Large Description (basic): 

Carbamazepine (CAR-buh-MAZ-uh-peen) is the generic name (non-brand name) of a widely used type of seizure medicine. Common brand names for carbamazepine include Tegretol and Carbatrol.

Used to treat: 

Forms (basic): 

Various companies make and sell carbamazepine under different names, including Epitol and Atretol. It is generally available in three forms:

  • Tablets: 200 milligrams (mg). These should be swallowed whole, not chewed.
  • Chewable tablets: 100 milligrams (mg). These can be either swallowed whole or chewed.
  • Suspension (liquid): 100 milligrams (mg) per 5 milliliters (mL or ml)

Products from different companies may look different. They all contain the same kind of medicine, but check with your doctor or the pharmacist if you get pills that look different from the ones you have been taking. You need to be careful because pills from a different company may not work the same way in your body.

Using generic medicines rather than brand-name ones is often suggested as a way to save money. Sometimes the savings are large, but with other medicines the price differences are pretty small. Investigate and shop around before deciding whether the savings are worth any possible problems.

People who switch from brand-name Tegretol, for instance, to generic carbamazepine possibly risk having more seizures or side effects during the changeover, because the body does not absorb the different types in the same way. Switching from one company's generic carbamazepine to another company's may have similar risks. So can switching from generic carbamazepine to Tegretol.

All these risks are not fully known. For some people the effects of changing from one type to another are very small. Some use generic carbamazepine successfully by always using the same company's product. Then the dosage can be adjusted to achieve the best results.

What's important is that you and the doctor should know what you're getting from the pharmacy and be able to control what type of seizure medicine you get.

Dosing (basic): 

See package insert.

How to take and store Carbamazepine?

Follow the doctor's directions. Call if you have any questions. Ask the doctor what to do if you forget a dose. The way the medicine is taken depends, of course, on what form the doctor has prescribed.

Most doctors recommend taking carbamazepine with food to avoid an upset stomach. Because food affects the way medicine is used by the body, try to be consistent day after day. A person who usually takes it with meals should do that all the time.

To use the liquid suspension, shake the bottle just before pouring it into a measuring spoon or filling a dropper. Use the same standard-size medicine spoon or dropper each time to get an accurate dose. Do not mix this form of carbamazepine with any other liquid or take it at the same time as another liquid medicine.

Don't drink grapefruit juice with carbamazepine, because it can interfere with the body's use of the medication.

As the doctor increases the amount of carbamazepine that you take, you may be given a different kind of tablet than the ones you've been taking. For example, you may start out using 100-mg tablets and then switch to 200-mg tablets. If this happens, be careful to use the correct number. Don't automatically continue to take the same number of tablets as before.

Store all types of carbamazepine at room temperature (below 86°F, 30°C). Protect the tablets from moisture. Don't keep them in the bathroom, where it's damp. Keep the bottle of the liquid in a cupboard where it won't get too much light.

What if I forget?

Take a forgotten dose as soon as you remember. If it almost time for the next dose, it may be a good idea to delay that dose for a few hours so you're not taking two doses very close together. If you're not sure what to do, call the doctor's office for more advice.

Do your best to follow the doctor's directions. The more often a medicine must be taken, the greater the chance of forgetting, and some people need to take carbamazepine four times every day. This can be difficult. If you forget doses often, it may be a good idea to get a special pillbox or watch with an alarm to remind you. Or ask the doctor whether you can switch to another form of carbamazepine that you can take less often.

Taking the right amount of seizure medicine on time every single day is the most important step in preventing seizures!

How does Carbamazepine effect the brain?

Brain cells need to work (fire) at a certain rate to function normally. During a seizure, brain cells are forced to work much more rapidly than normal. Carbamazepine helps prevent brain cells from working as fast as a seizure requires them to. In this way, seizures can be stopped when they are just beginning.

How does the body digest Carbamazepine?

After medicine is swallowed, it must be absorbed into the blood so it can move throughout the body. The process of absorbing, digesting, and excreting a medicine or food is called metabolism. The way the body metabolizes a particular medicine affects how often it must be taken. It also determines whether it will interact with other medicines or be affected by conditions such as liver disease.

Like many other medicines, carbamazepine is broken down (digested) in the liver. If the person also takes other medicines that are digested in the liver, things can get complicated. How well each medicine works and how quickly it leaves the body may be changed.

