Tiagabine

Tiagabine is a second-line drug for partial seizures with or without secondary generalisation. It is not used in any other seizure type. Tiagabine should only be initiated by a specialist.

• Adjunctive treatment for partial seizures with or without secondary generalisation not satisfactorily controlled with other antiepileptics

• Porphyria
• Not recommended in children under 12 years old

• Hepatic impairment
• May impair performance of skilled tasks (e.g. driving)
• Avoid abrupt withdrawal

• Tiagabine does not affect levels of carbamazepine but may reduce the plasma concentration of valproate, phenobarbital and phenytoin
• Enzyme-inducing antiepileptic drugs decrease the half-life of tiagabine and patients taking such drugs as concomitant medication may need to take tiagabine three times a day from the beginning of treatment

• The side effects are mainly CNS-related and are more common during drug titration
• The main side effects are sedation, headache, concentration difficulties, tiredness and dizziness

• Tremor, diarrhoea, irritability, confusion, and depression are seen occasionally
• Exacerbation of seizures and cases of non-convulsive status epilepticus have been reported
• Confusion, depression, drowsiness, psychosis, leucopenia may occur but are uncommon

• Adjunctive therapy, with enzyme-inducing drugs, 5 mg twice daily for 1 week, then increased at weekly intervals in steps of 5-10 mg daily
• The usual maintenance dose is 30-45 mg daily (doses above 30 mg given in 3 divided doses)
• For patients receiving non-enzyme-inducing drugs, initial maintenance dose should be 15-30 mg daily

• There is very little information on blood tiagabine levels in patients with epilepsy
• The target range for tiagabine is currently considered to be 200 -1100 nmol/l