There is good evidence in robust human clinical trials that CBD is of benefit for specific epilepsies, such as Dravet syndrome and Lennox Gastaut syndrome. An advantage for the pharmaceutical industry is that these rare diseases with no cure can be fast-tracked for drug development. On this basis, the US Food and Drug Administration is widely expected to grant a licence for CBD (under the tradename Epidiolex) to treat these epilepsies. If so, Epidiolex is likely to be available in US by late 2018. European approval is likely to follow.
Anecdotal evidence suggests that cannabis oil may help some of these people control their seizures and potentially save their lives. A small number of studies have shown that adding cannabis oil to existing medication may be effective in devastating, hard-to-treat epilepsy in children and adolescents.
Epilepsy drugs don’t work well, or at all, for about one-third of people with the condition. Unfortunately, these hard-to-treat epilepsies are associated with an increased risk of premature death.
I have been approached by Dragonfly Biosciences who produce and market cannabidiol (CBD) to sit on their Advisory Panel. I do not receive funding from Dragonfly Biosciences, but would be paid a consultancy fee if I join the Advisory Boorad. My scientific publication support the use of non-THC cannabidinoids, as reflected in this article. I have previously received funding from GW Pharmaceuticals, but I am currently not in receipt of such funding.
One of those people is 12-year-old Billy Caldwell. Billy was in the news recently after the cannabis oil prescribed for him was confiscated at Heathrow airport by the authorities. Billy’s mother, Charlotte, was attempting to bring the cannabis oil into the UK from Canada, where cannabis oil is legal.
Billy was seizure-free for more than 250 days when taking the oil, but his seizures started again when his cannabis oil was withdrawn. The home secretary, Sajid Javid, was persuaded to intervene and one of the seven bottles of cannabis oil was returned, with a 20-day licence to administer the medicine.
In [animal studies], THC has weak overall effects in reducing seizures and has also been shown to be a less effective anticonvulsant than CBD. THC, being a psychoactive substance, also has a number of side effects, including the well-known euphoric “high” associated with recreational use – which is a significant disincentive for the pharmaceutical industry to develop a medicine containing this compound.
A 2017 study published in JAMA found that 26 percent of products purchased online contained less CBD than their labels claimed.
A multitude of CBD-containing products are on the market, and some people have chosen to use them for seizure control. This trend is likely to grow, especially since the 2018 Farm Bill made hemp-derived products, including CBD, legal at the federal level.
CBD itself does not have abuse potential and does not produce the “high” that is typical of marijuana, so you do not need to worry about your child abusing the drug or becoming addicted to it. However, it is possible that others may misunderstand the effects of the drug, particularly because it is new and because it is derived from the same plant that marijuana is derived from.
In the aforementioned 2019 review of studies on this drug, however, researchers found that while adding Epidiolex to a treatment regimen may increase certain specific side effects, it may actually decrease the overall amount of side effects participants experienced.
At this time, cannabidiol has been proven effective for only a few medical conditions. Due to the side effects, it is recommended to be used with caution.
Seizures are caused by erratic electrical activity in the brain that can spread and cause uncontrolled physical movements and/or alterations of consciousness. Most anti-seizure drugs work by slowing down excitatory nerve activity in the brain.
Prescription CBD is specifically recommended for control of seizures in LGS and Dravet syndrome.
Three double blind randomised controlled trials of pure CBD in children and young people with these syndromes has shown a greater reduction in monthly seizures compared to placebos. There was also a greater reduction in drop seizures in people taking CBD compared to those on a placebo. Further open label studies have shown that it may also have an anti-epileptic effect in the epilepsies in general.
“Is or contains cannabis, cannabis resin, cannabinol or a cannabinol derivative; is produced for medicinal use in humans and is a medicinal product, or a substance or preparation for use as an ingredient of, or in the production of an ingredient of, a medicinal product”.
The reason that the BPNA is only recommending CBD is that there is some evidence to show that this newly developed drug can be effective in reducing some type of seizures in Dravet and Lennox Gastaut syndromes.
What is the evidence?
Dosing data for adults is currently very limited, although more information is expected shortly.
The body also has concerns about the ‘viability of the economic model’ used by GW Pharma, the company that developed the drug, to establish the cost to be charged to the NHS for it. It concluded that Epidyolex would not, at this stage, be an effective use of NHS resources.
THC is the psychoactive compound in cannabis. It is responsible for the “high” people feel. The legal limit of THC content in a product, as stipulated by the Home Office, is 0.2%.
On 1 November 2018, the Government's landmark decision to reschedule some cannabis based products for medicinal use, came into force. The change in law means that specialist doctors in the UK can now prescribe medicinal cannabis to people with a limited number of conditions, including epilepsy. Here we explain what the change in law means for people with epilepsy.