The efficacy of gabapentin in children of partial seizures and the blood levels

AimTo evaluate the long-term efficacy of gabapentin (GBP) and usefulness of measurement of the blood level for the observation of patients that have partial seizures.MethodsThirty patients (20 effective cases and 10 ineffective cases) treated with GBP for the localization related epilepsy had their peak blood levels of GBP. The levels were measured seven time points, one, 6, 12, 18, 24, 30, and 36 month after the start of medication. The efficacy of GBP was evaluated at one month after the initiation of medication and every year for 3 years, based on the R Ratio and the degree of improvement for the paroxysmal strength and length.ResultsGBP levels were higher in the effective cases than the levels in the ineffective cases 6 months after and 1 year after the initiation of medication (p < 0.05). The level 6 months after the start in the effective cases was 5.429 ± 2.384 μg/ml (mean ± SD), and 5.837 ± 3.217 μg/ml after 1 year. The cases that were effective for 1 year maintained approximately the same efficacy for 3 years after the initiation of medication, but there was no correlation between the level and the R Ratio, paroxysmal strength and length.ConclusionsNo precise definition of the therapeutic range was recognized because of no correlation between GBP level and the improvement of clinical manifestations. We recommend the GBP optimal range that is established the range within 3–8 μg/ml (mean; 5 μg/ml) as therapeutic target without the side effect.