Carbamazepine

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General

  • Type: Anticonvulsant, Antimanic, Bipolar Disorder
  • Dosage Forms:tablet (chewable, immediate-release, ER), capsule (ER), oral suspension
  • Common Trade Names: Tegretol, Equetro, Epitol, Tegretol XR, Carbagen SR, Carbatrol, Teril

Adult Dosing

Epilepsy

  • Maintenance dose:800-1200mg/day PO in divided doses
  • Therapeutic range: 4-12mg/L (16.9-50.8 micromoles/L)
  • Max dose: 1600mg/day (rarely 1.6-2.4g/day)

Trigeminal Neuralgia

  • Maintenance dose: 400-800mg/day PO in divided doses
  • Max dose: 1200mg/day

Biploar Mania

  • Initial 200mg PO q 12h increase by 200mg/day
  • Max dose 1600mg/day

Restless legs syndrome (off label)

  • 100-600mg PO qHS up to 5 weeks

Schizophrenia (off label)

  • 200-1300mg/day for 2.5-8 weeks

Postherpatic Neuralgia (off label)

  • 100-200mg PO qDay, may increase slowly to 1200mg/day

Pediatric Dosing

Epilepsy

<6 years old

  • Initial: tablet- 10-20mg/kg/d PO q8-12h, suspension-10-20mg/kg/d PO q6h
  • Maintenance: may divide frequency into 3-4 times daily not to exceed 35mg/kg/day


>6 years old

  • Inital: suspension- 50mg PO q6h, tablet- 100mg PO q12h, may increase q week by 100mg/day
  • Maintenance: 400-800mg/day PO q6-8h (immediate release), q12h (ER)

>12 years old

  • Initial: suspension- 10mL (200mg) PO q6h; tablet- 200mg PO q12h, may increase qWeek q12h (ER); q6-8h (other formulations)

Special Populations

  • Pregnancy Rating: D
  • Lactation: Enters breast milk; not recommended
  • Renal Dosing
    • Adult: GFR<10: 75% of dose and monitor
    • Pediatric: same
  • Hepatic Dosing
    • Adult: Use caution, drug primarily metabolized in live
    • Pediatric: same

Contraindications

  • Allergy to class/drug
  • History of bone marrow suppresion
  • MAOI use within last 14d
  • coadministration with nefazodone, NNRTIs
  • Jaundice, hepatitis
  • Pregnancy, especially 1st trimester

Adverse Reactions

Serious

Toxic epidermal necrolysis/Stevens-Johnson syndrome especially in Asians
Aplastic anemia and agranulocytosis

Common

Ataxia, Dizziness, Drowsiness, Nausea, Vomiting, Dry mouth

Pharmacology

  • Half-life: 25-65 hr (initial dosing), 10-20 hr after autoinduction; 35-40h (extended release)
  • Metabolism: hepatic CYP3A4
  • Excretion: Urine (72%), Feces (28%)
  • Mechanism of Action: stabilizes inactivated state of sodium channels, making neurons less excitable

See Also

References

Medscape