This is why the doctor needs to know about everything that a person takes—not just prescription medicines but even things like vitamins, herbs, and aspirin! These things can affect how much carbamazepine is prescribed.

How well does the Carbamazepine work?

Many studies suggest that some seizure medications, like carbamazepine, may control seizures in about 70% of people taking the drug.  

These promising results are not always matched in everyday life. Sometimes patients don't take all their medicine on time. Not everyone's seizures can be controlled at a dose that can be taken without side effects. Because of individual differences, there is no "best" amount for everyone. Adjustments are often needed to reduce seizures or side effects.

Many studies have compared carbamazepine with other seizure medicines, to see which medicine is best for people who have just begun treatment for epilepsy. On average, the results were about the same for carbamazepine as for several other seizure medicines that are often used.

Differences in side effects may be important in deciding which medicine is best for each person. In one study, people who took carbamazepine had fewer problems with side effects. Because some people do better with carbamazepine and others do better with something else, it's difficult to forecast the results in any given person.

If seizures continue, the doctor probably will change the amount of carbamazepine prescribed. If that doesn't work, the next step may be either to prescribe a different seizure medicine by itself or to prescribe a combination of carbamazepine and another seizure medicine. Many are available. No single combination is best for everyone.  The choice of medication should consider a number of factors such as a person's seizure type, possible side effects, drug interactions, other medical conditions the person may have, and cost. 

 

 

What are the most common side effects of Carbamazepine?

Most people who take carbamazepine don't have too much trouble with side effects. That's one of the reasons it’s used so much. The most common complaints (usually not too severe) are:

  •    dizziness
  •    sleepiness
  •    unsteadiness
  •    upset stomach
  •    blurred or double vision
  •    headache

If you notice any of these problems, call the doctor. Sometimes the doctor can help by changing the amount or type of carbamazepine prescribed. No one should stop taking carbamazepine or change the amount they take without their doctor's guidance.

People who have just started taking carbamazepine (or who have just started taking a larger amount) should be careful during activities that might be dangerous, until they know whether they are having any side effects.

Allergic reactions
About 5% to 10% of people who take carbamazepine have a red rash within in the first month of taking it. If this happens, tell the doctor or nurse, to be sure that it's not the beginning of a serious problem.

What are the most serious side effects of Carbamazepine?

A few people have serious reactions to carbamazepine. These serious problems are very rare but everyone who takes this medicine should at least be aware of them because a very small number of people have died because of them. A complete list of all reactions to carbamazepine can be found in the package insert, but it is important to remember that only a tiny number of people have any of these serious problems.

On December 12, 2007, the Food and Drug Administration informed healthcare professionals that dangerous or even fatal skin reactions (called Stevens Johnson syndrome and toxic epidermal necrolysis), that can be caused by carbamazepine, are significantly more common in patients who have a particular type of gene, called “HLA-B*1502”. This gene occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians. Patients with ancestry from these areas in which HLA-B*1502 is present should have a blood test by their physicians to see if they have the “HLA-B*1502” gene before starting treatment with carbamazepine. If these individuals test positive, carbamazepine should not be started unless the expected benefit clearly outweighs the increased risk of serious skin reactions. Patients who have been taking carbamazepine for more than a few months without developing skin reactions are at low risk of these events ever developing from carbamazepine. This is even true for patients who test positive for HLA-B*1502. (source: http://www.fda.gov/medwatch/safety/2007/safety07.htm#carbamazepine)

Other serious side effects from carbamazepine are certain kinds of blood abnormalities. Only about 1 in 30,000 people who take carbamazepine will develop one of these disorders, but the risk is higher than the risk for other people. The doctor will probably recommend a complete blood test before starting the carbamazepine. Then it will be possible to recognize and follow any changes that occur. Many people do have some small changes in their blood that reverse on their own.

The first symptoms of a blood disorder may include:

  •  fever
  •  sore throat
  •  sores in the mouth
  •  nosebleeds or other unusual bleeding or bruising
  •  tiny red spots on the skin

If you notice any of these things, call the doctor right away, but do not stop using the carbamazepine unless the doctor says so.

Liver problems are another serious disorder that occurs in a few people who take carbamazepine. These may be the first symptoms:

  •  yellow eyes or skin
  •  loss of appetite
  •  upset stomach with vomiting
  •  black or pale bowel movements

Tell the doctor right away if you notice any of these problems, but don't stop using the carbamazepine unless the doctor says so.

