Epidyolex is a controlled drug because of its impurity. The impurity in this case is the controlled substance tetrahydrocannabinol (THC). As is well known, both CBD and THC are products derived from cannabis.
Things have moved fast in the regulation of cannabis. It was only in 2018 that legislation for cannabis-based products for medicinal use (CBPM) was introduced. In an important change, some unlicensed CBPMs could be prescribed by a doctor on the Specialist Register of the General Medical Council.
In September 2019, the marketing of Epidyolex was approved by the European Commission for the treatment of some seizures. For the UK’s Misuse of Drugs Regulations 2001 purposes, it became a licensed medicinal product.
The summary of its product characteristics on the electronic medicines compendium makes it clear that “Epidyolex should be initiated and supervised by physicians with experience in the treatment of epilepsy”. The need for specialist experience in prescribing it is also flagged up in the BNF.
In January, the Advisory Council on the Misuse of Drugs (ACMD) wrote to the government to recommend the re-scheduling of Epidyolex, which paved the way for the recent change.
What effect will rescheduling have?
The Drugs and Firearms Licensing Unit of the Home Office has received almost 1,500 import or export requests for Epidyolex as a Schedule 2 drug since it received marketing authorisation.
The rescheduling will mean that the medicine is no longer subject to the Schedule 2 prohibition rules on its importation, exportation and possession. As well as reducing commercial paperwork and fees, this is useful for patients travelling with Epidyolex.
Prescriptions of Epidyolex are now valid for six months and administration becomes easier, as prescriptions can be repeatable and emergency supplies can be made. Epidyolex will no longer be subject to the strictest safe custody requirements.
The maximum quantity of Epidyolex prescribed can now exceed the 30-day supply limit recommended for Schedule 2, 3 and 4 drugs. Pharmacies are probably not overwhelmed with prescriptions for Epidyolex, but the move to Schedule 5 will mean that prescribers can increase the quantity of Epidyolex supplied through one prescription. This rescheduling has the potential to reduce the frequency of dispensing and have a knock-on decline in pharmacy revenue.
One of the more significant implications may be that the prescriptions can now be signed by prescribers based in the European Economic Area (EEA) and Switzerland. Will this open the floodgates to distance-selling pharmacies with prescribing arrangements overseas?
Epidyolex controls: risk of harm or public policy?
The main constituent of Epidyolex – CBD – is not a controlled substance, Home Office guidance says. The World Health Organisation’s 2017 report on CBD concluded that “in humans, CBD exhibits no effects indicative of any abuse or dependence potential”. Indeed, in its letter the ACMD concluded that “Epidyolex…has a low risk of abuse potential, low risk of dependency and low risk of diversion”.
The purpose behind the Misuse of Drugs Act 1971 was to put controls on dangerous drugs. Although all new medicines require scrutiny, from the comments made by the ACMD there appears to be no indication that Epidyolex is dangerous or otherwise harmful to the extent that it requires heightened legislative control.
Looking at the numbers, it is the level of the THC in Epidyolex that brings it under the controlled drug regime. The ACMD criteria for Epidyolex’s rescheduling limits the THC content to no more than 0.1 milligram per millilitre. It is interesting to note that this level of THC is close to the regulatory definition of a product that is exempt from prohibitions on import, export and prohibitions.
The regulations state that to be a product that is exempt from these controls, among other things, the amount of a controlled substance must be no more than 1 milligram per millilitre in each product or preparation. Home Office guidance clarifies that the interpretation of “product or preparation” should be taken to mean the exemption is per container and not per dose.
This is, of course, a sensitive subject. Not only is the CBD industry huge, but professional reputations are on the line. A former chair of the ACMD, Professor David Nutt, was asked to resign for his outspoken comments on the harm caused by some controlled drugs. It is now notable that there is no suggestion from the ACMD that Epidyolex should be further outside the Schedule 5 controls.
It may be that in this difficult area it is more important to be consistent from a political and public policy point of view than from a legal point of view.
Susan Hunneyball is consultant solicitor at Gordons Partnership law firm