
HALF-LIFE: Initially 25-65 hours, then 15 hours after 2-4 weeks
STARTING DOSE: 200mg PO BID
TARGET DOSING RANGE: 400mg-600mg PO BID
BEST TIME TO DOSE: Any
HOW TO DOSE:
>Initial 200mg PO BID
>Increase by 200mg/d every 3-4 days to target dose
>Max dose 800mg PO BID
PREGNANCY: AVOID
BREASTFEEDING: AVOID
FDA INDICATIONS:
1) Seizures
2) Trigeminal Neuralgia
3) Acute mania associated with Bipolar Disorder (Equetro)
Mechanism of Action
- Blocks voltage sensitive sodium channels
Notable Adverse Effects
-
Leukopenia
-
Thrombocytopenia
-
Rare Aplastic Anemia (fever, fatigue, pallor, bleeding gums)
-
Risk of Aplastic Anemia increased by coadministration with clozapine
-
Rare Agranulocytosis
-
Rash (increased risk of SJ/TEN in Asians with HLA-B1502 allele (recommend testing for this allele prior to prescribing carbamazepine to individuals of Asian descent)
-
Syndrome of Inappropriate ADH (Hyponatremia)
-
Very rare hepatotoxicity
-
Rashes are common (up to 5% of patients)
-
Slows cardiac conduction
-
Elevated GGT (not concerning unless >3x normal limit)
-
Sedation
-
Fatigue
-
Nausea
-
Dizziness
-
Ataxia
-
diplopia
-
muscle incoordination
-
nystagmus
Drugs that may increase carbamazepine levels:
Cimetidine
Ciprofloxacin
Diltiazem
Fluoxetine
Fluvoxamine
Doxycycline
Erythromycin (and other macrolide antibiotics)
Fluconazole
Grapefruit juice
Isoniazid (INH)
Ketoconazole
TCAs
Valproate
Warfarin
Norfloxacin
Verapamil
Drugs whose blood levels are decreased by carbamazepine:
Atypical antipsychotics (olanzapine, risperidone, clozapine)
Benzodiazepines
Doxycycline
Ethosuximide
Fentanyl
Glucocorticoids
Haloperidol
Methadone
Oral contraceptives
Phenothiazines
Phenytoin
Sertraline
TCAs
Theophylline
Additional Information
-
Reports of CNS toxicity (dizziness, diplopia) associated with combination of carbamazepine and lamotrigine
-
Metabolized primarily by CYP3A4 and also induces its own metabolism by inducing CYP3A4
-
Induces multiple other CYP450 isozymes as well as P-Glycoprotein
-
May test positive (false positive) for tricyclics (TCAs)
References
- Cooper, J. R., Bloom, F. E., & Roth, R. H. (2003). The biochemical basis of neuropharmacology (8th ed.). New York, NY, US: Oxford University Press.
- Iversen, L. L., Iversen, S. D., Bloom, F. E., & Roth, R. H. (2009). Introduction to neuropsychopharmacology. Oxford: Oxford University Press.
- Puzantian, T., & Carlat, D. J. (2016). Medication fact book: for psychiatric practice. Newburyport, MA: Carlat Publishing, LLC.
- J. Ferrando, J. L. Levenson, & J. A. Owen (Eds.), Clinical manual of psychopharmacology in the medically ill(pp. 3-38). Arlington, VA, US: American Psychiatric Publishing, Inc.
- Schatzberg, A. F., & DeBattista, C. (2015). Manual of clinical psychopharmacology. Washington, DC: American Psychiatric Publishing.
- Schatzberg, A. F., & Nemeroff, C. B. (2017). The American Psychiatric Association Publishing textbook of psychopharmacology. Arlington, VA: American Psychiatric Association Publishing.
- Stahl, S. M. (2014). Stahl’s essential psychopharmacology: Prescriber’s guide (5th ed.). New York, NY, US: Cambridge University Press.
- Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY, US: Cambridge University Press.
- Whalen, K., Finkel, R., & Panavelil, T. A. (2015). Lippincotts illustrated reviews: pharmacology. Philadelphia, PA: Wolters Kluwer.