I am reliably informed that cannabis has been around since ancient times, probably as early as 4000 BC in China. I obviously cannot confirm this since I wasn’t there. Even if had been, just like the 1960s, I wouldn’t be expected to remember the actual events. Irrespective of the historical facts, cannabis is currently being decriminalised, legalised and even medicalised. This warrants a closer look at cannabis and its purported medicinal properties.
The hemp plant (Cannabis sativa) has been variously processed and used as either the dried chopped leaves, the dried compressed resinous sap from the leaves and stems, or as cannabis oil- the product of evaporation of the filtered resin after it has been dissolved in a commercial solvent. Each variant has a number of colloquial names, some in widespread usage. Cannabis is usually smoked in roll-up cigarettes (joints), pipes, hollowed stones, or single- or multi-stemmed water-cooled hookahs. Many inventive uses for the leaves and resin can be found closest to home in the “coffee shops” of Amsterdam.
Cannabis is the source of at least 144 cannabinoids, as well as flavonoids, terpenes, and other chemical substances. The cannabinoids include delta-9-tetrahydrocannabinol (THC) and cannabiodol (CBD). THC is responsible for the psychoactive properties of cannabis. High concentrations of THC are found in some high-strength street varieties of cannabis which have emerged in the face of criminalisation of cannabis use, including so-called “skunk,” which contain very little protective CBD. The use of skunk increases the risk of dependence and psychosis in users. CBD, on the other hand, is relatively well tolerated and antagonises some of the effects of THC. The cannabinoids act on cannabinoid receptors, which form part of the endocannabinoid system in the human body. This important regulatory system modulates mood, memory, appetite, sleep, pain, and muscle tone, explaining some of the potential medical benefits of treatment with CBD
From November 1, 2018 onwards, cannabis was moved from the Schedule 1 to Schedule 2 of the UK Misuse of Drugs Act of 1971, thereby relaxing restrictions on use. Two products are licensed for medical use in the UK: nabiximols (Sativex), a 1:1 mixture of THC and CBD-for the treatment of spasticity in multiple sclerosis, and nabilone (Cesamet), a synthetic cannabinoid that mimics THC-for nausea and vomiting caused by anti-cancer drug treatment that has not responded to the usual treatments. Epidiolex, a pure form of CBD, has been approved by the FDA in the US for the treatment of severe forms of certain rare forms of childhood epilepsy-Lennox-Gastaut and Dravet syndromes, that are resistant to standard treatments.
Medical cannabis has yet to take off in the UK, as prescription is limited to specialists and GPs acting on specialist advice. In addition, NICE (National Institute for Health and Care Excellence) released draft guidance for consultation in August 2019, only recommending nabilone as an add-on treatment for nausea and vomiting caused by cancer chemotherapy. NICE did not recommend the use of nabiximols, as it was not found to be cost-effective, nor of Epidiolex for treatment-resistant epilepsy in the absence of supporting evidence.
Cannabis is widely used for its recreational properties-the so-called “high”- which include a sensation of well being and relaxation, along with distorted time and perception, and intensified sensory experiences. Attention and short-term memory are frequently impaired, and symptoms such as a dry mouth and dizziness may be reported. In some people, anxiety, panic reactions, paranoia, hallucinations and even psychosis may result.
The decriminalisation and legalisation of cannabis use have taken off, but the case for medicinal cannabis use is still being made. High-profile cases of people who have benefited from cannabis treatment, such as that of Billy Caldwell-who suffers from Dravet syndrome- in 2018 have led to campaigns for making medical cannabis more readily available. Given the paucity of recognised indications for this form of treatment and a lack of evidence for the benefits, this is likely to be an uphill struggle. For people who have demonstrably benefited from treatment for cannabis, the barriers to prescription should be lowered.
Ashis Banerjee (ex-NHS)