Carbamazepine

Most people take carbamazepine for at least six months.

You and your doctor should talk about how long you need to take carbamazepine before you start your treatment.

You might have to change your dose to get the best effect for you.

If you only get ill every 12 months you will probably need to take it for longer than 12 months to get any benefit.

You will get the best effect from this medicine if you take it regularly without missing doses.

Make sure that you know your dose. If it is not written on the label, check it with your pharmacist or doctor.

You may have to take it more than once a day.

You will probably start on a low dose and it will increase until it is right for you.

It doesn’t matter what time you take it each day – choose a time that you can always remember. This could be a mealtime, or when you brush your teeth.

You can take it before or after food.

Different brands of carbamazepine tablets can release slightly different amounts of carbamazepine, even if they are the same strength. Ask your pharmacist to always give you the same brand of tablets. Keep the box or blister pack to show them. This is more important if you are taking carbamazepine for seizures (fits).

If you forget to take a dose, take it as soon as possible unless it is less than four to six hours until your next dose.

If you forget to take it by the time of the next dose, just take the next dose.

Do not take a double dose.

If you forget to take your tablets for a few days, you may start getting your old symptoms back. Talk to your doctor if this happens.

You may need to restart the carbamazepine slowly or find a different treatment.

Once you start taking carbamazepine, the brain adjusts to the new balance of chemicals.

If you stop taking the carbamazepine all at once, the balance starts to change again. You could get your old symptoms back.

There is a risk that you may get seizures (fits). This is because even if you are not taking the carbamazepine for epilepsy, your body has got used to having an anticonvulsant medication on board.

When you decide with your doctor to stop taking carbamazepine, you will probably reduce the dose slowly over at least a month to stop you getting any uncomfortable withdrawal symptoms.

Go and speak to your doctor if you have missed a few doses or have decided to stop taking your medication.

If you have taken more carbamazepine than the dosage recommended by the doctor who prescribed it to you, you must get medical help immediately – even if you do not feel any different.

While taking carbamazepine some people may think about hurting themselves or taking their own lives. You must go straight to hospital with your tablets if you have any of these thoughts.

If you get a rash just after starting to take carbamazepine, especially if you are from a Han Chinese or Thai family, you must stop the tablets and see a doctor straight away. You may get a fever, headache and body ache, like having flu, and then ulcers in your mouth and all over your body.

Carbamazepine may also cause other serious side effects: allergic reactions (difficulty breathing, swelling of your face or throat, itching skin lumps), and other serious symptoms that you can find here. Go to a hospital with your medicine if you get any of these symptoms.

Do not take carbamazepine if you have taken a monoamine oxidase inhibitor antidepressant (MAOI) like moclobemide, phenelzine, isocarboxazid or tranylcypromine in the last 14 days.

Carbamazepine can make the contraceptive pill or implant less effective – use a barrier method to stop you getting pregnant.

Stopping carbamazepine suddenly can cause serious side effects – go to your doctor if you want to stop, or if you are having these effects.

You might feel sleepy or dizzy in the first few days after taking carbamazepine – do not drive a car, ride a bike or operate machines until you see how this affects you.

Use good contraception while you are taking carbamazepine.

If you take carbamazepine while you are pregnant, it may affect the developing baby. It can also cause symptoms in newborn babies if you take it at the end of pregnancy. Talk to your doctor or midwife about this and get their help.

If you have taken more carbamazepine than the dosage recommended by the doctor who prescribed it to you – even if you do not feel any different. Go to A&E. Take your medicine with you to show to the doctors. Tell them how much you have taken. Get a friend or family member to go with you if you can, just in case you feel ill on the way.

You might get any of the following signs:

• feeling sleepy or confused
• slurring when you speak
• feeling agitated or sensing things that are not there
• unusual movements that you cannot control
• having seizures (fits)
• your breathing going very slow
• fast heartbeat, and a possible heart attack
• being sick
• blurred eyesight
• finding it hard to go for a wee

While taking carbamazepine, some people may think about hurting themselves or taking their own lives. This can happen to anyone, including people who are under 18. You must go straight to hospital if you have any of these thoughts. Take your tablets with you and tell the doctor that you are taking carbamazepine.

Stop taking carbamazepine and go to a doctor or hospital straight away if you get any of the following symptoms:

• serious skin reactions such as rash; red skin; blistering of the lips, eyes or mouth, or sex organs; or skin peeling with a fever (these reactions may be more frequent in patients of Chinese or Thai origin)
• mouth ulcers or unexplained bruising or bleeding
• sore throat or high temperature, or both
• jaundice (yellowing of your skin or the whites of your eyes)
• swollen ankles, feet or lower legs
• pain in your joints and muscles, a rash across the bridge of the nose and cheeks, and problems with your breathing (these may be the signs of a rare reaction known as systemic lupus erythematosus (SLE))
• fever, skin rash, joint pain, and unusual results of blood and liver function tests (these may be the signs of a multi-organ sensitivity problem)
• wheezing and coughing, difficulty breathing, feeling faint, rash, itching or facial swelling (these may be the signs of a severe allergic reaction)
• severe stomach pain

Side effects that start when you begin taking carbamazepine should improve or go away after a few days or weeks. If they don’t, or they get worse, you should go back to your doctor.

Do not stop taking the tablets until you talk to your doctor, or you may get withdrawal symptoms as well.

Very common side effects of taking carbamazepine (affecting more than one in ten people) include:

• leucopoenia (a reduced number of the cells which fight infection making it easier to catch infections)
• dizziness and tiredness
• feeling unsteady or finding it difficult to control your movements
• feeling or being sick
• changes in liver enzyme levels (usually without any symptoms)
• skin reactions, which may be serious

Common side effects of taking carbamazepine (affecting up to one in ten people) include:  

• changes in the blood making you more likely to bruise or bleed
• fluid retention and swelling
• weight increase
• low sodium in the blood which might result in confusion
• headache
• double or blurred vision
• dry mouth
• loss of appetite

There are other side effects that you can get when taking this medicine – we have only included the most common ones here. Please look at the leaflet inside your medicine box, or ask a doctor or pharmacist, if you want to know if you are getting a side effect from your medicine.

When taking this medication, you are also at risk of developing a rare side effect called Steven-Johnson Syndrome. Symptoms are flu-like at first (fever, headache and all-over body ache) then ulcers could appear in your mouth, throat, nose and sex organs. You could also get conjunctivitis (red eyes) and a rash that spreads all over your body. If you think you are getting these symptoms, stop taking the tablets immediately and see a doctor without delay.