Lacosamide as adjunctive therapy in treatment-resistant epilepsy in childhood

Lacosamide (LCM) is a novel anti-epileptic drug (AED) that enhances the slow inactivation of voltage-gated sodium channels. Its efficacy as adjunctive therapy for focal seizures is confirmed in adult placebo controlled trials with >50% reduction in seizure frequency in up to 50% patients. There is paucity of data on its efficacy and tolerance in treatment-resistant epilepsy in childhood (TREC). This study aims to assess efficacy and tolerance of LCM as adjunct therapy in TREC.

Audit of medical records and seizure diaries in children with TREC on LCM. A response (RR) was defined as ≥50% reduction in seizure frequency.

Forty children (age range: 2-19 years) with TREC received LCM as add-on therapy. All had abnormal electroencephalograms, and 36 had abnormal neuroimaging. All children failed >2 AED trials, nine had trialled the ketogenic diet, five had failed the vagal nerve stimulator and 11 had failed resective epilepsy surgery. Median dose and duration of LCM therapy were 5.7 mg/kg/day and 10.5 months, respectively. RR was seen in 20% with persistence of RR in 8/36, 8/30 and 8/26 children on LCM at 3-, 6- and 9-month follow-up. Two children became seizure free. Retention on LCM was 65% at 9 months. LCM was well tolerated with minor side effects in seven children; no child discontinued LCM because of side effects.

LCM is a well-tolerated AED with RR in 20%: in 5%, it resulted in seizure freedom. LCM may be useful even in TREC when seizures have not responded to intervention with multiple modalities.