different combinations.
Since medicinal cannabis is mostly unlicensed, doctors will only prescribe it for needs that can't be met by licensed medicines.
Sativex spray, which is a 50-50 combination of THC and CBD, has been approved for use in the Britain by the Medicines and Healthcare products Regulatory Agency as a treatment for multiple sclerosis.
However, the National Institute for Health and Care Excellence (NICE), which issues guidance to NHS doctors, in 2014 recommended against prescribing Sativex because it was not cost-effective.
Sativex costs about £140 per 10ml bottle, which contains 90 doses.
Will the UK ease up the rules?
Health secretary, Matt Hancock, has admitted that the current system for prescribing medicinal cannabis is not working after Emma Appleby had a supply of medical cannabis for her severely epileptic nine-year-old daughter, Teagan, confiscated while trying to enter the UK in early April.
The government has asked NICE to develop additional clinical guidelines on cannabis-based medicinal products, which are due to be released in October.
With attitudes changing on medicinal cannabis, Thomas expects the government will eventually relax the rules on the drug.
“Absolutely, I think the door is open, a very small distance, and it will inevitably open wider and wider,” he said.
“At the moment regulators are under top-down pressure from the politicians and are resisting that pressure, or struggling to cope with that pressure, but they are working hard to deliver for UK patients in accessing medical cannabis.”
“And I do think that the UK medicinal cannabis market will end up being the largest in Europe, which in turn will significantly compete with, if not dwarf, what we’ve seen in North America.”
Thomas said there is a big opportunity in the UK given that it has a large aging population, which he sees as a “positive indicator to medical cannabis uptake”.
Will the UK ever legalise recreational cannabis?
The UK remains well behind the curve compared to North America. Canada legalised recreational cannabis in October 2018 and has allowed the use of medicinal cannabis since 2011.
While cannabis remains illegal at a federal level in the US, recreational marijuana is now legal in 10 states and medical marijuana is legal in 33.
Thomas sees the UK following suit on recreational cannabis eventually but not any time soon.
“When I was first interviewed after setting up Sativa Investments in 2017 I was asked when I thought the regulations would change to approve medicinal cannabis in the UK and I said two to three years and it turned out to be four to five months,” he said.
“If you ask me now about recreational use in the UK, I would suggest it was a long way down the road but who knows it does make sense."
Thomas said there is a case for legalising recreational cannabis as it could mean people stop buying high strength cannabis illegally from the streets and start using regulated products with lower levels of THC.
“(Recreational use) is not a position Sativa Investments takes – it’s a medicinal cannabis company – but if I was to put money on it, I should think that we would follow the rest of the countries around the world.”
New research underway
Sativa Investments has teamed up with King's College London to research the impact of cannabinoids on inflammation and respiratory diseases.
READ: Sativa Investments teams up with King's College London to research cannabinoids for medicinal use
Under the agreement, Sativa Investments will supply the university with specific strains of cannabis plants that contain various combinations of the spectrum of at least 113 known cannabinoids.