In a group of children and young adults with the most intractable forms of epilepsy, a liquid form of marijuana called cannabidiol reduced seizures by more than 50% without causing the drug's usual "high," researchers said.
In an open-label study that enrolled 213 people with a dozen types of severe epilepsy, researchers found that cannabidiol, which is taken by mouth, was relatively well tolerated. In all, 12 subjects, or 6%, ceased taking the drug, also known as CBD, because of side effects, which included drowsiness, tiredness, diarrhea and decreased appetite. In a open-label study, patients and researchers know what drug is being tested.
Among the side effects missing from the medicinal extract of marijuana is the buzz that has made marijuana a popular recreational drug for centuries. CBD accounts for as much as 40% of the marijuana plant but does not impart a buzz.
Over 12 weeks, patients who suffered from Dravet syndrome and Lennox-Gastaut syndrome, which can cause lifelong seizures that lead to intellectual impairments, saw 53% and 55% reductions in seizures.
Dr. Orrin Devinsky of New York University's Langone Medical Center, the senior author of the preliminary study, said it was one of the first formal studies of CBD, and a hopeful development for children with severe, debilitating seizures, who have few effective options.
Devinsky, who will present his findings next week at the American Academy of Neurology's annual meeting, said that the early finding needs to be tested further in double-blind, placebo-controlled studies with a larger population of participants.
CBD is one of at least 85 cannabinoids that have been identified in the marijuana plant and is being investigated as a treatment for a wide range of disorders of the brain, including Alzheimer's disease and schizophrenia. The Food and Drug Administration has granted Epidiolex, made by the British firm GWPharma, orphan drug status as a treatment for Dravet syndrome, indicating that it could be available to patients on a fast-track basis.
The subjects in this preliminary study range in age from toddlers to adults, but the median age was 11. All had severe epilepsy that did not respond to other treatments.