Journal list menu

Free Access

An update on medical cannabis prescribing in the UK

Angela Dowden

Angela Dowden

Angela Dowden is a freelance journalist and registered nutritionist

Search for more papers by this author
First published: 23 March 2021
Citations: 3


In November 2018, legalisation of medical cannabis in the UK was announced, following media reports about children with unmanageable epilepsy being denied the drug. Over two years on, the number of patients who have received NHS prescriptions for licensed cannabis medicines is estimated to be in the low hundreds, but the number of prescriptions issued for unlicensed products has been vanishingly small. This article examines the reasons why, and discusses the future role of medical cannabis.

It has been more than two years since the UK government introduced a law change to enable the legal prescription of cannabis-based medicinal products (CBMPs) for the first time. But few subjects seem to stir up stronger debate among doctors, scientists, researchers, policy makers and the public than medical cannabis.

The reclassification in November 2018 moved cannabis-based products from Schedule 1 – a drug with no perceived therapeutic value – to Schedule 2 of the Misuse of Drugs Regulations. But while cannabis campaigners and patients initially rejoiced, the hope that it would make obtaining cannabis-based medicines easy has largely not been realised.

However, the situation is markedly different for patients in a position to pay, with the figure for CBMP prescriptions being issued privately in the UK currently estimated at around 2500 and rising.

Barriers to NHS prescribing

A major hurdle is that the vast majority of CBMPs are unlicensed medicines that have to be prescribed as ‘specials’. It means they can only be prescribed by a specialist doctor after all existing licensed options and off-label medications have been exhausted.

But this poses a problem, as such prescribing is outside the normal expertise of most doctors who have been taught little about cannabis and the endocannabinoid system as part of conventional medical training.

Prescribing these products is also quite complex as the two main cannabinoids in cannabis – cannabidiol or CBD (the non-psychoactive component) and tetrahydrocannabinol or THC (which produces the marijuana ‘high’) – can be combined in many different ratios along with other minor cannabinoids and terpenes from the whole plant.

But perhaps the biggest reason they are not being prescribed is because of NICE's November 2019 guideline (NG144)1 that gave only lukewarm support to CBMPs. Though NICE guidelines aren't mandatory, most NHS trusts won't support prescribing outside them. Meanwhile, the OTC market for CBD oils is booming (see Table 1).

Table 1. Over-the-counter (OTC) cannabidiol (CBD): fast facts
  • While patients struggle to get medical cannabis, the OTC market for CBD oils – which can be sold legally in the UK as long as they contain isolated CBD without THC – is booming; the Centre for Medicinal Cannabis (CMC) estimates that the UK market could be worth almost £1bn a year by 2025
  • CBD oils currently sold as supplements in the UK are not considered CBPMs
  • To be exempt from control, CBD products must contain no more than 1mg tetrahydrocannabinol (THC) per container, whether that is a 250ml bottle of “CBD-enhanced water” or a 5ml dropper bottle of CBD oil
  • Products on the market may not contain the ingredients they claim. In a CMC-commissioned lab test, of 30 products that were blind tested only 38% contained the stated amount of CBD and 50% exceeded the legal amount of THC
Table 2. Medical cannabis educational resources
Box 1. Meet the medical cannabis clinicians

Specialist doctors may be the prescribers, but GPs, nurses and pharmacists are increasingly involved in helping patients access cannabis-based medicinal products. Prescriber talked to three of them.

The nurse

Sophie Hayes, specialist nurse at Integro Clinics (

What's your role?

I provide support to both patients and clinicians at the clinic. I will discuss with the patient their symptoms and background, and if they are a candidate for a cannabis medicine and receive a prescription, then it is my job to help that patient understand their medicine – how it might interact with other medications and the best ways to manage symptoms with it.

What led you into it?

I was previously an ICU nurse working with COVID patients, but I felt worn out and needed a change. I started at Integro in summer 2020, but I've been involved in cannabis patient advocacy since 2014 after my partner was diagnosed with Crohn's disease. He had found cannabis helped manage many of the symptoms he was experiencing four years prior to his diagnosis.

Why should nurses be educated on cannabis?

Nurses need to know about the medicinal applications of cannabis so they can better care for their patients. Most people who currently class their cannabis use as therapeutic are using illicitly sourced cannabis; nurses working in oncology, palliative care, neurology, gynaecology, urology, mental health and many other areas should understand that medical cannabis is relevant to them.

The pharmacist

Carl Holvey, Partnership Director and Chief Pharmacist, Sapphire Medical Clinics

What's your role?

I'm lead on the governance of medicines for our organisation. Legislation and national guidance around the use of cannabis medicines is the most restrictive of all prescribed medicines, requiring multiple checks being put in place to ensure we're meeting all requirements for supplying these medicines to patients safety. I spend a lot of time supporting doctors and patients to get the best out of their medicines.

