Oxcarbazepine

Drug Information: Oxcarbazepine

Oxcarbazepine is an anticonvulsant medication primarily used to treat seizures. It is a derivative of carbamazepine, but with a modified chemical structure that may offer a better tolerability profile. Oxcarbazepine works by stabilizing hyperexcited neuronal membranes, thus reducing the spread of seizure activity in the brain. It is available in oral tablet and suspension forms.

Category

Neurological Drugs – Anticonvulsant

Mechanism of Action

Oxcarbazepine’s primary mechanism of action involves the blockade of voltage-sensitive sodium channels in neuronal membranes. These channels are crucial for the generation and propagation of action potentials. By blocking these sodium channels, oxcarbazepine limits the repetitive firing of neurons, thereby reducing the spread of seizure activity. Specifically, oxcarbazepine and its active metabolite, 10,11-dihydro-10-hydroxycarbazepine (MHD), prolong the inactivated state of sodium channels. This prolongation means that the channels remain closed for a longer period after an action potential, making it harder for the neuron to fire again rapidly. This selective action on hyperexcited neurons makes oxcarbazepine an effective anticonvulsant. Furthermore, oxcarbazepine may also affect calcium channels and enhance potassium conductance, further contributing to its anti-seizure effects.

Clinical Uses

Oxcarbazepine is primarily used for the treatment of seizures, specifically partial-onset seizures, both as monotherapy and as adjunctive therapy in adults and children. It is effective in managing simple partial, complex partial, and secondarily generalized seizures. Off-label uses may include the treatment of trigeminal neuralgia, bipolar disorder (as a mood stabilizer), and neuropathic pain, although evidence for these uses is less robust than for seizure control. Clinical trials have demonstrated oxcarbazepine’s efficacy in reducing seizure frequency and improving overall seizure control in patients with epilepsy. Its improved tolerability profile compared to carbamazepine makes it a preferred choice for many patients initiating anticonvulsant therapy.

Dosage

Adults: The typical starting dose for adults is 300 mg twice daily. The dose may be gradually increased by 300 mg per day every week, as needed, up to a maximum of 1200 mg per day in divided doses.

Pediatrics (4-16 years): The initial dose is 8-10 mg/kg/day in two divided doses. Maintenance dose depends on weight and is usually in the range of 900mg to 1200 mg per day.

Route of Administration: Oral (tablets or suspension). The suspension should be shaken well before each dose.

Indications

* Partial-onset seizures (monotherapy or adjunctive therapy)
* Generalized tonic-clonic seizures (adjunctive therapy)

Contraindications

* Hypersensitivity to oxcarbazepine or eslicarbazepine acetate.
* Severe renal impairment (use with caution and dosage adjustment may be necessary).
* Patients with a history of serious dermatological reactions to carbamazepine (due to structural similarity).
* AV block (first-degree)

FAQ

Q: What is Oxcarbazepine used for?

A: Oxcarbazepine is used to treat partial-onset seizures in adults and children.

Q: How does Oxcarbazepine work?

A: It works by stabilizing hyperexcited nerve membranes and blocking sodium channels, reducing seizure activity.

Q: What are the common side effects of Oxcarbazepine?

A: Common side effects include dizziness, drowsiness, headache, nausea, vomiting, and double vision.

Q: Can I drink alcohol while taking Oxcarbazepine?

A: Alcohol should be avoided while taking Oxcarbazepine, as it can increase the risk of side effects, such as drowsiness and dizziness.

Q: Does Oxcarbazepine interact with other medications?

A: Yes, Oxcarbazepine can interact with several medications, including oral contraceptives, other anticonvulsants, and some antidepressants. Consult your doctor or pharmacist about potential interactions.

Q: What should I do if I miss a dose of Oxcarbazepine?

A: If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not double the dose to catch up.

Q: Is Oxcarbazepine safe during pregnancy?

A: Oxcarbazepine should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Discuss with your doctor regarding the benefits versus risks.

Q: Can I stop taking Oxcarbazepine suddenly?

A: No, you should not stop taking Oxcarbazepine suddenly without consulting your doctor. Abruptly stopping the medication can increase the risk of seizures.