Study Finds Cannabidiol Reduced Seizures in Young Adults

While discussions swirl around the largely untested benefits of medical marijuana and state-by-state policies, one medication derived from the marijuana plant is on its own trajectory. Now in a third published study of patients with rare seizure disorders, Epidiolex, a pure cannabidiol (CBD) oral solution with no THC, has been found to significantly reduce the frequency of drop seizures, a type of seizure that causes sudden loss of muscle strength.

Published in this week’s New England Journal of Medicine, the study comes less than a month after the drug unanimously passed a Food and Drug Administration advisory panel. 

The multi-center trial, which included the University of Cincinnati (UC) Medical Center, looked at the effectiveness of two dose levels of pure cannabidiol in reducing the frequency of drop seizures in patients who have Lennox-Gastaut syndrome (LGS)–a severe, yet rare form of epilepsy with an incidence of approximately two cases per 100,000 population.

"This trial involving children and adults with LGS showed that a pharmaceutical formulation of purified cannabidiol, resulted in a significantly greater reduction in the frequency of drop seizures than in placebo,” says Michael Privitera, MD, professor of neurology, director of the Epilepsy Center at the UC Gardner Neuroscience Institute and a co-author on the study.

In study participants, the average (median) seizure frequency dropped by 41.9 percent in the group that received 20 mg of cannabidiol and a 37.2 percent drop in seizure frequency in the group receiving 10 mg (compared to placebo results at just 17 percent).

A total of 225 patients (12 in Cincinnati) participated across 30 centers in the randomized, double-blind, placebo controlled trial; overall, 6 percent (13 patients) discontinued due to adverse events.

The most common adverse events cited among patients was drowsiness/sleepiness, decreased appetite and diarrhea. Abnormal liver function tests were seen in 9 percent of participants but were reversible in all cases. 

Privitera, who has been researching anti-seizure medication for 30 years, says this is a historic study. "The field has been waiting for rigorous, scientific evidence that cannabidiol is effective and safe for epilepsy,” he adds. "This study puts those doubts to rest.”

If the FDA follows the advisory panel’s recommendation, Epidiolex would be the first cannabis-derived prescription medicine available in the U.S. There are drugs on the market made from synthetic versions of THC or other compounds found in the plant.

The trial was funded by GW Pharmaceuticals, manufacturer of Epidiolex. Privitera cites no conflicts of interest.

You can read more about how the trial has impacted one family here: