Overview
11 DESCRIPTION Oxcarbazepine is an AED antiepileptic drug available as 150 mg, 300 mg, and 600 mg film-coated tablets for oral administration. Oxcarbazepine is 10,11-Dihydro-10-oxo-5 H -dibenz[b, f ]azepine-5-carboxamide, and its structural formula is: Oxcarbazepine USP is a light orange to creamish white or off-white powder.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The pharmacological activity of oxcarbazepine is primarily exerted through the 10-monohydroxy metabolite (MHD) of oxcarbazepine [see Clinical Pharmacology ( 12.3 )]. The precise mechanism by which oxcarbazepine and MHD exert their anti-seizure effect is unknown; however, in vitro electrophysiological studies indicate that they produce blockade of voltage-sensitive sodium channels, resulting in stabilization of hyperexcited neural membranes, inhibition of repetitive neuronal firing, and diminution of propagation of synaptic impulses. These actions are thought to be important in the prevention of seizure spread in the intact brain.
Indications
- 1 INDICATIONS AND USAGE Oxcarbazepine tablets are indicated for use as monotherapy or adjunctive therapy in the treatment of partial-onset seizures in adults and as monotherapy in the treatment of partial-onset seizures in pediatric patients aged 4 years and above, and as adjunctive therapy in pediatric patients aged 2 years and above with partial-onset seizures. Oxcarbazepine tablets are indicated for: • Adults: Monotherapy or adjunctive therapy in the treatment of partial-onset seizures • Pediatrics: - Monotherapy in the treatment of partial-onset seizures in children 4 to 16 years -...
Common Doses
- 600 mg
- 1200 mg
- 2400 mg
- 300 mg
Dosage
2 DOSAGE AND ADMINISTRATION Adults : initiate with a dose of 600 mg/day, given twice a day • Adjunctive Therapy: Maximum increment of 600 mg/day at approximately weekly intervals. The recommended daily dose is 1200 mg/day ( 2.1 ) • Conversion to Monotherapy: Withdrawal concomitant over 3 to 6 weeks; reach maximum dose of oxcarbazepine tablets in 2 to 4 weeks with increments of 600 mg/day at weekly intervals to a recommended daily dose of 2400 mg/day ( 2.2 ) • Initiation of Monotherapy: Increments of 300 mg/day every third day to a dose of 1200 mg/day ( 2.
Contraindications
- 4 CONTRAINDICATIONS Oxcarbazepine tablets are contraindicated in patients with a known hypersensitivity to oxcarbazepine or to any of its components, or to eslicarbazepine acetate [ see Warnings and Precautions ( 5.2 , 5.3 ) ]. Known hypersensitivity to oxcarbazepine or to any of its components, or to eslicarbazepine acetate ( 4 , 5.2 )
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are described below and elsewhere in the labeling: • Hyponatremia [see Warnings and Precautions ( 5.1 )] • Anaphylactic Reactions and Angioedema [see Warnings and Precautions ( 5.2 )] • Cross Hypersensitivity Reaction to Carbamazepine [see Warnings and Precautions ( 5.3 )] • Serious Dermatological Reactions [see Warnings and Precautions ( 5.4 )] • Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.5 )] • Cognitive/Neuropsychiatric Adverse Reactions [see Warnings and Precautions ( 5.
Interactions
- 7 DRUG INTERACTIONS • Phenytoin: Increased phenytoin levels. Reduced dose of phenytoin may be required ( 7.1 ) • Carbamazepine, Phenytoin, and Phenobarbital: Decreased plasma levels of MHD (the active metabolite). Dose adjustments may be necessary ( 7.1 ) • Oral Contraceptive: Oxcarbazepine may decrease the effectiveness of hormonal contraceptives ( 7.3 ) 7.1 Effect of Oxcarbazepine on Other Drugs Phenytoin levels have been shown to increase with concomitant use of oxcarbazepine at doses greater than 1200 mg/day [see Clinical Pharmacology ( 12.3 )].