Abstracts

Rationale: Eslicarbazepine Acetate (ESL) is a voltage-gated sodium and calcium channel blocker approved by the European Medicines Agency in 2009 and available in Portugal since February 2010, indicated as adjunctive therapy in adults with partial onset seizures (POS) with or without secondary generalization. Observational studies can be useful adjuncts to randomized, controlled trials to determine whether the demonstrated efficacy translates into effective treatment in routine clinical practice. The aim of this retrospective study was to evaluate the efficacy and tolerability of adjunctive ESL in adults with refractory POS treated in our epilepsy center. Methods: All patients treated in our center that started ESL from February 2010 till December 2012 were included. All subjects underwent periodic clinical and instrumental assessments. Retrospectively we collected information regarding demographics, epilepsy history and response to ESL treatment, including seizure frequency, tolerability and ESL withdrawal. Results: Our analysis included 34 patients: 14 (41.2%) were male, mean age was 40.0 years. At the start of ESL therapy mean epilepsy duration was 21.7 years and mean seizure frequency per 4 weeks was 34.6. Most frequently used concomitant AEDs (conAEDs) were: valproic acid (18; 52.9%), levetiracetam (14; 41.2%), lamotrigine (12; 35.3%) and carbamazepine (9; 26.5%). Sixteen (47.1%) patients were treated with 1-2 conAEDs and the remaining with more than 2. Most frequent etiologies were: idiopathic (9; 26.5%), mesial sclerosis (6; 17.6%), head trauma (4; 11.8%) and cerebrovascular disease (4; 11.8%). The main reasons to start therapy with ESL were refractoriness without epilepsy surgery indication (20; 58,8%) or refractoriness and adverse effects with previous drugs (14, 41,2%). At the last follow-up (FU) visit, 23 (67.6%) patients were still on therapy (mean FU duration was 496 days, range 152 - 791). Patients were taking the following ESL daily dosages: 800 mg (16; 69.6%), 1200 mg (4; 17.4%), 400 mg (2; 5.9 %) or 1600 mg (1; 2.9%). Main reasons for ESL withdrawal were: lack of efficacy (5; 14.7%), adverse events (2; 5.9%) or both (3; 8.8%). Reduction in seizure frequency was ≥50% in 21 (61.8%) patients and ≥75% in 16 (47.1%). Three (8.8%) patients were seizure free for more than 6 months. In patients still on ESL therapy (n=23) median relative reduction in seizure frequency was 88.0%; physicians rated "Clinical global impression of change - Global Improvement" as "very much improved" or "much improved" in 21 (91.3%) patients. Conclusions: ESL showed to be effective and well tolerated in this refractory population of adult patients with partial-onset seizures with or without secondary generalization treated at our center. Nevertheless the conclusions are limited by the retrospective nature of the study and also by the reduced number of subjects included.