Tiagabine

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: Tiagabine

Examples of brand names: Gabitril [DE]

ATC code: N03AG06

Main use (for orientation): Epilepsy

Documented research summary

Tiagabine and THC were combined in small human experiments: acute oral administration enhanced several THC effects; another study during tiagabine maintenance with smoked cannabis showed predominantly no change. Different exposures mean these findings are neither contradictory nor a general assurance of safety. The CBD/non-convulsive-status-epilepticus case involves polytherapy and is not established; mouse models show model-dependent combination effects.

Uncertainties and limitations

Does not establish safety for less-studied cannabinoids or untested formulations/doses.

Do not infer clinical dosage from preclinical effects or enzyme hypotheses.

Separately recorded findings

4 separately recorded findings. Each statement applies to its documented study context.

THC – clinically investigated

Finding ID: B0337

Type of result: Clinical evidence under study conditions

Observation: Tiagabine 12 mg substituted for the THC discrimination cue; the combination enhanced several THC effects, including subjective and performance measures.

Mechanism: Pharmacodynamic overlap between GABA reuptake inhibition and THC

Study type: Human laboratory experiment, 8 cannabis users

Context studied: Tiagabine 6/12 mg and oral Δ9-THC 5/15/30 mg, individually and combined.

Clinical interpretation: Do not transfer study conditions to individual use.

Limitations and uncertainties: Abstract only; small sample, no general dose/safety conclusion.

Original sources for this finding: Separate and combined effects of the GABA reuptake inhibitor tiagabine and Δ9-THC in humans discriminating Δ9-THC. [C_PR_21975195]

Cannabis (0%/5.9% THC; mixture) – clinically investigated

Finding ID: B0338

Type of result: Clinical evidence: predominantly no effect under study conditions

Observation: Tiagabine 12 mg/day predominantly did not alter cannabis effects or naturalistic use; small changes in craving/sleep.

Mechanism: Combination during maintenance treatment

Study type: Double-blind, placebo-controlled, within-person, n=12

Context studied: Two 12-day phases, smoked cannabis; not pure THC.

Clinical interpretation: Do not transfer study conditions to individual use.

Limitations and uncertainties: Abstract only; not general proof of safety, different route and maintenance rather than acute administration.

Original sources for this finding: Influence of tiagabine maintenance on cannabis effects and related behaviors in daily cannabis users. [C_PR_29863387]

CBD – clinical signals

Finding ID: B0339

Type of result: Clinical signal

Observation: Non-convulsive status epilepticus after adding CBD in a 63-year-old man; increase after CBD dose escalation, resolution after discontinuation.

Mechanism: Possible combined influence, not isolated

Study type: Single case receiving multiple antiseizure medicines

Context studied: Concomitant tiagabine, perampanel, levetiracetam, lacosamide and clonazepam; authors discuss a tiagabine interaction.

Clinical interpretation: Do not transfer study conditions to individual use.

Limitations and uncertainties: No isolated tiagabine causality/concentrations; abstract only.

Original sources for this finding: Non-convulsive status epilepticus in the setting of cannabidiol adjunctive therapy [CA_P_35770762]

CBD – laboratory and animal studies

Finding ID: B0340

Type of result: Preclinical evidence

Observation: Enhanced seizure suppression in the 2019 6-Hz mouse model; no synergistic/additive protection in the 2023 kindling model.

Mechanism: Preclinical pharmacokinetic/pharmacodynamic combination

Study type: Two different mouse models

Context studied: Do not combine into a universal effect; pharmacokinetic contribution possible in 2019.

Clinical interpretation: Do not transfer study conditions to individual use.

Limitations and uncertainties: Abstract-based details, not human medical dosage.

Original sources for this finding: Acute effect of cannabidiol on the activity of various novel antiepileptic drugs in the maximal electroshock- and 6 Hz-induced seizures in mice: Pharmacodynamic and pharmacokinetic studies. [CA_P_31377197]; Efficacy of the FDA-approved cannabidiol on the development and persistence of temporal lobe epilepsy and complex focal onset seizures. [C_PR_36216124]

References and access status

[C_LABEL_D0061] GABITRIL (TIAGABINE HYDROCHLORIDE) TABLET, FILM COATED [CARILION MATERIALS MANAGEMENT]

Original source / bibliographic reference

Authors: CARILION MATERIALS MANAGEMENT

Year: 2016

Source type: US Structured Product Label

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

Bibliographic attribution or source identity cross-checked.

[CA_P_35770762] Non-convulsive status epilepticus in the setting of cannabidiol adjunctive therapy

Original source / bibliographic reference

Authors: Tanwir A, Szabó CÁ.

Year: 2022

Source type: Journal Article

DOI: 10.1684/epd.2022.1435

PMID: 35770762

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)

[C_PR_36216124] Efficacy of the FDA-approved cannabidiol on the development and persistence of temporal lobe epilepsy and complex focal onset seizures.

Original source / bibliographic reference

Authors: Reddy DS, Mbilinyi RH, Ramakrishnan S.

Year: 2023

Source type: Primary source, abstract read

DOI: 10.1016/j.expneurol.2022.114240

PMID: 36216124

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)

[C_PR_29863387] Influence of tiagabine maintenance on cannabis effects and related behaviors in daily cannabis users.

Original source / bibliographic reference

Authors: Wesley MJ, Westgate PM, Stoops WW, Kelly TH, Hays LR, Lile JA.

Year: 2018

Source type: Primary source, abstract read

DOI: 10.1037/pha0000180

PMID: 29863387

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

PubMed Central – archived text

DOI – publisher access (access restrictions may apply)

[C_PR_21975195] Separate and combined effects of the GABA reuptake inhibitor tiagabine and Δ9-THC in humans discriminating Δ9-THC.

Original source / bibliographic reference

Authors: Lile JA, Kelly TH, Hays LR.

Year: 2012

Source type: Primary source, abstract read

DOI: 10.1016/j.drugalcdep.2011.09.010

PMID: 21975195

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

PubMed Central – archived text

DOI – publisher access (access restrictions may apply)

[CA_P_31377197] Acute effect of cannabidiol on the activity of various novel antiepileptic drugs in the maximal electroshock- and 6 Hz-induced seizures in mice: Pharmacodynamic and pharmacokinetic studies.

Original source / bibliographic reference

Authors: Socała K, Wyska E, Szafarz M, Nieoczym D, Wlaź P.

Year: 2019

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

DOI: 10.1016/j.neuropharm.2019.107733

PMID: 31377197

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