On July 10, 2008, an advisory panel was convened by the Food and Drug Administration (FDA) to review data that the FDA had previously collected from drug studies showing an association between many of the antiepileptic drugs (AEDs) and suicidal ideation and behavior, which together are called suicidality. According to the FDA’s Alert, among the patients with epilepsy in these drug studies, 1 out of 1000 people taking the placebo (inactive substance) showed suicidality compared to approximately 3.5 out of 1000 people who took an AED. The FDA advisory panel voted to accept the FDA's data at its meeting on July 10. The FDA has provided the following information for patients, family members, and caregivers at http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm100192.htm.

    Taking antiepileptic medicines may increase the risk of having suicidal thoughts or actions;

  •  Do not make any changes to the medication regimen without first talking with the responsible healthcare professional;
  •  Pay close attention to any day-to-day changes in mood, behavior and actions. These changes can happen very quickly so it is important to be mindful of any sudden differences.

    Be aware of common warning signs that might be a signal for risk of suicide. Some of these are:

  •    Talking or thinking about wanting to hurt yourself or end your life
  •     Withdrawing from friends and family
  •     Becoming depressed or having your depression get worse
  •     Becoming preoccupied with death and dying
  •     Giving away prized possessions

We again urge patients and families to contact their doctor before stopping an epilepsy medication because this may possibly lead to seizures and worsening of mood.

Impact of Carbamazepine on bone health

Carbamazepine use has been associated with osteoporosis and or osteopenia in both men and women taking this drug.  It is essential that if you taking this medication, that one take supplemental calcium of 1000 milligrams per day.  Talk to your doctor about bone health.  He/She may decide to check Vitamin D levels and other tests to check for the impact of this drug on your bones.

What else is Carbamazepine used for?

Carbamazepine has been used successfully for many years to treat a type of face pain called trigeminal neuralgia. It has been approved by the Food and Drug Administration (FDA) for that purpose.

Occasionally carbamazepine is also used by patients with some kinds of mental illness. Few studies have shown a definite benefit, however, and this kind of use is not approved by the FDA. It is legal to prescribe medicines for "off-label uses" even though the FDA has not formally approved such use.

Who should not take Carbamazepine?

Rashes that may be very serious are more likely to occur in persons with a particular gene called “HLA-B*1502”. This gene occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians. Patients with ancestry from these areas should have a blood test by their physician to see if they have the “HLA-B*1502” gene before starting treatment.  In addition gene HLA-A*3101 is also associated with severe rash in people who take this drug.  The gene HLA-A*3101 is reported in people of European descent.

Carbamazepine may worsen absence seizures or myoclonic seizures. People who have seizures of those types should not use it.

People with liver disease and those who must take certain other types of medicines may need to be more cautious than others about taking carbamazepine. Most of them can take it successfully, however, if they work with the doctor to determine the correct amount to take. That is why it is so important to make sure the doctor knows about any liver disease and about every kind of medicine you are taking.

Can Carbamazepine be taken with other medicines?

Sometimes one kind of medicine changes the way another kind of medicine works in the body. This is true not only for prescription medicines, but also for medicines you just pick up off the shelf at the store. It’s also true for herbal products, vitamins, a few kinds of food, and even cigarettes!

Any time a doctor suggests a new prescription, be sure to talk about what other medicines you are already using. If two kinds of medicine affect each other, the doctor may want to prescribe something else or change the amount to be taken.

Does carbamazepine affect other medicines?
Carbamazepine makes birth control pills less effective, so the chances of becoming pregnant are greater. Women who use pills for birth control should talk to the doctor who prescribed them right away if they start taking carbamazepine. The same is true for some other forms of birth control such as Depo-Provera and implants. Carbamazepine does not affect barrier types of birth control, like condoms, IUDs, and diaphragms.

Carbamazepine also affects the way the body handles many other seizure medicines. Some of these are:

  • Depakote (valproic acid)
  • Dilantin or Phenytek (phenytoin)
  • Klonopin (clonazepam)
  • Topamax (topiramate)

Do other medicines affect carbamazepine?

