Prescription CBD Helped About 1 in 4 Adults with Drug-Resistant Epilepsy, Regardless of Epilepsy Type | Research

The takeaway

In a French retrospective study, pharmaceutical-grade CBD (Epidiolex) produced meaningful seizure reduction in about 25-29% of adults with drug-resistant epilepsy, with no significant difference between epileptic encephalopathies and focal epilepsies.

Adults with drug-resistant epilepsy, neurologists, and epilepsy researchers.

~25-29% of patients with drug-resistant epilepsy responded to pharmaceutical CBD

What the researchers found

Among 73 patients (51 with epileptic encephalopathies, 22 with focal/multifocal epilepsy), 29.4% and 22.7% respectively were responders during follow-up, with no significant difference between groups (P=0.552). Clobazam co-administration was associated with better response (80% of responders vs 20% of non-responders). Somnolence was the most common side effect. About 30-40% discontinued treatment.

Why it matters

CBD is currently approved only for specific rare epilepsies (LGS, Dravet, TSC). This study suggests it may also benefit adults with other forms of drug-resistant epilepsy, including common focal epilepsies, potentially broadening its therapeutic application.

The numbers in context

73 patients; Group A (encephalopathies): 51 patients, 29.4% responders; Group B (focal): 22 patients, 22.7% responders; P=0.552; clobazam associated with better response; 29-40% discontinued treatment; somnolence most common side effect

How the study worked

Retrospective analysis of 73 patients from two French epilepsy reference centers who received high-purified CBD (Epidiolex) as add-on therapy for drug-resistant epilepsy.

What this study cannot tell us

Retrospective design without control group. Small sample, especially for focal epilepsy group. Variable follow-up periods. Responder definition and assessment may differ between centers. Cannot determine optimal dosing.

How to read the evidence

Retrospective study from two reference centers. No control group but provides real-world efficacy data across epilepsy types.

When this study was published

Published in 2024.

The bigger picture

If CBD's efficacy extends beyond the three currently approved conditions to other drug-resistant epilepsies, it could benefit a much larger patient population. The clobazam interaction (known to boost CBD levels) may be key to optimizing response.

Questions still open

Should clinical trials of CBD be expanded to include more common forms of drug-resistant epilepsy?
Is clobazam co-administration necessary for CBD efficacy, or does it work through other mechanisms?

Common questions

Does CBD only work for rare epilepsy syndromes?

This study suggests it may also help adults with more common forms of drug-resistant epilepsy, including focal epilepsies, though it is currently only approved for specific rare conditions.

How many patients benefited?

About 1 in 4 patients had meaningful seizure reduction, which is notable given that these patients had already failed multiple other treatments.

Read the original research

High-purified cannabidiol efficacy and safety in a cohort of adult patients with various types of drug-resistant epilepsies.

Revue neurologique, 180(3), 147-153

View on PubMed ↗Publisher’s paper ↗

Citation

Perriguey, M; Succar, M El; Clément, A; Lagarde, S; Ribes, O; Dode, X; Rheims, S; Bartolomei, F. (2024). High-purified cannabidiol efficacy and safety in a cohort of adult patients with various types of drug-resistant epilepsies.. Revue neurologique, 180(3), 147-153. https://doi.org/10.1016/j.neurol.2023.07.012