What led you to it?

I'd been an NHS pharmacist for around 20 years (10 years at senior manager level), and was ready for something new. I saw cannabis as a brand new therapy, and something with exciting potential that patients could potentially benefit from. Starting out in a new clinic was a steep learning curve. We've been learning from primary research and other clinicians in North America.

Why should pharmacists be educated on cannabis?

When they come into hospitals, pharmacists need to find out if and why patients are using cannabis, as many will be using it to treat medical illness. Patients could require adjustment of their pain medicines if they are unable to access cannabis while hospitalised, for instance. Pharmacists should also be aware of potential interactions with cannabis-based medicines relating to effects on liver enzymes.

The GP

Dr Leon Barron, London-based NHS GP

What's your role?

I'm a practising NHS GP, and the founder of the Primary Care Cannabis Network (PCCN), a growing network of UK GPs with a professional interest in medical cannabis.

What led you into it?

My initial interest in medical cannabis came from hearing about overseas patients who were benefiting from these therapies – most with very common conditions like complex pain syndromes, neurological conditions and even mood disorders, which we can struggle to treat here in the UK. I discovered that by understanding this group of medicines, I could suggest something extra that could potentially work for patients with these conditions.

Why should GPs be educated on cannabis?

When, as doctors, we are faced with questions [on medical cannabis] from patients, we need to give informed, evidence-based answers. We should never come from a place of ignorance when expressing a strong opinion on a medical treatment. It is essential for GPs to be equipped with a basic understanding of the endocannabinoid system and therapeutic potential of cannabis, as well as the UK regulatory landscape and the various referral pathways that currently exist.

What do the NICE CBMP guidelines say?

NICE considered the use of CBMPs in four specific conditions and their recommendations are as follows:
  • Spasticity – THC/CBD oromucosal spray Sativex (a licensed medicine) can be offered, initially as a four-week trial, to treat moderate to severe spasticity in adults with multiple sclerosis if other pharmacological treatments are not effective.1
  • Nausea and vomiting – Nabilone (a licensed synthetic cannabinoid that mimics THC) can be considered as an add-on treatment for adults with intractable chemotherapy-induced nausea and vomiting.1
  • Severe treatment-resistant epilepsy – In separate technology appraisal guidance,2, 3 licensed CBD medicine Epidyolex is recommended in combination with clobazam for treating seizures associated with Lennox-Gastaut syndrome and Dravet syndrome in patients aged two years and older.
  • Chronic pain – No CBMPs should be offered to manage chronic pain in adults, though CBD is allowable if part of a clinical trial.1

“In a nutshell, it now means we now have three licensed cannabis medicines – Sativex, Epidyolex and Nabilone – that the public purse will in theory pay for under very specific conditions, but a plethora of other products, which cannabis patients may benefit from more, left out in the cold to all but private practitioners,” says Consultant Neurologist and Medical Cannabis Clinicians Chair, Professor Mike Barnes.

“In particular, the NICE ruling that there is insufficient benefit to recommend cannabis medication in chronic pain is disappointing and not reflective of what members see when clinically treating patients with a multitude of chronic pain conditions.”

Is there a different type of evidence needed for cannabis?

Professor Barnes believes a large driver behind the cautiousness of the NICE guidelines is what they consider ‘good evidence’ – and that this may be different for cannabis.

“NICE strongly favours the randomised clinical trial (RCT), which is considered gold standard. While there are some RCTs for CBMPs, the cannabis plant doesn't always lend itself to being studied this way as it's a botanical product with several different components.”

According to Dr Mikael Sodergren, Managing Director and founder of Sapphire Clinics, and a Consultant Hepatobiliary and Pancreatic Surgeon at Imperial College Healthcare NHS Trust, the other problem is the way the cost effectiveness analysis was done for cannabis.

“The way NICE works is they benchmark cost effectiveness against the drug with the highest level evidence. For CBMPs as a whole, this was Sativex, which does have RCTs and is also expensive, because it's gone through the whole drug development pipeline.

“But Sativex wouldn't be the drug of choice for pain — in real-life clinical practice we are finding that a whole range of full-spectrum unlicensed cannabis products are more helpful, which is the same as in more mature medical cannabis markets like Germany, where only 15% of prescriptions for CBMPs are for finished pharmaceutical products.

“So, you can argue that performing an efficacy evaluation on a drug that will likely be prescribed to fewer than one in six patients lacks clinical applicability and therefore has limited relevance.”

But some experts caution against treating cannabis as a special case. “My view is that if we wish to consider cannabis-based products for medicinal use then we should also apply the same evidential and regulatory thresholds and standards used to evaluate and assess other medicines,” says Harry Sumnall, Professor of Substance Use at Liverpool John Moores University Public Health Institute.

