Oxcarbazepine pharmacokinetics and tolerability in children with inadequately controlled epilepsy

Area of Science:

• Pharmacology
• Pediatric Neurology
• Clinical Pharmacy

Background:

• Epilepsy affects children, necessitating effective combination therapies.
• Oxcarbazepine is an antiepileptic drug used in pediatric populations.
• Understanding age-related pharmacokinetic differences is crucial for optimizing pediatric dosing.

Purpose of the Study:

• To evaluate the pharmacokinetics, safety, and tolerability of oxcarbazepine in children aged 2-12 years.
• To compare oxcarbazepine metabolism and dosing requirements between younger (2-5 years) and older (6-12 years) children.
• To assess oxcarbazepine as a combination therapy for inadequately controlled epilepsy in pediatric patients.

Main Methods:

• Two-part, open-label pharmacokinetic and safety study involving 112 children.
• Part I: Single-dose pharmacokinetic assessment (5 mg/kg or 15 mg/kg) stratified by age.
• Part II: 4-month safety, tolerability, and pharmacokinetic study with daily doses ranging from 11 to 68 mg/kg/day.

Main Results:

• Younger children (2-5 years) exhibited approximately 30% lower mean specific AUC and t(1/2) values for the active metabolite (MHD) compared to older children.
• Higher daily oxcarbazepine doses (38% higher) were required in younger children to achieve comparable trough plasma MHD concentrations.
• Mean trough plasma MHD concentrations were 34% lower in younger children on equivalent mg/kg doses.
• Oxcarbazepine was safe and well-tolerated, with only 5% of children discontinuing due to adverse events.

Conclusions:

• Younger children (2-5 years) demonstrate rapid clearance of oxcarbazepine's active metabolite.
• Higher oxcarbazepine doses are necessary in younger pediatric patients to achieve therapeutic concentrations.
• Oxcarbazepine is a safe and effective adjunctive therapy for epilepsy in children aged 2-12 years, with age-specific dosing considerations.