Therapeutic Classification: anticonvulsants, mood stabilizers
Absorption: Absorption is slow but complete. Suspension produces earlier, higher peak, and lower trough levels.
Distribution: Widely distributed. Crosses the blood-brain barrier. Crosses the placenta rapidly and enters breast milk in high concentrations.
Protein Binding: Carbamazepine: 75–90%; epoxide: 50%.
Metabolism/Excretion: Extensively metabolized in the liver by the CYP3A4 isoenzyme to active epoxide metabolite; epoxide metabolite has anticonvulsant and antineuralgic activity.
Half-Life: Carbamazepine: single dose—25–65 hr, chronic dosing—Children: 8–14 hr; Adults: 12–17 hr; epoxide: 34±9 hr.
(anticonvulsant activity)
| ROUTE | ONSET | PEAK | DURATION |
|---|
| PO | up to 1 mo‡ | 4–5 hr‡ | 6–12 hr |
| PO-ER | up to 1 mo‡ | 2–3–12 hr‡ | 12 hr |
Contraindicated in:
- Hypersensitivity to carbamazepine or tricyclic antidepressants;
- Bone marrow suppression;
- Concomitant use or use within 14 days of MAO inhibitors;
- Concurrent use of nefazodone or NNRTIs that are CYP3A4 substrates;
- Lactation: Lactation.
Use Cautiously in:
- All patients (may ↑ risk of suicidal thoughts/behaviors);
- Cardiac or hepatic disease;
- Renal failure (dosing adjustment required for CCr <10 mL/min);
- ↑intraocular pressure;
- OB: Use during pregnancy only if potential maternal benefits outweigh potential fetal risks; additional vitamin K during last wk of pregnancy has been recommended;
- Geri: Appears on Beers list. May worsen or cause syndrome of inappropriate antidiuretic hormone (SIADH) secretion in older adults. Use with caution in older adults and closely monitor sodium concentrations when starting therapy or ↑ dose.
Exercise Extreme Caution in:
- Patients positive for HLA-B*1502 or HLA-A*3101 alleles (unless benefits clearly outweigh the risks) (↑ risk of serious skin reactions).
- When converting from immediate-release to extended-release formulation, administer same total daily dose (in 2 divided doses).
Seizures
- PO (Adults and Children >12 yr): 200 mg twice daily (immediate-release [IR] tablets and extended-release [ER] tablets/capsules) or 100 mg 4 times daily (suspension); ↑ by up to 200 mg/day in divided doses (every 12 hr for ER tablets; every 6–8 hr for IR tablets and suspension) every 7 days until therapeutic levels are achieved (usual range = 600–1200 mg/day); not to exceed 1000 mg/day in children 12–15 yrs old or 1200 mg/day in children 15–18 yrs old or 1600 mg/day in adults.
- PO (Children 6–12 yr): 100 mg twice daily (IR tablets or ER tablets/capsules) or 50 mg 4 times daily (suspension). ↑ by up to 100 mg/day in divided doses (every 12 hr for ER tablets; every 6–8 hr for IR tablets and suspension) every 7 days until therapeutic levels are achieved (usual range = 400–800 mg/day); not to exceed 1000 mg/day.
- PO (Children <6 yr): 10–20 mg/kg/day in 2–3 divided doses (IR tablets) or in 4 divided doses (suspension); may be ↑ at weekly intervals until optimal response and therapeutic levels are achieved; not to exceed 35 mg/kg/day.
Trigeminal Neuralgia
- PO (Adults ): 100 mg twice daily (IR or ER tablets), 200 mg once daily (ER capsules), or 50 mg 4 times daily (suspension); ↑ by up to 200 mg/day in divided doses (every 12 hr for IR tablets or ER tablets/capsules; every 6 hr for suspension) as needed until pain is relieved (usual range = 400–800 mg/day); not to exceed 1200 mg/day.
Acute Manic or Mixed Episodes Associated with Bipolar I Disorder
- PO (Adults ): Equetro: 200 mg twice daily; ↑ by 200 mg/day until optimal response is achieved; not to exceed 1600 mg/day.
