MONOZEB: Long-term observational study of eslicarbazepine acetate monotherapy

The aim of the study was to evaluate the effectiveness and tolerability of eslicarbazepine acetate (ESL) when used as monotherapy for 1 year or more in routine clinical use in patients with focal seizures in epilepsy clinics in Spain.

This is a retrospective, observational, noninterventional study. Eligible patients were aged ≥18 years, had focal seizures, and started on ESL ≥1 year before database closure. Primary endpoint was the following: proportion seizure-free for ≥6 months at 1 and 2 years. Secondary endpoints included retention on ESL monotherapy at 1 and 2 years, seizure frequency change, seizure worsening, and side effects. Other analyses included seizure freedom from baseline to 1 and 2 years and outcomes in special populations.

Four hundred thirty-five patients were included (127 on first-line monotherapy and 308 converting to ESL monotherapy): median daily dose was 800 mg at all time points; 63.2% were seizure-free at 1 year, 65.1% at 2 years, and 50.3% for the entire follow-up. Mean duration of ESL monotherapy was 66.7 months; retention was 88.0% at 1 year and 81.9% at 2 years. Mean reduction in seizure frequency was 75.5% at last visit. Over the entire follow-up, seizure worsening was seen in 22 patients (5.1%), side effects in 28.0%, considered severe in 1.8%, and leading to discontinuation in 5.7%. Dizziness, hyponatremia (sodium <135 mEq/l), and somnolence were the most frequent side effects. Outcomes in special populations (patients aged ≥65 years and those with psychiatric history or learning difficulty) were consistent with the overall population.

Patients with focal seizures taking ESL monotherapy had excellent retention, high seizure-free rates, and good tolerability up to 2 years.