Cannabidiol (prescription) and Carbamazepine interaction
Cannabidiol (prescription) and Carbamazepine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Carbamazepine (EQUETRO) label · effective 2025-08-19
CNS Depressants The concomitant use of EQUETRO and other CNS depressants can increase the risk of respiratory depression, profound sedation, hypotension, and syncope.
Limited evidence suggests that HLA-B*1502 may be a risk factor for the development of SJS/TEN in patients of Chinese ancestry taking other anti-epileptic drugs associated with SJS/TEN, including phenytoin.
Consider reducing the dose of CNS depressants or EQUETRO when using these drugs concomitantly.
Cytochrome (CYP) 3A4 inhibitors, epoxide hydrolase inhibitors, CYP3A4 inducers, drugs metabolized by CYP1A2 or CYP3A4 (oral contraceptives, delavirdine, nefazodone), phenytoin, CNS depressants, lithium, chloroquine, mefloquine ( 7.1 , 7.2 , 7.3 )
CNS depressants include: alcohol, opioid analgesics, benzodiazepines, tricyclic antidepressants, sedative/hypnotics, anticonvulsants, antipsychotics, antihistamines, anticholinergics, alpha and beta blockers, general anesthetics, muscle relaxants, and illicit CNS depressants.
From the Cannabidiol (prescription) (Epidiolex) label · effective 2026-05-29
Other CNS depressants, including alcohol, could potentiate the somnolence and sedation effect of EPIDIOLEX.
• Strong inducer of CYP3A4 or CYP2C19: Consider dose increase of EPIDIOLEX.
Effect of Other Drugs on EPIDIOLEX Strong CYP3A4 or CYP2C19 Inducers Concomitant use with a strong CYP3A4 and CYP2C19 inducer (rifampin 600 mg once daily) decreased cannabidiol and 7-hydroxy-cannabidiol (7-OH-CBD) plasma concentrations by approximately 32% and 63%.
Consider an increase in EPIDIOLEX dosage (based on clinical response and tolerability) up to 2-fold, when concomitantly used with a strong CYP3A4 and/or CYP2C19 inducer.
Effect of EPIDIOLEX on Other Drugs Antiepileptic Drugs Clobazam Concomitant use of EPIDIOLEX with clobazam increases plasma concentrations of N‑desmethylclobazam, the active metabolite of clobazam [see Clinical Pharmacology ( 12.3 )], which may increase the risk of clobazam-related adverse reactions [see Adverse Reactions ( 6.1 ) and Warnings and Precautions…
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.