Trileptal

(oxcarbazepine)

Trileptal (oxcarbazepine); not controlled

Summary

Trileptal is a sodium channel blocking antiepileptic, supplied as tablets and oral suspension, approved only for partial seizures: monotherapy from 4 years, adjunctive from 2 years. It carries no psychiatric indication at any age, so use for aggression, mood dysregulation or impulse control is entirely off-label. Its defining safety issue is hyponatremia, common enough to require scheduled sodium checks. Not controlled; brand and generic.

Forms & Strengths

• Tablets: 150 mg, 300 mg, 600 mg
• Oral suspension: 300 mg/5 mL
• Extended-release tablets: 150 mg, 300 mg, 600 mg

Dosing

• Age:
  • Partial seizures, monotherapy: 4 y/o and older
  • Partial seizures, adjunctive: 2 y/o and older
  • Psychiatric and behavioural use: no approved age; entirely off-label
• Onset: 2 to 4 weeks, the time titration takes to reach target
• Duration: continuous with twice-daily dosing
• Initial Dose:
  • Pediatric monotherapy, 4 to 16 y/o: 8 to 10 mg/kg/day in two divided doses
  • Pediatric adjunctive, 2 to 16 y/o: 8 to 10 mg/kg/day divided, generally not above 600 mg/day
  • Under 20 kg: 16 to 20 mg/kg/day may be considered
  • Adults, all uses: 600 mg/day in two divided doses
• Titration:
  • Pediatric monotherapy initiation: 5 mg/kg/day every 3 days
  • Pediatric conversion to monotherapy: up to 10 mg/kg/day weekly
  • Pediatric adjunctive: reach target over 2 weeks, or 2 to 4 weeks under 4 y/o
  • Adults: up to 600 mg/day weekly; 300 mg/day every third day for monotherapy
• Max Dose:
  • Pediatric adjunctive, 2 to under 4 y/o: 60 mg/kg/day
  • Adjunctive 4 to 16 y/o: 900 mg/day at 20 to 29 kg, 1200 mg/day at 29.1 to 39 kg, 1800 mg/day above 39 kg
  • Monotherapy maintenance: 600 to 900 mg/day at 20 kg, up to 1500 to 2100 mg/day at 70 kg
  • Adults: 2400 mg/day, which most patients cannot tolerate
• Considerations: All dosing is twice daily. Halve the starting dose to 300 mg/day and titrate slowly if creatinine clearance is under 30 mL/min; no adjustment for mild to moderate hepatic impairment.

Pharmacology

• Mechanism: Blocks voltage-gated sodium channels, stabilising hyperexcited membranes; no demonstrated interaction with brain neurotransmitter or modulator receptors
• Delivery / Release: immediate-release, completely absorbed, median Tmax 4.5 hours; with or without food
• Metabolism: prodrug converted to the active 10-monohydroxy derivative (MHD); half-life 2 hours parent, 9 hours MHD, 19 hours if creatinine clearance is under 30 mL/min
• Pharmacogenomics: HLA-B*1502 carriers risk Stevens-Johnson syndrome and toxic epidermal necrolysis. Test before starting in at-risk ancestry; avoid unless benefit clearly outweighs risk.
• Class Positioning: like carbamazepine but with much less enzyme induction; hyponatremia is more frequent, not less. Adjunct to an ADHD regimen (Concerta, Strattera, Qelbree), never a replacement.

Indications

• Partial Seizures, monotherapy (ICD-10: G40.1, G40.2): patients 4 y/o and older, and adults
• Partial Seizures, adjunctive therapy (ICD-10: G40.1, G40.2): patients 2 y/o and older, and adults
• No other approved indication exists, psychiatric or otherwise, at any age.

Off-Label Uses

• Aggression, irritability and mood dysregulation (ICD-10: F90.x, F91.x): limited data. Risperidone (Risperdal) has moderate graded evidence here; oxcarbazepine has none. (AHRQ 2017)
• Where the evidence does not support use:
  • Pediatric bipolar disorder (ICD-10: F31.x): insufficient; the carbamazepine analogy is pharmacological, not evidential.
  • Neuropathic pain, trigeminal neuralgia (ICD-10: G50.0, M79.2): insufficient; no pain indication at any age.
  • Generalized seizures (ICD-10: G40.3): insufficient and potentially harmful; can worsen some generalized epilepsies.

Contraindications & Warnings

• Class warning, suicidal behaviour and ideation: antiepileptics roughly double the risk (adjusted RR 1.8, 95% CI 1.2 to 2.7), from week one, in every indication.
• Contraindicated: known hypersensitivity to oxcarbazepine or any component.
• Use with caution:
  • Prior carbamazepine hypersensitivity: 25% to 30% cross-react. Ask directly.
  • Ancestry in a high HLA-B*1502 frequency population, for Stevens-Johnson syndrome and toxic epidermal necrolysis risk.
  • Any other sodium-lowering drug: thiazides, SNRIs, drugs causing inappropriate ADH secretion.
  • Creatinine clearance under 30 mL/min: halve the starting dose; MHD half-life roughly doubles.
  • Hormonal contraception in an adolescent, because oxcarbazepine reduces its effectiveness.
  • Pregnancy or possible pregnancy, because oxcarbazepine is likely a human teratogen.
• Screen before starting:
  • Baseline serum sodium; a later result cannot be interpreted without it.
  • Prior reaction to carbamazepine, asked as a direct question.
  • Ancestry, to decide whether HLA-B*1502 testing is indicated first.
  • Renal function; the medication list for sodium-lowering drugs and hormonal contraception.
  • Baseline mood and any history of suicidal ideation.

