Limited efficacy of gabapentin in severe therapy-resistant epilepsies of learning-disabled patients

Knowledge on the effects of gabapentin (GBP) in learning disabled patients is limited. The objective of this study was to assess antiepileptic efficacy and tolerability of GBP in routine therapy. A retrospective open observational study design was applied. Twenty-nine consecutive residential patients with simple and/or complex partial seizures with or without secondary generalization and with different degrees of learning disability were included. All patients had severe therapy-resistant epilepsy. GBP was administered as add-on therapy. Dosages were progressively increased up to 1600-2400 mg/day (in a number of cases up to 4800 mg/day), in accordance with clinical requirements. The seizure frequency was recorded and compared between a baseline and a treatment period (after 3 months of titration) of 3 months duration each. Only three patients (10.3%) had a reduction of their seizure frequency by 50% or more. No patient became seizure-free. Unwanted side effects, mostly mild and dose-dependent, occurred in 37.9% of all patients. Somnolence and ataxia were the most frequently observed unwanted effects. In two cases hyperphagia/weight increase, and in two other cases edema occurred.We conclude the efficacy of GBP in learning disabled patients with highly therapy-resistant partial seizures is limited.