Safety of Eslicarbazepine Acetate in Elderly Versus Non-Elderly Patients with Focal Seizures: From Pooled Data of Clinical Studies to 8 Years of Post-Marketing Experience

Abstract

Introduction: The prevalence of epilepsy increases in elderly patients aged > 65 years, and treatment is challenging because clinical data are limited. Objective: Our objective was to evaluate the safety of eslicarbazepine acetate (ESL) in patients aged ≥ 65 years versus non-elderly patients with focal seizures. Methods: The safety data of seven phase II and III, double-blind, open-label, randomized clinical studies of ESL in adults were pooled. At least possibly related treatmentemergent adverse events (TEAEs) and ESL post-marketing adverse drug reactions (ADRs) were analyzed separately by age categories. Results: The most frequently reported at least possibly related TEAEs in elderly (N = 120) versus non-elderly patients (N = 1863) were dizziness (10.8 vs. 20.3%), somnolence (9.2 vs. 12.6%), and hyponatremia (6.7 vs. 1.5%). Elderly patients presented a higher incidence of serious TEAEs (22.5 vs. 7.6%) and at least possibly related serious TEAEs (6.7 vs. 2.5%), probably because treatment was complicated by comorbidities and comedications. After an estimated cumulative exposure of over 2 million patient-months worldwide and 8 years of post-marketing surveillance, hyponatremia was the most frequently reported ADR (n = 232), accounting for 14.6% and 6.8% of the ADRs reported in elderly (n = 473) and non-elderly patients (n = 2406), respectively. This was followed by ADR/safety information such as drug–dose titration not performed (7.0 vs. 5.4%), product use in unapproved indication (4.9 vs. 1.9%), off-label use (3.4 vs. 2.2%), dizziness (3.4 vs. 3.5%), and seizure (2.1 vs. 5.8%). Conclusion: No specific safety issue was identified from the pooled studies for elderly compared with non-elderly patients. After 8 years of post-marketing surveillance, the qualitative safety of ESL remains similar to that observed in the clinical studies.