EpilepsyRx

Oxcarbazepine

Trileptal · Oxtellar XR

Seizure aggravation / coverage
May aggravate absence or myoclonic seizures; review syndrome before use (NICE NG217, UK guidance).

DailyMed-verified antiseizure indications

Indication / use

Label / evidence summary
Immediate-release oxcarbazepine / Trileptal: focal-onset seizures, as monotherapy or adjunctive therapy in adults; pediatric monotherapy from age 4 years and adjunctive therapy from age 2 years. Oxtellar XR: focal-onset seizures from age 6 years.
Role
Maintenance
Class
Sodium-channel modulation, predominantly through active MHD

Indications checked 26 September 2026. Product, route, age, and treatment-role limits apply. A DailyMed listing alone does not establish FDA approval.

Formulations & strengths

U.S. products unless another country is named. Strengths are per unit or stated volume.

Brand & formulation labels

Each link names the product and formulation it covers. Archived labels do not establish current availability.

Dosing & administration

Adult / product-specific schedule
Immediate release often starts 300 mg twice daily; titration and maximum depend on mono- vs adjunctive therapy.
Pediatric
Age 2–16 years: start 8–10 mg/kg/day divided twice daily (maximum starting dose 600 mg/day); typical adjunctive target 30–46 mg/kg/day, with weight-specific caps.
Titration / repeat dosing
Adults IR: start 300 mg twice daily; increase by up to 600 mg/day at approximately weekly intervals. Adjunctive target 1,200 mg/day; selected monotherapy regimens reach 2,400 mg/day. Pediatric dosing is weight based.

Practical administration

Product instructions
Immediate-release tablets and oral suspension may be taken with or without food and substituted at equal doses under prescriber supervision. Follow the exact extended-release product instructions separately.

Dose adjustment & concentrations

Renal impairment
Initiate at one-half usual starting dose when creatinine clearance <30 mL/min.
Hepatic impairment
No adjustment generally required in mild–moderate impairment; severe impairment not adequately studied.
Serum reference information
Mayo trough reference interval for the active monohydroxy metabolite (MHD/MHC): 10–35 mcg/mL. This is a metabolite measurement, not a parent oxcarbazepine level. Toxicity can occur within the interval.

Safety

Boxed warning
No boxed warning.
Contraindications
Hypersensitivity to oxcarbazepine, ingredients or eslicarbazepine acetate.
Serious precautions & monitoring
Monitor sodium when clinically indicated. May reduce hormonal contraceptive effectiveness and can cross-react with carbamazepine hypersensitivity.

Common / selected adverse effects

  • Dizziness
  • Somnolence
  • Diplopia
  • Fatigue
  • Nausea
  • Vomiting

Drug interactions: toxicity & clinical action

Partner / combinationClinical effectClinical action
PhenytoinCan increase phenytoin, especially with oxcarbazepine doses above 1,200 mg/day.Monitor phenytoin concentration and neurotoxicity; reduction may be needed.
Enzyme-inducing ASMs / sodium-lowering medicinesInducers lower active MHD exposure; sodium-lowering drugs add hyponatremia concerns.Monitor seizure control and sodium; reassess after partner changes.
Hormonal contraceptives / eslicarbazepineReduced contraceptive exposure; eslicarbazepine duplicates active-drug exposure.Use additional/alternative nonhormonal contraception; avoid adjunctive eslicarbazepine.

Pregnancy & contraception

Fetal / neonatal risk
Available oxcarbazepine pregnancy data have not demonstrated increased major-malformation prevalence, but study limitations remain. AAN/AES/SMFM recommends considering it when appropriate for the epilepsy syndrome and seizure-control needs.
Contraception
Oxcarbazepine reduces ethinylestradiol and levonorgestrel exposure. Use additional nonhormonal contraception.
Pregnancy / postpartum monitoring
The active MHD concentration may fall during pregnancy and rise postpartum. Monitor seizure control and consider MHD levels and dose reassessment.

Clinical evidence

Research summaries describe studied populations and outcomes; they do not add indications or constitute treatment recommendations.

Direct pivotal trial Guideline-supported off-label use

Trial summary

Study design / duration
Randomized, double-blind, placebo-controlled adjunctive focal-seizure trials in adults and children plus active-controlled conversion-to-monotherapy studies; dose-response and seizure-frequency endpoints were used.
Primary endpoint
No single pivotal endpoint is identified in the cited source.
Results
Pivotal adjunctive focal-seizure trials demonstrated dose-related median reductions of approximately 26–40% versus about 8–9% with placebo. Pediatric adjunctive data showed a median reduction of about 35% versus 9% with placebo.

Trial publications

Mechanism of action

  • Oxcarbazepine is rapidly reduced to S- and R-licarbazepine, collectively called its 10-monohydroxy derivative (MHD); pharmacological activity is predominantly mediated by MHD.
  • Oxcarbazepine and MHD inhibit voltage-sensitive sodium channels in experimental studies, stabilizing excitable membranes and limiting repetitive firing and seizure spread. The exact clinical mechanism is not fully established.
  • MHD is a mixture, not a synonym for pure eslicarbazepine: the S-enantiomer predominates, but the R-enantiomer is also present. Oxcarbazepine is not the acetate prodrug.

Pharmacology

Adult values unless specified. Vd/F denotes apparent oral distribution volume.

Pharmacokinetics

Bioavailability
Completely absorbed orally and rapidly converted to active MHD; oral tablet and suspension have similar exposure.
Elimination half-life
Parent oxcarbazepine: approximately 2 hours.
Volume of distribution
Apparent distribution volume of active MHD: approximately 49 L; the cited label does not give a corresponding parent value.
Active metabolite(s)
Yes: 10-monohydroxy derivative (MHD; licarbazepine enantiomers), responsible for most antiseizure activity.
Active-metabolite half-life
MHD: approximately 9 hours; approximately 19 hours with creatinine clearance <30 mL/min in the label study.
Protein binding
MHD ~40%
Metabolism / elimination
Rapid cytosolic reduction to active MHD; glucuronidation

Do not use the short parent half-life to infer the duration of action of active MHD.

Molecular structure

Molecular structure of Oxcarbazepine — administered parent compound
Parent compound shown. The active MHD metabolites have a different structure.
NIH PubChem structure and record ↗

Product history

Initial U.S. approval
2000
Brands
Trileptal · Oxtellar XR
Manufacturer / marketer
Novartis (Trileptal); Supernus (Oxtellar XR)
Generic availability
Yes (immediate-release); ER status varies
Related drugs
Keto analogue of carbamazepine; rapidly converted to eslicarbazepine/MHD, the same active metabolite emphasized by eslicarbazepine acetate.

Sources & review status

Representative sources are selected product labels, not an exhaustive list of generic manufacturers. Consult the exact product and formulation prescribed. Brand-name package inserts are linked separately.

Brand references: Trileptal tablets / suspension ↗ · Oxtellar XR ↗

Indications and DailyMed PDFs checked: 2026-09-26. Other profile sources reviewed: 2026-09-15 · label revision noted at that review: 1/2026. This is a draft reference; final review is pending.

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