Gabapentin as add-on therapy in children with refractory partial seizures: a 12-week, multicentre, double-blind, placebo-controlled study. Gabapentin Paediatric Study Group. Gabapentin (Neurontin) as add-on therapy in patients with partial seizures: a double-blind, placebo-controlled study. The International Gabapentin Study Group. Double-blind study of Gabapentin in the treatment of partial seizures. Gabapentin as add-on therapy in refractory partial epilepsy: a double-blind, placebo-controlled, parallel-group study. The US Gabapentin Study Group No. 5.
To evaluate the efficacy and safety of gabapentin (Neurontin; GBP) as add-on therapy for refractory partial seizures in paediatric patients aged 3-12 years.
                After a 6-week baseline period, 247 patients (54 centres) entered a 12-week double-blind phase and were randomized to receive either GBP (t.i.d., titrated to 23-35 mg/kg/ day) or placebo. Seizure activity and type were recorded daily. Efficacy variables included Response Ratio (RRatio), responder rate, and percentage change in frequency (PCH) for all partial seizures; PCH and RRatio for individual types of partial seizures; and investigator and parent/guardian global assessments of seizure frequency and patient well-being.
                RRatio for all partial seizures was significantly lower (better) for GBP-treated patients (p = 0.0407). Responder rate favored GBP, but the difference between treatment groups was not statistically significant. Median PCH for all partial seizures for the GBP treatment group (-17.0%) was better than that for the placebo group (-6.5%). Median PCH for specific seizure types showed GBP to be most effective in controlling complex partial seizures (-35%) and secondarily generalized seizures (-28%) when compared with placebo (-12%, +13%, respectively). A greater percentage of GBP-treated patients exhibited improvement according to investigator and parent/guardian global assessments, with a statistically significant difference observed in the parent/guardian global assessment of seizure-frequency reduction (p = 0.046). Three GBP patients and one placebo patient were seizure free during the double-blind treatment period. GBP was well tolerated.
                GBP was effective and well tolerated as an add-on therapy for partial seizures in paediatric patients with previously drug-resistant seizures. A multicenter, double-blind, randomized, placebo-controlled study evaluated the efficacy and safety of gabapentin (Neurontin, GBP) as add-on therapy in 272 patients with refractory partial seizures who were receiving one to two standard antiepileptic drugs (AEDs). Efficacy assessments compared the frequency of partial seizures during the 12-week treatment phase (T) and the 12-week baseline period (B). The primary analysis compared data for patients receiving GBP 900 mg/day with placebo; the GBP 1,200-mg/day group provided dose-response data. Efficacy criteria were percentage of change in seizure frequency (PCH), responder rate (percentage of patients with > or = 50% reduction in seizure frequency), and response ratio, where RRatio = (T-B)/(T + B). Median PCH was -21.8% in the 900-mg/day group and -17.8% in the 1,200-mg/day group as compared with -0.3% in the placebo group. Responder rate was 22.9% in the 900-mg/day group and 10.1% in the placebo group (p = 0.020, Fisher's exact test). Adjusted mean RRatio was -0.136 in the 900-mg/day group and -0.025 in the placebo group (p = 0.0046, analysis of variance ANOVA). Results showed slightly greater improvement for the 1,200-mg/day than for the 900-mg/day group (RRatio = -0.157, responder rate 28.0%). Adverse events (AE) occurred in 69% of patients in the 900-mg/day group and in 64% in the 1,200-mg/day group as compared with 52% in patients receiving placebo as add-on therapy. The most frequent AE among patients treated with GBP were somnolence, dizziness, and fatigue. Clinical laboratory evaluations showed no clinically important trends and no evidence of hepatic or hematopoietic effects.(ABSTRACT TRUNCATED AT 250 WORDS) Forty-three patients completed a double-blind, placebo-controlled study of Gabapentin (GBP) as add-on therapy in partial and secondarily generalized seizures. All patients were followed for an initial 3-month baseline period, after which they were randomly allocated to receive either a placebo or 900 or 1,200 mg/day GBP for 3 months. A statistically significant difference in seizure frequency from the baseline to the treatment phase was noted between patients receiving placebo and GBP 1,200 mg, in whom seizure frequency decreased 57%. The GBP dosage of 900 mg appeared to be ineffective. A close relationship was observed between the serum GBP concentrations and the GBP dosage based on the seizure frequency. Serum GBP concentrations greater than 2 micrograms/ml resulted in a lower frequency of seizures. The adverse effects were minor and consisted mainly of transient drowsiness. GBP appears to be effective in the treatment of partial epileptic seizures in a dosage-related manner. Gabapentin, administered as add-on therapy, was safe and effective in this 12-week, multicenter, placebo-controlled, parallel-group study in 306 patients with refractory partial epilepsy. For patients in each gabapentin treatment group (600, 1,200, or 1,800 mg/d), the mean response ratio was significantly better than that of a placebo group. The percentage of patients achieving at least a 50% reduction in seizure frequency was 8% among placebo-treated patients and ranged from 18% to 26% for patients who received gabapentin. Adverse events were generally mild and transient and occurred at a slightly higher frequency among patients receiving gabapentin than among those receiving placebo. Gabapentin did not affect the serum concentrations of concurrent antiepileptic drugs and was not regularly associated with any deviations in clinical laboratory values. Gabapentin's low inherent toxicity and its lack of drug interactions make it an ideal candidate for use as add-on therapy in patients with refractory partial epilepsy.
Gabapentin has efficacy as an add-on treatment in people with drug-resistant partial epilepsy. However, trials reviewed were of relatively short duration, and provide no evidence for the long-term efficacy of gabapentin. Results cannot be extrapolated to monotherapy or people with other epilepsy types.