Phenobarbital

For an informed discussion with your doctor or pharmacist. This information collection is not a clinically validated interaction checker. Missing data do not establish safety. Do not change or stop prescribed medicines on the basis of this information. The findings apply to the specific conditions studied; laboratory and animal studies cannot be directly extrapolated to humans.

Active substance: Phenobarbital

Examples of brand names: Luminal [DE]

ATC code: N03AA02

Main use (for orientation): Epilepsy

Documented research summary

CL20 found no significant association between CBD and concentrations. No verified controlled human pharmacokinetic experiment in the material screened. Animal data considered separately: beagle pharmacokinetics without a significant interaction; neonatal rats with enhanced anticonvulsant effects, but increased neuronal death in another model/dose context.

Uncertainties and limitations

Legacy SPL is officially accessible labelling, not evidence of a modern FDA authorisation review; no extrapolation of animal doses.

Separately recorded findings

1 separately recorded finding. Each statement applies to its documented study context.

CBD – clinical signals

Finding ID: B0068

Type of result: No / minor effect under the conditions studied

Observation: No concentration signal; p=0.8230.

Mechanism: PK observation

Study type: Observational study: no signal detected

Context studied: n=9.

Clinical interpretation: Not ruled out

Limitations and uncertainties: Context / limitations of CL20; a lack of statistical significance does not establish equivalence.

Original sources for this finding: Final analysis of potential drug-drug interactions between highly purified cannabidiol and anti-seizure medications in an open-label expanded access program [CL20]

References and access status

[CA_L_D0045] PHENOBARBITAL ORAL SOLUTION (PHENOBARBITAL ORAL) SOLUTION [BPI LABS LLC]

Original source / bibliographic reference

Authors: BPI Labs LLC

Year: 2025

Source type: Current published human-use SPL / product information

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

[CL20] Final analysis of potential drug-drug interactions between highly purified cannabidiol and anti-seizure medications in an open-label expanded access program

Original source / bibliographic reference

Authors: Gaston TE; Bebin EM; Cutter GR; Grayson L; Szaflarski JP

Year: 2023

Source type: Open-label longitudinal observational study

DOI: 10.1002/epi4.12815

PMID: 37593907

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

DOI – publisher access (access restrictions may apply)

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_34727050] Drug-drug interaction between cannabidiol and phenobarbital in healthy dogs.

Original source / bibliographic reference

Authors: Doran CE, McGrath S, Bartner LR, Thomas B, Cribb AE, Gustafson DL.

Year: 2021

Source type: Randomized Controlled Trial, Veterinary; Journal Article

DOI: 10.2460/ajvr.21.08.0120

PMID: 34727050

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_40633622] Cannabidiol potentiates phenobarbital-induced cell death in the developing brain.

Original source / bibliographic reference

Authors: Fernandes RA, Ribeiro JVM, Torres RE, Borges GB, Freitas LGR, de Castro OW, Moraes MFD, Garcia-Cairasco N, Moreira FA, Santos VR.

Year: 2025

Source type: Journal Article

DOI: 10.1016/j.neuro.2025.06.005

PMID: 40633622

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_41293208] Cannabidiol potentiates phenobarbital effects in the control of pentylenetetrazole (PTZ)-induced epileptic seizures in neonate rats.

Original source / bibliographic reference

Authors: Pinto LS, de Oliveira MS, Borges GB, de Castro OW, Moreira FA, Santos VR.

Year: 2025

Source type: research-article; Journal Article

DOI: 10.3389/fped.2025.1673345

PMID: 41293208

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_22970845] Cannabidivarin is anticonvulsant in mouse and rat.

Original source / bibliographic reference

Authors: Hill AJ, Mercier MS, Hill TD, Glyn SE, Jones NA, Yamasaki Y, Futamura T, Duncan M, Stott CG, Stephens GJ, Williams CM, Whalley BJ.

Year: 2012

Source type: Research Support, Non-U.S. Gov't; research-article; Journal Article

DOI: 10.1111/j.1476-5381.2012.02207.x

PMID: 22970845

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_808653] Anticonvulsant nature of marihuana smoking.

Original source / bibliographic reference

Authors: Consroe PF, Wood GC, Buchsbaum H.

Year: 1975

Source type: Research Support, U.S. Gov't, Non-P.H.S.; Journal Article; Case Reports

DOI: 10.1001/jama.1975.03260160054015

PMID: 808653

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

Research as of 23 October 2026. Not all original full texts could be reviewed in full. Source accessibility and the strength of scientific evidence must be assessed separately. An accessible link does not establish medical approval; a bibliographic record with an abstract does not replace the original full text.

Drug search and explanation of the evidence · Guide: cannabinoids and medicines · Author and responsibility