Yes, some medicines can cause carbamazepine to build up in the blood. Having too much carbamazepine in the blood makes people feel dizzy, unsteady, or sleepy. Some of the medicines and other things that may have this effect include:

  • Depakote and other valproate seizure medicines
  • some medicines for high blood pressure, including Cardizem (diltiazem) and verapamil
  • Prozac (fluoxetine)
  • certain antibiotics, including erythromycin
  • cimetidine (Tagamet, also available without a prescription)
  • several types of anti-fungus medications
  • painkillers Darvon and Darvocet
  • grapefruit juice

On the other hand, some medicines reduce the amount of carbamazepine in the blood. More seizures may occur unless a higher dosage of carbamazepine is taken. Medicines that may have this effect include:

  • Dilantin or Phenytek (phenytoin)
  • Trileptal (oxcarbazepine)
  • Felbatol (felbamate)
  • phenobarbital
  • Mysoline (primidone)
What are the effects of Carbamazepine on Children?

Carbamazepine is useful in treating many kinds of seizures that occur in children. But other types that are also common can be made worse, so a correct diagnosis is very important.

Children’s bodies break down carbamazepine faster than adults’ bodies do. This means that young children need to take a larger amount, pound for pound, than adults. By the time children reach their early teens, however, they their bodies absorb, digest, and excrete medicines more like adults do, so they may need to take less than before.

Because children absorb carbamazepine so quickly, side effects like sleepiness, double vision, or dizziness can be a problem for children. Parents and doctors also need to watch for problems with thinking or behavior. These problems are uncommon, but if they occur they can interfere with the child’s development and school performance.

If a woman takes Carbamazepine during pregnancy will it hurt the baby?

Carbamazepine can cause harm to your baby if taken while you are pregnant.

Research studies suggest that there may be an association between the use of carbamazepine during pregnancy and congenital malformations, including spina bifida. There have also been reports that associate carbamazepine with developmental disorders and congenital anomalies (e.g. craniofacial defects, cardiovascular malformations, hypospadias, and anomalies involving various body systems). Developmental delays have been reported. If you are worried about the effects of the drug on your unborn child, you should talk to your doctor and ask about the risks of using the drug while pregnant. You need to weigh the benefits of the drug against the risks. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be aware of the potential risks to your baby.

Studies suggest that, there is a higher risk of malformations associated with the use of more than one anti-seizure drug at any given time. Therefore, if therapy is to be continued, monotherapy may be preferable for pregnant women.

What are the dose ranges for Carbamazepine?

The best amount is the amount that completely controls seizures without causing troublesome side effects. It depends on many factors, which are different for every individual. Follow the doctor's directions. Call if you have any questions.

No one should stop taking carbamazepine or change the amount they take without talking to the doctor first. Stopping any seizure medicine all at once can cause a problem that may be life-threatening.

Don’t use more than the doctor prescribes. If a little extra (such as one or two extra tablets) is taken by accident, call the doctor for advice. For a larger overdose, call a poison control center or emergency room right away unless you have other specific directions from your doctor.

To avoid unwanted side effects, the doctor will prescribe a low dose to start and increase it gradually. People over 12 years of age usually start by taking carbamazepine twice a day. The doctor gradually prescribes more until their seizures are controlled. Most people need to take carbamazepine three or four times a day.

Special Concerns for Carbamazepine

See package insert.

Read the package insert of Carbamazepine

In the United States, companies that manufacture medicines are required to publish certain kinds of information about each product. This document is commonly known as a “package insert” because it is usually included with each package of the medicine.

You can also read these documents (also called "prescribing information") online. The U.S. package insert for Tegretol (carbamazepine) is found at:

Some of the information may differ in other countries.

To learn how to read and understand a package insert, see "How to read a package insert."

Large Description (adv): 

Carbamazepine (CAR-buh-MAZ-uh-peen) is the generic name of a widely used antiepileptic drug (AED). Brand names for carbamazepine in the United States include Tegretol and Carbatrol. In other countries, brand names include Carbagen SR, Mazepine, Tegrital, Teril, and Timonil.

Indications (adv): 

Carbamazepine is indicated for use as an anticonvulsant in people of all ages. Evidence supporting efficacy of carbamazepine as an anticonvulsant was derived from active drug-controlled studies that enrolled patients with the following seizure types:

  • Partial seizures with complex symptomatology (psychomotor, temporal lobe). Patients with these seizures appear to show greater improvement than those with other types.
  • Generalized tonic-clonic seizures (grand mal).
  • Mixed seizure patterns that include the above, or other partial or generalized seizures.

Forms (adv): 

Various companies make and sell carbamazepine under different names, including Epitol and Atretol. It is generally available in three forms:

  • 200-mg tablets: to be swallowed whole, not chewed
  • 100-mg chewable tablets: to be either swallowed whole or chewed
  • Suspension (100 mg/5 mL)

Dosing (adv): 

See package insert.

