CBD works for seizures whether or not patients also take clobazam

A meta-analysis of four trials found CBD reduced seizures in both Dravet and Lennox-Gastaut syndrome regardless of whether patients were also taking the benzodiazepine clobazam.

Lattanzi, Simona et al.·Epilepsia·2020·Strong EvidenceMeta-Analysis
RTHC-02674Meta AnalysisStrong Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Meta-Analysis
Evidence
Strong Evidence
Sample
N=714

What This Study Found

Across four RCTs with 714 participants, CBD was associated with significantly higher seizure response rates compared to placebo both in patients taking clobazam (52.9% vs 27.8%, RR=1.85) and those not taking it (29.1% vs 15.7%, RR=1.80). The effect sizes were similar regardless of clobazam status.

Key Numbers

714 participants (429 CBD, 285 placebo); CLB-On: 52.9% vs 27.8% response (RR=1.85, p<0.001); CLB-Off: 29.1% vs 15.7% response (RR=1.80, p=0.015).

How They Did This

Meta-analysis of four randomized, placebo-controlled trials in Dravet and Lennox-Gastaut syndrome, stratified by concomitant clobazam use. Risk ratios estimated using inverse variance method.

Why This Research Matters

A key debate in epilepsy medicine was whether CBD works on its own or only because it boosts clobazam blood levels through a drug interaction. This analysis suggests CBD has independent anti-seizure efficacy.

The Bigger Picture

This finding strengthens the case that CBD is a genuine anti-seizure medication, not just a drug interaction booster. It supports broader use of CBD in epilepsy patients regardless of their existing medication regimen.

What This Study Doesn't Tell Us

Patients were not randomized to clobazam status (post-hoc subgroup analysis); limited sample sizes in subgroups; all trials used pharmaceutical-grade CBD (Epidiolex).

Questions This Raises

  • ?Does CBD interact with other anti-epileptic drugs in ways that affect efficacy?
  • ?Should dosing be adjusted based on concomitant medications?

Trust & Context

Key Stat:
CBD effective with clobazam (RR 1.85) and without it (RR 1.80)
Evidence Grade:
Strong: meta-analysis of four RCTs, though clobazam subgroup analysis was post-hoc.
Study Age:
Published 2020.
Original Title:
Cannabidiol efficacy and clobazam status: A systematic review and meta-analysis.
Published In:
Epilepsia, 61(6), 1090-1098 (2020)
Database ID:
RTHC-02674

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Combines results from multiple studies to find an overall pattern.

What do these levels mean? →

Frequently Asked Questions

Does CBD only work because it interacts with clobazam?

No. This meta-analysis found CBD significantly reduced seizures both in patients taking clobazam (RR 1.85) and those not taking it (RR 1.80), suggesting independent efficacy.

Were response rates different with and without clobazam?

Overall response rates were higher in the clobazam group (52.9% vs 29.1% for CBD), but the relative benefit of CBD over placebo was similar regardless of clobazam status.

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Cite This Study

RTHC-02674·https://rethinkthc.com/research/RTHC-02674

APA

Lattanzi, Simona; Trinka, Eugen; Striano, Pasquale; Zaccara, Gaetano; Del Giovane, Cinzia; Nardone, Raffaele; Silvestrini, Mauro; Brigo, Francesco. (2020). Cannabidiol efficacy and clobazam status: A systematic review and meta-analysis.. Epilepsia, 61(6), 1090-1098. https://doi.org/10.1111/epi.16546

MLA

Lattanzi, Simona, et al. "Cannabidiol efficacy and clobazam status: A systematic review and meta-analysis.." Epilepsia, 2020. https://doi.org/10.1111/epi.16546

RethinkTHC

RethinkTHC Research Database. "Cannabidiol efficacy and clobazam status: A systematic revie..." RTHC-02674. Retrieved from https://rethinkthc.com/research/lattanzi-2020-cannabidiol-efficacy-and-clobazam

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.