Epidiolex (cannabidiol)
An approved treatment for Dravet Syndrome.
The same compound appears under different names depending on the context. Here is how to identify Cannabidiol wherever you encounter it, plus the key facts at a glance.
- Generic name
- Cannabidiol
- Brand name
- Epidiolex
- Development code
- GWP42003
- Drug class
- Cannabinoid anticonvulsant
- Manufacturer
- Jazz Pharmaceuticals (originally GW Pharmaceuticals)
- How it's taken
- Taken by mouth as an oral solution (100 mg/mL), twice daily.
The first FDA-approved prescription medicine with a purified ingredient derived from the Cannabis sativa plant. Reduces seizure frequency in Dravet syndrome through multiple brain pathways without causing a psychoactive high.
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Where Cannabidiol fits
Add-on anti-seizure therapy for Dravet syndrome alongside other epilepsy medications. Also approved for Lennox-Gastaut syndrome and tuberous sclerosis complex seizures.
How Cannabidiol works
The FDA label says the exact way cannabidiol (CBD) prevents seizures is unknown, and that it does not appear to work through the brain's cannabinoid receptors. Researchers are studying several other pathways that may calm overactive brain cells. Unlike THC, it does not produce a high.
Mechanism: Plant-derived cannabinoid with multiple proposed mechanisms including GABA enhancement, glutamate reduction, and modulation of endocannabinoid signaling
Side effects and safety
Common side effects include sleepiness, fatigue, decreased appetite, diarrhea, rash, and sleep disturbances. A serious risk is liver enzyme elevation (ALT increases above 3 times the upper limit of normal in 13% of patients with Lennox-Gastaut or Dravet syndrome in controlled trials), requiring regular blood tests. Risk is higher in patients also taking valproate. Increased sedation may occur when taken with clobazam. Like other seizure medicines, it can raise the risk of suicidal thoughts or actions, so report any new or worsening mood changes right away. The label also warns about allergic reactions (get medical help right away) and says it should not be stopped suddenly, since that can bring on more seizures.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Cannabidiol
Taken by mouth as an oral solution (100 mg/mL), twice daily. Starting dose is 2.5 mg/kg twice daily, increased weekly to a typical maintenance dose of 5 mg/kg twice daily (up to 10 mg/kg twice daily maximum). Can be given through a nasogastric or G-tube.
Availability and cost
Only available as the brand-name product.
Pharmaceutical-grade cannabidiol requiring extensive purification and quality control. Approved for multiple rare epilepsies (Dravet, Lennox-Gastaut, tuberous sclerosis complex).
Help paying for Epidiolex
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
Eligible commercially insured patients may pay as little as $0 per prescription; monthly or annual limits may apply. No enrollment needed; the pharmacy checks eligibility.
For: private insurance · source - Bridge or quick-start supply
Quick Start Program: up to 60 days of EPIDIOLEX for eligible patients waiting on insurance coverage.
The official page does not say who qualifies. Ask the program. · source - Free medicine program
Patients who are uninsured or whose insurance does not cover EPIDIOLEX may get it free through the Patient Assistance Program.
For: no insurance, underinsured · source - Insurance and case manager help
Nurse Navigators help with starting treatment, dosing questions and side effects, and insurance and financial assistance options.
The official page does not say who qualifies. Ask the program. · source
Good to know: Copay program excludes Medicare Part D, Medicaid, Medigap, VA/DoD/TRICARE and IHS. Mon-Fri 8 AM-8 PM ET.
- From a charity · Dravet Syndrome FoundationPatient Assistance Grant (PAG) Program fundOpen
Pays for: Medical equipment, therapy devices and educational aids, up to $1,500 per year.
The foundation says: “Our grant application period runs from January 1st – November 30th each year. We cannot accept applications during the month of December.”
Clinical trial results
Two Phase 3 trials (GWPCARE1 and GWPCARE2) in 319 Dravet patients aged 2-18 showed cannabidiol significantly reduced seizure frequency compared to placebo over 14-15 weeks. Effects were sustained in long-term extension studies. Also approved for Lennox-Gastaut syndrome and tuberous sclerosis complex.
