ADJUNCTIVE TREATMENT OF PARTIAL SEIZURES WITH TIAGABINE - A PLACEBO-CONTROLLED TRIAL

Tiagabine is a new antiepileptic drug which acts by a novel mechanism, inhibiting the reuptake of the inhibitory neurotransmitter gamma-amin obutyric acid (GABA) into neurones and glia. A double-blind, placebo-c ontrolled, crossover trial was undertaken, based upon a response-depen dent design. Ninety-four patients with complex partial seizures with o r without secondary generalised tonic-clonic seizures were recruited i nto an open screening phase and tiagabine was added to their existing drug therapy in doses titrated to reduce seizure frequency by greater than or equal to 25% or to the limit of tolerance. Forty-six responder s were subsequently randomised to a double-blind crossover trial in wh ich tiagabine was compared with placebo. Forty-two patients completed the trial. A significant reduction in the frequency of complex partial and secondary generalised tonic clonic seizures was seen. Twenty-six percent had a reduction of greater than or equal to 50% in the frequen cy of their complex partial seizures, and of the 27 patients who also had secondary generalised tonic clonic seizures, 63% experienced a red uction of greater than or equal to 50%. No interactions with baseline antiepileptic drugs were detected and no serious adverse reactions occ urred. The commonest adverse events were tiredness, dizziness and head ache. We conclude that tiagabine has promising antiepileptic effects. Further trials are underway.