What is oxcarbazepine used for in adults and children with a history of seizures or epilepsy, or a diagnosis of bipolar disorder?

Oxcarbazepine Indications

Oxcarbazepine is FDA-approved for the treatment of partial-onset seizures in adults and children, used either as monotherapy or adjunctive therapy. 1

Primary FDA-Approved Indication: Epilepsy

Adult Patients

• Oxcarbazepine is indicated for monotherapy or adjunctive therapy in the treatment of partial-onset seizures in adults 1
• Clinical trials demonstrate efficacy comparable to phenytoin and valproic acid for reducing generalized tonic-clonic and partial seizure frequency in newly diagnosed patients 2
• As adjunctive therapy, oxcarbazepine at doses of 600,1200, and 2400 mg/day significantly reduced seizure frequency compared to placebo in 692 patients with refractory partial seizures 2

Pediatric Patients

• For monotherapy: oxcarbazepine is approved for children aged 4 years and older with partial-onset seizures 1
• For adjunctive therapy: oxcarbazepine is approved for children aged 2 years and older with partial-onset seizures 1
• The American Academy of Neurology recommends initiating oxcarbazepine at 8-10 mg/kg/day divided into 2-3 doses, titrated by 10 mg/kg/day weekly to target doses of 30-46 mg/kg/day for pediatric epilepsy 3
• Efficacy is similar to phenytoin in treating children and adolescents with newly diagnosed partial or generalized tonic-clonic seizures 2, 4

Special Epilepsy Populations

• For patients with benign familial infantile epilepsy (BFIE) carrying PRRT2 mutations, oxcarbazepine is a preferred anti-epileptic drug due to known favorable response in patients with paroxysmal kinesigenic dyskinesia 5

Off-Label Use: Bipolar Disorder

• Oxcarbazepine has been studied for use in bipolar disorder and schizoaffective disorder, though this is not an FDA-approved indication 6
• Clinical trials suggest potential usefulness for manic symptoms in bipolar and schizoaffective patients, with case reports and prospective studies indicating possible prophylactic efficacy 6
• However, this remains an off-label use with limited controlled trial data and relevant methodological shortcomings in existing studies 6

Key Clinical Considerations

Advantages Over Carbamazepine

• Oxcarbazepine has a more favorable pharmacokinetic profile with linear pharmacokinetics, no autoinduction, and minimal interaction with other antiepileptic drugs 7
• Better tolerated than phenytoin in both adults and children, with fewer adverse events leading to treatment withdrawal (<8% discontinuation rate) 2
• Lower propensity for drug interactions because its major metabolic pathway is mediated by noninducible enzymes 2

Important Safety Monitoring

• Hyponatremia occurs in 2.7-3% of patients, though usually asymptomatic 2, 7
• Close monitoring of sodium levels is required in elderly patients at risk for hyponatremia 1
• Serum sodium monitoring is unnecessary unless relevant risk factors or clinical pointers exist 8

Critical Drug Interactions

• Oxcarbazepine decreases the effectiveness of oral contraceptives containing ethinylestradiol or levonorgestrel 1, 8
• Alternative or additional non-hormonal contraceptive methods must be used 3, 1
• Can inhibit CYP2C19 and induce CYP3A4/CYP3A5, potentially interfering with metabolism of other drugs like phenytoin 4

Cross-Sensitivity Warning

• Many people allergic to carbamazepine are also allergic to oxcarbazepine 1
• Oxcarbazepine is not the first-choice alternative for patients developing a carbamazepine rash due to increased rash rate in carbamazepine-sensitive subjects 8