And while it is different, some accounts from users have claimed to find similar benefits from using cannabis oil, though this has never been scientifically backed by doctors, so is not advised as an alternative to other treatments.
Campaigners have welcomed the go-ahead but said thousands of other people who could benefit from cannabis-based medicines were left in limbo.
Cannabis oil can be beneficial in a variety of ways, from helping promote sleep to boosting appetite and reducing stress, anxiety and depression.
What is cannabis oil used for?
Though research is limited, there is evidence to support the idea that medical marijuana, which contains small amounts of the illegal compound THC, can alleviate some of the side-effects of cancer treatment including nausea during chemotherapy.
However, many have been reluctant to do so, citing a lack of guidance and costing concerns.
One type of oil or Cannabidol is CBD which has been promoted as a possible treatment method for those living with addiction or anxiety.
Millie Hinton, from the group End Our Pain, said it had been “a massive missed opportunity”.
CBD is an anticonvulsant, and some other compounds in the plant, including THC and cannabidivarin, may be too. There is good evidence from clinical trials in the US and Europe that pharmaceutical preparations of CBD can treat two severe forms of childhood epilepsy known as Dravet syndrome and Lennox-Gastaut syndrome. Both forms of epilepsy often fail to improve with existing epilepsy drugs. CBD is generally considered safe, but some trials have reported side effects including dry mouth, lightheadedness and altered liver enzyme activity.
Cannabis oils are extracts from cannabis plants. Unprocessed, they contain the same 100 or so active ingredients as the plants, but the balance of compounds depends on the specific plants the oil comes from. The two main active substances in cannabis plants are cannabidiol, or CBD, and delta-9 tetrahydrocannabinol, or THC. Oil extracted from hemp plants can contain a lot of CBD, while oil from skunk plants will contain far more THC. THC produces the high that recreational cannabis users seek, while oils for medical use contain mostly CBD.
Does it work as a medicine?
Cannabis oil can only be sold legally in Britain if it contains less than 0.05% THC. But the nation’s medicines regulator, the MHRA, announced recently that even pure CBD could not be sold as a medicine without first going through the usual clinical testing and safety checks required for all new medicines. This month, the US Food and Drug Administration will consider the approval of Epidiolex, a CBD-based medicine from GW Pharmaceuticals, which has completed such clinical trials. The European Medicines Agency (EMA) will rule on the drug early next year. If the EMA approves Epidiolex, it could be available to prescribe to named patients in Britain next year, Brexit notwithstanding.
Four drugs based on cannabis compounds are already on the market in Europe. Among them are Nabilone, a synthetic compound that mimics THC, is prescribed for nausea and vomiting caused by chemotherapy, and Sativex, an oil that contains equal parts THC and CBD, is used to treat muscle spasms in multiple sclerosis. Both contain too much THC to administer to children. “The only medicines that are approved in the UK would get children stoned,” said David Nutt, professor of neuropsychopharmacology at Imperial College, London.
Other forms of cannabis are solid and are usually sold either as resin or dried plant material. In commercially-produced medical cannabis oils, the concentrations of CBD and THC tend to be well-controlled, which makes it easy to calculate doses.
What is the evidence that cannabis oils can help treat epilepsy?
Cannabis oil is extracted from the cannabis plant Cannabis sativa. The plants medicinal properties have been touted for more than 3,000 years. It was described in the ancient Eygyptian Ebers papyrus around 1550BC, and it was likely used as a medicine in China before that. Some varieties of the plant contain high levels of the psychoactive substance tetrahydrocannabinol (THC), which is responsible for the “high” that comes from smoking or eating cannabis leaves or resin. The plant’s other major chemical component is cannabidiol, which has no psychoactive effect. Both act on the body’s natural cannabinoid receptors which are involved in many processes such as memory, pain and appetite. The cannabis plant also contains more than 100 other different cannabinoid compounds at lower concentrations.
The first part of the review will look at the evidence for the therapeutic value of cannabis-based products. It can recommend any promising ones for the second part of the review. This will be carried out by the government’s Advisory Council for the Misuse of Drugs, which can recommend a change to the legal medical status of cannabis and cannabinoids.
However, it is possible the drug is not as effective as cannabis oil containing THC, says Nutt. For example, the cannabis oil used to treat Billy Caldwell, the boy at the centre of the recent cannabis oil confiscation furore, contained cannabidiol and a low dose of THC, because cannabidiol alone did not stop all his seizures.
The situation is less clear when it comes to the use of commercial cannabis oils to control seizures, where the evidence is mainly anecdotal, and the oils can contain differing concentrations of cannabidiol and THC.