Cannabidiol Shows Some Success in Reducing Epileptic Seizures

Some parents of children with severe epilepsy have moved their families to Colorado to get access to legal marijuana, their relocation decisions made on the basis of anecdotal reports that cannabis can help. The science on whether cannabis works that way is struggling to keep up.

The use of marijuana for medical purposes has been a hot topic at the American Epilepsy Society 69^th Annual Meeting in Philadelphia, PA.

Two researchers said cannabidiol—a marijuana plant extract that does not have psychoactive effects—is showing promise in treatment-resistant forms of epilepsy in children. The product is still experimental and is in clincal trials in the US.

In one study of cannabidiol (Epidiolex/GW Pharmaceuticals) 261 people, mostly children, got the drug in gradually increasing doses in addition to existing anti-epileptics. The study was conducted at NYU Langone Medical Center’s Comprehensive Epilepsy Center in New York City. The lead investigator was Orrin Devinsky, MD.

On average these patients were taking three such antiseizure drugs before adding cannabidiol to their regimens.

The patients' seizures were tracked by families and caregivers, noting both those events that happened before the study and during the study. The researchers said that after three months of treatment, the number of seizures in these patients was reduced by a mean of 45%. Nine percent of patients were reported to be seizure-free.

There were adverse events, leading to discontinuation in 4% of patients. The study was promising in assessing safety and efficacy, but is not conclusive, Devinsky said. Randomized controlled studies are underway with results expected next year.

The same product was studied at the University of California San Francisco.

Pediatric patients (25 participants) took cannabidiol in addition to their usual drug regimen. After 12 months, said lead researcher Michael Oldham, MD, MPH, now at the University of Louisville, Louisville, KY, one patient was seizure-free, 12 patients discontinued the therapy because it did not work, and 10 patients saw a 50% reduction in seizures.

Oldham said the treatment shows promise as an add-on therapy in appropriate patients. Two other studies, both pre-clinical involving lab animals, were also presented.