French Pharmacovigilance Data Show Most Cannabinoid-Related Seizures Occur in People With Pre-existing Risk Factors
Analysis of 130 seizure reports from French pharmacovigilance databases found 68% of individuals had at least one pre-existing seizure risk factor, with recreational users showing higher risk (79%) than medical users (31%), primarily driven by co-use of epileptogenic medications and other drugs.
Quick Facts
What This Study Found
130 seizure cases among 4,296 cannabinoid reports (3%). 75.4% were recreational use, 23.3% medical (mostly CBD). 81.1% were serious. 67.7% had pre-existing seizure risk factors (78.6% of recreational vs. 31.0% of medical users). Main recreational risks: epileptogenic medications (39.8%), illicit drugs (33.7%), alcohol (32.7%). Main medical risks: CBD inefficacy (17.2%), fatigue (13.8%), concomitant epileptogenic meds (10.3%).
Key Numbers
4,296 cannabinoid reports; 130 (3%) convulsive; 78.7% male; median age 29; 81.1% serious; 38.8% of recreational users had epilepsy history; 68.4% of those were on antiepileptics.
How They Did This
Retrospective analysis of French pharmacovigilance and addictovigilance databases plus Eudravigilance (1985-2023). MedDRA "convulsive" SMQ term with all cannabinoid products. 130 cases analyzed for demographics, circumstances, and risk factors.
Why This Research Matters
As CBD gains popularity for epilepsy treatment and recreational cannabis use grows, understanding seizure risks is critical. This study shows most seizures occur in people with pre-existing vulnerability, particularly from drug interactions.
The Bigger Picture
The high prevalence of drug interactions as a risk factor suggests that seizure risk is modifiable. Better screening for concomitant medications and substances could reduce cannabinoid-associated seizure events.
What This Study Doesn't Tell Us
Spontaneous reporting captures only a fraction of events. Cannot establish causation. Recreational use data may include multiple substances confounding attribution. Long study period spans changing cannabis potency and availability.
Questions This Raises
- ?Should CBD prescribing include mandatory drug interaction screening?
- ?Are seizures from recreational cannabis primarily caused by cannabis or co-used substances?
Trust & Context
- Key Stat:
- 68% had pre-existing seizure risk factors
- Evidence Grade:
- Large pharmacovigilance database spanning decades, but spontaneous reporting and lack of denominator data limit precision.
- Study Age:
- 2025 analysis of 1985-2023 French and European pharmacovigilance data.
- Original Title:
- Cannabinoids and Adverse Convulsive Effects: A Pharmacovigilance and Addictovigilance Analysis of Cases Reported in France.
- Published In:
- Fundamental & clinical pharmacology, 39(4), e70028 (2025)
- Authors:
- Laroche, Marie-Laure, Labetoulle, Marion, Jouanjus, Emilie(5), Kröger, Edeltraut, Zongo, Arsène
- Database ID:
- RTHC-06898
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Can cannabis cause seizures?
In this analysis, 3% of cannabinoid adverse event reports involved seizures, but 68% of those individuals had pre-existing risk factors including epilepsy history and use of other seizure-triggering substances.
Is CBD safe for people with epilepsy?
Most medical-use seizure cases involved CBD inefficacy or drug interactions rather than CBD directly causing seizures. Interaction screening is important.
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Cite This Study
https://rethinkthc.com/research/RTHC-06898APA
Laroche, Marie-Laure; Labetoulle, Marion; Jouanjus, Emilie; Kröger, Edeltraut; Zongo, Arsène. (2025). Cannabinoids and Adverse Convulsive Effects: A Pharmacovigilance and Addictovigilance Analysis of Cases Reported in France.. Fundamental & clinical pharmacology, 39(4), e70028. https://doi.org/10.1111/fcp.70028
MLA
Laroche, Marie-Laure, et al. "Cannabinoids and Adverse Convulsive Effects: A Pharmacovigilance and Addictovigilance Analysis of Cases Reported in France.." Fundamental & clinical pharmacology, 2025. https://doi.org/10.1111/fcp.70028
RethinkTHC
RethinkTHC Research Database. "Cannabinoids and Adverse Convulsive Effects: A Pharmacovigil..." RTHC-06898. Retrieved from https://rethinkthc.com/research/laroche-2025-cannabinoids-and-adverse-convulsive
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.