Oxcarbazepine exerts its therapeutic effects through its action on voltage-gated sodium channels in the brain. Its key mechanisms include:

1. Sodium Channel Blockade:
   • Oxcarbazepine and its active metabolite, 10-hydroxycarbazepine (MHD), stabilize neuronal membranes by blocking voltage-gated sodium channels.
   • This prevents the repetitive firing of action potentials, which is crucial in controlling seizure activity.
2. Potassium Channel Modulation:
   • Oxcarbazepine enhances potassium conductance, promoting neuronal membrane stabilization.
3. Reduction of Excitatory Neurotransmission:
   • By reducing the release of excitatory neurotransmitters like glutamate, oxcarbazepine further contributes to its anticonvulsant effects.
4. Calcium Channel Modulation:
   • Oxcarbazepine may also inhibit high-voltage-activated calcium channels, which play a role in neurotransmitter release.

Oxcarbazepine is approved for specific clinical conditions, including:

1. Epilepsy:
   • Treatment of focal (partial) seizures with or without secondary generalization in adults and children aged 6 years and older.
   • Monotherapy or adjunctive therapy for focal seizures.
2. Off-Label Uses:
   • Bipolar disorder (as a mood stabilizer).
   • Trigeminal neuralgia (in cases where carbamazepine is not tolerated).
   • Neuropathic pain.

The dosage of oxcarbazepine varies depending on the indication, patient age, and clinical response. The following dosing guidelines are based on the British National Formulary (BNF) and clinical pharmacology references:

1. Epilepsy:
   • Adults: Start with 300 mg twice daily, increasing gradually to a maintenance dose of 600–2400 mg daily in divided doses.
   • Children (6–17 years): Start with 8–10 mg/kg/day in divided doses, increasing gradually to a maintenance dose of 20–30 mg/kg/day.

Important Considerations:

• Oxcarbazepine is available in oral tablets and oral suspension.
• Dose adjustments may be necessary for patients with renal impairment.

Therapeutic drug monitoring is not routinely required but may be useful in certain cases.

Oxcarbazepine is generally well-tolerated, but it is associated with a range of side effects, some of which can be serious. Common side effects include:

1. Central Nervous System:
   • Dizziness, drowsiness, headache, and ataxia.
2. Gastrointestinal:
   • Nausea, vomiting, and abdominal pain.
3. Dermatological:
   • Skin rashes, which may progress to severe reactions like Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN).
4. Hematological:
   • Hyponatremia (low sodium levels), which can lead to symptoms like confusion, seizures, and lethargy.
5. Other:
   • Fatigue, blurred vision, and diplopia (double vision).

Serious Side Effects:

• Severe Skin Reactions: SJS and TEN are life-threatening conditions requiring immediate discontinuation of the drug.
• Hyponatremia: Regular monitoring of serum sodium levels is recommended, particularly in elderly patients and those on high doses.
• Hepatotoxicity: Elevated liver enzymes and, rarely, severe liver damage.

Oxcarbazepine requires careful monitoring and adherence to specific precautions to ensure patient safety:

1. Hyponatremia Monitoring:
   • Regular monitoring of serum sodium levels is essential, particularly during the first three months of treatment.
2. Pregnancy and Lactation:
   • Oxcarbazepine should be used during pregnancy only if the potential benefits outweigh the risks. It is excreted in breast milk, so breastfeeding is generally not recommended.
3. Elderly Patients:
   • Lower doses may be required due to increased sensitivity to side effects, particularly hyponatremia and dizziness.
4. Hepatic and Renal Impairment:
   • Dose adjustments are necessary for patients with impaired liver or kidney function.
5. Suicidal Risk:
   • Like other anticonvulsants, oxcarbazepine may increase the risk of suicidal thoughts or behavior.

Oxcarbazepine has a moderate potential for drug interactions due to its effects on hepatic enzymes. Key interactions include:

1. CYP3A4 Inducers:
   • Oxcarbazepine induces CYP3A4, reducing the levels of drugs metabolized by this enzyme (e.g., oral contraceptives, statins).
2. CYP2C19 Inhibitors:
   • Drugs like fluoxetine and fluvoxamine can increase oxcarbazepine levels, increasing the risk of side effects.
3. Other Anticonvulsants:
   • Phenytoin and carbamazepine can decrease oxcarbazepine levels, reducing its efficacy.
4. Oral Contraceptives:
   • Oxcarbazepine reduces the efficacy of hormonal contraceptives by increasing their metabolism.
5. Other Interactions:
   • Warfarin: Oxcarbazepine can alter anticoagulant effects.
   • Lithium: Increased risk of neurotoxicity.

Oxcarbazepine is the generic name for this medication. It is marketed under various brand names, depending on the country and manufacturer. Some examples include:

• Trileptal (a well-known brand in the United States and other regions).
• Oxcarbazepine Accord.
• Oxcarbazepine Mylan.
• Oxetol.