A form of medicinal cannabis, cannabidiol, has significantly reduced convulsive seizures in a group of children with a severe form of epilepsy. Five per cent of children became seizure-free.
The international study, published in The New England Journal of Medicine, focused on Dravet syndrome, a severe form of epilepsy beginning in infancy that is associated with drug-resistant seizures and a high mortality.
An international team of researchers including University of Melbourne Chair of Paediatric Neurology and Austin Health Director of Paediatrics, Professor Ingrid Scheffer, studied cannabidiol for the treatment of their seizures.
Known as CBD, cannabidiol is a natural compound found in cannabis seeds, stalks and flowers. Studies have shown it does not have the psychoactive properties of THC.
Conducted for the Cannabidiol in Dravet Syndrome Study Group, the randomised, double-blind, placebo-controlled trial involved 120 children and young adults across the US and Europe. They received cannabidiol oral solution or a placebo, in addition to standard antiepileptic treatment.
Seizure frequency was measured over a 14-week treatment period. The median frequency of convulsive seizures per month decreased from 12.4 to 5.9 with cannabidiol, compared with a decrease from 14.9 to 14.1 with placebo.
The percentage of patients whose convulsive seizure frequency fell by at least 50 per cent was 43 per cent with cannabidiol and 27 per cent with placebo.
The patient’s overall condition improved by at least one category on the seven-category Caregiver Global Impression of Change scale in 62 per cent of the cannabidiol group, compared with 34 per cent of the placebo group.
The frequency of total seizures of all types was significantly reduced with cannabidiol, but there was no significant reduction in nonconvulsive seizures. Five per cent of patients taking cannabidiol became seizure-free, compared with none of the placebo group.
Side effects were more frequent in the cannabidiol group and included diarrhoea, vomiting, fatigue, increased body temperature, drowsiness and abnormal liver-function tests
Professor Scheffer welcomed the findings.
“I am delighted that we finally have high level evidence that cannabidiol is effective for uncontrolled seizures in Dravet syndrome,” she says.
“Until now, there has only been anecdotal evidence but now we have scientific evidence proving that cannabidiol is definitely effective in severe epilepsy.
“The next question is whether cannabidiol is effective in other forms of epilepsy and it is great that there are trials already underway of cannabidiol in other groups of patients with epilepsy.”