Tiagabine

Licensed as adjunctive therapy for partial seizures in adults and adolescents over 12 years; safety and effectiveness have not been established for any other indication. Dosing schemes may need to be individualised based on the patient's characteristics such as age and concomitant medicines. Concomitant CYP3A4/5 inducers: as CYP3A4/5 is involved in tiagabine metabolism, adjust the dose when combined with CYP3A4/5 inducers — the estimated plasma concentration in non-induced patients is more than twice that in patients receiving enzyme-inducing agents, so non-induced patients require lower and less frequent doses and may need slower titration; reconsider the dose whenever the patient's enzyme-inducing status changes. Rapid titration and/or large dose increments may not be well tolerated and should be avoided. Children under 12 years: there is no experience in this age group and tiagabine should not be used. Elderly: pharmacokinetics do not appear significantly modified, but only limited information is available — use with caution. Hepatic impairment: reduce the individual doses and/or prolong the dose intervals in mild to moderate impairment and monitor closely for dizziness and tiredness; contraindicated in severely impaired hepatic function. Withdrawal: although there is no evidence of withdrawal seizures, taper off treatment over 2–3 weeks. Post-marketing reports of new onset seizures and status epilepticus in patients without epilepsy — contributing factors include high dosage and fast titration rate.