Tiagabine

Pronunciation: tye-AG-a-been.

Generic name
tiagabine hydrochloride
Drug class
Anticonvulsant (GABA reuptake inhibitor)
Form
Film-coated tablet (2 mg, 4 mg, 12 mg, 16 mg, 20 mg in the US; 5 mg, 10 mg, 15 mg in the UK/EU/Australia)
Route
Oral (tablet, taken with meals)
Legal status
Prescription-only in all markets reviewed

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Australia

Australia: Gabitril (4) · Full directory

What tiagabine hydrochloride is and how it works

Tiagabine is an anticonvulsant (anti-seizure) medicine approved ONLY as an add-on (adjunctive) treatment for partial seizures in people aged 12 and over whose epilepsy is not adequately controlled by other antiepileptic drugs alone. It is not approved, and should not be used, for any other condition. (1)

A real and important safety issue with tiagabine is that it has been linked to new, first-time seizures in people who do NOT have epilepsy, when it has been used off-label for other conditions (historically including anxiety or sleep problems). This risk does not apply in the same way to its approved, on-label use in people who already have epilepsy under specialist care -- the concern is specifically about giving this seizure medicine to people without a seizure disorder for an unapproved reason.

Mechanism of action: how tiagabine hydrochloride works

Tiagabine is a potent, selective inhibitor of GABA reuptake into neurons and glial cells, increasing the availability of GABA (the brain's principal inhibitory neurotransmitter) at synapses, which enhances GABAergic inhibition and helps suppress excessive neuronal firing associated with partial seizures. (2) (1)

What tiagabine hydrochloride is used for

Adjunctive (add-on) therapy for partial seizures -- ON-LABEL USE ONLY

Approved only as an add-on treatment, alongside other antiepileptic drugs, for partial seizures (with or without secondary generalisation) in people 12 years and older whose seizures are not adequately controlled by other antiepileptic medicines alone. This is tiagabine's ONLY approved use. (1) (2)

Before taking tiagabine hydrochloride

Do not take / not appropriate for

  • Do not take tiagabine if you have a known hypersensitivity (allergic) reaction to tiagabine or any of its ingredients. (all countries) (1)
  • Do not take tiagabine for any condition other than adjunctive partial-seizure treatment -- it is not approved or established as safe/effective for any other use, and using it off-label carries a real, documented risk of new-onset seizures even in people who have never had epilepsy. (all countries) (1) (2)
  • Do not take tiagabine if you have severe liver (hepatic) impairment, or together with St John's Wort. (United Kingdom, European Union) (2)

Tell your clinician about

  • Whether you have ever had epilepsy or a seizure disorder -- if you do not, tiagabine should only ever be prescribed for its approved partial-seizure indication, never for another condition.
  • Any liver problems.
  • All other medicines you take, especially antidepressants, antipsychotics, stimulants, or narcotics (medicines that can lower the seizure threshold), CYP3A4/5 inducers, and St John's Wort.
  • Any history of depression, suicidal thoughts, or mood changes, since antiepileptic drugs as a class carry a real, small increased risk of suicidal thinking or behaviour.
  • Any vision changes, since visual field defects have been reported and may warrant an eye specialist review.
(1) (2)

How to take tiagabine hydrochloride

  • Take by mouth, with meals, exactly as prescribed by your specialist as an add-on to your other antiepileptic medicine(s).
  • Do not use tiagabine for any purpose other than the epilepsy treatment your specialist prescribed it for.
  • Do not stop taking tiagabine suddenly, or change your dose, without your prescriber's guidance -- withdrawal should be gradual to reduce the chance of increased seizure frequency.
(2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

If you miss a dose, take it as soon as you remember unless it is almost time for your next dose -- do not double up. Because abrupt changes in tiagabine dosing can affect seizure control, contact your prescriber if you miss doses regularly or are unsure what to do.

Overdose

Seek emergency medical help immediately or contact a poison control centre for a suspected tiagabine overdose. Reported overdose effects include CNS depression, confusion, drowsiness, and seizures. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Dizziness (reported in around 27% of patients).

What to notice: Dizziness (reported in around 27% of patients).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Asthenia/fatigue (around 20%).

What to notice: Asthenia/fatigue (around 20%).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Somnolence/drowsiness (around 18%).

What to notice: Somnolence/drowsiness (around 18%).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea (around 11%), nervousness (around 10%), and tremor (around 9%).

What to notice: Nausea (around 11%), nervousness (around 10%), and tremor (around 9%).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

New-onset seizures or status epilepticus in people WITHOUT epilepsy (off-label use) — emergency

Symptoms: A first-ever seizure, or prolonged/repeated seizures (status epilepticus), in someone who has never had epilepsy.

