Trileptal (oxcarbazepine) is a second-generation antiepileptic drug (AED) indicated for the treatment of partial seizures in adults and children as young as 2 years of age, both as monotherapy and adjunctive therapy. Its active metabolite, 10-hydroxycarbazepine (MHD), exerts a primary mechanism of action through voltage-sensitive sodium channel blockade, stabilizing hyperexcited neuronal membranes and inhibiting repetitive neuronal firing. Clinically, it offers a favorable pharmacokinetic profile with minimal hepatic enzyme induction and a reduced risk of significant drug interactions compared to first-generation agents. This profile makes it a versatile option in comprehensive epilepsy management protocols.

Features

• Active ingredient: Oxcarbazepine
• Available in 150 mg, 300 mg, and 600 mg film-coated tablets
• Also available as a 300 mg/5 mL oral suspension
• Mechanism: Blocks voltage-sensitive sodium channels
• Primary active metabolite: 10-hydroxycarbazepine (MHD)
• Linear pharmacokinetics with dose-proportional increases in plasma concentration
• Half-life of MHD is approximately 8–10 hours
• Steady-state concentrations reached within 2–3 days of twice-daily dosing
• Minimal protein binding (<40%)
• Primarily metabolized via hepatic cytosolic enzymes (not CYP450-dependent)
• Excreted renally (>95% as metabolites)

Benefits

• Provides effective reduction in seizure frequency and severity in partial-onset seizures
• Demonstrated efficacy as both monotherapy and adjunctive treatment
• Lower potential for pharmacokinetic drug interactions compared to carbamazepine and phenytoin
• Generally well-tolerated with a manageable side effect profile
• Available in multiple formulations for dosing flexibility across age groups
• Does not require therapeutic drug monitoring under routine circumstances

Common use

Trileptal is primarily indicated for the treatment of partial seizures, with or without secondary generalization, in adults and pediatric patients. It is approved for initial monotherapy in adults with newly diagnosed epilepsy and as conversion to monotherapy in adults. In children aged 2–16 years, it is indicated as adjunctive therapy. Off-label uses may include the treatment of bipolar disorder, neuropathic pain conditions such as trigeminal neuralgia, and mood stabilization, though these are not FDA-approved indications.

Dosage and direction

Dosage must be individualized based on clinical response and tolerability. For adults initiating therapy: start with 600 mg/day (300 mg twice daily). May be increased by 300 mg/day at approximately weekly intervals. Recommended daily dose for adjunctive therapy is 600–2400 mg/day. For monotherapy in adults: target maintenance dose is 1200–2400 mg/day. For pediatric patients (aged 2–16 years): initial dose is 8–10 mg/kg/day, not to exceed 600 mg/day, given twice daily. Target maintenance dose should be achieved over two weeks, based on weight: 20–29 kg: 900 mg/day; 29.1–39 kg: 1200 mg/day; >39 kg: 1800 mg/day. Oral suspension should be shaken well before use and may be taken with or without food.

Precautions

Hyponatremia (sodium <125 mmol/L) may occur; monitor serum sodium levels during initial treatment and periodically thereafter, particularly in patients on other medications that lower sodium or those with conditions predisposing to hyponatremia. Serious dermatological reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, have been reported; discontinue at first sign of rash. May cause dizziness and somnolence; advise patients to exercise caution when operating machinery or driving. Use with caution in patients with renal impairment (creatinine clearance <30 mL/min); dose adjustment recommended. Withdraw gradually to minimize risk of increased seizure frequency.

Contraindications

Hypersensitivity to oxcarbazepine or any component of the formulation. Cross-hypersensitivity with carbamazepine occurs in approximately 25–30% of patients; use with extreme caution in patients with known hypersensitivity to carbamazepine.

Possible side effect

Common adverse reactions (≥5%): dizziness (23%), somnolence (23%), headache (15%), nausea (15%), vomiting (13%), diplopia (11%), fatigue (11%), ataxia (5%), abnormal vision (5%).
Serious adverse reactions: hyponatremia, serious dermatological reactions, anaphylactic reactions, suicidal behavior and ideation, hematologic effects (agranulocytosis, aplastic anemia), drug reaction with eosinophilia and systemic symptoms (DRESS).

Drug interaction

May decrease efficacy of hormonal contraceptives; additional non-hormonal forms of contraception are recommended. May reduce plasma concentrations of felodipine and other calcium channel blockers. Strong CYP3A4 inducers (e.g., carbamazepine, phenobarbital) may decrease MHD concentrations. Alcohol and other CNS depressants may enhance sedative effects.

Missed dose

If a dose is missed, it should be taken as soon as possible. However, if it is almost time for the next dose, the missed dose should be skipped. Doubling of doses is not recommended.

Overdose

Symptoms may include drowsiness, dizziness, nausea, vomiting, hyperkinesia, hyponatremia, ataxia, nystagmus, and coma. Management includes supportive care and gastric lavage if presented early. Hemodialysis may be effective due to low protein binding.

Storage

Store at 25°C (77°F); excursions permitted to 15–30°C (59–86°F). Keep oral suspension in original bottle and use within 7 weeks of first opening. Keep tightly closed and protect from moisture.

Disclaimer

This information is for educational purposes and does not replace professional medical advice. Always consult a healthcare provider for diagnosis and treatment decisions. Dosage and indications may vary based on individual patient factors and regional prescribing information.

Reviews

Clinical trials and post-marketing surveillance demonstrate that Trileptal is effective in reducing seizure frequency with a generally favorable tolerability profile. Many clinicians appreciate its lower interaction potential compared to older antiepileptics. Some patients report improved quality of life due to reduced side effects such as cognitive blunting. However, hyponatremia and dizziness remain notable considerations in certain populations. Long-term studies support its use as a maintenance therapy in appropriate patients.