Carbamazepine
Generic Details
Generic Name
Carbamazepine
Other Names
- Tegretol
- Epitol
- Equetro
Drug Class
- Anticonvulsant
- Mood stabilizer
Chemical Formula
C15H12N2O
Molecular Weight
236.27 g/mol
Mechanism of Action
- Blocks voltage-gated sodium channels
Indications
- Epilepsy
- Trigeminal neuralgia
- Bipolar disorder
- Schizophrenia
- Neuropathic pain
Common Dosage Forms
- Tablet
- Extended-release tablet
- Suspension
Typical Dosage
- 200-400 mg 2-3 times daily for epilepsy
- 100-200 mg 2-4 times daily for trigeminal neuralgia
Pediatric Dosage
- 5-10 mg/kg/day divided into 2-3 doses
Geriatric Dosage
- Lower initial dosages and slower titration due to decreased metabolism
Side Effects
- Dizziness
- Drowsiness
- Nausea
- Vomiting
- Blurred vision
- Headache
- Rash
- Hepatotoxicity
Contraindications
- Hypersensitivity to carbamazepine
- History of bone marrow suppression
- Use of MAO inhibitors
Pregnancy Category
- Category D - Positive evidence of risk
Lactation Safety
- Compatible with breastfeeding, monitor infant for drowsiness and adequate weight gain
Drug Interactions
- Warfarin
- SSRIs
- Oral contraceptives
- Lithium
- CYP3A4 inducers/inhibitors
Overdose Symptoms
- Nausea
- Vomiting
- Ataxia
- Coma
- Respiratory depression
Antidote for Overdose
- Supportive care, activated charcoal, consider hemodialysis in severe cases
Storage Conditions
- Store at room temperature away from moisture and heat
Pharmacokinetics
- Absorption: Rapid and almost complete
- Distribution: Highly protein-bound, crosses the blood-brain barrier
- Metabolism: Hepatic via CYP3A4 and CYP2C8 enzymes
- Excretion: Primarily renal
Precautions
- Monitor CBC and liver function tests regularly
- Caution in patients with cardiac disease
- Caution in patients with a history of mood disorders
Warnings
- Risk of severe dermatologic reactions like Stevens-Johnson syndrome and toxic epidermal necrolysis
Others
- Carbamazepine may cause hyponatremia, especially in elderly patients.