Action: This is a real, well-documented risk specifically tied to tiagabine being used off-label (for a condition other than its approved partial-seizure indication) -- seizures have been reported at doses as low as 4 mg/day, sometimes near a dose increase. If you develop a seizure while taking tiagabine and do not have a prior epilepsy diagnosis, get emergency medical help immediately; tiagabine should be discontinued and you should be evaluated for an underlying seizure disorder. (1) (2)

Suicidal thoughts or behaviour — high caution

Symptoms: New or worsening depression, thoughts of self-harm or suicide, unusual changes in mood or behaviour.

Action: Contact your prescriber promptly, or seek emergency help if thoughts of self-harm are urgent -- antiepileptic drugs as a class carry an approximately twofold increase in suicidal thinking/behaviour risk in pooled clinical-trial data, which can emerge as early as one week into treatment. (1)

Increased seizure frequency from abrupt withdrawal — high caution

Symptoms: Seizures returning or worsening after stopping tiagabine suddenly.

Action: Tiagabine should be withdrawn gradually, under your prescriber's guidance, to reduce this risk -- never stop abruptly on your own. (1) (2)

Cognitive and CNS effects — high caution

Symptoms: Confusion, impaired concentration, marked drowsiness, or fatigue significant enough to affect daily activities.

Action: Tell your prescriber if these effects are significant -- they led to treatment discontinuation in a notable minority of patients in clinical trials (6% versus 2% on placebo). (1)

Visual field changes — high caution

Symptoms: New difficulty with peripheral vision or other visual changes.

Action: Tell your prescriber promptly -- an ophthalmology (eye specialist) referral may be recommended. (2)

Interactions

  • Medicines that can lower the seizure threshold (antidepressants, antipsychotics, stimulants, narcotics) -- most patients who developed new-onset seizures on tiagabine while not having epilepsy were also taking one of these. (1)
  • CYP3A4/5 inducers (tiagabine is metabolised via this pathway) -- dose adjustment may be needed. (2)
  • St John's Wort -- contraindicated in the UK/EU product information. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

No comprehensive regulator-reviewed pregnancy safety data were identified in the sources reviewed for this dossier; as with other antiepileptic drugs, use in pregnancy should be a decision made with your specialist, weighing seizure control against any potential risk. (1) (2) (3) (4) (5) (6)

Breastfeeding

No comprehensive regulator-reviewed breastfeeding safety data were identified in the sources reviewed; discuss with your specialist. (1) (2) (3) (4) (5) (6)

Children

Approved for adjunctive partial-seizure treatment in children 12 years and older only; not established as safe/effective below that age. (1) (2) (3) (4) (5) (6)

Elderly

No separate systemic dose adjustment based on age alone was identified in the sources reviewed beyond the general individualized titration already used for all patients. (1) (2) (3) (4) (5) (6)

Renal_impairment

No specific regulator-reviewed renal-impairment dose adjustment was identified in the sources reviewed for this dossier. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Confirm the patient has a genuine epilepsy/partial-seizure diagnosis -- tiagabine should not be started for any other reason.
  • Review other medicines for seizure-threshold-lowering interactions, CYP3A4/5 inducers, and St John's Wort.
  • Baseline liver function assessment given the severe-hepatic-impairment contraindication.

During treatment

  • Watch for any new seizure activity, especially in anyone without a prior epilepsy diagnosis.
  • Monitor mood and for suicidal thoughts, particularly in the first weeks of treatment.
  • Monitor for visual changes and cognitive/CNS effects.
(1) (2)

Storage

Store at room temperature, away from moisture and heat, out of reach of children, as directed on your product's packaging.

Professional information

Clinician-facing context only, sourced from the current US DailyMed label and UK EMC SmPC for tiagabine; verify against the current full label before prescribing.

United States, United Kingdom, European Union, Australia

Indication: Adjunctive therapy for partial seizures, age 12+, ON-LABEL USE ONLY

Dose summary: Individualised, gradual titration; UK: initial 5-10 mg/day, weekly increments of 5-10 mg, maintenance 15-30 mg/day (30-45 mg/day if enzyme-induced), divided into 2-3 daily doses with meals.

Renal context: No specific regulator-reviewed renal dose adjustment identified in the sources reviewed. (2)

Mechanism of action

Hepatic guidance

Contraindicated in severe hepatic impairment per the UK/EU product information; dose adjustment relevant given hepatic CYP3A4/5-mediated metabolism.

