Carbamazepine

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Feb 06, 2023

Warnings


Carbamazepine Risks, Warnings, and Complications


Carbamazepine can cause or worsen health problems in some people. Talk to your doctor or pharmacist about other treatment options if you are at increased risk of complications from carbamazepine use.

  • STEVENS-JOHNSON SYNDROME AND TOXIC EPIDERMAL NECROLYSIS: In some people, carbamazepine therapy can lead to life-threatening skin reactions called Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). These effects occur usually during the first few months of treatment but can happen anytime. People of Asian descent and those who carry the HLA-B-1502 gene are at higher risk of these dangerous skin reactions. Your doctor may order a genetic test before starting carbamazepine to check for this specific gene. Stop taking carbamazepine and call your doctor immediately if you develop a severe skin rash or any systemic symptoms while on this medicine.

  • BLOOD DISORDERS AND BONE MARROW DEPRESSION: Carbamazepine therapy can lead to an increased risk of certain blood problems like aplastic anemia, agranulocytosis, and decreased platelet and white blood cell counts. Your doctor may order certain lab tests to keep an eye on your white blood cells and platelets. Call your doctor without delay if you develop weakness, fever, sore throat, shortness of breath, unusual bleeding or bruising, bleeding gums, or blood in the urine or stool.

  • SEVERE ALLERGIC REACTIONS: A small number of people can develop severe allergic reactions to carbamazepine with signs and symptoms such as skin rash, fever, facial swelling, swollen lymph nodes, and organ failure. People who carry the HLA-A3101 gene are at increased risk. Tell your doctor if you have had an allergic reaction in the past to other seizure medicines, for example, oxcarbazepine, which is similar to carbamazepine. Get medical help right away if you develop any symptoms of an allergic reaction. 

  • CARBAMAZEPINE-INDUCED HYPONATREMIA: Carbamazepine can lead to low sodium levels in the blood. The risk is greater if you are over 65 years of age, take diuretics (water pills), or are dehydrated. Very low levels of sodium in the blood can lead to coma and even death. Tell your healthcare provider if you develop severe headaches, confusion, problems with thinking or concentration, memory problems, unsteadiness, or weakness while on carbamazepine. Seek immediate medical attention if you develop hallucinations, fainting, or increased seizures. 

  • LIVER DAMAGE: Carbamazepine can cause liver damage. This is typically mild but can occasionally be severe. Your doctor will order blood tests to check liver enzymes before starting carbamazepine and during treatment with this medication to keep an eye on liver function. Tell your doctor right away if you develop fatigue, nausea, vomiting, right-sided abdominal pain, poor appetite, dark urine, or yellowing of the skin or eyes.

  • EFFECTS ON HORMONAL BIRTH CONTROL: Carbamazepine can make birth control pills and other forms of hormonal birth control such as patches, vaginal rings, intrauterine devices, implants, and injections less effective. Talk to your doctor about appropriate methods of birth control before starting carbamazepine. Tell your doctor immediately if you become pregnant while on carbamazepine. This medicine can increase the risk of birth defects in an unborn baby.

  • SUICIDAL THOUGHTS OR BEHAVIOR: Taking carbamazepine and other drugs used to control seizures can increase your risk of suicidal thoughts or behavior. Look out for any new or worsening depression or mood changes, especially when you first start taking carbamazepine. Tell your family members to be aware of any unusual behaviors or moods as well. Call 911 or get immediate medical attention if you have thoughts of hurting yourself.

  • WITHDRAWAL SEIZURES: Stopping carbamazepine suddenly can lead to new or worsening seizures. Do not stop taking this medicine without talking to your doctor first. Your doctor will tell you how to slowly lower the dose of carbamazepine.


Precautions Before Starting Carbamazepine

Tell your healthcare provider if you have ever had an allergic reaction to carbamazepine; other seizure medicines like oxcarbazepine, valproic acid, phenytoin, phenobarbital; tricyclic antidepressants (such as amitriptyline, desipramine) or any other medications. Your pharmacy can give you a full list of active and inactive ingredients in carbamazepine formulations.

Some medications should not be taken together with carbamazepine. Give your doctor and pharmacist a complete list of all your medicines, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements. This can help avoid dangerous interactions between your medications.

Give your doctor a complete medical history. Carbamazepine may not be right for people with certain medical conditions, such as liver disease, kidney disease, heart disease, thyroid disease, and glaucoma. 

Carbamazepine can make hormonal birth control less effective. Talk to your doctor about other birth control methods to prevent pregnancy while on carbamazepine. Tell your doctor if you develop any unusual bleeding or bleeding between periods while on this medicine.

Tell your healthcare provider if you are pregnant, could be pregnant, are planning a pregnancy, or are breastfeeding. Carbamazepine can cause birth defects in an unborn baby.

The liquid suspension of carbamazepine contains sorbitol, a sweetener with a fruit sugar called fructose. Tell your doctor if you have fructose intolerance.

Precautions During Use of Carbamazepine

Keep all your healthcare appointments during your treatment with carbamazepine. This medication will control seizures but will not cure your condition. Continue taking carbamazepine even if you feel well. Do not stop taking carbamazepine without your doctor’s approval.

If you are taking other liquid medicines, do not take them at the same time as carbamazepine liquid suspension.

Call your doctor immediately if you become pregnant while on carbamazepine. This medicine can be harmful to an unborn baby.

Tell all your healthcare providers you are on carbamazepine, especially before any surgery, including dental procedures.

Carbamazepine can cause drowsiness and dizziness. Be careful while driving, operating heavy machinery, or doing anything that requires full concentration until you know how this medicine affects you.

Avoid alcoholic drinks while on carbamazepine. Drinking alcohol can worsen side effects like dizziness and drowsiness, putting you at risk of accidents and injuries.

Carbamazepine and other seizure medicines can cause suicidal thinking and behaviors. Look out for any changes in mood or unusual behavior while on this medicine. Make sure people in your household know how to get help in case you cannot do so yourself.

Carbamazepine Drug Interactions

Certain other medicines can affect how carbamazepine works. Possible interactions between carbamazepine and other medicines can increase the risk of severe adverse effects.

Do not take carbamazepine at the same time as or within 14 days of taking monoamine oxidase (MAO) inhibitors such as linezolid (Zyvox), isocarboxazid (Marplan), methylene blue, selegiline (Emsam, Zelapar), phenelzine (Nardil), and tranylcypromine (Parnate). 

Some of the other medicines that can have a drug reaction with carbamazepine include:

  • Acetaminophen (Tylenol)
  • Ibuprofen (Advil, Motrin)
  • H2 blockers like cimetidine (Tagamet)
  • Proton pump inhibitors like omeprazole (Zegerid OTC, Prilosec OTC)
  • Antihistamines like loratadine (Claritin)

This is not a complete list of carbamazepine drug interactions. Give your doctor and pharmacist a list of all the medicines you take, including prescription drugs, over-the-counter medicines, dietary supplements, and herbal products. Also, tell your healthcare professionals if you smoke, drink alcohol, or use illegal drugs because some of these substances can cause serious health complications when used with prescription medications.