Tablet
- Strengths
- 2, 4, 12, 16 mg
- Product note
- Available strength set depends on manufacturer; take with food.
Tiagabine
Gabitril
Seizure aggravation / coverage
May aggravate absence or myoclonic seizures; review syndrome before use (NICE NG217, UK guidance).
May aggravate absence or myoclonic seizures; review syndrome before use (NICE NG217, UK guidance).
DailyMed-verified antiseizure indications
Indication / use
- Label / evidence summary
- Tiagabine: adjunctive treatment of focal (partial) seizures from age 12 years.
- Role
- Maintenance
- Class
- Selective GAT-1 GABA-reuptake inhibition
Indications checked 26 September 2026. Product, route, age, and treatment-role limits apply. A DailyMed listing alone does not establish FDA approval.
- Tiagabine tablet U.S. label
Focal seizures · 12 years and older · MaintenanceAdjunctive therapy.
Formulations & strengths
U.S. products unless another country is named. Strengths are per unit or stated volume.
Brand & formulation labels
Each link names the product and formulation it covers. Archived labels do not establish current availability.
Dosing & administration
- Adult / product-specific schedule
- With enzyme inducers: start 4 mg daily; titrate weekly to 32–56 mg/day divided.
- Pediatric
- With enzyme-inducing ASMs, ages 12–18: start 4 mg/day; increase by 4 mg at week 2, then 4–8 mg/day at weekly intervals to response, up to 32 mg/day in 2–4 doses. Without inducers use lower doses/slower titration; below age 12 not established.
- Titration / repeat dosing
- In adults taking enzyme-inducing ASMs, start 4 mg once daily; increase by 4–8 mg/week, adding divided doses, to 32–56 mg/day. Patients without inducers require lower/slower dosing because exposure is higher.
Dose adjustment & concentrations
- Renal impairment
- No adjustment generally.
- Hepatic impairment
- Reduce dose and/or interval.
- Serum reference information
- No established therapeutic range
Safety
- Boxed warning
- No boxed warning. New-onset seizures and status epilepticus have occurred in patients without epilepsy; incidence is not reliably estimable from postmarketing reports.
- Contraindications
- Hypersensitivity to tiagabine or ingredients.
- Serious precautions & monitoring
- Can provoke seizures/status in nonepileptic patients; take with food.
Common / selected adverse effects
- Dizziness
- Asthenia
- Nervousness
- Tremor
- Abdominal pain
- Difficulty concentrating
Drug interactions: toxicity & clinical action
| Partner / combination | Clinical effect | Clinical action |
|---|---|---|
| Carbamazepine, phenytoin, phenobarbital or primidone | Induction increases tiagabine clearance; withdrawing an inducer can cause a marked rise in exposure. | Use lower doses/slower titration in non-induced patients; reassess when an inducer is stopped. |
| Other sedatives | Additive CNS impairment. | Monitor cognition/somnolence; investigate new confusion or seizures rather than assuming simple sedation. |
Pregnancy & contraception
- Fetal / neonatal risk
- Adequate controlled human pregnancy studies are lacking. Tiagabine caused embryofetal toxicity in animals at doses above the human therapeutic range.
- Contraception
- At 8 mg/day, tiagabine did not show a clinically significant interaction with the combined oral contraceptive studied in the label; this does not establish effects at every dose or regimen.
Clinical evidence
Research summaries describe studied populations and outcomes; they do not add indications or constitute treatment recommendations.
Direct pivotal trial
Trial summary
- Study design / duration
- Multiple randomized, double-blind, placebo-controlled adjunctive focal-seizure trials used prospective baselines and 12–16-week treatment, evaluating seizure-frequency change and responder rates.
- Primary endpoint
- No single pivotal endpoint is identified in the cited source.
- Results
- Pivotal adjunctive focal-seizure studies showed dose-related seizure-frequency reductions and responder rates; effective regimens generally produced roughly 20–30% median reductions versus smaller placebo changes.
Trial publications
Mechanism of action
- Inhibits GAT-1-mediated neuronal/glial GABA reuptake, prolonging extracellular GABA availability.
- Acts on the transporter rather than directly modulating GABA-A receptors or irreversibly blocking GABA degradation as vigabatrin does.
Pharmacology
Adult values unless specified. Vd/F denotes apparent oral distribution volume.
Pharmacokinetics
- Bioavailability
- Approximately 90% absolute oral bioavailability; >95% is absorbed. Food slows the peak without reducing the extent of absorption.
- Elimination half-life
- 7–9 hours without enzyme induction; approximately 2–5 hours with enzyme-inducing ASMs.
- Volume of distribution
- Approximately 1 L/kg (UK SmPC).
- Active metabolite(s)
- No active metabolites identified in the cited product information.
- Active-metabolite half-life
- Not applicable — no clinically established active metabolite.
- Protein binding
- 96%
- Metabolism / elimination
- Primarily CYP3A
Enzyme-inducing background therapy materially changes exposure and dosing requirements.
Molecular structure
NIH PubChem structure and record ↗
Product history
- Initial U.S. approval
- 1997
- Brands
- Gabitril
- Manufacturer / marketer
- Cephalon/Teva legacy brand (Gabitril)
- Generic availability
- Yes
- Related drugs
- Mechanistically distinct; selectively inhibits GABA transporter GAT-1.
Sources & review status
Representative sources are selected product labels, not an exhaustive list of generic manufacturers. Consult the exact product and formulation prescribed. Brand-name package inserts are linked separately.
Brand reference: Gabitril — archived 2016 brand label ↗
Indications and DailyMed PDFs checked: 2026-09-26. Other profile sources reviewed: 2026-09-15 · label revision noted at that review: 11/2018. This is a draft reference; final review is pending.