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.
Neurologists prescribing CBD, psychiatrists managing lithium, and pharmacists monitoring drug interactions.
CBD-lithium interaction caused toxicity weeks after CBD initiation
What the researchers 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.
Why it 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 numbers in context
Lithium toxicity developed weeks after CBD initiation; symptoms: hypersomnolence, ataxia, decreased oral intake; resolved after lithium discontinuation; patient became seizure-free on CBD.
How the study worked
Single case report documenting the clinical timeline and management of lithium toxicity precipitated by CBD addition in a patient with complex neuropsychiatric comorbidities.
What this study cannot 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.
How to read the evidence
Preliminary: single case report; clinically important but cannot establish mechanism or frequency.
When this study was published
Published 2020.
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.
Questions still open
- Does CBD affect lithium renal clearance or absorption? Should lithium levels be routinely monitored when starting CBD?
Common questions
Can CBD interact with psychiatric medications?
Which medications does CBD interact with?
Read the original research
Drug-Drug Interactions Between Cannabidiol and Lithium.
Child neurology open, 7, 2329048X20947896
Citation
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
Explore the wider topic
- CBD Oil Quality Guide: How to Avoid Snake Oil
- Anxiety After Quitting Weed: When to Consider Medication
- Cannabis for Chemotherapy Nausea: What the Evidence Actually Shows
- Cannabis for Chronic Pain: What the Research Actually Supports
- Cannabis and Epilepsy: The Epidiolex Story and What It Means
- Does CBD Actually Work for Anxiety? What the Evidence Shows
- Does CBD Help with Weed Withdrawal? What Studies Show
- CBD vs THC: The Differences That Actually Matter
- The Proven Medical Benefits of Cannabis: What Research Supports
- Quitting Weed Before Surgery
- Weed and Medications: What Changes When You Quit
- Quitting Weed During Pregnancy: What You Need to Know
- Quitting Weed While Pregnant: What You Need to Know
- Cannabis and Older Adults: Risks Seniors Should Know
- Cannabis and Breastfeeding: THC in Breast Milk