Carbamazepine 200mg ER Capsules
WARNING: Blood cell problems have happened, like aplastic anemia and a type of low white blood cell count. Tell your doctor right away if you feel very tired or weak or have a fever, chills, shortness of breath, any unexplained bruising or bleeding, or purple "splotches" on your skin.Call your doctor right away if you have any signs of infection like fever, chills, flu-like signs, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or a wound that will not heal.A severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause severe health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.People with a certain gene (HLA-B*1502) have a higher chance of severe and sometimes deadly skin reactions with this drug. This gene is more common in Asian people, including South Asian Indian people. If you have questions, talk with the doctor.People with a certain gene (HLA-A*3101) may have a higher chance of severe allergic reactions with this drug. Allergic reactions can be deadly. If you have questions, talk with the doctor. @ COMMON USES: It is used to treat seizures.It is used to treat pain caused by a problem with a nerve in the face.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Anticonvulsant; Mood Stabilizer; Trigeminal Neuralgia Agent
Pharmacologic Class
Iminostilbene derivative; Voltage-gated sodium channel blocker
Pregnancy Category
Category D
FDA Approved
Mar 1997
DEA Schedule
Not Controlled
Overview
What is this medicine?
Carbamazepine is a medication used to treat certain types of seizures (epilepsy), nerve pain (trigeminal neuralgia), and bipolar disorder. It works by calming overactive nerve signals in the brain.
How to Use This Medicine
Taking Your Medication
To take this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. Swallow the capsule whole - do not chew, break, or crush it. If you have trouble swallowing the capsule, you can sprinkle its contents onto a soft food like applesauce. However, do not chew the mixture. Swallow it immediately and follow with a glass of water or juice.
Storing and Disposing of Your Medication
Store this medication at room temperature, away from light and moisture. Keep it in a dry place, such as a closet or drawer, and avoid storing it in the bathroom. Keep all medications out of the reach of children and pets to ensure their safety. If you have unused or expired medication, dispose of it properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best way to dispose of your medication, as there may be drug take-back programs available in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To take this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. Swallow the capsule whole - do not chew, break, or crush it. If you have trouble swallowing the capsule, you can sprinkle its contents onto a soft food like applesauce. However, do not chew the mixture. Swallow it immediately and follow with a glass of water or juice.
Storing and Disposing of Your Medication
Store this medication at room temperature, away from light and moisture. Keep it in a dry place, such as a closet or drawer, and avoid storing it in the bathroom. Keep all medications out of the reach of children and pets to ensure their safety. If you have unused or expired medication, dispose of it properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best way to dispose of your medication, as there may be drug take-back programs available in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take exactly as prescribed, do not crush, chew, or open extended-release capsules.
- Take with food to reduce stomach upset and improve absorption.
- Avoid grapefruit or grapefruit juice as it can increase drug levels.
- Avoid alcohol and other CNS depressants as they can increase drowsiness and dizziness.
- Do not stop taking this medication suddenly, as it can lead to increased seizures.
- Use effective birth control methods if you are a woman of childbearing potential, as this medication can reduce the effectiveness of hormonal contraceptives and may cause birth defects.
- Wear medical alert identification if you have epilepsy.
Available Forms & Alternatives
Available Strengths:
- Carbamazepine 100mg/5ml Shake Well
- Carbamazepine 200mg Tablets
- Carbamazepine 200mg Tablets
- Carbamazepine 100mg Chewable Tabs
- Carbamazepine ER 200mg Tablets
- Carbamazepine ER 400mg Tablets
- Carbamazepine 200mg ER Capsules
- Carbamazepine 100mg ER Capsules
- Carbamazepine 100mg ER Capsules
- Carbamazepine 300mg ER Capsules
- Carbamazepine 200mg ER Capsules
- Carbamazepine ER 100mg Tablets
- Carbamazepine ER 100mg Tablets
- Carbamazepine ER 200mg Tablets
- Carbamazepine ER 400mg Tablets
- Carbamazepine 200mg Chw Tablets
Dosing & Administration
Adult Dosing
Standard Dose:
Epilepsy: Initial 200 mg ER orally twice daily. Maintenance 800-1200 mg/day in 2 divided doses.