How to take and store Carbamazepine?

Most doctors recommend taking carbamazepine with food to avoid an upset stomach, but it can also be taken on an empty stomach. Consistency is important, to avoid variations in absorption.

Remind patients using the suspension to shake the bottle just before measuring. Advise them not to mix carbamazepine suspension with any other liquid or take it at the same time as another liquid medication. (A precipitate may be produced when carbamazepine suspension is mixed with some other liquids.)

Store all types of carbamazepine at controlled room temperature (below 86°F, 30°C). Protect the suspension from light.

Missed doses of carbamazepine are common because many people need to take it three or four times per day. Advise patients to take a forgotten dose immediately unless it is almost time for the next dose. In that case, they should either skip the forgotten dose (rather than taking a double dose) or make it up with the next 2 or 3 doses.

Patients who often forget doses may benefit from using a special pillbox or watch with an alarm. Switching to a twice-a-day extended-release form (in the U.S., Tegretol-XR or Carbatrol) may also be helpful.

Missed Doses

Missed doses of carbamazepine are common because many people need to take it three or four times per day. Advise patients to take a forgotten dose immediately unless it is almost time for the next dose. In that case, they should either skip the forgotten dose (rather than taking a double dose) or make it up with the next 2 or 3 doses.

Patients who often forget doses may benefit from using a special pillbox or watch with an alarm. Switching to a twice-a-day extended-release form (in the U.S., Tegretol-XR or Carbatrol) may also be helpful.

Mechanisms of actions of Carbamazepine

Carbamazepine blocks frequency-, use- and voltage-dependent neuronal sodium channels, and therefore limits repetitive firing of action potentials.

It also affects calcium channels, GABA receptors, and adenosine receptors, and increases concentrations of serotonin and other neurotransmitters. Whether these effects contribute to its anticonvulsant activity is not clear.

Clinical Pharmacology of Carbamazepine

Carbamazepine is metabolized and eliminated by the liver. It is metabolized by the hepatic P450 system (in particular, the 3A4 isoenzyme). Carbamazepine is ~70-80% protein-bound.

Carbamazepine induces its own metabolism (autoinduction) within the first month of treatment and also accelerates the metabolism of other hepatically metabolized drugs (see Interactions with other medications). The half-life in chronic therapy (that is, after autoinduction is complete) is 10-20 hours.

The main metabolite of carbamazepine is carbamazepine-10,11-epoxide. This metabolite is active and also is associated with neurotoxicity.

Efficacy of Carbamazepine

Carbamazepine is effective against partial seizures, secondarily generalized seizures, and tonic-clonic seizures. It is not effective against other generalized seizure types, such as absence seizures or myoclonic seizures.

Effective serum concentrations generally range from 4-12 mg/L, though lower or higher concentrations may be necessary in some individual patients. Serum concentrations should be checked after approximately one month of treatment, when autoinduction may occur.

A VA Cooperative study in adults with partial and generalized tonic-clonic seizures (Mattson et al. 1985) showed that CBZ was as effective as phenytoin and better tolerated than phenobarbital or primidone. Another VA study (Mattson et al. 1992) showed that CBZ was as effective as valproate for secondarily generalized seizures and more effective for partial seizures.

If carbamazepine alone does not stop all seizures, a combination of carbamazepine and another AED may be more effective. Phenytoin or valproate are often used, but many newer AEDs are also available.

Common side effects of Carbamazepine

Dose-related side effects
The most common side effects are neurotoxic and dose-related. They include:

  • drowsiness
  • diplopia
  • headache
  • ataxia
  • nausea
  • vomiting
  • dizziness

These side effects tend to occur within a week of initiation or dosage increase. In chronic therapy, they typically are noticeable 3-4 hours after a dose (associated with peak serum concentrations).

They can be lessened by:

  •  reducing the total daily dosage
  •  splitting the total daily dosage into more frequent doses
  •  shifting more of the total daily dosage to bedtime, especially for patients with nocturnal or early-morning seizures
  •  switching to an extended-release form of carbamazepine, like Tegretol-XR or Carbatrol

Other systemic side effects include:

  •  abdominal pain
  •  constipation
  •  diarrhea
  •  loss of appetite

Hyponatremia is generally asymptomatic, though fluid retention, confusion, and increased seizures may signal symptomatic hyponatremia. In such cases, fluid restriction may be helpful. If symptomatic hyponatremia persists, discontinuation is warranted. Elderly patients and others with heart disease appear to be at particular risk for hyponatremia. Serum sodium should be checked before treatment and within the first month of treatment.

