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7 September 2015

Will cannabis help in treating epilepsy?

The latest trials of cannabis in the treatment of children with epilepsy suggest a pure form of the drug may be of benefit. But Professor Helen Cross of Great Ormond Street Hospital, London, stressed that the benefit may be no greater than that of one of the new, standard anti-epileptic drugs.

Speaking at the 31st International Epilepsy Congress in Istanbul, she said there was a lot of interest in the use of cannabis in treating seizures but that more tests were needed to evaluate the safety and efficacy of the drug. ‘We have to be particularly concerned about the effects of the drug on the developing brain in children,’ she said.


Professor Cross is the chief UK clinical investigator in the first UK trials of cannnabidiol, a component of cannabis which does not contain the psychoactive component THC.

The drug has been developed as Epidiolex by the UK company GW Pharmaceuticals and early studies have already shown it has the potential to reduce seizure frequency and severity.

Trials involving 137 patients  in the States were reported earlier this year. At the end of a 12 week period, nine per cent of all patients  on Epidiolex were seizure free. In the specific group with Dravet syndrome, the number who were seizure free was 16 per cent.

Across the whole group, the number of seizures decreased by an average of 54 per cent. A total of 12 people stopped taking the drug due to side effects. The side effects that occurred in more than 10 per cent of participants included drowsiness, diarrhoea and loss of appetite.

Cannabis trial in UK

The randomised control study in the UK is being carried out at Great Ormond Street Hospital and the University of Edinburgh Muir Maxwell Epilepsy Centre. The Royal Hospital for Sick Children in Glasgow and Alder Hey Children’s Hospital in Liverpool are also involved.

Professor Cross  continued: ‘It is vital that we carry out further long-term safety tests into cannabidiol so that we can ensure its tolerability, sustainability and efficacy. I have been asked whether cannabis is a miracle or a fairytale. It is neither.’