Abstracts

RATIONALE:_ Tiagabine is a new AED approved in the US since 1997 for adjunctive treatment of partial seizures in adults and adolescents at least 12 years of age. Children <12 years were recruited from short-term studies to be followed for long-term treatment with tiagabine. The study recently ended and this is the first report of the complete long-term data. METHODS: Children entered long-term therapy from the short-term studies after parents or guardians signed an informed consent. The children were given open-label tiagabine as adjunctive therapy 2-4 times daily up to 1.0 mg/kg/day for those <10 years old and 80 mg for those 10-12 years old. Titration was 0.25 mg/kg every 2 weeks for those <10 years old and 2-12 mg every 4-7 days if 10-12 years old. Exposure to tiagabine was counted from the first day in the short-term study if the "gap" between studies was <30 days. Conversion to monotherapy was considered attained if continuous for at least 60 days. Adverse events, physical examinations, and laboratory tests were routinely collected. Those continuing on the day of termination of the study were considered completers. These children were offered treatment in a compassionate use study. RESULTS: Thirty-one (31) children with partial seizures entered the study from three short-term studies and 26 (84%) completed. Three were lost to follow-up and two discontinued for lack of efficacy. Twenty-nine children (94%) had exposure to tiagabine of at least one year. The average daily dose was 0.34 mg/kg (range 0.10-0.65). Twenty-three children achieved monotherapy for an average of 964.7 days (range 175-1381). Eighteen of the 26 completers (69%) were on monotherapy at study completion. The most frequent adverse events were infection, somnolence, fever, and headache. No child discontinued for an adverse event. Adverse events were most common during the first six months of therapy. There were no consistent laboratory abnormalities related to study drug. CONCLUSIONS: Tiagabine was well tolerated as adjunctive long-term therapy for partial seizures in children and enabled a majoirty to attain monotherapy.