OUTCOME EVALUATION OF GABAPENTIN AS ADD-ON THERAPY FOR PARTIAL SEIZURES

Objective: The safety, tolerability, efficacy, and impact on quality o f life of gabapentin (Neurontin(R)) as adjunctive therapy to carbamaze pine (CBZ) and/or phenytoin (PHT) was assessed in epileptic patients w ith partial seizures. Methods: NEON (Neurontin Evaluation of Outcomes in Neurological Practice) was an open-label, prospective, multicentre study conducted in patients on a stable dose of CBZ and/or PHT and exp eriencing an average of up to 4 complex partial seizures with or witho ut secondary generalization per month, with no seizure-free months. Th e treatment lasted 20 weeks. Gabapentin was started at 400 mg/day and was individually titrated to effective tolerable dose up to 2400 mg/da y. Quality of life was evaluated using the QOLIE-10 questionnaire. Res ults: A total of 141 patients were enrolled at 36 sites; 114 patients were evaluable for efficacy analyses. The mean maintenance dose of gab apentin was 1600 mg/day (range = 300-3200). A decrease of 50% or more in frequency of complex partial + secondarily generalized seizures was observed in 81 (71%) patients (p = 0.0001). Fifty two (46%) patients were seizure-free during the last 8 weeks of treatment. A significant improvement (p < 0.05) was observed in 5 of the 10 questions of the QO LIE-10, as well as in the composite QOL score (p = 0.0002). The most f requent adverse events included somnolence (16%), dizziness (9%), and asthenia (6%). Twenty-five (18%) patients prematurely discontinued the study, 16 (11%) of them due to adverse events. Conclusions: This stud y indicates that treatment with gabapentin as adjunctive therapy to st andard antiepileptic drugs in this group of patients not only provides significant improvement in seizure control, but also has a positive i mpact on quality of life. The clinical benefits in efficacy, safety an d tolerability demonstrated at 20 weeks are sustained, and no toleranc e develops with gabapentin in longer term use.