An open study of tiagabine in partial epilepsy

OBJECTIVE: To make an open assessment of the efficacy and tolerance of tiagabine in a population of patients with drug resistant partial seizures. PATIENTS AND METHODS: We did an open multicentric study, in Spain, in which patients with partial epilepsy treated with one or more drugs were also given tiagabine. The main objective of the study was to determine the initial dose and titration of the drug and secondly to evaluate its efficacy and safety. We recorded data on the etiology of the seizures, their frequency and type and the occurrence of adverse effects. The study took place over a period of one year during which there were five appointments for consultation (after six weeks, three months, six months, nine months and one year). RESULTS: We initially included 1,010 patients of which 941 fulfilled the selection criteria. The average age was 32.2 years. The aetiology was symptomatic in 45%. 61.7% of the patients had had previous treatment with three or more anti epileptic drugs. The doses were changed at a rate of 5mg/day per week. The average dose of tiagabine reached during the maintenance phase was 34mg/day. 9.9% of the patients who were followed up for one year (426) had no seizures after the second consultation (when the maintenance dose of tiagabine was reached). 35% of those who came to their final consultation appointment had had no seizures in the previous three months. 81.7% of the patients followed up for a year had an overall reduction in the number of seizures of over 50% between the first and last consultations. An over 50% reduction in seizures was seen in both those of 12 25 years and the 26 65 years old (75% and 73.1% respectively) whilst 86.7% of the patients aged over 65 years also had this degree of improvement. 48.5% of the patients had some type of adverse effect during the study. Somnolence was the commonest side effect (28.2% of the patients), followed by dizziness (21.5%). In most cases the adverse effects were transient or mild (tolerable). During the study 104 patients had their treatment with tiagabine stopped (11.1%) for intolerance and 113 patients (12%) because it was ineffective. No patient had non convulsive status epilepticus. CONCLUSION: Tiagabine is an effective, well tolerated drug when used as additional treatment in patients with partial epilepsy.