The electronic health record database was queried to identify patients with a diagnosis of epilepsy (ICD-10 G40*; N=99) or focal epilepsy (ICD-10 G40.0*-G40.2*; n=55), aged ≥4 years, currently treated with ESL, and sodium values available within 3 months prior to ESL initiation (baseline). Serum sodium levels obtained during baseline were compared to levels during ESL treatment (6 months, 1 year). These levels were summarized as the average of all lab values for all patients up to the date of interest and as the single lab value closest to the date of interest (max event) per individual patient.

Most patients started ESL at 400 or 800 mg/day. The mean serum sodium level for epilepsy patients during baseline was 138.9±8.6 mEq/L and remained stable through 12 months of ESL treatment (138.8±6.2 mEq/L), similar to focal epilepsy patients (baseline, 139.2±9.6 mEq/L; 12 months, 137.5±6.6 mEq/L). These results remained when assessing the max event. 4 focal epilepsy patients demonstrated serum sodium level ≤125 mEq/L at ≥1 timepoints during 12 months of ESL treatment. All observations were made in the context of routine delivery of care.

Mean serum sodium values in patients treated with ESL did not change from baseline in a real-world clinical setting over 12 months.