Cannabidiol almost halves seizure frequency in children with Dravet syndrome, according to a new study.

During the phase 3 study, 199 children with drug-resistant Dravet syndrome received 10 or 20mg/kg highly purified cannabidiol or placebo added to a median of three other anticonvulsants for 14 weeks. The mean age of the children was nine years.

The study reported that 10 and 20mg/kg cannabidiol reduced the frequency of convulsive seizures by 49 and 46 per cent respectively compared with the four-week baseline. This was statistically significant compared with the 27 per cent reduction in those taking placebo.

Cannabidiol increased the proportion of patients showing at least a halving in seizure frequency (44 and 49 per cent with 10 and 20mg/kg respectively compared with 26 per cent in the placebo group) and significantly improved total seizure frequency with reductions of 56, 47 and 30 per cent respectively.