III. 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

IV. Adverse Effects: Common (Dose related)

V. 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)

VI. 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

VII. Safety

  1. Pregnancy Category C
  2. Avoid in Lactation

VIII. Metabolism

  1. Renal excretion
    1. Decrease dose to 50% if Creatinine Clearance < 30 ml/min

IX. 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

XI. 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]

Images: Related links to external sites (from Bing)

Related Studies

Cost: Medications

oxcarbazepine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
OXCARBAZEPINE 150 MG TABLET Generic $0.14 each
OXCARBAZEPINE 300 MG TABLET Generic $0.20 each
OXCARBAZEPINE 300 MG/5 ML SUSP Generic $0.28 per ml
OXCARBAZEPINE 600 MG TABLET Generic $0.39 each
trileptal (on 8/17/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
TRILEPTAL 300 MG TABLET Generic $0.20 each
TRILEPTAL 300 MG/5 ML SUSP Generic $0.28 per ml
TRILEPTAL 600 MG TABLET Generic $0.38 each
oxtellar xr (on 1/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
OXTELLAR XR 150 MG TABLET $7.70 each
OXTELLAR XR 300 MG TABLET $10.74 each
OXTELLAR XR 600 MG TABLET $19.63 each