Development history
Developed by GW Pharmaceuticals (now part of Jazz Pharmaceuticals), Epidiolex was the first plant-derived cannabinoid medicine approved by the FDA in June 2018. It transformed the regulatory landscape for cannabis-derived medicines and is now one of the standard treatments for Dravet syndrome.
Explore Dravet Syndrome trials
Other Dravet Syndrome treatments
Common questions about Cannabidiol
▸What is Cannabidiol (Epidiolex)?
The first FDA-approved prescription medicine with a purified ingredient derived from the Cannabis sativa plant. Reduces seizure frequency in Dravet syndrome through multiple brain pathways without causing a psychoactive high.
▸How does Cannabidiol work?
The FDA label says the exact way cannabidiol (CBD) prevents seizures is unknown, and that it does not appear to work through the brain's cannabinoid receptors. Researchers are studying several other pathways that may calm overactive brain cells. Unlike THC, it does not produce a high.
▸What are the side effects of Cannabidiol?
Common side effects include sleepiness, fatigue, decreased appetite, diarrhea, rash, and sleep disturbances. A serious risk is liver enzyme elevation (ALT increases above 3 times the upper limit of normal in 13% of patients with Lennox-Gastaut or Dravet syndrome in controlled trials), requiring regular blood tests. Risk is higher in patients also taking valproate. Increased sedation may occur when taken with clobazam. Like other seizure medicines, it can raise the risk of suicidal thoughts or actions, so report any new or worsening mood changes right away. The label also warns about allergic reactions (get medical help right away) and says it should not be stopped suddenly, since that can bring on more seizures.
▸How is Cannabidiol taken?
Taken by mouth as an oral solution (100 mg/mL), twice daily. Starting dose is 2.5 mg/kg twice daily, increased weekly to a typical maintenance dose of 5 mg/kg twice daily (up to 10 mg/kg twice daily maximum). Can be given through a nasogastric or G-tube.
▸Is Cannabidiol FDA approved?
Yes, Cannabidiol (Epidiolex) is FDA approved (2018) for the treatment of Dravet Syndrome.
▸Is Epidiolex the same as CBD oil I can buy online?
No. Epidiolex is a pharmaceutical-grade, FDA-approved prescription medication with precisely controlled CBD concentration (100 mg/mL). Over-the-counter CBD products are unregulated, may contain variable amounts of CBD, could include THC or contaminants, and have not been tested in clinical trials for seizure disorders. The purity, consistency, and dosing of Epidiolex cannot be replicated with store-bought CBD products, and substituting them for Epidiolex is not recommended.
▸Does Epidiolex cause a high or psychoactive effects?
No. Cannabidiol (CBD) is a non-psychoactive component of the cannabis plant. Epidiolex contains no THC (tetrahydrocannabinol), which is the compound responsible for the high associated with marijuana. Epidiolex will not produce euphoria, altered consciousness, or impairment. It was specifically developed to provide the anti-seizure benefits of CBD without psychoactive effects.
▸Can Epidiolex interact with other seizure medications?
Yes. Cannabidiol raises blood levels of the active breakdown product of clobazam (commonly used in Dravet syndrome) about 3 times, which may lead to more sleepiness. It can also raise levels of stiripentol and some other medicines broken down by liver enzymes. When Epidiolex is combined with valproate, the risk of liver enzyme elevation increases significantly. Your neurologist will monitor drug levels and liver function and may need to adjust doses of other medications.
▸Is Epidiolex approved for conditions other than Dravet syndrome?
Yes. Epidiolex is also FDA-approved for seizures associated with Lennox-Gastaut syndrome and tuberous sclerosis complex. All 3 uses are approved for patients 1 year of age and older. These approvals mean Epidiolex has the broadest indication of the three Dravet-approved therapies, and physicians may have experience with it from treating other epilepsy syndromes.
▸How long does it take for Epidiolex to start working?
In clinical trials, seizure reduction was typically observed within the first few weeks of reaching the maintenance dose. The dose is gradually increased over the first 1-2 weeks to reach the target range (5-10 mg/kg twice daily). Some patients see improvement during the titration phase, while others may take longer to respond. Your neurologist will assess effectiveness over several months before making treatment decisions.