Efficacy and safety of phenytoin and levetiracetam for acute symptomatic seizures in children with acute encephalitis syndrome: an open label, randomised controlled trial

•Intention-to-treat analysis for both best and worst-case scenarios showed insignificant differences.•No children experienced seizure recurrence after 1 week in either group.•All the outcomes were comparable in both groups (p>0.05 for all).•Drug acquisition costs were significantly higher in the levetiracetam group.•Adverse events were significantly higher in the phenytoin group. Seizures represent a significant comorbidity in children with acute encephalitis syndrome (AES). Despite this, there is a notable absence of randomized controlled trials (RCTs) directly comparing antiseizure medications (ASMs) in children with AES. This RCT aimed to assess the efficacy and safety of phenytoin and levetiracetam in controlling seizures among children with AES. Both ASMs were administered with a loading followed by maintenance dose. After a 12-week period, children exhibiting a normal electroencephalogram and no seizure recurrence underwent tapering and discontinuation of ASM. Clinical follow-up occurred daily for the first week, and subsequently at 4, 12, and 24 weeks, evaluating seizure recurrence, incidence of status epilepticus, cognition, behavior, functional status, ASM acquisition cost, and adverse effects. A total of 100 children (50 in each group) were enrolled. Within the first week, 5 and 3 children in the phenytoin and levetiracetam groups expired. Up to 1 week or death (whichever occurred earliest), 46 (92 %) and 44 (88 %) children remained seizure-free. Intention-to-treat analysis for both best and worst-case scenarios showed insignificant differences (p=0.52 and 1.0). No children experienced seizure recurrence after 1 week in either group. The number of patients with breakthrough status epilepticus, need for mechanical ventilation, duration of hospital stay, presence of epileptiform abnormalities in repeat electroencephalogram at 12 weeks, functional outcomes at 1, 12, and 24 weeks, as well as cognition and behavioral profiles at 24 weeks, were comparable in both groups (p>0.05 for all). However, the incidence of treatment-emergent adverse events (TEAEs) causally related to study medications was significantly higher in the phenytoin group (p=0.04). Levetiracetam and phenytoin are comparable in efficacy in terms of achieving clinical seizure control in children with acute encephalitis syndrome, although levetiracetam group demonstrated fewer adverse effects.