Abstracts

Rationale: The use of ezogabine for the treatment of partial-onset seizures has been well-established among adult patients with epilepsy since its emergence in 2011. This medication has a novel mechanism of action, enhancing transmembrane potassium channels. While its safety and efficacy has been studied within the adult population, its use among pediatric patients is less established, possibly owing to its side effect profile and lack of published data exploring the use of this drug in children. The aim of this study was to retrospectively examine the efficacy and safety of ezogabine among pediatric patients from two tertiary care children's hospitals. Methods: We performed a retrospective review of clinical records from two academic centers, and pediatric epilepsy patients treated with ezogabine were included. Weight-based dosing was determined for the initial and maximum doses, and duration of treatment was noted in addition to type and etiology of seizures. Subsequent clinical notes were reviewed to determine if there was a clinically significant reduction in seizure frequency (greater than 50% seizure reduction), as well as to determine the emergence of potentially adverse events attributed to the use of ezogabine. Results: Twelve patients were treated with ezogabine. Two patients were excluded from analysis of seizure reduction due to treatment duration of less than 14 days. Patient ages ranged from 15 months to 17 years. Of the ten patients treated for at least 14 days, four patients reported seizure reduction, but in only two patients (20%) was the reduction in seizure frequency greater than 50%. Adverse events were noted in eight patients (67%). Reasons for discontinuation of medication in seven patients included adverse events in 5 of these patients. Adverse events likely related to ezogabine included: urinary retention (4 patients), seizure exacerbation (2 patients), and behavior change (1 patient). One patient died during treatment from medical problems unrelated to ezogabine usage. One patient was noted to have an orbital tumor seven months after discontinuing ezogabine treatment. Conclusions: Overall, the majority of patients within this study did not respond to treatment with ezogabine. Urinary retention seemed to occur at a rate higher than that reported in studies of ezogabine usage in adults. While reduction of seizures with ezogabine was not appreciated in the majority of patients reviewed for this study, further prospective studies are needed to better delineate the effectiveness and safety of ezogabine in the treatment of pediatric epilepsy. In this case series, we cannot exclude selection bias and confounding by indication, specifically that patients treated with ezogabine had more severe epilepsy than patients in previous trials, as this medication was usually added in extremely refractory epilepsy patients.