Article Info
More than 17 countries permit the medicinal use of cannabis, but the UK is not one of them. Cases of children with severe epilepsy who have seen benefit with cannabinoid derivatives from the cannabis plant but cannot access the medication have reignited the debate over medicinal cannabis. The UK’s legislative polices and intense bureaucracy over individual licensing are a source of inertia for clinicians and distress for patients. Part of the problem is the confusion between medicinal cannabis using the whole cannabis plant and cannabinoid derivatives, of which there are over 100. The most commonly studied cannabinoid is cannabidiol—a non-psychoactive derivative, which differs from the psychoactive cannabinoid Δ-9-tetrahydrocannabinol (THC). Cannabis oil usually contains a high ratio of cannabidiol to THC.
Humankind’s experience with cannabis has been long and relatively benign. Written evidence for medicinal uses of cannabis dates back to around 1700 BC. 3000 years later, William O’Shaughnessy studied the medicinal uses of Cannabis indica in the 1840s and the drug gained traction in modern medicine. The Lancet published a series of articles documenting the use of Indian hemp in conditions from dental operations to tetanus during this period. In the 1970s, preclinical epilepsy studies started exploring cannabinoids. Since 2015, one open-label study and two randomised controlled trials have shown a benefit of cannabidiol in treatment-resistant epilepsy and two complex forms of childhood epilepsy—Dravet and Lennox-Gastaut syndromes. In these three studies, adverse events were reported in 75–93% of participants. Conflicting legislature of psychoactive constituents and differing pharmaceutical formulations have made research into side-effects inconsistent. The evidence for cannabinoids in focal epilepsy, chronic pain, autism, and psychiatric disorders is preliminary and mixed.
Fundamentally, cannabinoids are like any other medication and should follow a regulatory pathway, based on clinical evidence, to licensing. In the interim, a risk balance approach is justified. In severe epilepsy, where a child might be on different medications with cognitive and physical side-effects and still having several seizures a day, cannabinoid derivatives should be available.
