How does this medication work? What will it do for me?
Carbamazepine is used to manage certain types of seizures, alone or in combination with other medications. It is also used to treat the nerve pain of trigeminal neuralgia and to treat acute mania and prevention of bipolar (manic-depressive) disorders.
This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
What form(s) does this medication come in?
Controlled release (CR) tablets
Each yellow-brown, oblong, biconvex, film-coated tablet, marked with "G | G" on one side and "CB | R2" on the other side, contains carbamazepine 200 mg. Nonmedicinal ingredients: colloidal anhydrous silica, croscarmellose sodium, ethanol (dehydrated), ethylcellulose, hydroxypropylmethyl cellulose, iron oxide black, iron oxide red, iron oxide yellow, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyacrylate dispersion 40%, purified talc, and titanium dioxide.
Each yellow-brown, oblong, biconvex, film-coated tablet, marked with "G | G" on one side and "CB | R4" on the other side, contains carbamazepine 400 mg. Nonmedicinal ingredients: colloidal anhydrous silica, croscarmellose sodium, ethanol (dehydrated), ethylcellulose, hydroxypropylmethyl cellulose, iron oxide black, iron oxide red, iron oxide yellow, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyacrylate dispersion 40%, purified talc, and titanium dioxide.
How should I use this medication?
Recommended doses of carbamazepine vary greatly, depending on the condition being treated and the age and circumstances of the person being treated.
Seizure disorder: The starting dose for adults and children over 12 years of age is 100 mg to 200 mg once or twice daily. Depending on the effectiveness of the medication, the doctor may increase the dose gradually up to 1,600 mg daily in divided doses. Most people achieve the best response at daily doses between 800 mg and 1,200 mg.
The starting dose for children between 6 and 12 years of age is 100 mg daily in divided doses and increased by 100 mg daily until the best response is achieved. The daily maximum dose for children is 1,000 mg daily in divided doses.
If carbamazepine is being added to medications that are already being taken for seizures, the starting doses may be lower.
Trigeminal neuralgia pain: The starting dose of carbamazepine for treating the pain of trigeminal neuralgia is 100 mg taken twice daily. The dose is increased to a maximum of 1,200 mg daily, depending on the effectiveness of the medication.
Mania and bipolar disorders: The usual starting dose for the treatment of mania and bipolar disorders is 200 mg to 400 mg daily, taken in divided doses. The daily dose is then increased as instructed by the doctor to a maximum of 1,600 mg daily. If other medications, such as lithium, are being taken, the starting dose will be lower.
Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
Carbamazepine should be taken with meals whenever possible.
The controlled release tablets should be swallowed whole with some liquid during or after a meal. They should not be crushed or chewed.
When taking carbamazepine suspension, shake the medication bottle well before measuring the dose of medication. An oral syringe should be used to measure each dose of the liquid, as it provides a more accurate measurement than household teaspoons.
It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store all forms of this medication at room temperature, away from humidity, and out of reach of children. The chewable tablets and liquid should be protected from light.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not take carbamazepine if you:
- are allergic to carbamazepine or any ingredients of the medication
- are allergic to tricyclic compounds such as amitriptyline, trimipramine, or imipramine
- have a history of acute intermittent porphyria
- have a history of bone marrow depression
- have a serious blood disorder
- have severe heart disease (heart block)
- have liver disease
- have taken an MAO inhibitor (e.g., phenelzine, tranylcypromine) within the past 14 days or will take one within the next 14 days (If you have taken an MAO inhibitor recently but more than 14 days ago, your dosage of carbamazepine should be low initially, and increased very gradually.)
- are taking the antifungal medication itraconazole or voriconazole
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- clumsiness or unsteadiness
- dryness of mouth or throat
- hair or nail changes
- increased sensitivity of skin to sunlight (skin rash, itching, redness, or severe sunburn)
- increased weight
- loss of appetite
- memory loss
- red eyes
- ringing in the ears
- sexual problems (males)
- taste changes
- weight increase
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Check with your doctor immediately if any of the following side effects occur:
- rapid development of signs of anemia or bleeding, sometimes combined with fever
- rapid development of signs of liver damage
- signs of an allergic reaction (e.g., wheezing, tightness in chest, troubled breathing, shortness of breath, or cough)
- signs of neuroleptic malignant syndrome (e.g., high fever, muscle stiffness, sweating, racing or irregular heartbeat)
- signs of severe skin reactions (e.g., blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)
- sores, ulcers, or white spots on lips or in the mouth
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.