Adverse effects on cognition, memory, or mood generally are not commonly associated with carbamazepine.

To avoid possible bone loss associated with long-term use, patients should be advised to meet recommended requirements for vitamin D and calcium, expose their skin to sunlight in moderation, and engage in antigravity exercises.

Idiosyncratic reactions
Idiosyncratic reactions include a morbilliform rash in approximately 5-10% of patients. More serious rashes, such as Stevens-Johnson syndrome, photosensitivity, exfoliative dermatitis, and erythema multiforme, occur rarely.

Serious Side effects of Carbamazepine

Potentially life-threatening reactions to carbamazepine involve aplastic anemia, toxic hepatitis, pancreatitis and skin reactions, specifically Stevens Johnson syndrome and toxic epidermal necrolysis.

About 1 in 30,000 people who take carbamazepine will develop serious blood disorders. Baseline blood and platelet counts should be obtained and repeated early in the course of therapy. Generally, discontinuation of carbamazepine is not necessary unless blood counts are significantly reduced or leukopenia persists. (Up to 10% of patients have a leukopenia that reverses within 1-2 weeks.) Patients should be told to report easy bruising, fever, or infections.

Renal and hepatic function tests also can be performed before treatment and repeated later if clinically indicated. Patients should be advised to report possible symptoms of hepatitis, including:

  •   yellow eyes or skin
  •   loss of appetite
  •   upset stomach with vomiting
  •   black or pale bowel movements

On December 12, 2007, the Food and Drug Administration informed healthcare professionals that dangerous or even fatal skin reactions (Stevens Johnson syndrome and toxic epidermal necrolysis), that can be caused by carbamazepine therapy, are significantly more common in patients with a particular human leukocyte antigen (HLA) allele, HLA-B*1502. This allele occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians. Patients with ancestry from areas in which HLA-B*1502 is present should be screened for the HLA-B*1502 allele before starting treatment with carbamazepine. If these individuals test positive, carbamazepine should not be started unless the expected benefit clearly outweighs the increased risk of serious skin reactions. Patients who have been taking carbamazepine for more than a few months without developing skin reactions are at low risk of these events ever developing from carbamazepine. This is true for patients of any ethnicity or genotype, including patients positive for HLA-B*1502. (source: http://www.fda.gov/medwatch/safety/2007/safety07.htm#carbamazepine)

If you believe that you have experienced a serious side effect from a medication, you or your physician can bring it to the attention of the FDA, through their MedWatch program, by completing an adverse event report form (http://www.fda.gov/medwatch/getforms.htm). MedWatch is the FDA's program for reporting serious reactions and problems with medical products, such as drugs and medical devices. (http://www.fda.gov/medwatch/getforms.htm.) To learn more about the Medwatch program go to: http://www.fda.gov/medwatch/report/consumer/consumer.htm

On July 10, 2008, an advisory panel was convened by the Food and Drug Administration (FDA) to review data that the FDA had previously collected from drug studies showing an association between many of the antiepileptic drugs (AEDs) and suicidal ideation and behavior, which together are called suicidality. According to the FDA’s Alert, among the patients with epilepsy in these drug studies, 1 out of 1000 people taking the placebo (inactive substance) showed suicidality compared to approximately 3.5 out of 1000 people who took an AED. The FDA advisory panel voted to accept the FDA's data at its meeting on July 10. The FDA has provided the following information for patients, family members, and caregivers at http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm100192.htm.

   Taking antiepileptic medicines may increase the risk of having suicidal thoughts or actions;

  •  Do not make any changes to the medication regimen without first talking with the responsible healthcare professional;
  •  Pay close attention to any day-to-day changes in mood, behavior and actions. These changes can happen very quickly so it is important to be mindful of any sudden differences.

    Be aware of common warning signs that might be a signal for risk of suicide. Some of these are:

  •    Talking or thinking about wanting to hurt yourself or end your life
  •     Withdrawing from friends and family
  •     Becoming depressed or having your depression get worse
  •     Becoming preoccupied with death and dying
  •     Giving away prized possessions

We again urge patients and families to contact their doctor before stopping an epilepsy medication because this may possibly lead to seizures and worsening of mood.

