Epileptic seizure frequency fell by 86% in children treated with whole-plant medicinal cannabis.
Further therapeutic benefits of whole plant products are now worth exploring, say researchers.
Epileptic seizure frequency fell by an average of 86% among ten children treated with whole-plant medicinal cannabis. None of the children had responded to other treatments, including the only cannabidiol (CBD) product licensed for their condition.
The findings prompt the researchers to call for further exploration of the potential therapeutic benefits of whole plant medicinal cannabis products.
Substantial anecdotal evidence on the value of medicinal cannabis for treating childhood epilepsies has been accumulating since the 1800s, say the researchers. But there's not been much recent scientific evidence on the effectiveness of whole-plant cannabis extracts.
Whole plant cannabis includes tetrahydrocannabinol (or THC for short), the plant's principal active ingredient responsible for the characteristic 'high' associated with recreational use, plus cannabidiol, other neuroactive cannabinoids, and molecules such as terpenes.
Both recreational and medical cannabis was made illegal in many countries, so cannabis research largely ceased, point out the researchers. But prompted by parents whose children had responded well to whole plant medicinal cannabis extracts, but not to conventional antiepileptic drugs or purified cannabidiol (CBD oil), medicinal (whole plant) cannabis was designated a prescription medicine for the treatment of severe childhood epilepsy in 2018. But some doctors have been highly reluctant to prescribe this to children with severe epilepsy, primarily because of the lack of confirmatory clinical trial data.
Researchers evaluated the use of whole plant medicinal cannabis in 10 children whose severe epilepsy hadn't responded to conventional treatment and two of whom hadn't responded to the only pharmaceutical grade, purified CBD oil licensed for the condition in children (Epidyolex).
The researchers wanted to assess the percentage change in monthly seizure frequency and the impact of medicinal cannabis on changes in conventional epilepsy drug use. They also wanted to report the strengths, doses used, and costs incurred.
All the participants were recruited from two charities representing children using medicinal cannabis to treat their severe epilepsy. The children's average age was six but ranged from 1 to 13 years. They had a range of epilepsies, and three had other concurrent issues, including infantile spasms, learning disabilities, and global developmental delay.
Data was collected from their parents or carers via phone or video conference calls between January and May 2021. The children had tried an average of 7 conventional epilepsy drugs. After taking medicinal cannabis, this fell to an average of 1 each, with seven of the children stopping them altogether. Monthly seizure frequency was reduced for all ten children by an overall average of 86%.
Complete chemical analysis of the whole plant medicinal cannabis products used is ongoing, but the researchers could assess the THC and CBD content. This showed that the children took an average of 5.15 mg THC and 171.8 mg CBD every day.
Parents and carers reported significant improvements in the health and wellbeing of their children, including in sleep, eating, behavior, and cognition, after they started to take the whole plant medicinal cannabis products. Only a few minor side effects, such as tiredness, were reported.
This is an observational study involving a small number of participants. And the researchers acknowledge that it was retrospective and relied on parental recall, with no comparator group. And it's possible that only those parents in whom medicinal cannabis worked well decided to take part.
But the researchers highlight that their findings align with several observational and controlled interventional studies showing significant reductions in seizure frequency after treatment with medicinal cannabis.
What's more, the new data suggest that whole-plant medicinal cannabis products are more effective than CBD products.
"Further research is required to elucidate the mechanisms by which the respective additive constituents of whole-plant products lead to superior clinical results," write the researchers. And this must include comparing the unwanted effects of whole plant medicinal cannabis with the known harmful effects of conventional epilepsy medicines, they say.
- Professor David Nutt BMJ