Dose Range:
400 - 1600 mg
Condition-Specific Dosing:
epilepsyInitial:
200 mg ER orally twice daily
epilepsyMaintenance:
800-1200 mg/day in 2 divided doses (max 1600 mg/day)
trigeminalNeuralgiaInitial:
100 mg ER orally twice daily
trigeminalNeuralgiaMaintenance:
400-800 mg/day in 2 divided doses (max 1200 mg/day)
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Epilepsy (6-12 years): Initial 100 mg ER orally twice daily or 10 mg/kg/day in 2 divided doses. Increase weekly by 100 mg/day. Maintenance 400-800 mg/day (max 1000 mg/day).
Adolescent:
Epilepsy (>12 years): Initial 200 mg ER orally twice daily. Increase weekly by 200 mg/day. Maintenance 800-1200 mg/day in 2 divided doses (max 1600 mg/day).
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment, monitor for adverse effects.
Moderate:
No specific adjustment, monitor for adverse effects.
Severe:
No specific adjustment, monitor for adverse effects; caution due to potential for metabolite accumulation.
Dialysis:
Carbamazepine is not significantly dialyzable. No supplemental dose needed after dialysis, but monitor levels.
Hepatic Impairment:
Mild:
Caution, monitor liver function tests and carbamazepine levels.
Moderate:
Caution, monitor liver function tests and carbamazepine levels; consider lower initial doses.
Severe:
Use with extreme caution or avoid; monitor liver function tests and carbamazepine levels closely.
Pharmacology
Mechanism of Action
Carbamazepine stabilizes inactivated voltage-gated sodium channels, thereby inhibiting repetitive neuronal firing and reducing synaptic transmission. It also has effects on calcium channels and potassium channels, and may modulate central noradrenergic and serotonergic systems.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 80% (variable)
Tmax:
Extended-release: 3-12 hours (range 3-24 hours)
FoodEffect:
Food can increase the rate and extent of absorption for ER formulations.
Distribution:
Vd:
0.8-1.9 L/kg
ProteinBinding:
75-80%
CnssPenetration:
Yes
Elimination:
HalfLife:
Initial: 25-65 hours; Chronic (autoinduction): 12-17 hours
Clearance:
Decreases with chronic use due to autoinduction
ExcretionRoute:
Renal (72%), Fecal (28%)
Unchanged:
2-3% (renal)
Pharmacodynamics
OnsetOfAction:
Variable, typically within hours to days for therapeutic effect
PeakEffect:
Achieved after several days to weeks of consistent dosing due to autoinduction and reaching steady state.
DurationOfAction:
12 hours (for ER formulation, allowing twice-daily dosing)
Confidence:
High
Safety & Warnings
BLACK BOX WARNING
SERIOUS DERMATOLOGIC REACTIONS AND APLASTIC ANEMIA/AGRANULOCYTOSIS: Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS), have been reported with carbamazepine treatment. These reactions are estimated to occur in 1 to 6 per 10,000 new users in countries with mainly Caucasian populations, but the risk in some Asian countries is about 10 times higher. Studies in patients of Chinese ancestry have shown a strong association between the risk of developing SJS/TEN and the presence of HLA-B*1502 allele. Prior to initiating carbamazepine, patients of Asian ancestry should be screened for the presence of HLA-B*1502 allele. Carbamazepine should not be used in patients positive for HLA-B*1502 unless the benefits clearly outweigh the risks. Aplastic anemia and agranulocytosis have been reported in association with the use of carbamazepine. Patients should be advised of the early toxic signs and symptoms of a potential hematologic problem and the need to report to the physician immediately any such signs or symptoms.
