Pharm

Oxcarbazepine

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Oxcarbazepine, Trileptal, Oxtellar XR

  • See Also
  1. Seizure Disorder
  2. Carbamazepine
  3. Eslicarbazepine
  • Indications
  1. Simple Partial Seizures
  2. Complex Partial Seizures
  3. Generalized Tonic Clonic Seizures
  4. Trigeminal Neuralgia
  5. Mania
  • Mechanism
  1. Dibenzazepine Anticonvulsant with chemical structure similar to Tricyclic Antidepressants
  2. Primary anticonvulsant effects
    1. Inhibits Neuron depolarization and Glutamate release
    2. Sodium Channel Blocker (similar to Eslicarbazepine and Oxcarbazepine)
      1. Binds Sodium channels that are in an inactive state
      2. Decreases Sodium, Calcium and Potassium currents across Neuronal membranes
  3. Other effects
    1. Diuretic
  • Adverse Effects
  • Common (Dose related)
  1. Nausea or Vomiting
  2. Dizziness or Vertigo
  3. Ataxia
  4. Headache
  5. Diplopia
  6. Sedation
  7. Lethargy
  8. Tremor
  9. Rash
  • Adverse Effects
  • Other
  1. Hyponatremia
    1. Monitor Serum Sodium
    2. Higher risk than with Carbamazepine
    3. Risk Factors include Diuretic use, elderly, Selective Serotonin Reuptake Inhibitor use
  2. Cardiac Arrhythmia
  3. Osteoporosis (longterm use)
  4. Bone Marrow suppression
  5. Life-Threatening Drug-Induced Rashes (25-30% chance of cross sensitivity with Carbamazepine)
    1. Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS Syndrome)
    2. Stevens-Johnson Syndrome or Toxic Epidermal Necrolysis (TEN)
      1. Most common with asian descent and HLA-B 1502 Mutation (and possibly HLA-B3101)
  • Dosing
  1. Adult (includes elderly)
    1. Initial: 300 mg orally twice daily
    2. Increase by 300 mg/day every 3 to 7 days
    3. Typical effective dose 1200 mg/day divided twice daily
    4. Maximum: 2400 mg/day
  2. Child: Age 2 to 16 years old
    1. Initial: 8-10 mg/kg/day (up to 600 mg/day) divided twice daily
    2. May be increased by 5 mg/kg/day up to every 3 days, up to target typical dose or maximum dose
    3. Typical effective dose
      1. Age 2 to 4 years old
        1. Maximum 60 mg/kg/day divided twice daily
      2. Age 4 to 16 years old
        1. Weight 20 to 29 kg: 900 mg/day divided twice daily
        2. Weight 29 to 39 kg: 1200 mg/day divided twice daily
        3. Weight >39 kg: 1800 mg/day divided twice daily
  • Safety
  1. Pregnancy Category C
  2. Avoid in Lactation
  • Metabolism
  1. Renal excretion
    1. Decrease dose to 50% if Creatinine Clearance < 30 ml/min
  • Drug Interactions
  1. Fewer Drug Interactions than with Carbamazepine (no autoinduction and less enzyme induction)
  2. Decreases Oral Contraceptive efficacy (and may impact etonogestrel implant efficacy)
  3. Interacts with Dihydropyridine Calcium Channel Blockers
  4. Mechanisms
    1. Inhibits CYP2C19
    2. Induces CYP3A4 and CYP3A5
  • Resources
  1. Oxcarbazepine (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=17325a80-fb9c-4a83-b4b4-98e0b999d852
  • References
  1. (2022) Presc Lett, Resource #361206, Antiseizure Medications
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 56-7
  3. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  4. Liu (2017) Am Fam Physician 96(2): 87-96 [PubMed]