Drug Interactions

• Hormonal contraceptives (oral, patch, ring): effectiveness is reduced. Arrange an alternative or added method before the first dose.
• Other antiepileptics (carbamazepine, phenytoin, phenobarbital): mutual changes in exposure above 1200 mg/day. Check their levels through titration and at any dose change.
• Calcium antagonists (felodipine, verapamil): exposure is altered. Recheck blood pressure after any change.
• Other sodium-lowering drugs (thiazides, SSRIs, SNRIs, desmopressin, carbamazepine): additive hyponatremia. Check sodium 2 to 4 weeks after starting and at any dose change.
• Laboratory tests: T4 falls without T3 or TSH change. Read an isolated low T4 as a drug effect, not hypothyroidism.

Administration

• Give twice daily at roughly 12-hour intervals. The extended-release oxcarbazepine product is a separate NDA and must not be substituted milligram for milligram.
• May be taken with or without food.
• Use the oral suspension for weight-based pediatric dosing rather than splitting tablets.
• The suspension is 60 mg/mL: divide the milligram dose by 60 for millilitres.
• Shake the suspension; measure with a calibrated oral syringe, never a kitchen spoon.
• Do not stop abruptly. See Discontinuation & Taper.

Side Effects

• Common (at least 5%, above placebo): dizziness, somnolence, diplopia, fatigue, nausea, vomiting, ataxia, abnormal vision, abdominal pain, tremor, dyspepsia, abnormal gait
• Serious:
  • Hyponatremia: sodium below 125 mmol/L in 2.5% of treated patients, usually asymptomatic. Reduce the dose or stop.
  • Anaphylaxis and angioedema of the larynx, glottis, lips or eyelids: stop and never rechallenge.
  • Stevens-Johnson syndrome and toxic epidermal necrolysis, median onset 19 days. Stop for any rash.
  • DRESS: fever, rash or lymphadenopathy with organ involvement. Discontinue unless another cause is established.
  • Dose-related psychomotor slowing, impaired concentration, speech problems, ataxia and gait disturbance.
  • Pancytopenia, agranulocytosis and leukopenia, rare: consider discontinuation.

Monitoring & Labs

• Serum sodium: baseline, 2 to 4 weeks after starting, after every dose increase, at 3 months, then at least every 6 months; also 2 to 4 weeks after adding any sodium-lowering drug.
• Serum sodium, unscheduled: for nausea, malaise, headache, lethargy, confusion, obtundation, or rising seizure frequency. Act before 125 mmol/L.
• Suicidality and mood: at 1 week, 1 month, every dose change, and each routine visit thereafter.
• Skin: ask about rash at every visit for the first 3 months; the family reports any rash the same day.
• Cognitive and motor function: ask family and school about concentration, sleepiness and falls at each dose increase and every 6 months.
• Contraception review: every visit, in any adolescent who could become pregnant.

Discontinuation & Taper

• Withdraw gradually, per the label, to minimise increased seizure frequency. This holds even for off-label behavioural use.
• Converting to another antiepileptic: withdraw over 3 to 6 weeks while the replacement reaches target over 2 to 4 weeks.
• Stop permanently, no rechallenge, for anaphylaxis, angioedema or any serious dermatological reaction.
• Discontinue for DRESS unless an alternative cause is established.
• Reduce or stop for clinically significant hyponatremia; sodium normalises within a few days.
• Drug holidays are not appropriate for either use.

Pregnancy & Lactation

• Pregnancy: No adequate controlled studies; the label states oxcarbazepine is likely a human teratogen. Use only if benefit justifies risk.
• Pregnancy, dosing: plasma MHD falls through pregnancy and returns after delivery; monitor seizure control across pregnancy and postpartum.
• Lactation: milk-to-plasma ratio 0.5; levels low, adverse effects not expected beyond 2 months. Monitor infant drowsiness, weight gain, milestones. (LactMed 2024)
• Exposure Registry: North American Antiepileptic Drug Pregnancy Registry, 1-888-233-2334; the patient enrolls herself.

Counseling Points

• Counsel the family on:

  • This being a seizure medicine; behavioural use is off-label, with no approved dose ladder.
  • The sodium blood test schedule, done even when the child feels well; most affected children have no symptoms.
  • Reporting any rash the same day; name blistering, peeling and mouth or eye sores.
  • Sleepiness, unsteadiness and double vision being dose-related; report after an increase.
  • Never stopping suddenly, even if it seems to be doing nothing: that can trigger seizures.
  • For an adolescent who could become pregnant: less reliable hormonal birth control, likely fetal harm.

• Advise them to call for:

  • Blistering or peeling skin, or mouth, eye or genital sores, immediately.
  • Swelling of the lips, tongue, eyelids or throat, or trouble breathing.
  • Fever with swollen glands, with or without rash.
  • Headache with unusual sleepiness, confusion, unsteadiness, or more frequent seizures.
  • New or worsening talk of self-harm, or a sudden mood change.
  • Unusual bruising, bleeding, or repeated infections.

References

1. DailyMed. Trileptal (oxcarbazepine) tablets prescribing information. 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=33af9350-95f3-384e-e054-00144ff88e88
2. LactMed. Oxcarbazepine. Drugs and Lactation Database, National Institute of Child Health and Human Development. 2024. https://www.ncbi.nlm.nih.gov/books/NBK501243/
3. AHRQ. First- and second-generation antipsychotics in children and young adults: systematic review update. Comparative Effectiveness Review No. 184. 2017. https://www.ncbi.nlm.nih.gov/books/NBK442344/
4. FDA. National Drug Code Directory, openFDA. Queried by generic name oxcarbazepine. 2026. https://api.fda.gov/drug/ndc.json?search=generic_name:%22oxcarbazepine%22&limit=1000