Overdose note

No specific antidote; overdose is managed supportively, with attention to CNS depression, seizures, and cardiorespiratory status. (2) (1)

Frequently asked questions

Why does tiagabine carry a warning about seizures if it's a seizure medicine?

This is a real and important nuance. Tiagabine is only approved as an add-on treatment for people who already have partial seizures (epilepsy) not fully controlled by other medicines. The specific, well-documented warning is about new, first-time seizures occurring in people who do NOT have epilepsy when tiagabine has been used off-label for something else (historically, conditions like anxiety or sleep problems). The US FDA and the drug's manufacturer issued a real safety communication about this in 2005, following postmarketing reports of new-onset seizures -- including status epilepticus -- in non-epileptic patients, more than half of which were tied to off-label psychiatric use. This is not a formal FDA boxed warning, but it is a prominent, dedicated warning in the current label. (1) (2)

Can tiagabine be used for anxiety or insomnia?

No -- tiagabine is not approved for anxiety, insomnia, or any condition besides adjunctive partial-seizure treatment, and using it off-label for these purposes carries a real, documented risk of triggering new seizures in people who don't have epilepsy. (1)

Is tiagabine available in Canada or New Zealand?

This review found no confirmation of current Canadian marketing -- consistent independent sources describe it as not available in Canada, though this rests on secondary sources rather than a directly confirmed Health Canada database result. New Zealand's current market status could not be reliably confirmed either; an older reference described it as approved but not yet marketed, and this review could not verify whether that has since changed. (5) (6)

Can I stop taking tiagabine suddenly?

No -- stopping abruptly can increase the risk of seizures returning or worsening. Any change to your tiagabine dose, including stopping it, should be done gradually and only under your prescriber's guidance. (1)

What is the mechanism of action of tiagabine hydrochloride?

Tiagabine is a potent, selective inhibitor of GABA reuptake into neurons and glial cells, increasing the availability of GABA (the brain's principal inhibitory neurotransmitter) at synapses, which enhances GABAergic inhibition and helps suppress excessive neuronal firing associated with partial seizures. (2) (1)

What is the generic name of Tiagabine?

The generic name is tiagabine hydrochloride. (1) (2)

What class of drug is tiagabine hydrochloride?

Tiagabine is classed as: Anticonvulsant (GABA reuptake inhibitor). (1) (2)

References

  1. GABITRIL (tiagabine hydrochloride) tablet -- full prescribing informationDailyMed (U.S. National Library of Medicine) -- FDA-approved prescribing information · United States · accessed 2026-07-30 · source 1
  2. Gabitril 10 mg Film-coated Tablets -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Teva UK Limited (formerly Cephalon UK Limited) · United Kingdom · accessed 2026-07-30 · source 2
  3. Tiagabine -- list of nationally authorised medicinal products (PSUSA/00002942/202406)European Medicines Agency (EMA) -- Periodic Safety Update Report Single Assessment (PSUSA) list of nationally authorised medicinal products · European Union · accessed 2026-07-30 · source 3
  4. GABITRIL tiagabine (as hydrochloride monohydrate) 5mg/10mg/15mg tablets -- ARTG registrationsTherapeutic Goods Administration (TGA), Australia -- Australian Register of Therapeutic Goods (ARTG) entries · Australia · accessed 2026-07-30 · source 4
  5. Tiagabine/Gabitril Canadian availability -- secondary source consensusConsistent independent secondary consumer-medicine and pharmacy-reference sources · Canada · accessed 2026-07-30 · source 5
  6. Tiagabine/Gabitril New Zealand status -- approved but marketing status unconfirmed as currentSecondary reference derived from a Medsafe-adjacent professional safety article (dated, exact current date unconfirmed) · New Zealand · accessed 2026-07-30 · source 6

Brand names by country

Single-ingredient tiagabine hydrochloride names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Gabitril (1)FDA approved dailymed confirmed · 2 mg, 4 mg, 12 mg, 16 mg, 20 mg (generic tiagabine tablets, per current market) · Multiple generic manufacturers (patent expired April 2016)

United Kingdom

  • Gabitril (2)MHRA licensed emc smpc confirmed · 5 mg, 10 mg, 15 mg · Teva UK Limited (formerly Cephalon UK Limited)

Australia

  • Gabitril (4)TGA ARTG registered 2006-09-14 confirmed · 5 mg, 10 mg, 15 mg · Teva Pharma Australia Pty Ltd
View brands in additional countries.

European Union

Gabitril (3)

This page provides general reference information about tiagabine and is not a substitute for advice from the clinical team managing your treatment. Tiagabine is approved only as an add-on treatment for partial seizures in people already diagnosed with epilepsy; do not use it for any other purpose without your prescriber's explicit guidance.

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