GABI-balance--a non-interventional observational study on the effectiveness of tiagabine in add-on therapy in partial...

Effectiveness of tiagabine (TGB) in open-label studies tends to be higher than in controlled, especially premarketing, studies. This article presents results of an open-label prospective study GABI-balance carried out in Poland and designed to evaluate effectiveness of TGB in add-on therapy of refractory partial and/or secondarily generalized epilepsy.

Data of 1979 patients (54%--M, 46%--F, mean age 39.2 years) with a mean history of 10.9 years of epilepsy were analyzed. Total initial number of epileptic seizures (n = 12,162) included simple partial seizures (n = 4702; 38.7%), complex partial seizures (n = 7083; 58.7%) and/or secondarily generalized partial seizures (n = 6408; 52.7%). The mean 4-week seizure rate per patient during the period preceding TGB therapy was 6.4. TGB was used over 16 weeks, starting from 5 mg/day with subsequent upwards titration. Results of the treatment were evaluated after 8 and 16 weeks. Assessments included reduction of mean monthly seizure rate, percentage of responders with seizure rate reduction of 50% or more, number of patients who completed the study, adverse effects, and Clinical Global Impression (CGI) scale.

The mean initial seizure rate per patient (6.4) decreased to 3.3 after 8 weeks and to 1.8/month after 16 weeks. The mean initial dose of TGB--9.2 mg/day--was contemporarily increased to 23.4 and 29.9 mg/d, respectively. Percentage of responders with > or = 50% reduction of seizure rate reached 52% after 8 weeks and 77.2% after 16 weeks; 93.7% of patients were still observed after 16 weeks. Adverse effects, reported by 12.7% of patients after 8 weeks and 8.6% after 16 weeks, were mild or moderate. No serious adverse events were observed. The most frequent were somnolence/fatigue, headache/nausea, anxiety/mood disorders. According to treating physicians, add-on therapy with tiagabine in the GABI-balance study was highly effective in more than 80% of patients.

Our results indicate that in everyday neurological outpatient practice, the add-on TGB therapy in patients with active partial and/or secondarily generalized epilepsy improved efficacy of the treatment with high safety maintained. Higher doses resulted in better effects of the therapy, and adverse effects were mild and less frequent with treatment duration.