carbamazepine

Mood stabilizer

Brands: TEGRETOL

Last reviewed 2025-12-28

Reviewed by PsychMed Editorial Team.

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Quick answers

What is carbamazepine?
Carbamazepine is a voltage-gated sodium channel blocker used off-label as a mood stabiliser for acute mania, mixed episodes, and rapid-cycling bipolar disorder when lithium or valproate are not tolerated.
What is TEGRETOL?
TEGRETOL is a brand name for carbamazepine.
What is TEGRETOL (carbamazepine) used for?
Label indications include: Seizures (various types); trigeminal neuralgia; off‑label for bipolar mania (consult guidelines).
What drug class is TEGRETOL (carbamazepine)?
Mood stabilizer.
What is the mechanism of action of TEGRETOL (carbamazepine)?
Voltage‑gated sodium channel blocker; reduces high‑frequency neuronal firing.
What strengths does TEGRETOL (carbamazepine) come in?
Immediate-release tablets/chewables 100–200 mg, oral suspension 100 mg/5 mL, extended-release tablets/capsules 100–400 mg.
Is TEGRETOL (carbamazepine) a controlled substance?
No — it is not scheduled as a controlled substance under U.S. federal law.

Snapshot

Class: Mood stabilizer
Common US brands: TEGRETOL
Therapeutic drug monitoring recommended; reference range 4000–12000 ng/mL.
Last reviewed: 2025-12-28

Label indications

Seizures (various types); trigeminal neuralgia; off‑label for bipolar mania (consult guidelines).

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Clinical Highlights

Carbamazepine is a voltage-gated sodium channel blocker used off-label as a mood stabiliser for acute mania, mixed episodes, and rapid-cycling bipolar disorder when lithium or valproate are not tolerated. Autoinduction, a narrow therapeutic range, and extensive drug interactions require careful titration, TDM, and patient education.

The compare view and carbamazepine evidence feed can support shared decision-making on dosing and monitoring tradeoffs; the carbamazepine print page provides printable counselling sheets.
The bipolar disorder hub supports sequencing guidance, contraception considerations, and relapse-prevention workflows.
Autoinduction means serum levels can drift downward weeks after initiation; a planned level recheck after 3–4 weeks helps avoid silent underdosing and relapse.
Early adverse effects (dizziness, diplopia) often improve with slower titration; rash, fever, or mucosal symptoms are higher-risk signals and warrant urgent evaluation.
Seizure disorders (FDA 1974); trigeminal neuralgia (FDA 1968)
Generic: All formulations available generically.

Dosing & Formulations

Immediate-release tablets/chewables 100–200 mg, oral suspension 100 mg/5 mL, extended-release tablets/capsules 100–400 mg; taking with food can mitigate GI upset. Typical bipolar regimen: start 200 mg BID and increase by 200 mg/day every 3–5 days to 800–1,200 mg/day (max 1,600 mg/day) as tolerated.

Geriatric or medically complex patients: initiate 100 mg BID; titrate cautiously, with closer sodium monitoring given hyponatremia risk.
Target trough 4–12 µg/mL; recheck levels 3–5 days after dose changes and again after 3–4 weeks to account for autoinduction.

Monitoring & Risks

Boxed warnings: serious dermatologic reactions (SJS/TEN) and aplastic anemia/agranulocytosis; baseline and periodic CBC monitoring is standard. HLA-B*1502/HLA-A*3101 screening is recommended in at-risk ancestry to reduce severe rash risk.

Hyponatremia and SIADH: serum sodium monitoring is typically emphasized, especially in older adults or those on diuretics.
Hepatotoxicity and hematologic toxicity (leukopenia, thrombocytopenia): LFT and CBC monitoring is commonly more frequent during titration and then every 3–6 months thereafter.
Neurologic adverse effects (dizziness, diplopia, ataxia) are dose-related; dose adjustments can help if persistent.

Drug Interactions

Potent inducer of CYP3A4/CYP1A2/UGT enzymes—lowers levels of antipsychotics, antidepressants, benzodiazepines, oral contraceptives, and anticoagulants; this often requires co-therapy adjustments and non-hormonal contraception planning. CYP3A4 inhibitors (e.g., erythromycin, ketoconazole, grapefruit) markedly raise carbamazepine concentrations; toxicity monitoring and dose reductions may be needed.

Valproate inhibits epoxide hydrolase, increasing active metabolite exposure; dizziness/diplopia monitoring and dose adjustments may be needed.

Practice Notes

Baseline labs: CBC, CMP, pregnancy test, HLA-B*1502/HLA-A*3101 genotyping; repeat sodium/CBC/LFTs monitoring is typically more frequent during titration and then periodic during maintenance. Contraception interactions (hormonal methods can be less effective), rash warning signs, and infection symptoms are typically reviewed; abrupt discontinuation is generally avoided.

Reinforce adherence and monitoring plans with printable resources from the carbamazepine print page and coordinate dosing changes with pharmacy given autoinduction.
Because enzyme induction affects many medications (including hormonal contraception), medication lists are commonly revisited whenever carbamazepine is started, stopped, or dose-adjusted.

References

TEGRETOL (carbamazepine) prescribing information — DailyMed (2025)
CANMAT/ISBD 2021 guidelines for the management of bipolar disorder — Bipolar Disorders (2021)
Bipolar disorder: assessment and management (CG185) — National Institute for Health and Care Excellence (2014)
Clinical pharmacokinetics of carbamazepine — Clinical Pharmacokinetics (1978)
Extended Release Carbamazepine Capsules IN THE Treatment OF Acute Mania — American Journal of Psychiatry (2004)
FDA Carbamazepine Pharmacogenetics 2024