Retention rate of Clobazam, Topiramate and Lamotrigine in children with intractable epilepsies at 1 year

UNLABELLED Clobazam (CLB), Topiramate (TOP) and Lamotrigine (LAM) are newer second-line antiepileptic drugs (AEDs) used in children. This is a single-centre retrospective observational study of the efficacy, tolerability and retention rate in 224 separate treatment episodes in 194 children, aged 0.1-16.7 years (median 9.4) over an 8 year period. The median age of epilepsy onset was 3.3 years (range 0-15.1). 79% started CLB, TOP or LAM as at least the 3rd AED, with 39% having been withdrawn from at least 2 AEDs. 53% had generalised and 37% idiopathic epilepsies. The maintenance doses for CLB ranged 0.12-3.50 mg/kg/day (mean 0.7); for TOP 0.45-32.0 mg/kg/day (mean 7.1) and for LAM 1.13-16.0 mg/kg/day (mean 5.6). The study comprised 75 person-treatment years for CLB, 56 for TOP, 124 for LAM. RESULTS CLB, TOP and LAM were well tolerated with 51%, 37% and 69% remaining on treatment beyond 1 year respectfully. 1 serious adverse event for CLB (inducing seizures) and 2 for LAM (rashes) were reported, and 60%, 47% and 39% had possibly and probably related adverse events for CLB, TOP and LAM respectively. Beyond 12 months seizure improvement (< 50% seizure frequency compared to baseline) was reported in 43%, 35% and 44% on CLB, TOP and LAM, including 5% and 8% remaining seizure free on CLB and LAM respectively. CONCLUSION Our results demonstrate the efficacy and tolerability of CLB, TOP and LAM in children with difficult to treat epilepsies and a good response in CLB and LAM, and a reasonable response in TOP beyond 12 months.