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of low sodium levels, including:
+ Headache
+ Difficulty focusing
+ Memory problems
+ Confusion
+ Weakness
+ Seizures
+ Changes in balance
Changes in speech
Hallucinations (seeing or hearing things that are not there)
Changes in eyesight
Difficulty walking
A severe and potentially life-threatening condition has been reported in people taking seizure medications like this one. Seek medical help immediately if you experience:
+ Swollen glands
+ Fever
+ Rash
+ Painful sores in the mouth or around the eyes
+ Chest pain
+ Signs of kidney problems, such as:
- Inability to pass urine
- Changes in the amount of urine passed
+ Signs of liver problems, including:
- Dark urine
- Fatigue
- Decreased appetite
- Upset stomach or stomach pain
- Light-colored stools
- Vomiting
- Yellow skin or eyes
Neuroleptic malignant syndrome (NMS), a rare but potentially life-threatening condition, may occur. Seek medical help immediately if you experience:
+ Fever
+ Muscle cramps or stiffness
+ Dizziness
+ Severe headache
+ Confusion
+ Changes in thinking
+ Rapid heartbeat
+ Abnormal heartbeat
+ Excessive sweating
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people may not experience any side effects or may only have mild ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor or seek medical help:
Feeling dizzy, sleepy, tired, or weak
Upset stomach or vomiting
Dry mouth
Constipation
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of low sodium levels, including:
+ Headache
+ Difficulty focusing
+ Memory problems
+ Confusion
+ Weakness
+ Seizures
+ Changes in balance
Changes in speech
Hallucinations (seeing or hearing things that are not there)
Changes in eyesight
Difficulty walking
A severe and potentially life-threatening condition has been reported in people taking seizure medications like this one. Seek medical help immediately if you experience:
+ Swollen glands
+ Fever
+ Rash
+ Painful sores in the mouth or around the eyes
+ Chest pain
+ Signs of kidney problems, such as:
- Inability to pass urine
- Changes in the amount of urine passed
+ Signs of liver problems, including:
- Dark urine
- Fatigue
- Decreased appetite
- Upset stomach or stomach pain
- Light-colored stools
- Vomiting
- Yellow skin or eyes
Neuroleptic malignant syndrome (NMS), a rare but potentially life-threatening condition, may occur. Seek medical help immediately if you experience:
+ Fever
+ Muscle cramps or stiffness
+ Dizziness
+ Severe headache
+ Confusion
+ Changes in thinking
+ Rapid heartbeat
+ Abnormal heartbeat
+ Excessive sweating
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people may not experience any side effects or may only have mild ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor or seek medical help:
Feeling dizzy, sleepy, tired, or weak
Upset stomach or vomiting
Dry mouth
Constipation
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- New or worsening skin rash, blistering, peeling skin, or sores in the mouth, nose, eyes, or genitals (signs of severe skin reactions like SJS/TEN).
- Fever, chills, sore throat, mouth sores, easy bruising or bleeding, unusual tiredness (signs of blood problems).
- Yellowing of the skin or eyes, dark urine, severe stomach pain (signs of liver problems).
- Swelling of the face, lips, or tongue, difficulty breathing (signs of allergic reaction).
- Confusion, severe dizziness, unsteadiness, or problems with coordination.
- Changes in vision (e.g., blurred vision, double vision).
- Increased seizures.
Before Using This Medicine
Before taking this medication, it is essential to inform your doctor about the following:
Any allergies you have, including allergies to this drug, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have kidney disease, as this may affect how your body processes the medication.
A history of certain health conditions, such as bone marrow problems or porphyria, which may require special consideration when taking this medication.
Any medications you are currently taking, including prescription and over-the-counter drugs, natural products, and vitamins. This is crucial because some medications, such as those used to treat hepatitis C, HIV, infections, and other conditions, may interact with this drug and should not be taken concurrently.
* If you have taken specific medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of very high blood pressure.
It is critical to note that this is not an exhaustive list of all potential interactions or health problems that may affect the safety of taking this medication. Therefore, it is vital to inform your doctor and pharmacist about all your medications, health conditions, and any concerns you may have. Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety and the effectiveness of your treatment plan.
Any allergies you have, including allergies to this drug, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have kidney disease, as this may affect how your body processes the medication.
A history of certain health conditions, such as bone marrow problems or porphyria, which may require special consideration when taking this medication.
Any medications you are currently taking, including prescription and over-the-counter drugs, natural products, and vitamins. This is crucial because some medications, such as those used to treat hepatitis C, HIV, infections, and other conditions, may interact with this drug and should not be taken concurrently.
* If you have taken specific medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of very high blood pressure.
It is critical to note that this is not an exhaustive list of all potential interactions or health problems that may affect the safety of taking this medication. Therefore, it is vital to inform your doctor and pharmacist about all your medications, health conditions, and any concerns you may have. Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to ensure your safety and the effectiveness of your treatment plan.
Precautions & Cautions
Important Warnings and Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Caution with Daily Activities
Avoid driving and engaging in activities that require alertness until you understand how this medication affects you.
