Could Marijuana Chemical Help Ease Epilepsy?
Early research suggests yes, but laws limit access to the drug and its compounds
"When you look at the combined weight of the animal data, it appears that cannabidiol appears to have 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 childhood-onset 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.
But the results may be marred by the fact that this was an open-label trial, in which both the researchers and the patients knew what drug was being administered, Friedman added. As a result, people may have experienced some improvement just because they expected the drug to produce positive results.
There are also some concerns regarding marijuana's effect on the developing brain. Studies involving recreational users have shown that pot can alter the structure of the brain in young people, the authors said.
On the other hand, severe epilepsy itself can affect brain development, and researchers suspect some of the approved anti-seizure medications may also affect the brain, Friedman 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.