Abstracts

Rationale: Brivaracetam (BRV) is the latest antiepileptic drug (AED) to be licensed in Europe and the USA as add-on therapy in focal pharmacoresistant epilepsies. BRV is an n-propyl analogue of levetiracetam (LEV), with more selective affinity to the synaptic vesicle protein 2A (SV2A). We aim to evaluate the real-life experience with BRV in a Spanish tertiary hospital, with special interest on those patients that switched LEV for BRV. Methods: Patients older than 18 years that had received BRV orally were retrospectively evaluated. Data from clinical records were analyzed at baseline, 3, 6, 12 months and later on to assess dosages, effectiveness, tolerability, adverse-events (AEs) profile and retention rate. Results: Seventy-four patients (37 female) patients were included in the observational study. The average age was 42.5 y.o. (SD 15), the median age at epilepsy onset 12 (3.4-18) y.o. The median follow-up was 6.8 months (SD 5.5). The most frequent epileptic syndromes were epilepsy of unknown cause (39.7%), mesial temporal lobe epilepsy with hippocampal sclerosis 10 (13.7%) and malformations of cortical development 5 (6.8%). The median seizure frequency prior BRV onset was 5 seizures/month (IR 2.5-13). 5 patients were treated with 50mg BRV per day (7.1%), 1 with 75mg (1.4%), 9 with 100mg (12.9%), 8 with 150mg (11.4%), 41 with 200mg (58.6%) and 6 with 300mg (8.6%). At the end of follow up, 4 patients (6.2%) were seizure-free, 12 (18.5%) had a reduction = 80%, 8 patients (12.3%) showed a reduction of 50%, 24 patients (36.9%) reported no changes and 12 (18,5%) got worse. No differences were found among those patients with doses higher than 100 or 200 mg/d. 2/4 generalized epilepsies showed improvement.10 (13.5%) of patients presented AEs, the most common being irritability, depression, sleep disorders and somnolence. No laboratory alterations were detected except in one patient (mild thrombocytopenia). The final retention rate was 79.1%. The switch from LEV to BRV was conducted in 26 (35.1%) cases, mainly due to LEV inefficacy 22 (84.6%), AEs 2 (7.6%) or both 2 (7.6%). The switch was done overnight in 72% of patients and gradually in 28%, during a median of 4 (IC 4-11.5) weeks. The mean dose ratio was 1 mg BRV per 12.7mg LEV. 9 out of 26 (34.6%) patients showed an improvement in seizure frequency after the switch, and BRV was well tolerated in 3/4 cases with previous AEs on LEV. No differences in effectiveness or EAs were observed in those cases with overnight switch. Conclusions: BRV shows a positive efficacy in the treatment of focal pharmacoresistant epilepsies. It is very well tolerated and shows a high retention rate (approximately 80%). The overnight switch from LEV to BRV could be performed in a safe manner with minimum equivalence ratio of 1mg of BRV per 10mg of LEV. Funding: None