Epidiolex reduced key seizures by 17-23% more than placebo in children with severe epilepsy
A clinical pharmacology review of Epidiolex (pure plant-derived CBD) found it reduced convulsive seizures in Dravet and drop seizures in Lennox-Gastaut by 17-23% over placebo, with important drug interactions with clobazam and valproate.
Quick Facts
What This Study Found
In the GWPCARE trial series, CBD reduced key seizure frequencies by 17-23% compared to placebo as adjunctive therapy in patients 2+ years old. Common adverse effects: somnolence, diarrhea, elevated liver enzymes. Important drug interactions with clobazam, valproates, and CYP2C19/3A4 inhibitors/inducers. This is the first cannabis-derived FDA-approved medication.
Key Numbers
Seizure reduction: 17-23% over placebo. Approved for patients 2+ years old. Key interactions: clobazam, valproates, CYP2C19 and CYP3A4 modulators. Adverse effects: somnolence, diarrhea, hepatic transaminase elevations.
How They Did This
Review of EMBASE and MEDLINE (1946-October 2018) plus product labeling and ClinicalTrials.gov for efficacy, safety, pharmacology, and pharmacokinetics of Epidiolex in Dravet and Lennox-Gastaut syndromes.
Why This Research Matters
This clinical pharmacy-focused review provides the practical dosing, monitoring, and interaction information clinicians need to safely prescribe CBD for epilepsy, going beyond efficacy to address real-world implementation.
The Bigger Picture
Epidiolex approval created a new category of prescription drug that requires clinicians to understand cannabinoid pharmacology. This review bridges the gap between the clinical trial data and day-to-day prescribing decisions.
What This Study Doesn't Tell Us
Approved for only two epilepsy syndromes. Long-term safety data still accumulating. Drug interactions complicate use in patients on multiple anti-epileptic drugs. Mechanism of action remains hypothesized, not confirmed.
Questions This Raises
- ?Will CBD gain approval for additional epilepsy syndromes?
- ?How should hepatic monitoring be optimized?
- ?Can drug interaction management be standardized?
Trust & Context
- Key Stat:
- 17-23% over placebo
- Evidence Grade:
- Rated strong because the review is based on Phase III GWPCARE RCTs that led to FDA approval.
- Study Age:
- Published in 2019, shortly after FDA approval of Epidiolex.
- Original Title:
- Cannabidiol: A New Hope for Patients With Dravet or Lennox-Gastaut Syndromes.
- Published In:
- The Annals of pharmacotherapy, 53(6), 603-611 (2019)
- Authors:
- Chen, Jeffrey W, Borgelt, Laura M(8), Blackmer, Allison B
- Database ID:
- RTHC-01980
Evidence Hierarchy
Summarizes existing research on a topic.
What do these levels mean? →Frequently Asked Questions
How effective is Epidiolex?
It reduced convulsive seizures (Dravet) and drop seizures (Lennox-Gastaut) by 17-23% more than placebo, on top of standard anti-epileptic drugs.
What drug interactions should be watched?
Clobazam, valproates, and drugs that affect CYP2C19 and CYP3A4 enzymes. Liver function monitoring is important, especially with concurrent valproate use.
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Cite This Study
https://rethinkthc.com/research/RTHC-01980APA
Chen, Jeffrey W; Borgelt, Laura M; Blackmer, Allison B. (2019). Cannabidiol: A New Hope for Patients With Dravet or Lennox-Gastaut Syndromes.. The Annals of pharmacotherapy, 53(6), 603-611. https://doi.org/10.1177/1060028018822124
MLA
Chen, Jeffrey W, et al. "Cannabidiol: A New Hope for Patients With Dravet or Lennox-Gastaut Syndromes.." The Annals of pharmacotherapy, 2019. https://doi.org/10.1177/1060028018822124
RethinkTHC
RethinkTHC Research Database. "Cannabidiol: A New Hope for Patients With Dravet or Lennox-G..." RTHC-01980. Retrieved from https://rethinkthc.com/research/chen-2019-cannabidiol-a-new-hope
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.