Tiagabine
๐ About
Always check the BNF link here before prescribing.
- ๐ Tiagabine is an anticonvulsant used as adjunctive therapy.
- Not used as monotherapy; reserved for partial seizures uncontrolled by first-line agents.
โ๏ธ Mode of Action
- Blocks neuronal GABA reuptake (GAT-1 inhibitor).
- โก๏ธ Increases extracellular GABA concentration โ enhanced inhibitory neurotransmission.
๐ Indications
- Adjunctive treatment of partial seizures with or without secondary generalisation.
- Not licensed for primary generalised epilepsy.
๐ Dose
- Start: 4โ5 mg OD, increase gradually every 1โ2 weeks.
- Maintenance: 15โ30 mg/day in divided doses (usually TDS).
- Higher doses may be required in patients on enzyme inducers (e.g. carbamazepine, phenytoin).
๐ Interactions
- See BNF for full list.
- Metabolised by CYP3A4 โ levels affected by inducers/inhibitors.
- Other CNS depressants (benzodiazepines, alcohol) โ additive sedation, dizziness.
โ Contraindications / Cautions
- Not recommended in absence or myoclonic seizures (may worsen).
- Caution in hepatic impairment (hepatic metabolism).
- Psychiatric history โ can exacerbate depression, psychosis, or suicidal ideation.
โ ๏ธ Side Effects
- ๐ Dizziness, ataxia, tremor.
- ๐ Tiredness, somnolence, confusion.
- ๐ง Depression, anxiety, irritability (psychiatric symptoms more common than with many other antiepileptics).
- Rare: non-convulsive status epilepticus, worsening of seizures.
๐ Clinical Pearls
- Not a first-line drug; consider in refractory partial epilepsy only.
- Titrate dose slowly to reduce risk of CNS and psychiatric side effects.
- Always monitor mood and mental health during treatment.
- Avoid abrupt withdrawal โ risk of rebound seizures/status epilepticus.
๐ References