Main Entry Criteria. Patients aged 18 to 65 years with medication-resistant partial seizures with or without secondary generalization on one to three antiepileptic drugs (AEDs) who responded to tiagabine (≥25% reduction in seizure frequency compared with 8-week baseline) during an open screening phase

Comparator. 12 to 52 mg/day tiagabine (titrated to ≥25% reduction in seizure frequency or unacceptable adverse effects) versus placebo during the 23-week double-blind crossover phase

Number of Patients. Forty-six responders of 94 patients in the open screening phase entered the double-blind phase; 42 completed the study.

Primary Outcome Variable; Important Secondary Variables. Seizure frequency, median percentage seizure reduction, 50% responder rate

Results. Significant reductions in frequency of complex partial seizures and secondary generalized seizures were seen in patients on tiagabine compared to placebo.

Main Entry Criteria. Patients aged 12 to 75 years with medication-resistant partial seizures with or without secondary generalization on one to three AEDs, one of which had to be an enzyme-inducing AED (valproate monotherapy excluded)

Comparator. Tiagabine 16 mg twice daily versus tiagabine 8 mg four times daily versus placebo

Number of Patients. 318 patients entered double-blind phase (351 patients enrolled).

Primary Outcome Variable; Important Secondary Variables. Median change in 4-week rate of complex partial seizures from baseline, 50% responder rate

Results. A significant reduction in frequency of complex partial seizures per 4 weeks was seen in patients on tiagabine q.i.d. compared with placebo. The median change in complex partial seizures frequency per 4 weeks was not significantly different between the tiagabine b.i.d. group and placebo. Fifty percent responder rate was significantly greater in both the tiagabine groups compared to placebo.

Main Entry Criteria. Patients aged 12 to 77 years with medication-resistant complex partial seizures on one to three enzyme-inducing AEDs

Comparator. Tiagabine given q.i.d. for total dose of 16 mg/day versus 32 mg/day versus 56 mg/day versus placebo

Number of Patients. 297

Primary Outcome Variable; Important Secondary Variables. Median change in 4-week complex partial seizure frequency and adverse events; 50% responder rate

Results. Significant reductions in frequency of complex partial seizures per 4 weeks were seen in patients on Tiagabine 32 mg/day or 56 mg/day compared to placebo. Fifty percent responder rates were significantly greater in the 32 mg/day and 56 mg/day tiagabine groups compared to placebo.

Main Entry Criteria. Patients aged 16 to 75 years with medication-resistant partial seizures with or without secondary generalization on one to three AEDs

Comparator. Add-on tiagabine 12 mg/day (divided t.i.d.) titrated up to 30 mg/day versus placebo

Number of Patients. 154

Primary Outcome Variable; Important Secondary Variables. Fifty percent responder rate, median change in 4-week rate of seizures from baseline, number of seizure-free days

Results. A significant reduction in frequency of simple partial seizures and in all partial seizures per 4 weeks was seen in patients on tiagabine compared to placebo. Fifty percent responder rates were not significantly greater in the tiagabine group compared to placebo, and no significant differences were seen between tiagabine and placebo for complex partial or secondarily generalized seizures analyzed as separate groups. The percentage of patients attaining ≥50% increase in seizure-free days (all partial seizures) was significantly greater in the tiagabine group than the placebo group.

Main Entry Criteria. Patients aged 18 to 65 years with medication-resistant partial seizures with or without secondary generalization on one to three AEDs who responded to tiagabine (≥25% reduction in seizure frequency compared to the 8-week baseline)
during an open screening phase (majority were on enzyme-inducing AEDs)

Comparator. 12 to 64 mg/day tiagabine divided q.i.d. (titrated to ≥25% reduction in seizure frequency or unacceptable AE) versus placebo during the 23-week double-blind crossover phase