What is the most common antiepileptic (antiseizure) medication for children?

Most Common Antiseizure Medication for Children

Levetiracetam is the most commonly used antiseizure medication in contemporary pediatric practice, though traditional first-line agents like carbamazepine, phenobarbital, phenytoin, and valproic acid remain standard options depending on seizure type and clinical context. 1, 2

Current Practice Patterns

The landscape of pediatric antiseizure medication has evolved significantly:

• Levetiracetam has emerged as a preferred choice due to its broad-spectrum efficacy, favorable safety profile, minimal drug interactions, and ease of use in children 3, 4, 5
• The drug is FDA-approved for adjunctive therapy in pediatric patients aged 4 years and older with partial-onset seizures, and for patients 12 years and older with juvenile myoclonic epilepsy 3
• In clinical trials, levetiracetam demonstrated 26.8% greater reduction in partial seizure frequency compared to placebo in children, with responder rates (≥50% seizure reduction) significantly higher than placebo 3

Traditional First-Line Agents

Despite levetiracetam's popularity, guidelines still recommend traditional agents as standard first-line options:

• For focal (partial-onset) seizures: Carbamazepine remains the guideline-recommended first-line agent, particularly effective in children and adults 2
• For generalized epilepsy: Valproic acid or phenobarbital are standard options, with phenobarbital specifically recommended as first choice in resource-limited settings due to lower cost 1, 2
• Phenytoin is another standard option but may have higher risk of behavioral adverse effects in children with intellectual disability compared to valproic acid or carbamazepine 2

Levetiracetam-Specific Considerations in Children

Efficacy Profile

• Effective for both partial and generalized seizures in pediatric populations 4, 5
• Responder rates in resistant partial epilepsy reach 64%, with 8-23% achieving seizure freedom 5
• Shows comparable efficacy in children with intellectual disability (83% with >50% seizure reduction) versus normal intelligence (96%), though slightly lower in the ID population 6

Dosing in Pediatrics

• Initial dosing: 20 mg/kg/day in two divided doses 3
• Target dose: 60 mg/kg/day, titrated in 20 mg/kg/day increments at 2-week intervals 3
• Children generally require 130-140% of adult doses due to faster metabolism 5

Safety and Tolerability

• Generally well-tolerated with 75% retention rates at 2 years in both children with normal intelligence and intellectual disability 6
• Most common adverse effects: Behavioral changes, irritability, and psychotic reactions, occurring more frequently in younger patients under 4 years of age 4, 7
• Behavioral side effects typically occur early (even during titration) and at low doses (<20 mg/kg/day), but are reversible upon discontinuation 4
• Important mitigation strategy: Pyridoxine supplementation may ameliorate behavioral side effects, with evidence from randomized controlled trials showing more prominent improvement compared to placebo 7

Clinical Decision Algorithm

For new-onset epilepsy in children:

1. Determine seizure type first - this drives medication selection more than any other factor 1, 2

2. For partial-onset seizures:

   • Start with carbamazepine as guideline-recommended first-line 2
   • Consider levetiracetam as alternative if carbamazepine contraindicated or not tolerated 2, 3

3. For generalized seizures:

   • Valproic acid is standard (avoid in females of childbearing potential) 1, 2
   • Phenobarbital in resource-limited settings 1
   • Levetiracetam as alternative for juvenile myoclonic epilepsy 3

4. For refractory epilepsy:

   • Levetiracetam shows particular promise as adjunctive therapy with 38.7% achieving ≥50% seizure reduction 8

Critical Pitfalls to Avoid

• Don't routinely prescribe antiseizure medications after a first unprovoked seizure - this exposes children to unnecessary side effects 1, 2
• Don't overlook behavioral monitoring with levetiracetam - especially in children under 4 years where behavioral side effects are more common 4
• Don't use rapid titration with levetiracetam - slow titration helps avoid increased seizure frequency as an adverse reaction 5
• Don't forget pyridoxine trial - if behavioral side effects emerge on levetiracetam, try therapeutic-dose pyridoxine before switching medications 7
• Don't use valproic acid as first-line in adolescent females - teratogenic risk necessitates alternative agents 2

Special Population: Seizure Prophylaxis

For specific high-risk scenarios, levetiracetam is explicitly recommended:

• CAR T-cell therapy recipients with CNS disease or seizure history should receive levetiracetam prophylaxis at 10 mg/kg (maximum 500 mg) every 12 hours for 30 days post-infusion 9
• This reflects levetiracetam's favorable profile with minimal drug-drug interactions and no effect on cytokine levels 9