Anemia: Carbamazepine may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia), such as shortness of breath, feeling unusually tired or pale skin, contact your doctor as soon as possible.
Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.
Birth control: Carbamazepine, like other anticonvulsants, may reduce the effectiveness of birth control pills. Women taking carbamazepine should use an alternative, non-hormonal birth control method such as condoms. If you become pregnant while taking this medication, contact your doctor immediately.
Bleeding: Carbamazepine may cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.
Bone strength: Long term use of antiepileptics has been associated with a risk of weakened or brittle bones. If you have osteoporosis, are at risk for developing osteoporosis, or have a history of disease affecting your bones, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Cancer: Some studies indicate a possible risk of developing cancer with long term use of carbamazepine. Discuss the potential benefits and possible risks of taking this medication with your doctor.
Depression: Carbamazepine has been known to cause mood swings and symptoms of depression. If you have depression or a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking this medication, contact your doctor as soon as possible.
Drowsiness/reduced alertness: Carbamazepine may cause dizziness and drowsiness. People taking carbamazepine should avoid operating hazardous machinery (including cars) until they are certain that the medication does not affect their mental alertness, judgment, or physical coordination.
Heart disease: If you have coronary artery disease, organic heart disease, or congestive heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Hypersensitivity syndrome: A severe allergic reaction called hypersensitivity syndrome has occurred for some people with the use of carbamazepine. This reaction involves a number of organs in the body and may be fatal if not treated quickly. Stop taking the medication and get immediate medical attention if you have symptoms of a severe allergic reaction, including fever, swollen glands, yellowing of the skin or eyes, or flu-like symptoms with skin rash or blistering.
Glaucoma: Carbamazepine may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking this medication.
Periodic eye examinations are recommended for people who take this medication.
Infection: Carbamazepine can reduce the number of cells that fight infection in the body (white blood cells). If you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness, contact your doctor. Let your doctor know if you are experiencing more frequent infections than normal. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.
Kidney function: If you have kidney disease or decreased kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Carbamazepine can cause decreased liver function and may cause liver failure. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.
If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Lupus: In rare cases, carbamazepine can cause lupus. If you experience symptoms such as fever, facial rash or joint pain, or your lupus symptoms worsen while taking this medication, contact your doctor.
Neuroleptic malignant syndrome (NMS): Carbamazepine, like other medications used to treat some psychiatric illnesses, can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, or fainting, get immediate medical attention.
Psychiatric issues: Carbamazepine may activate certain mental disorders or cause confusion and agitation for seniors. When used to treat bipolar disorder, some people have experienced worsening of their symptoms of depression, feeling unlike themselves, or they may want to hurt themselves or others. People should be closely monitored by their doctor for emotional and behavioural changes.
Skin reactions: Although uncommon, carbamazepine has been linked to serious skin reactions. If you experience symptoms of a serious skin reaction (such as skin rash; redness of the skin; skin peeling; or blisters on the lips, eyes, or mouth) with fever, chills, headache, cough, or body aches, contact your physician immediately.
Stopping the medication: Suddenly stopping carbamazepine can cause seizures. Before stopping this medication, discuss with your doctor how you should gradually reduce the dose.
Low thyroid hormones: Carbamazepine can cause thyroid hormones to be removed from the body more quickly than usual. This is most noticeable if you take thyroid replacement therapy. If you have an underactive thyroid, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your thyroid function with blood tests when you first start taking carbamazepine.
Pregnancy: Women with epilepsy who are pregnant or intend to become pregnant need special care. The potential benefits of carbamazepine must be weighed against its risks, particularly during the first 3 months of pregnancy. If needed to prevent major seizures, do not stop taking the medication. Usually, women with epilepsy who are pregnant should be treated with only one medication to prevent seizures.
Additional folic acid supplementation may be advisable for women taking carbamazepine, as this medication may contribute to a lack of folic acid in the body. Talk to your doctor about the benefits and risks of using carbamazepine during pregnancy.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking carbamazepine, it may affect your baby. If a mother taking carbamazepine breast-feeds her infant, the infant must be observed for possible side effects (e.g., drowsiness or skin rash). The benefits of breast-feeding should be weighed against the possible risks to the infant. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using carbamazepine to treat trigeminal neuralgia or psychiatric disorders in children have not been established. The use of this medication for these conditions in this age group is not recommended.
What other drugs could interact with this medication?
There may be an interaction between carbamazepine and any of the following:
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.