Adding CBD to a patient medications caused lithium toxicity, revealing a previously unknown drug interaction
An autistic patient with Lennox-Gastaut syndrome developed lithium toxicity several weeks after starting CBD (Epidiolex), revealing a clinically important drug-drug interaction between CBD and lithium.
Quick Facts
What This Study Found
An autistic patient with LGS and psychiatric comorbidities on multiple medications including lithium developed hypersomnolence, ataxia, and decreased oral intake several weeks after starting CBD. He was found to have lithium toxicity. After lithium was discontinued, symptoms resolved. He remained on CBD and other anti-seizure medications, becoming seizure-free with improved behavior.
Key Numbers
Lithium toxicity developed weeks after CBD initiation; symptoms: hypersomnolence, ataxia, decreased oral intake; resolved after lithium discontinuation; patient became seizure-free on CBD.
How They Did This
Single case report documenting the clinical timeline and management of lithium toxicity precipitated by CBD addition in a patient with complex neuropsychiatric comorbidities.
Why This Research Matters
CBD drug interactions with anti-seizure medications are increasingly recognized, but this is among the first reports of CBD interacting with a psychiatric medication (lithium). Patients on CBD often take multiple medications, making interaction awareness critical.
The Bigger Picture
As CBD is prescribed to patients with epilepsy who often have psychiatric comorbidities, the potential for interactions with psychiatric medications needs systematic study. Lithium has a narrow therapeutic index, making any pharmacokinetic interaction dangerous.
What This Study Doesn't Tell Us
Single case report; multiple concurrent medications confound attribution; mechanism of CBD-lithium interaction not confirmed; lithium levels before CBD not reported; cannot determine if interaction is consistent across patients.
Questions This Raises
- ?Does CBD affect lithium renal clearance or absorption?
- ?Should lithium levels be routinely monitored when starting CBD?
Trust & Context
- Key Stat:
- CBD-lithium interaction caused toxicity weeks after CBD initiation
- Evidence Grade:
- Preliminary: single case report; clinically important but cannot establish mechanism or frequency.
- Study Age:
- Published 2020.
- Original Title:
- Drug-Drug Interactions Between Cannabidiol and Lithium.
- Published In:
- Child neurology open, 7, 2329048X20947896 (2020)
- Authors:
- Singh, Rani K, Dillon, Brittany, Tatum, David A, Van Poppel, Katherine C, Bonthius, Daniel J
- Database ID:
- RTHC-02847
Evidence Hierarchy
Describes what happened to one person or a small group.
What do these levels mean? →Frequently Asked Questions
Can CBD interact with psychiatric medications?
Yes. This case report documented lithium toxicity developing weeks after starting CBD (Epidiolex), revealing a previously unknown interaction. Patients on CBD and lithium should have lithium levels monitored closely.
Which medications does CBD interact with?
CBD is known to interact with several anti-seizure medications (especially clobazam and valproate). This case adds lithium to the list. CBD inhibits certain liver enzymes that metabolize other drugs, potentially increasing their blood levels.
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Cite This Study
https://rethinkthc.com/research/RTHC-02847APA
Singh, Rani K; Dillon, Brittany; Tatum, David A; Van Poppel, Katherine C; Bonthius, Daniel J. (2020). Drug-Drug Interactions Between Cannabidiol and Lithium.. Child neurology open, 7, 2329048X20947896. https://doi.org/10.1177/2329048X20947896
MLA
Singh, Rani K, et al. "Drug-Drug Interactions Between Cannabidiol and Lithium.." Child neurology open, 2020. https://doi.org/10.1177/2329048X20947896
RethinkTHC
RethinkTHC Research Database. "Drug-Drug Interactions Between Cannabidiol and Lithium." RTHC-02847. Retrieved from https://rethinkthc.com/research/singh-2020-drugdrug-interactions-between-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.