Does cannabis help seizures?
Early evidence from laboratory studies, anecdotal reports, and small clinical studies over a number of years suggest that cannabidiol (CBD) could potentially help control seizures. Research on CBD has been hard to do and taken time due to federal regulations and limited access to cannabidiol. There are also many financial and time constraints. In recent years, a number of studies have shown the benefit of specific plant-based CBD product in treating specific groups of people with epilepsy who have not responded to traditional therapies.
What studies exist to support the use of CBD in epilepsy?
Epidiolex (Cannabidiol, CBD)
Studies in the U.S. of Epidiolex (a plant-based CBD formulation) have been ongoing for a number of years. Data from these studies has helped provide evidence that led to the FDA approval of this product on June 25, 2018.
Epidiolex is a purified (> 98% oil-based) CBD extract from the cannabis plant. It is produced by Greenwich Biosciences (the U.S. based company of GW Pharmaceuticals) to give known and consistent amounts in each dose.
Researchers studied this medicine in controlled clinical trials. These studies used a control group with some people taking a placebo while others were given CBD at different doses. Researchers did not know who was getting the placebo and who was getting CBD. These tpyes of studies are called “gold standard” studies.
A summary of the Epidiolex clinical trials is found below:
- In controlled and uncontrolled trials in people with Lennox-Gastaut syndrome (LGS) and Dravet syndrome, 689 people were treated with Epidiolex (CBD), including 533 people treated for more than 6 months and 391 people treated for more than 1 year.
- In an expanded access program and other compassionate use programs, 161 people with Dravet syndrome and LGS were treated with Epidiolex, including 109 people treated for more than 6 months.
- All study participants were taking other seizure medications.
- In controlled trials, the rate of stopping the medicine due to any side effect was small and happened most in people taking the higher dose of Epidiolex.
- The most frequent cause of stopping treatment with Epidiolex was a change in liver function.
- Sleepiness, sedation, and lethargy led to stopping Epidiolex in 3% of people taking the higher dose.
- The most common side effects were sleepiness, decreased appetite, diarrhea, change in liver function, fatigue, malaise, asthenia (weakness or lack of energy), rash, insomnia, sleep disorder, poor quality sleep, and infections.
Summarized below are the results from a study published in the New England Journal of Medicine in May 2018.
- Randomized double-blind, placebo-controlled trial (gold standard) was done at 30 clinical centers.
- People with LGS (age range 2 to 55 years) who had had two or more drop (atonic) seizures each week during a 28-day baseline period were included. They were randomly selected to receive CBD oral solution at a dose of either 20 milligram per kilogram of body weight (20-mg cannabidiol group) or 10 milligram per kilogram of body weight (10-mg cannabidiol group) or matching placebo.
- A total of 225 people were enrolled in the 3 groups:
- 76 people were assigned to the 20-mg CBD group
- 73 to the 10-mg CBD group
- 76 to the placebo (no CBD) group
- CBD was given to people twice a day for 14 weeks.
- The researchers measured the percentage of change in drop seizures from baseline.
- During the 28-day baseline period, the average number of drop seizures was 85 in all 3 groups combined.
- During the treatment period, drop seizures decreased from baseline by:
- 41.9% in the 20-mg CBD group
- 37.2% in the 10-mg CBD group
- 17.2% in the placebo group
- The most common side effects in people taking cannabidiol were sleepiness, decreased appetite, and diarrhea. These happened more often in people taking the higher dose of CBD.
- Only 6 people in the 20-mg CBD group and 1 person in the 10-mg CBD group stopped the study because of side effects.
- 14 people who received CBD had an increase in a test of liver function. Many of these children were on valproic acid too.