Abstracts

Rationale: Eslicarbazepine acetate (ESL) is a voltage-gated sodium channel blocker approved in Europe since 2009. It is available in Portugal since April 2010. In spite of the good safety and efficacy shown in clinical trials, little is known about its safety and effectiveness in clinical practice. Our aim was to assess the safety profile and retention rates of ESL in the outpatient clinic patients, from our tertiary epilepsy center. Methods: All outpatients who initiated treatment with ESL between 04/01/2010 and 03/31/2012 were consecutively included. We retrospectively collected data on demographics, clinical features, neurophysiology, imaging, treatment response, compliance and side effects. Only patients with at least one follow-up visit were included in the safety analysis. Follow-up time was defined as the time between ESL initiation and the last follow-up visit. Results: We included 148 patients in the safety analysis, 72 (48.6%) were women. Mean age at ESL initiation was 38.5 years-old (sd=14.4), mean epilepsy duration was 26.0 years (sd=13.3) and median seizure frequency was 10 seizures/month. At the baseline, 58.8% were taking ≤2 antiepileptic drugs (AEDs). The median follow-up time was 12.3 months (IQR=5.4-20.1). The retention rates at 6 months, 12 months and 18 months, were 80.1% (109/136 patients), 65.8% (75/114) and 52.7% (48/91), respectively. Forty five patients (30.4%) discontinued ESL during the follow-up; 2 after 18 months. Therapy discontinuation was due to side effects in 28 patients (62.2%), lack of efficacy in 14 patients (31.1%) and other causes in 3 patients (6.7%). Total adverse event rate was 39.2% (58 patients); in 51.7% (30 patients) the adverse events did not lead to treatment discontinuation. The most frequent adverse events were somnolence/cognitive slowness (16 patients), dizziness (15) and gastrointestinal symptoms (7). Conclusions: In our series, ESL appears to be well-tolerated. Adverse events were present in approximately 2 out of 5 patients, but only in half led to the discontinuation of medication.