Two-Year Retention Rate and Clinical Usefulness of Eslicarbazepine Acetate in Epilepsy Patients

Eslicarbazepine acetate (ESL) is a third-generation antiseizure medication (ASM) approved for the treatment of focal seizures. Because of the delayed approval of ESL in Asian countries, there is limited information on the clinical usefulness of ESL in the Asian population. We performed a retrospective analysis of retention rate and seizure outcomes for ESL treatment in Korean epilepsy patients.

A 2-year retrospective observational study was conducted, in which 160 epilepsy patients (82 males; age range, 17-81 years) were treated with ESL. The starting dose of ESL was 400 mg/d, and optimal dose adjustments were made based on individual clinical responses. We analyzed efficacy and tolerability during the 2-year follow-up period.

This study found that the overall retention rate was 81.5% at 1 year and 76.1% at 2 years. The retention rate at 2 years was 86.5% in the monotherapy group and 69.8% in the adjunctive therapy group. Adverse events, mostly dizziness/somnolence and skin eruption, were reported in 38 (23.8%) of patients, leading to discontinuation of ESL in 24 patients. Laboratory hyponatremia was noted in 2 patients, but neither of them experienced symptomatic hyponatremia. Switching from other dibenzazepine ASMs, carbamazepine and oxcarbazepine, was performed in 31 patients (19.4%), and most patients (26 of 31 patients, 83.9%) continued to take ESL until their last follow-up.

Our study demonstrates that treatment with ESL results in favorable retention rates and tolerability among Korean epilepsy patients, which is consistent with data from Western countries. Additionally, our findings suggest that ESL-induced hyponatremia is infrequent and largely asymptomatic when used cautiously and switching from other dibenzazepine ASMs may be a useful option for selected patients.