“While I do not think research evidence should necessarily be limited to RCTs, there is nothing exceptional about cannabis, and data from other types of research design should be scrutinised in the same way as we would expect for other candidate medicines.”

Monitoring outcomes

One way forward is through collecting observational data on cannabis use from patient registries. This was a key recommendation of the August 2019 Barriers to Accessing Cannabis-based Products for Medicinal Use on NHS Prescription4 report commissioned by Health Secretary, Matt Hancock, as an urgent review into the lack of cannabis prescriptions.

The NHS has now confirmed it is launching the Patient Registry for Cannabis-Based Products this year. This will join two private medicine cannabis registries that are already creating outcomes on medical cannabis prescribing: the UK Medical Cannabis Registry established by Sapphire Medical Clinic physicians, and Project Twenty21 from Drug Science, who describe themselves as “an independent scientific body working to provide clear, evidence-based information on drugs without political or commercial interference.” (Qualifying patients for Project Twenty21 will have their cannabis medicine costs subsidised up to a maximum of £150 a month).

However, whether the NHS will embrace the data from these cannabis databases, or if it will just cement a further division between state and private healthcare, remains to be seen.

“Because prescriptions within the NHS have largely been for licensed cannabis-based medicines such as Sativex or Epidyolex, the NHS registry will hold very little information about unlicensed CBMPs that private clinics and patients prefer and find more useful,” says Professor Barnes. “In short, it may well be a waste of time, unless the private sector contributes.”

The rise of private cannabis clinics

While the evidence is still being gathered, private cannabis clinics have been springing up apace. There are now six that are Care Quality Commission (CQC) registered in the UK and more in the pipeline. Some clinics are tied to specific suppliers of cannabis products, while others have no such ties and can prescribe a wider spectrum of medicines – including those that are consumed, applied or vaporised.

Dr Sodergren says that at Sapphire Clinics, they apply exactly the same framework as is applied to evaluating complicated patients in the NHS. “Patients are seen by sub-specialists in their own field. They must be at the right stage in their patient pathway journey and have exhausted the normal treatment options.

“The specialist can form an opinion, but no decisions are made outside a multidisciplinary team. Once a week, we have a meeting with at least seven clinicians in attendance, discussing each case and the merits of prescribing for that individual patient.”

Dr Sodergren adds that it's a misconception that cannabis medicines are expensive. “This is still the case with some of the early full-spectrum branded oils for children with intractable epilepsy, and these children should be allowed to continue to have these, as their condition can be sensitive to even tiny changes in prescription. But for our average pain patient, which is 60 to 65% of whom we see, the total cost of both medicines and clinic appointments is less than £5 a day – or as we say, less than two regular Costa coffees.”

Science vs commercial interest

Could there be danger that the scientific evidence may stop being top priority for commercial cannabis clinics?

According to Professor Sumnall, there's no particular need for concern if beliefs or popular interests motivate some cannabis studies, because scientific and methodological robustness can be independently scrutinised. However, he thinks that the interactions between the emerging cannabis industry and researchers, including how commercial interests might affect the science, is worthy of scrutiny.

Says Professor Sumnall: “It would be useful to better understand how commercial interests might affect the science, or how different studies are interpreted and prioritised. We now have, for example, medical training on cannabinoids funded and delivered by the cannabis industry, and patient and lobby groups directly supported by industry arguing for different approaches to research methodology, knowledge transfer partnerships between universities and the CBD ‘wellness’ sector, and new initiatives such as patient registries designed to generate data on the medicinal use of cannabis.

“This is not to suggest that these interactions are problematic or that they will undermine research and practice, but I think it would be useful to have some clear principles governing these interactions.”

The future

Next out of the blocks will be a new report from the International Association for Pain taskforce, which is currently reviewing the cannabis evidence and is expected to publish its findings in 2021. The task force's findings are expected to be influential, but it's uncertain whether they will find sufficient high-quality evidence to point to a change in practice.

Instead, it is likely that data from robust cannabis patient registries and, longer term, from more randomised clinical trials will be the real drivers behind a wider adoption of evidence-based and cost-effective cannabis medicines within the NHS.

Some sort of change is surely needed if the results of a November 2019 survey on illicit cannabis use are a true reflection on reality. The poll, undertaken by YouGov on behalf of the Centre for Medicinal Cannabis and patient advocacy group CPASS, estimates that the number of people in the UK who resort to sourcing and using illegal or ‘street’ cannabis (marijuana) to treat chronic health conditions is much higher than previously understood and close to 1.4 million users (2.8% of the adult population).5

That's a lot of people putting themselves at potential risk from both prosecution and substandard medicine.

Declaration of interests

None to declare.