Monitoring and Follow-up
Regular blood tests will be necessary, as directed by your doctor. Be sure to schedule an eye exam as recommended by your doctor.
Interference with Lab Tests
This medication may affect the results of certain lab tests. Inform all your healthcare providers and lab personnel that you are taking this medication.
Pregnancy Tests and Contraception
This medication may cause false results in some pregnancy tests. Discuss this with your doctor. Additionally, if you are using birth control pills or other hormone-based contraception, they may not be effective in preventing pregnancy. Consider using an alternative method, such as condoms, while taking this medication.
Interactions with Other Substances
Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may cause drowsiness, consult with your doctor. If you regularly drink grapefruit juice or eat grapefruit, discuss this with your doctor as well.
Stopping the Medication
Do not suddenly stop taking this medication without consulting your doctor, as this may increase the risk of seizures. If you need to stop taking this medication, your doctor will guide you on how to gradually discontinue it.
Seizure Management
If your seizures change or worsen after starting this medication, inform your doctor promptly.
Mental Health
Like other medications used to treat seizures, this medication may rarely increase the risk of suicidal thoughts or actions, particularly in individuals with a history of suicidal ideation. Monitor your mood and behavior, and immediately report any new or worsening symptoms, such as depression, anxiety, restlessness, or mood changes, to your doctor. If you experience suicidal thoughts or actions, seek medical attention right away.
Cardiovascular Risks
This medication may cause heart problems, including heart failure and abnormal heart rhythms, which can be fatal. Seek immediate medical attention if you experience a rapid, slow, or irregular heartbeat, severe dizziness, fainting, shortness of breath, significant weight gain, or swelling in your arms or legs.
Allergic Reactions
In rare cases, this medication can cause a severe allergic reaction called angioedema, which can be life-threatening. Seek medical help immediately if you experience swelling of your hands, face, lips, eyes, tongue, or throat, difficulty breathing, swallowing, or unusual hoarseness.
Special Considerations
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
Reproductive Health
This medication may affect fertility in men. Discuss this with your doctor. If you are pregnant or become pregnant while taking this medication, inform your doctor immediately, as it may harm the unborn baby. If you are breastfeeding, consult with your doctor to discuss potential risks to your baby.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Caution with Daily Activities
Avoid driving and engaging in activities that require alertness until you understand how this medication affects you.
Monitoring and Follow-up
Regular blood tests will be necessary, as directed by your doctor. Be sure to schedule an eye exam as recommended by your doctor.
Interference with Lab Tests
This medication may affect the results of certain lab tests. Inform all your healthcare providers and lab personnel that you are taking this medication.
Pregnancy Tests and Contraception
This medication may cause false results in some pregnancy tests. Discuss this with your doctor. Additionally, if you are using birth control pills or other hormone-based contraception, they may not be effective in preventing pregnancy. Consider using an alternative method, such as condoms, while taking this medication.
Interactions with Other Substances
Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may cause drowsiness, consult with your doctor. If you regularly drink grapefruit juice or eat grapefruit, discuss this with your doctor as well.
Stopping the Medication
Do not suddenly stop taking this medication without consulting your doctor, as this may increase the risk of seizures. If you need to stop taking this medication, your doctor will guide you on how to gradually discontinue it.
Seizure Management
If your seizures change or worsen after starting this medication, inform your doctor promptly.
Mental Health
Like other medications used to treat seizures, this medication may rarely increase the risk of suicidal thoughts or actions, particularly in individuals with a history of suicidal ideation. Monitor your mood and behavior, and immediately report any new or worsening symptoms, such as depression, anxiety, restlessness, or mood changes, to your doctor. If you experience suicidal thoughts or actions, seek medical attention right away.
Cardiovascular Risks
This medication may cause heart problems, including heart failure and abnormal heart rhythms, which can be fatal. Seek immediate medical attention if you experience a rapid, slow, or irregular heartbeat, severe dizziness, fainting, shortness of breath, significant weight gain, or swelling in your arms or legs.
Allergic Reactions
In rare cases, this medication can cause a severe allergic reaction called angioedema, which can be life-threatening. Seek medical help immediately if you experience swelling of your hands, face, lips, eyes, tongue, or throat, difficulty breathing, swallowing, or unusual hoarseness.
