Carbamazepine

​Like all medications, carbamazepine may cause side effects but not everyone experiences them. Consult your healthcare professional if any of the side effects lasts more than a few days or becomes severe and bothersome.

The common side effects of carbamazepine include:

• Dizziness, feeling lightheaded
• You can get up slowly from a sitting or lying down position to reduce this
• Drowsiness
• Avoid driving, operating machinery or doing strenuous physical activities
• Avoid taking over-the-counter medicines (such as cold or allergy medicines) that could also add on to the drowsiness
• Diarrhoea
• Drink more water to keep hydrated if you do experience diarrhoea
• Constipation
• Drink more water or consume more high-fibre foods and exercise regularly if you experience constipation
• Nausea, vomiting
• Take the medicine with or after food to reduce nausea and vomiting
• Avoid food that is too rich, spicy or has strong smells
• Loss of appetite, stomach upset
• Take the medicine with or after food to reduce stomach upset
• Headache, back pain
• Take paracetamol, if necessary, to relieve headache or back pain

 If the following serious side effects happen, you should consult your healthcare professional immediately:

• Blistering, peeling, red skin rash due to Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)
• SJS and TEN are rare and serious skin reactions. Symptoms include face swelling, blisters on skin, skin rashes that spread within hours to days. It usually occurs within the first few months (monitor closely for the first 3 months) of treatment.
• As SJS and TEN progress rapidly, please consult your healthcare professional if you show the first sign of rash.
• Fever, chills, sore throat, mouth ulcers or sores
• Unusual bruising or bleeding
• Chest pain or a fast, pounding or irregular heartbeat
• Changes in how much and how often you urinate
• Liver problems: Dark coloured urine or light coloured stools, yellowing of your eyes or skin, severe loss of appetite, stomach pain, nausea, vomiting that does not go away
• Blurred vision or double vision
• Feeling clumsy, unsteady movements

In rare cases, this medication may cause the following changes to a person's mental condition, especially in the first few weeks of treatment or during dose changes:

• Worsening agitation, restlessness, violent behaviour, or
• New or worsening thoughts of harming yourself or ending your life
• Other changes in mood or behavior 

Please inform your doctor as soon as possible, or for your family or caregiver to inform your doctor if you are unable to seek treatment on your own.

Do not stop taking this medication on your own without discussing with your doctor.

It is important to note that your doctor has prescribed this medication as he/she feels you will benefit more from taking this medication over the possible risks that it may cause, which have a low chance of occurring, and most people take this medication without any such problems.

The symptoms of a drug allergy include one or more of the following:

• Swollen face/eyes/lips/tongue
  
• Difficulty in breathing
  
• Itchy skin rashes over your whole body
  

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

​In accordance to the Health Science Authority (HSA) regulation, it is compulsory for all Asian patients who are first prescribed with carbamazepine to be tested for a specific gene (HLA-B*1502) that could result in higher risk of Stevens-Johnson Syndrome (SJS) or Toxic Epidermal Necrolysis (TEN). SJS and TEN are rare and serious skin reactions which can happen after using some medications. Symptoms include mouth ulcers, face swelling, blisters on skin, skin rashes that spread throughout the body within hours to days after the medication. It usually occurs within the first few months (monitor closely for the first 3 months) of treatment. Those who have been taking carbamazepine for more than 3 months without developing skin reactions are at low risk of SJS and TEN.

Inform your healthcare professional if you have the following medical conditions before starting on carbamazepine:

• Liver problems
• Kidney problems
• Heart problems
• Blood related diseases
• Drug allergies

For female patients of child-bearing age: Discuss with your doctor regarding family planning if you will be starting or currently taking carbamazepine.

Consult your healthcare professional immediately if your seizures get worse or change differently after you start on this medication.

• ​Carbamazepine may decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, injections, implants or intrauterine devices) that prevents pregnancy. Discuss with your healthcare professional regarding birth control while on carbamazepine.
• Antibiotics such as erythromycin and clarithromycin should not be taken with carbamazepine.
• Avoid eating grapefruit or drinking grapefruit juice while you are on carbamazepine.
• Avoid drinking alcohol while taking this medication.
• Please consult your healthcare professional before using any other medications, including over-the-counter medications, supplements and herbal products as some of these may have unwanted effects on the carbamazepine in your body.