CBD Plus Clobazam Achieved 48% Seizure Response Rate in Severe German Epilepsy Patients
In 126 German patients with LGS or DS receiving CBD with clobazam, 47.5% achieved 50%+ seizure reduction at 3 months, with 63% showing tonic-clonic seizure response and 70% remaining on treatment at 1 year.
Quick Facts
What This Study Found
50%+ seizure reduction in total seizures: 47.5% at 3 months, 45.5% at 12 months. For generalized tonic-clonic seizures: 63.0% at 3 months, 56.9% at 12 months. Seizure days decreased from 30 to 15 per month (p<0.001). CGI-C improvement: 66%. Behavioral improvement: 67%. Retention: 89.7% (3 mo), 80.7% (6 mo), 69.8% (12 mo). Main AEs: sedation (23.8%), diarrhea (10.3%).
Key Numbers
126 patients (102 LGS, 24 DS). Mean age: 23.2 years. Prior ASMs: median 6. Target CBD: 11.1 mg/kg/day. CLB: 0.14 mg/kg/day. 50%+ response: 47.5% (3 mo), 45.5% (12 mo). GTCS response: 63.0% (3 mo), 56.9% (12 mo). Seizure days: 30 to 15/month. Retention: 69.8% at 12 mo. Sedation: 23.8%.
How They Did This
Retrospective multicenter chart review of 126 patients (102 LGS, 24 DS) from 6 German epilepsy centers receiving adjunctive CBD with concomitant clobazam for up to 12 months.
Why This Research Matters
CBD is approved in the EU specifically for use with clobazam for LGS and DS. This study provides real-world evidence for this specific combination, which showed numerically higher response rates than the broader population (RTHC-07737), likely due to the known pharmacokinetic interaction between CBD and clobazam.
The Bigger Picture
The CBD-clobazam combination appears to enhance seizure control compared to CBD with other medications, consistent with the known pharmacokinetic interaction where CBD increases clobazam's active metabolite levels. The trade-off is higher sedation rates.
What This Study Doesn't Tell Us
Retrospective chart review. No comparator group without clobazam. Selection bias. CBD-clobazam interaction makes it difficult to attribute benefit to CBD alone. Higher sedation may reflect the drug interaction.
Questions This Raises
- ?How much of the benefit is from CBD vs. the CBD-clobazam pharmacokinetic interaction?
- ?Should clobazam doses be reduced when adding CBD to minimize sedation?
Trust & Context
- Key Stat:
- Evidence Grade:
- Multicenter real-world data on the specifically approved CBD-clobazam combination with sustained outcomes supports strong evidence.
- Study Age:
- German multicenter data up to 12 months of treatment.
- Original Title:
- Real-world experience of cannabidiol in conjunction with clobazam for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome: Results from a retrospective multicentre chart review in Germany.
- Published In:
- Epilepsy & behavior : E&B, 166, 110302 (2025)
- Authors:
- Strzelczyk, Adam(4), Schubert-Bast, Susanne(4), von Podewils, Felix(4), Knake, Susanne, Mayer, Thomas, Klotz, Kerstin Alexandra, Buhleier, Elisa, Herold, Luise, Immisch, Ilka, Kurlemann, Gerhard, Rosenow, Felix
- Database ID:
- RTHC-07738
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
Is CBD better with clobazam?
Response rates were numerically higher with the CBD-clobazam combination (48%) than in the broader CBD population (43%), consistent with a known pharmacokinetic interaction that increases clobazam's active metabolite.
What are the main side effects of CBD + clobazam?
Sedation was the most common (23.8%), likely amplified by the drug interaction between CBD and clobazam. Diarrhea (10.3%) and behavioral changes (7.1%) were also reported.
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Cite This Study
https://rethinkthc.com/research/RTHC-07738APA
Strzelczyk, Adam; Schubert-Bast, Susanne; von Podewils, Felix; Knake, Susanne; Mayer, Thomas; Klotz, Kerstin Alexandra; Buhleier, Elisa; Herold, Luise; Immisch, Ilka; Kurlemann, Gerhard; Rosenow, Felix. (2025). Real-world experience of cannabidiol in conjunction with clobazam for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome: Results from a retrospective multicentre chart review in Germany.. Epilepsy & behavior : E&B, 166, 110302. https://doi.org/10.1016/j.yebeh.2025.110302
MLA
Strzelczyk, Adam, et al. "Real-world experience of cannabidiol in conjunction with clobazam for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome: Results from a retrospective multicentre chart review in Germany.." Epilepsy & behavior : E&B, 2025. https://doi.org/10.1016/j.yebeh.2025.110302
RethinkTHC
RethinkTHC Research Database. "Real-world experience of cannabidiol in conjunction with clo..." RTHC-07738. Retrieved from https://rethinkthc.com/research/strzelczyk-2025-realworld-experience-of-cannabidiol
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.