Special Considerations
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
Reproductive Health
This medication may affect fertility in men. Discuss this with your doctor. If you are pregnant or become pregnant while taking this medication, inform your doctor immediately, as it may harm the unborn baby. If you are breastfeeding, consult with your doctor to discuss potential risks to your baby.
Overdose Information
Overdose Symptoms:
- Dizziness
- Drowsiness
- Nausea
- Vomiting
- Unsteady gait (ataxia)
- Nystagmus (involuntary eye movements)
- Blurred vision
- Slurred speech
- Tremor
- Agitation
- Coma
- Seizures
- Respiratory depression
- Cardiac conduction disturbances (e.g., bradycardia, AV block)
What to Do:
Seek immediate medical attention or call 911. Call 1-800-222-1222 (Poison Control Center).
Drug Interactions
Contraindicated Interactions
- MAO inhibitors (within 14 days)
- Nefazodone
- Delavirdine
- Boceprevir
- Telaprevir
Major Interactions
- Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, voriconazole, clarithromycin, ritonavir, grapefruit juice) - significantly increase carbamazepine levels.
- Strong CYP3A4 inducers (e.g., rifampin, phenytoin, phenobarbital) - significantly decrease carbamazepine levels.
- Oral contraceptives (decreased efficacy of contraceptives)
- Warfarin (decreased anticoagulant effect)
- Lamotrigine (increased lamotrigine levels)
- Valproic acid (decreased valproic acid levels, increased carbamazepine-10,11-epoxide levels)
- Clozapine (increased risk of bone marrow suppression)
- Lithium (increased neurotoxicity risk)
- Immunosuppressants (e.g., cyclosporine, tacrolimus, sirolimus, everolimus - decreased levels of immunosuppressants)
Moderate Interactions
- Other CNS depressants (e.g., alcohol, benzodiazepines, opioids) - additive CNS depression.
- Diuretics (e.g., hydrochlorothiazide, furosemide) - increased risk of hyponatremia.
- Antidepressants (e.g., tricyclic antidepressants, SSRIs) - altered carbamazepine levels, increased risk of serotonin syndrome with some SSRIs.
- Calcium channel blockers (e.g., felodipine, verapamil, diltiazem) - altered carbamazepine levels.
- Theophylline (decreased theophylline levels)
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Complete Blood Count (CBC) with differential and platelet count
Rationale: Risk of aplastic anemia and agranulocytosis (Black Box Warning).
Timing: Prior to initiation
Liver Function Tests (LFTs)
Rationale: Risk of hepatic dysfunction.
Timing: Prior to initiation
Renal Function Tests (BUN, Creatinine)
Rationale: Assess baseline kidney function.
Timing: Prior to initiation
Serum Sodium
Rationale: Risk of hyponatremia.
Timing: Prior to initiation
HLA-B*1502 allele testing (for patients of Asian ancestry)
Rationale: Strong association with increased risk of Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).
Timing: Prior to initiation
HLA-A*3101 allele testing (for patients of European, Japanese, Native American, and Hispanic ancestry)
Rationale: Associated with increased risk of SJS/TEN, DRESS, and maculopapular rash.
Timing: Consider prior to initiation
Routine Monitoring
Carbamazepine serum levels
Frequency: Initially after 3-5 days, then weekly/bi-weekly during titration, then every 3-6 months or as clinically indicated.
Target: 4-12 mcg/mL (therapeutic range)
Action Threshold: Levels >12 mcg/mL may indicate toxicity; levels <4 mcg/mL may indicate subtherapeutic dosing.
CBC with differential and platelet count
Frequency: Every 2 weeks for the first 2 months, then monthly for 6 months, then annually or as clinically indicated.
Target: WBC >3000/mm³, ANC >1500/mm³, Platelets >100,000/mm³
Action Threshold: Discontinue if WBC <3000/mm³ or ANC <1000/mm³; consider discontinuation if WBC <4000/mm³ or ANC <1500/mm³.
Liver Function Tests (LFTs)
Frequency: Every 3-6 months or as clinically indicated.
Target: Within normal limits
Action Threshold: Significant elevations (e.g., >2-3x ULN) may require dose reduction or discontinuation.
Serum Sodium
Frequency: Every 3-6 months or as clinically indicated, especially in elderly or those on diuretics.
