II. Indication
- Simple Partial Seizures
- Complex Partial Seizures
- Generalized Tonic Clonic Seizures
- Trigeminal Neuralgia
-
Bipolar Disorder
- Frequently reserved for use as a second agent
- Resistant Schizophrenia
- Restless Leg Syndrome
- Psychosis in Dementia
- Post-Traumatic Stress Disorder
III. Contraindications
- MAO Inhibitor use within last 14 days
- Bone Marrow suppression
- Pregnancy
- Tricyclic compound sensitivity
- Asian patients who are positive for HLA-B1502
- Risk of Steven's Johnson: 5% if HLA-B1502 positive
- Also associated with Toxic Epidermal Necrolysis
- FDA has issued a black box warning
- Man (2007) Epilepsia 48(5):1015-8 [PubMed]
IV. Adverse Effects: Dose related
V. Adverse Effects: Other
- Morbilliform rash
- Gingival Hyperplasia
- Blood dyscrasias
- Cardiac conduction abnormality (increases A-V delay)
-
Hyponatremia
- Occurs in up to 40% of patients
- Elderly are at higher risk of SIADH
- Liver failure
- Osteoporosis
- Serum Sickness
- Stevens-Johnson Syndrome
- Toxic Epidermal Necrolysis
VI. Mechanism
VII. Pharmacokinetics
- Delayed effects after ingestion, peaking at up to 12 hours after ingestion (96 hours for extended release formulations)
-
Elimination Half-Life: 18 hours
- Zero order kinetics in Overdose (linear, constant elimination rate regardless of concentration)
VIII. Drug Interactions (Numerous)
- Substrate of Cytochrome P450 2C8/9
- Substrate of Cytochrome P450 3A4
- Induces Cytochrome P450 1A2
- Induces Cytochrome P450 2B6
- Induces Cytochrome P450 2C8/9
- Induces Cytochrome P450 2C19
- Induces Cytochrome P450 3A4
IX. Dose: General
- Titrate dose to serum concentration and effect
- Target serum concentration: 4-12 mcg/ml
- Observe closely for concentration 8 mcg/ml or higher
- Toxic serum concentration: >15 mcg/ml
X. Dose: Adults
-
Seizure Disorder
- Initial: 200 mg orally twice daily
- Increase by 200 mg/day increments weekly
- Typically up to 800-1200 mg/day (max: 2400 mg/day) in divided dosing
- Target concentration: 4 to 12 mcg/ml
-
Trigeminal Neuralgia
- Initial: 100 mg orally twice daily
- Increase by 100 mg/day increments weekly
- Target: 400-800 mg/day divided twice daily
-
Bipolar Disorder
- Initial: 200 mg twice daily
- Increase by 200 mg as often as daily in acute mania as tolerated
- Slower titration results in fewer side effects
- Target: 200-1600 mg per day
- Target serum level: 4 to 12 mcg/ml
XI. Dose: Elderly
- Initial: 100 mg orally twice daily
- Increase by 100 mg/day increments weekly
- Target: 400-1000 mg/day divided three to four times daily
XII. Management: Toxicity, Poisoning or Overdose
- See Adverse Effects above (dose dependent)
- Lab Testing and Diagnostics
- See Unknown Ingestion (includes Serum Glucose, other Toxicology Screening)
- Serial Serum Carbamazepine levels
- Electrocardiogram (EKG)
- Supportive Care
- Oral Activated Charcoal in an alert patient if presentation within 1-2 hours of ingestion
- Whole Bowel Irrigation (and repeat Activated Charcoal) if sustained release Carbamazepine ingestion
- Hypotension management
- QRS Widening
- Sodium Bicarbonate IV ampules until QRS narrows
- Seizures
- Hemodialysis Indications
- Refractory Seizures
- Cardiac Instability
- Disposition
- May discharge home if asymptomatic at 4 to 6 hours after ingestion and decreasing Serum Carbamazepine levels
XIII. Monitoring
- Routine labs
- Obtain monthly for first 2 months, then every 3 to 12 months
- Complete Blood Count with Platelet Count
- Liver Function Tests
- HLA-B1502
- Indicated before starting in asian patients
- See contraindications above
- Serum Carbamazepine level
- Initial: Every 1-2 weeks
- Later: Every 3-6 months
- Also check before and after dose changes
- Other tests previously monitored with Carbamazepine use
XIV. References
- Tomaszewski (2022) Crit Dec Emerg Med 36(9): 32
Images: Related links to external sites (from Bing)
Related Studies
carbamazepine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
CARBAMAZEPINE 100 MG TAB CHEW | Generic | $0.24 each |
CARBAMAZEPINE 100 MG/5 ML SUSP | Generic | $0.11 per ml |
CARBAMAZEPINE 200 MG TABLET | Generic | $0.15 each |
CARBAMAZEPINE ER 100 MG CAP | Generic | $1.16 each |
CARBAMAZEPINE ER 100 MG TABLET | Generic | $0.39 each |
CARBAMAZEPINE ER 200 MG CAP | Generic | $1.09 each |
CARBAMAZEPINE ER 200 MG TABLET | Generic | $0.66 each |
CARBAMAZEPINE ER 300 MG CAP | Generic | $1.00 each |
CARBAMAZEPINE ER 400 MG TABLET | Generic | $1.54 each |
tegretol (on 7/27/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
TEGRETOL 100 MG/5 ML SUSP | Generic | $0.11 per ml |
TEGRETOL 200 MG TABLET | Generic | $0.15 each |
TEGRETOL XR 100 MG TABLET | Generic | $0.39 each |
TEGRETOL XR 200 MG TABLET | Generic | $0.66 each |
TEGRETOL XR 400 MG TABLET | Generic | $1.54 each |