Oxcarbazepine Dosing Frequency
Oxcarbazepine should be administered twice daily rather than three times daily for most patients, as the half-life of its active metabolite (MHD) supports twice-daily dosing with adequate therapeutic coverage and improved compliance. 1
Pharmacokinetic Rationale
The active metabolite of oxcarbazepine (monohydroxy derivative; MHD) has a plasma half-life that makes twice-daily administration pharmacokinetically appropriate and sufficient for maintaining therapeutic drug levels throughout the dosing interval. 1
Unlike immediate-release formulations of some antiepileptics that require three-times-daily dosing, oxcarbazepine's metabolite profile does not necessitate more frequent administration. 1
Standard Dosing Recommendations
For adults: Initiate oxcarbazepine at 150 mg at night and increase by 150 mg every 2 days until reaching a target dose of 900-1200 mg/day administered in two divided doses. 2
For children: Start at 8-10 mg/kg/day in two to three divided doses, with dose increases of 8-10 mg/kg/day in weekly increments as needed for seizure control. 2, 3
Faster titration is possible, starting with up to 600 mg/day and increasing by 600 mg/day weekly if clinically indicated. 2, 3
Compliance and Practical Considerations
Twice-daily dosing offers superior compliance compared to three-times-daily regimens while maintaining adequate therapeutic coverage throughout the 24-hour period. 4
The risk of breakthrough seizures from missed doses must be balanced against convenience—twice-daily administration provides a reasonable "forgiveness period" if a dose is omitted, whereas once-daily dosing carries higher risk despite marginally better compliance. 4
Three-times-daily dosing is mentioned as an option primarily in pediatric populations where smaller, more frequent doses may be preferred for tolerability, but this is not the standard recommendation. 2, 3
Clinical Advantages of Twice-Daily Dosing
Oxcarbazepine's minimal hepatic enzyme induction and low protein binding result in fewer drug interactions, making twice-daily dosing both practical and effective without the need for more frequent administration. 3, 5
The drug does not require slow titration like some antiepileptics, and twice-daily dosing provides adequate seizure control with better tolerability than more frequent dosing schedules. 3, 5
In summary, standard practice supports twice-daily oxcarbazepine administration for both adults and most children, with three-times-daily dosing reserved only for specific pediatric cases where smaller divided doses improve tolerability. 2, 3