Target: 135-145 mEq/L
Action Threshold: <130 mEq/L may require intervention; symptomatic hyponatremia requires immediate attention.
Symptom Monitoring
- Skin rash (especially severe, blistering, or spreading)
- Fever
- Sore throat
- Mouth ulcers
- Easy bruising or bleeding
- Unusual weakness or fatigue
- Jaundice (yellowing of skin/eyes)
- Dark urine
- Abdominal pain
- Swelling of face, lips, or tongue
- Difficulty breathing
- Confusion
- Ataxia (uncoordinated movements)
- Dizziness
- Drowsiness
- Vision changes (e.g., blurred vision, diplopia)
Special Patient Groups
Pregnancy
Carbamazepine is classified as Pregnancy Category D due to evidence of human fetal risk. It is associated with an increased risk of major congenital malformations, particularly neural tube defects (e.g., spina bifida), craniofacial defects, and developmental delays. Use only if the potential benefit outweighs the potential risk to the fetus. Folic acid supplementation is recommended for women of childbearing potential.
Trimester-Specific Risks:
First Trimester:
Highest risk for neural tube defects and other major congenital malformations.
Second Trimester:
Continued risk of developmental effects; potential for growth restriction.
Third Trimester:
Risk of withdrawal symptoms in the neonate (e.g., irritability, tremor, poor feeding) if exposed late in pregnancy; potential for bleeding disorders in the neonate due to vitamin K deficiency.
Lactation
Carbamazepine and its active metabolite are excreted into breast milk. The American Academy of Pediatrics considers it compatible with breastfeeding, but monitoring the infant for adverse effects (e.g., drowsiness, poor feeding, weight gain, liver toxicity, blood dyscrasias) is recommended.
Infant Risk:
L3 (Moderately safe) - Monitor infant for sedation, poor feeding, and weight gain. Rare reports of liver dysfunction or blood dyscrasias in infants.
Pediatric Use
Dosing is weight-based and age-dependent. Children may metabolize carbamazepine more rapidly than adults, requiring higher mg/kg doses. Close monitoring of serum levels and adverse effects is crucial. Risk of severe dermatologic reactions (SJS/TEN) is higher in children, especially those of Asian ancestry with HLA-B*1502 allele.
Geriatric Use
Elderly patients may be more sensitive to the effects of carbamazepine, particularly CNS side effects (dizziness, ataxia, confusion) and hyponatremia. Lower initial doses and slower titration are recommended. Close monitoring of serum sodium levels is important.
Clinical Information
Clinical Pearls
- Always screen patients of Asian ancestry for HLA-B*1502 allele before initiating carbamazepine due to the high risk of SJS/TEN.
- Counsel patients on the importance of reporting any rash, fever, sore throat, or unusual bruising/bleeding immediately.
- Carbamazepine is a potent enzyme inducer; anticipate numerous drug interactions, especially with hormonal contraceptives, warfarin, and other AEDs.
- Extended-release formulations (Carbatrol, Tegretol XR) are designed for twice-daily dosing and should not be crushed or chewed.
- Therapeutic drug monitoring (TDM) of carbamazepine levels is essential for optimizing therapy and minimizing toxicity, especially during initiation and dose adjustments.
- Hyponatremia is a common side effect, particularly in the elderly or those on diuretics; monitor serum sodium regularly.
Alternative Therapies
- For Epilepsy: Levetiracetam, Lamotrigine, Valproic Acid, Phenytoin, Oxcarbazepine, Topiramate, Gabapentin, Pregabalin.
- For Trigeminal Neuralgia: Oxcarbazepine, Gabapentin, Pregabalin, Baclofen.
- For Bipolar Disorder: Lithium, Valproic Acid, Lamotrigine, Atypical Antipsychotics (e.g., Quetiapine, Olanzapine).
Cost & Coverage
Average Cost:
Varies widely, typically $50-$200+ per 30 capsules (200mg ER)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic), Tier 3 or 4 (Brand)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. This medication is accompanied by a Medication Guide, which provides crucial information for patients. Please read this guide carefully and review it again whenever you receive a refill of this medication. If you have any questions or concerns about this medication, consult with your doctor, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the overdose, be prepared to provide details about the medication taken, the amount, and the time it occurred.