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.

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 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 hepatic porphyria (acute intermittent porphyria, variegate porphyria, porphyria cutanea tarda)
• 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 medications itraconazole or voriconazole

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.

• abdominal pain
• acne
• changes in skin colour
• clumsiness or unsteadiness
• constipation
• confusion
• diarrhea
• dizziness
• drowsiness
• dryness of mouth or throat
• excessive growth of body or facial hair
• falls
• fatigue
• hair or nail changes
• headache
• increased sensitivity of skin to sunlight (skin rash, itching, redness, or severe sunburn)
• increased sweating
• loss of appetite
• memory loss
• mouth sores
• muscle or joint aches
• nausea
• red eyes
• red, sore tongue
• ringing in the ears
• sexual problems (men)
• taste changes
• vomiting
• weight gain

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:

• behavioural changes (e.g., confusion, agitation, or hostility)
• blood pressure changes
• blurred vision
• breast enlargement
• continuous "back-and-forth" eye movements
• decreased consciousness
• decreased coordination
• decreased hearing
• difficulty speaking or slurred speech
• double vision
• fainting
• fast, slow, or pounding heartbeat
• glaucoma (increased pressure in the eye, eye pain)
• hallucinations (seeing or hearing things that are not there)
• male infertility
• mood or other mental changes
• nervousness
• numbness, tingling, pain, or weakness in hands and feet
• painful swelling and redness along a vein
• reactivation of herpes virus (cold sores, genital sores)
• reddish-purple bumps on skin (may be itchy)
• severe headache
• severe nausea and vomiting
• signs of allergic skin reaction (e.g., skin rash, hives, or itching)
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of bleeding (e.g., black, tarry stools, blood in urine or stools, pinpoint-sized red spots on skin, unusual bruising, bleeding that does not stop easily)
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worst when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of depression with restlessness (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of infection (e.g., cough or hoarseness, sore throat, chills, fever, swollen or painful glands, unusual tiredness or weakness)
• signs of inflammation of the colon (e.g., abdominal pain, diarrhea, fever)
• signs of kidney problems (e.g., change in the amount or colour of urine, increased urination at night, blood in the urine, swelling in the feet or legs)
• signs of liver damage (e.g., darkening of urine, pale stools, yellow eyes or skin)
• signs of low sodium in the blood (e.g., muscle twitching, confusion, increased seizures, unusual drowsiness)
• signs of meningitis not caused by infection (e.g., headache [severe], throbbing, or with stiff neck or back)
• signs of pancreatitis (inflammation of the pancreas; e.g., severe upper abdominal pain, loss of appetite, vomiting)
• signs of porphyria (e.g., darkening of urine, severe abdominal pain, excessive sweating)
• swelling of face, hands, feet, or lower legs
• symptoms of irregular heartbeat (e.g., chest pain, dizziness, rapid or pounding heartbeat, shortness of breath)
• symptoms of lupus (e.g., fever, general feeling of being unwell, joint pain, confusion, muscle aches, skin rash)
• trembling or loss of muscle coordination
• unusual breast milk secretion
• weakness

Check with your doctor immediately if any of the following side effects occur:

• loss of consciousness
• rapid development of signs of anemia or bleeding, sometimes combined with fever
• rapid development of signs of liver or other organ 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, altered consciousness)
• 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
• thoughts of suicide or self-harm

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.

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.

Alcohol and other medications that cause drowsiness: Consuming alcohol can make some of the side effects of carbamazepine worse. Avoid drinking alcohol while you are using this medication.

Other medications that have similar side effects such as decreased coordination, drowsiness, falls (e.g., antidepressants, opioid pain relievers, other seizure medications) can increase the likelihood of experiencing these effects with carbamazepine. If you are taking other medications, talk to your doctor or pharmacist about how to manage these side effects.

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. Effective birth control should be used while taking carbamazepine and for at least 2 weeks after taking the last dose. 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.

Decreased effectiveness: Over time, there may be a need to increase the dose of carbamazepine to maintain control of the symptoms you are treating. If you experience an increase in the frequency of seizures or pain associated with trigeminal neuralgia, contact your doctor as soon as possible.

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.

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.

Grapefruit and grapefruit juice:  Avoid drinking grapefruit juice or eating grapefruit while you are taking this medication as it can increase the levels of carbamazepine in your blood, resulting in side effects.

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.

Multi-organ hypersensitivity reaction: Some people taking carbamazepine have experienced a severe allergic reaction. This reaction involves several 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, joint swelling, muscle and joint pain, yellowing of the skin or eyes, or flu-like symptoms with skin rash or blistering.

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.

Sorbitol: Carbamazepine suspension contains sorbitol. You should not take the liquid form of this medication if you have a hereditary problem of fructose intolerance.

Stopping the medication: Suddenly stopping carbamazepine can cause seizures. Before stopping this medication, discuss with your doctor how you should gradually reduce the dose.

Suicidal thoughts and behaviour: Some people taking anti-seizure medications may have suicidal thoughts or behaviour. If this happens to you or you notice this in a family member who is taking this medication, contact your doctor immediately. You should be closely monitored by your doctor for emotional and behaviour changes while taking this medication.

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: People 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, people with epilepsy who are pregnant should be treated with only one medication to prevent seizures.

Additional folic acid supplementation may be advisable for people 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 and taking carbamazepine, it may affect your baby. If a person taking carbamazepine breast-feeds their 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.

Seniors: People over the age of 65 years may require lower doses of this medication.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other 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.

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.