A chemical found in marijuana might help prevent epilepsy seizures, but drug laws have hampered research efforts, a new study says.
Cannabidiol is one of the main active chemical compounds found in pot. But it doesn’t make people high, the study authors said. Cannabidiol has already been shown to prevent seizures in animal studies and in one ongoing human trial, said lead author Dr. Daniel Friedman, a neurologist and epilepsy specialist at NYU Langone Medical Center in New York City.
Epilepsy Foundation President and CEO Phil Gattone said the review highlights how current federal laws have limited our understanding of marijuana’s potential effectiveness as an anti-seizure medication.
“Friedman and [co-author Dr. Orrin] Devinsky point out that while we don’t know all of the long-term and short-term side effects of using cannabis and cannabidiol, we do know the impact of uncontrolled epilepsy, and that must be considered when looking at the use of cannabis,” Gattone said.
About 30 percent of people with epilepsy continue to have uncontrolled seizures, even though there are more than 20 different anti-seizure drugs currently on the market, the authors said.
In their review of the current evidence, the researchers explained a major brain receptor that responds to marijuana—cannabinoid receptor 1, or CB1—has anti-seizure effects when activated.
“When you look at the combined weight of the animal data, it appears that cannabidiol has the most consistent anti-seizure effect,” Friedman said, adding that the anti-seizure effects of cannabidiol are not fully understood.
One ongoing human trial involving Epidiolex, a British-made cannabis extract that’s 99 percent cannabidiol, has shown that the chemical can be effective in humans, he said.
In the trial, several institutions in the United States received compassionate use waivers from the U.S. Food and Drug Administration to give the medication to people with severe epilepsy who haven’t responded to available medical therapy, Friedman said.
About two out of every five patients with severe treatment-resistant epilepsy experienced a 50 percent reduction in the frequency of their major seizures, he said.
“A handful of these children and young adults with epilepsy who have never had prolonged periods of seizure freedom did actually become seizure-free, at least in the short-term of this study,” Friedman said.
Based on these results, at least three companies are developing cannabidiol-based drugs, and trials are either underway or set to start soon, he said.
“Until we get more long-term safety data, there will have to be a risk-benefit calculation made by the physician and the parents,” he said.
In testimony before Congress this June, the director of the U.S. National Institute on Drug Abuse said that her agency will support future cannabidiol (CBD) research.
“There is significant preliminary research supporting the potential therapeutic value of CBD, and while it is not yet sufficient to support drug approval, it highlights the need for rigorous clinical research in this area. Dr. Nathan Fountain, chair of the Epilepsy Foundation Professional Advisory Board, said he hopes the upcoming clinical trials will resolve these questions.
Journal reference: New England Journal of Medicine