Impact of Carbamazepine on bone health

Carbamazepine use has been associated with osteoporosis and or osteopenia in both men and women taking this drug.  It is essential that if you taking this medication, that one take supplemental calcium of 1000 milligrams per day.  Talk to your doctor about bone health.  He/She may decide to check Vitamin D levels and other tests to check for the impact of this drug on your bones.

Other Uses of Carbamazepine

Carbamazepine is a first-line treatment and FDA-approved for trigeminal neuralgia. It also is used to treat glossopharyngeal neuralgia and painful peripheral neuropathy (particularly due to diabetes).

The use of carbamazepine in the management of patients with acute mania is supported by a number of studies, which have found it similar in effectiveness to lithium.

The literature also supports the use of carbamazepine for long-term prophylaxis of bipolar disorder, particularly for rapid cyclers.

It is sometimes used for other psychiatric disorders and diabetes insipidus, but few studies have been performed to confirm its effectiveness for those conditions.

Carbamazepine Contraindications

Carbamazepine may exacerbate absence and myoclonic seizures. Therefore, if complex partial seizures are diagnosed on the basis of the history and the episodes increase after carbamazepine is started, one possibility is that the patient actually has absence seizures. EEG testing should be undertaken to classify the seizure type.

Rashes that may be very serious are more likely to occur in persons with a particular gene called “HLA-B*1502”. This gene occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians. Patients with ancestry from these areas should have a blood test by their physician to see if they have the “HLA-B*1502” gene before starting treatment.

Carbamazepine should not be taken by anyone who:*

  • is allergic to carbamazepine or to any ingredients of the tablets or suspension
  • is allergic to tricyclic compounds such as amitriptyline, trimipramine, or imipramine
  • has liver disease
  • has a history of acute intermittent porphyria
  • has a history of hyponatremia
  • has a serious blood disorder
  • has a history of bone marrow depression
  • has taken an MAO inhibitor within the past 14 days or will take one within the next 14 days
  • has certain kinds of heart rhythm disturbances (AV block)

*Information adapted from www.HealthyOntario.com, accessed Aug. 12, 2003.

Carbamazepine Interactions with other medications

Effects of carbamazepine on other drugs
Because carbamazepine accelerates hepatic metabolism, it will increase the clearance of:

  • oral contraceptives
  • valproate
  • phenytoin
  • phenobarbital
  • primidone
  • clonazepam
  • topiramate
  • ethosuximide
  • corticosteroids
  • warfarin
  • antipsychotics
  • cyclosporine

Effects of other drugs on carbamazepine
Drugs that will increase the serum concentration of carbamazepine by inhibiting its hepatic metabolism include:

  • valproate
  • cimetidine
  • dextropropoxyphene
  • diltiazem
  • erythromycin
  • isoniazid
  • verapamil
  • viloxazine
  • fluconazole, ketoconazole, metronidazole, nefazodone
  • fluoxetine

Grapefruit juice has a similar effect.

Taking carbamazepine simultaneously with lamotrigine may increase the likelihood of neurotoxic side effects. Staggering the doses of carbamazepine and lamotrigine by 1 to 2 hours may lessen this effect.

On the other hand, drugs that accelerate hepatic metabolism will lower serum concentrations of carbamazepine. These include:

  • phenytoin
  • oxcarbazepine
  • phenobarbital
  • primidone
  • felbamate

AED Interaction Sheets:
Seizure drugs are often affected by drug-drug interactions. Print these informative sheets for practical help.

Interaction sheet for carbamazepine (Tegretol, Tegretol XR, Carbatrol)

Carbamazepine effects on Children

Carbamazepine is useful in treating many kinds of seizures that occur in children. But other types can be exacerbated (see Contraindications), so a correct diagnosis is critical.

Because children metabolize and eliminate carbamazepine faster than adults do, they require higher doses, relative to their weight. Their blood levels may fluctuate widely, so they often are more affected by dose-related side effects and may need to take smaller, more frequent doses. Using an extended-release form like Tegretol-XR or Carbatrol may reduce this problem. These differences diminish by the early to mid teens.

The initial dosage for children is generally 5-10 mg/kg, divided into two daily doses. Increases usually go no higher than 35 mg/kg, divided into 3 or 4 doses if an extended-release form is not used. Very young children and infants tend to require higher dosages relative to weight than older children.

Carbamazepine and Pregnancy

Carbamazepine is listed in Pregnancy Category D. A warning appears in the package insert.

