CBD's seizure benefit may come from boosting clobazam levels, not direct anti-seizure effects

Clinical trial simulations suggest CBD's reduction of seizures in Lennox-Gastaut syndrome could be explained by its drug interaction with clobazam, which raises levels of clobazam's active metabolite 2- to 7-fold.

Bergmann, Kirsten Riber et al.·British journal of clinical pharmacology·2020·Moderate EvidenceObservational
RTHC-02417ObservationalModerate Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Simulations showed that the observed seizure reduction from CBD could be replicated by assuming: (1) patients on clobazam had a 2- to 7-fold increase in norclobazam (active metabolite) exposure, and (2) patients not on clobazam had seizure reduction and variability similar to placebo. This suggests CBD's apparent anti-seizure effect may be primarily a drug interaction rather than a direct pharmacological effect.

Key Numbers

CBD dose: 20 mg/kg/day. Norclobazam exposure increase: 2- to 7-fold. Simulated patients on 10 or 20 mg clobazam.

How They Did This

Clinical trial simulations modeling the effect of 20 mg/kg/day CBD on drop-seizure frequency in Lennox-Gastaut syndrome, assuming known CBD-clobazam interaction parameters.

Why This Research Matters

If CBD's benefit is primarily through boosting clobazam, simply increasing clobazam doses might achieve the same effect at lower cost, though with potentially more side effects.

The Bigger Picture

This challenges the narrative that CBD has independent anti-seizure properties and has implications for the FDA registration of Epidiolex and for patients and families investing in CBD treatment.

What This Study Doesn't Tell Us

Simulation study, not empirical trial. Assumptions may not fully reflect clinical reality. Does not account for all possible mechanisms of CBD action.

Questions This Raises

  • ?If the benefit is from drug interaction, should clobazam doses be increased instead?
  • ?Does CBD have any direct anti-seizure effects independent of drug interactions?

Trust & Context

Key Stat:
CBD raises clobazam's active metabolite 2-7 fold
Evidence Grade:
Simulation study based on known pharmacokinetic data, providing a plausible hypothesis but not proof.
Study Age:
2020 simulation study.
Original Title:
Clinical trial simulations of the interaction between cannabidiol and clobazam and effect on drop-seizure frequency.
Published In:
British journal of clinical pharmacology, 86(2), 380-385 (2020)
Database ID:
RTHC-02417

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

Does CBD directly stop seizures?

This simulation study suggests CBD's seizure benefit may come from raising levels of clobazam's active metabolite rather than from direct anti-seizure effects, though other studies provide some evidence of independent action.

How does CBD interact with clobazam?

CBD increases levels of norclobazam (clobazam's active metabolite) 2- to 7-fold, which could account for the observed seizure reduction in patients taking both drugs.

Read More on RethinkTHC

Cite This Study

RTHC-02417·https://rethinkthc.com/research/RTHC-02417

APA

Bergmann, Kirsten Riber; Broekhuizen, Karen; Groeneveld, Geert Jan. (2020). Clinical trial simulations of the interaction between cannabidiol and clobazam and effect on drop-seizure frequency.. British journal of clinical pharmacology, 86(2), 380-385. https://doi.org/10.1111/bcp.14158

MLA

Bergmann, Kirsten Riber, et al. "Clinical trial simulations of the interaction between cannabidiol and clobazam and effect on drop-seizure frequency.." British journal of clinical pharmacology, 2020. https://doi.org/10.1111/bcp.14158

RethinkTHC

RethinkTHC Research Database. "Clinical trial simulations of the interaction between cannab..." RTHC-02417. Retrieved from https://rethinkthc.com/research/bergmann-2020-clinical-trial-simulations-of

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.