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.
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.
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.
Don’t we already have cannabis-based drugs?
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.
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.
Europe is a patchwork of cannabis legislation. In the Netherlands, doctors can prescribe cannabis and cannabis preparations for symptoms caused by multiple sclerosis, HIV/AIDS, cancer, long-term pain and the tics associated with Tourette’s syndrome. Other European nations are following suit. In the US, at least 29 states allow medical uses of cannabis, and earlier this year, California became the eighth state to permit recreational use of the drug, too.
In addition to treating epilepsy, research has shown CBD may help reduce anxiety for people who have schizophrenia or psychosis, or who are addicted to opiates.
Currently the Food and Drug Administration has only approved one CBD product, a prescription drug called Epidiolex to treat two rare forms of epilepsy. In July, the FDA expanded what the drug is approved to treat, saying it can also be used for seizures associated with tuberous sclerosis complex.
What does it do?
Most of the products claim to ease pain and anxiety. But whether or not these products actually contain the amount of CBD they advertise is up for debate, since they’re not approved by the FDA.
Interest continues to grow. Last year, the federal government pledged $3 billion to research CBD.
CBD is the abbreviation for cannabidiol, one of the many cannabinoids, or chemical compounds, found in marijuana and hemp.