Carbamazepine
Generic: carbamazepine · Brand: Tegretol® / Tegretol XR® / Equetro® · Class: Mood Stabilizer / Anticonvulsant
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How It Works
Carbamazepine is a mood stabilizer and anticonvulsant that works by blocking sodium channels in neurons, reducing excessive electrical activity in the brain. It has FDA approval for acute manic and mixed episodes (as Equetro) and is particularly effective for patients who have not responded to lithium, or who have rapid cycling, dysphoric mania, or comorbid substance use. Carbamazepine is a potent inducer of liver enzymes (CYP3A4), which means it speeds up the breakdown of many other medications — including itself — causing significant drug interactions. Careful monitoring of levels and regular labs are required.
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What It Treats
Bipolar I — Acute ManiaFDA-approved as Equetro for acute manic and mixed episodes
Treatment-Resistant BipolarOften effective when lithium or valproate have failed
Seizure DisordersFDA-approved for partial, tonic-clonic, and mixed seizures
Trigeminal NeuralgiaFDA-approved for severe facial nerve pain — highly effective
Rapid Cycling BipolarSometimes effective for rapid cycling when other agents have failed
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Dosing Overview
| Population | Start | Typical Range | Target Level |
|---|---|---|---|
| Adults Acute Mania | 200 mg twice daily | 400–1600 mg/day | 4–12 mcg/mL |
| Adults Maintenance | 200 mg twice daily | 400–1200 mg/day | 4–8 mcg/mL |
| Older Adults Start low | 100 mg twice daily | 200–800 mg/day | 4–8 mcg/mL |
Tegretol XR taken twice daily; regular Tegretol taken 3–4 times daily. Take with food. Levels are checked after 5–7 days at a stable dose. Levels may drop over first few weeks as the medication induces its own metabolism (autoinduction).
🔬 Required Monitoring
Carbamazepine LevelEvery 3–6 months — levels fluctuate due to autoinduction
CBC / WBCEvery 3–6 months — risk of low white blood cells
Liver FunctionLFTs every 6 months
Sodium LevelPeriodically — carbamazepine can cause low sodium (SIADH)
Drug InteractionsReview all medications — induces CYP3A4 extensively
Genetic TestingHLA-B*1502 testing recommended in Asian patients before starting
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Side Effects
Common
- Dizziness or unsteadiness
- Drowsiness
- Nausea
- Blurred or double vision
- Dry mouth
- Mild rash
- Low sodium symptoms (headache, confusion)
- Increased liver enzymes
Call us if you notice
- Severe rash or blistering skin (SJS/TEN)
- Signs of low white blood cells (fever, sore throat)
- Signs of liver damage (jaundice, dark urine)
- Confusion or severe low sodium symptoms
- Unusual bleeding or bruising
Dizziness and sedation are most common when starting and often improve as your body adjusts. Taking with food helps nausea. Carbamazepine has many drug interactions — always check with your provider or pharmacist before starting any new medication.
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Tips for Success
Same Time DailyTake at the same time each day for consistent blood levels.
With FoodTaking with food reduces stomach upset for most mood stabilizers.
Never Stop AbruptlyStopping suddenly can trigger a mood episode. Always taper with your provider.
Limit AlcoholAlcohol can worsen mood instability and interact with these medications.
Tell All ProvidersMood stabilizers interact with many medications — always share your full list.
Keep Lab AppointmentsBlood level monitoring is essential for safety — never skip labs.
Many Drug InteractionsCarbamazepine affects many other medications including birth control pills, other mood stabilizers, and antibiotics. Always check before starting anything new.
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Important Safety Information
Stevens-Johnson Syndrome / TEN: A rare but potentially life-threatening skin reaction. Risk is significantly higher in people of Asian descent with the HLA-B*1502 genetic variant. Any rash with blistering, peeling, or fever requires immediate emergency care.
Genetic Testing — Asian Patients: The FDA recommends testing for the HLA-B*1502 allele before starting carbamazepine in patients of Asian ancestry (including South Asian, East Asian, and Southeast Asian descent) due to significantly elevated Stevens-Johnson Syndrome risk.
Aplastic Anemia / Agranulocytosis — BLACK BOX WARNING: Rare but potentially fatal suppression of bone marrow causing dangerously low blood cell counts. Signs include fever, sore throat, mouth sores, unusual bruising, or fatigue. Seek immediate care if these develop.
Extensive Drug Interactions: Carbamazepine induces CYP3A4 and reduces levels of many medications including oral contraceptives (reducing effectiveness), other anticonvulsants, warfarin, antipsychotics, and many antibiotics. Always review all medications with your provider.
Pregnancy: Carbamazepine is associated with neural tube defects and other fetal malformations. Use effective contraception — note that oral contraceptive pills are less effective when taken with carbamazepine.
Low Sodium (Hyponatremia): Carbamazepine can cause the body to retain too much water, lowering sodium levels. Symptoms include headache, confusion, nausea, and seizures. Report any sudden headache or confusion.
Questions? I am here.
Reach me between appointments if you have concerns about side effects, lab results, or your medication. Do not wait until your next visit if something feels wrong.
360-389-3712
info@rootedmindspsychiatry.com