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 types 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.