Patients who require carbamazepine monotherapy to control their seizures can be advised that up to 90% of women who use it during pregnancy have normal, healthy babies. Approximately 0.5% of fetuses exposed to carbamazepine during weeks 4-6 have spina bifida, so Level II ultrasound at 16 weeks gestation is recommended, as is amniocentesis in selected cases. Minor craniofacial defects, fingernail hypoplasia, and developmental delay may occur somewhat more frequently.

The risk of defects is higher for women who take several medicines, and for women with a family history of birth defects.

Women who are capable of becoming pregnant should be advised to take at least 400 mcg (0.4 mg) of folic acid (folate) daily to help prevent neural tube defects. Women at high risk, such as those with a history of a neural tube defect in a previous pregnancy, should take 4000 mcg (4 mg) daily, beginning before they become pregnant.

Check the levels of carbamazepine in the woman's blood at intervals during pregnancy, since changes in her body may affect them. Dosage adjustments may be needed to prevent seizures or side effects.

During the last month of pregnancy, the woman should take 10 mg per day of vitamin K to prevent a bleeding disorder that affects some babies born to mothers who are taking anticonvulsants.

No studies have been performed to demonstrate the effect of specific AEDs during labor and delivery. Possible causes of seizures include:

  • failure or inability to take medication
  • sleep deprivation
  • hyperventilation
  • stress
  • pain

If the mother is taking carbamazepine, a breast-fed newborn will get about 2-5 mg per day in the breast milk. The effect of such a dose has not been evaluated but is unlikely to be harmful for a healthy, full-term baby.

Carbamazepine Dosing and titration

Rashes that may be more serious are more likely to occur in persons with a particular gene called “HLA-B*1502”. This gene occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians. Patients with ancestry from these areas should have a blood test to see if they have the “HLA-B*1502” gene before starting treatment. Further Information for Healthcare Professionals Related to this Topic:
http://www.fda.gov/cder/drug/InfoSheets/HCP/carbamazepineHCP.htm

Carbamazepine should be started at 100-200 mg per day and titrated by increments of 100-200 mg every week or two as clinically needed. The average maintenance dose as monotherapy for adults is 600-1200 mg per day. In children over 6, the usual maintenance dose is 15-30 mg/kg per day. The dosage may need to be increased within a month of initiation due to autoinduction. (See Clinical pharmacology.)

Many people (especially children) need to take carbamazepine in three or four doses a day. The extended-release forms, Tegretol-XR or Carbatrol, are often preferable for patients who have trouble with compliance and for those whose blood levels fluctuate widely throughout the day.

Algorithm for Dosing Carbamazepine

Special Concerns for Carbamazepine

See package insert.

Carbamazepine Package insert

In the United States, companies that manufacture medicines are required to publish certain kinds of information about each product. This document is commonly known as a “package insert” because it is usually included with each package of the medicine.

You can also read these documents (also called "prescribing information") online. The U.S. package insert for Tegretol (carbamazepine) is found at:

Some of the information may differ in other countries.

To learn how to read and understand a package insert, see "How to read a package insert."

Carbamazepine References for Professionals

Abstracts of articles relevant to this topic are available through PubMed, a service of the National Library of Medicine.

Mattson, RH, Cramer, JA, et al. Comparison of carbamazepine, phenobarbital, phenytoin and primidone in partial and secondarily generalized tonic clonic seizures. N Engl J Med 313:145-151, 1985. PMID: 3925335.

Carbamazepine was more effective than primidone (Mysoline) or phenobarbital in controlling partial seizures. Overall, carbamazepine and phenytoin (Dilantin) are the first choices for a single medication to treat adults with newly diagnosed partial seizures, generalized tonic-clonic seizures, or both.

Mattson, RH, Cramer, JA, et al. A comparison of valproate with carbamazepine for the treatment of partial seizures and secondarily generalized tonic-clonic seizures in adults. N Engl J Med, 327:765-771, 1992. PMID: 1298221.

Carbamazepine and valproate (Depakote) are equally effective for treating generalized tonic-clonic seizures in adults. Although other studies show that valproate is effective for newly diagnosed partial seizures, in this study carbamazepine provided better control of complex partial seizures. The side effects of these two medications are different.

Snead OC III, Hosey LC. Exacerbation of seizures in children by carbamazepine. N Engl J Med 1985;313:916-21.

A call for caution when using carbamazepine in children with mixed seizure disorders.