CarbamazepineReturn to Carbamazepine overview
If I could go back in time to before I started taking meds, I would tell myself to persevere as things will get better, even if it doesn’t feel that way.
- It prevents mood swings from bipolar disorder
- It has also been used to treat low mood (depression), some anxiety and panic disorders, aggressive behaviour in people with schizophrenia, and alcohol withdrawal symptoms
Carbamazepine can help to calm down the brain
- There are gateways in the brain called ‘sodium channels’, which can be open or closed. When they are open, there is more electrical activity in the brain
- Carbamazepine locks on to closed sodium channels, and keeps them closed.
- Reduced electrical activity leads to reduced release of chemical transmitters that excite the brain. It lowers the amount of glutamate, dopamine and noradrenaline circulating round the brain.
Take your carbamazepine as agreed with your doctor
- You will get the best effect from this medicine if you take it regularly every day.
- 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.
- Do not take carbamazepine tablets with grapefruit juice. Grapefruit juice may increase absorption of carbamazepine from the gut and cause the levels of carbamazepine to increase.
- The ‘prolonged-release’ tablets must be swallowed with water, and not chewed, as they release the medicine inside over a few hours.
- Some of the normal tablets and ‘prolonged-release’ tablets have a line where you can break them in half if you find them too big to swallow, but they must not be chewed.
- 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 fits.
If you forget to take a dose then just take it as soon as possible unless it is getting close to your next dose
What to do if you miss a dose:
- If you remember later during the day, take it as soon as possible unless it is less than 4 to 6 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.
What might happen?
- If you forget to take your tablets for a few days, you may start getting your old symptoms back. This means that you should talk to your doctor about it.
- You may need to restart the carbamazepine slowly or find a different treatment.
You must go to A&E if you take too much
What to do if you take too much:
- If you have taken more carbamazepine than it said on the label, you must get help quickly – 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 really there
- Unusual movements that you cannot control
- Having 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
It should take a few days for carbamazepine to start helping
- It just takes a few days for carbamazepine to some effect.
- Your doctor might start you on a low first dose, and then bring it up to your normal dose to reduce the chance of side effects.
- The effect will build over the first 1 to 2 weeks and takes a few weeks at your normal dose of carbamazepine to show its full effect.
Most people take carbamazepine for at least 6 months
You and your doctor should talk about how long you need to take carbamazepine.
- You will get the full effect after a few weeks
- You might have to change your dose to get the best effect for you.
- You should probably take it for at least 6 months - otherwise your symptoms can come back.
- If you only get ill every 12 months you will probably need to take it for longer than 12 months to get any benefit. If you are getting lots of side effects than you will need to talk to your doctor about whether carbamazepine is the right medicine for you.
If you get a rash in the first few weeks after taking carbamazepine, you must stop the tablets and get help from a doctor
- Carbamazepine can cause a very serious reaction in some people when they start taking it
- There is a higher risk of these reactions happening for people from Han Chinese and Thai families than for other people*, but anyone can get it
- First you might get flu-like symptoms – fever, headache and all-over body ache
- Then ulcers could appear on your mouth, throat, nose, and sex organs, and you could also get red eyes (conjunctivitis).
- The rash can then spread to other parts of your skin.
- It is called Stevens-Johnson Syndrome
- If you think you are getting these symptoms, you must stop the tablets and see a doctor straight away.
*If you are from a Han Chinese or Thai family, you can get a blood test from your doctor before you start the tablets to check if you are at risk of this problem.
Tell your doctor or pharmacist before you take carbamazepine if any of these apply to you
You need to talk to your doctor or pharmacist before you take carbamazepine if any of the following apply to you:
- you think you may be allergic to carbamazepine or similar medicines like oxcarbazepine (Trileptal™), to tricyclic antidepressants like amitriptyline, or to an epilepsy medicine called phenytoin
- you have any heart or liver problems
- you have ever had problems with your bone marrow
- you have a blood problem called porphyria
- you are from a Han Chinese or Thai family background
- you have taken drugs called monoamine oxidase inhibitors (MAOIs), used to treat depression, within the last 14 days
- You are pregnant, or planning to become pregnant
- You are breastfeeding
- You have epilepsy where you get mixed types of fits (seizures) which include absences
- You have any eye problems such as glaucoma (increased pressure in the eye).
If any of these apply to you, carbamazepine may not be the right medicine for you.
If you have any thoughts of suicide, or of other ways of hurting yourself, go straight to a hospital with your tablets.
Whilst taking carbamazepine, some people may think about hurting themselves or have suicidal thoughts. 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 you must tell the doctor that you are taking carbamazepine. There are other things you can take instead.
Carbamazepine has side effects, and if they happen they can be serious
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
- Yellowing of your skin or the whites of your eyes
- Swollen ankles, feet or lower legs
- Any signs of nervous problems or confusion
- 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 in breathing, feeling faint, rash, itching or facial swelling (these may be the signs of a severe allergic reaction)
- Pain in the area near the stomach.
Some side-effects that do appear should get better after a few days. If they do not, or they get worse you should go back to your doctor.
If you get any side effects not listed here please look at the patient leaflet in the medicine pack
Some side-effects of carbamazepine may – strangely - seem like symptoms of other mental health conditions. Some side-effects here are also the opposites of each other. The balance of chemicals in the brain is very fragile, and hard to control! If they do not get better after a few days on the tablets, go back to the 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 (could affect more than 1 in 10 people)
- 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 (could affect up to 1 in 10 people)
- 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
- 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.
- If you do get a side-effect, please think about reporting it via the Yellow Card scheme.
Carbamazepine does always not mix well with some other medicines and drugs
Many medicines, including some vitamins, do not mix well with carbamazepine and the dose of some medicines will need to be adjusted. If you are taking any other medicines (prescribed or bought in a shop), or if you start or stop any other medicines whilst on carbamazepine, speak to your doctor or pharmacist.
Talk to your doctor or pharmacist if you are taking any other medicines.
Always talk to the doctor if you are taking other medicines.
Tell the pharmacist you are taking carbamazepine if you buy medicines (including things you put on your skin) for common illnesses.
If you are from a Han Chinese or Thai family background, get a blood test before you start carbamazepine to lower your risk of serious side-effects
- Serious skin reactions such as rash, red skin, blistering of the lips, eyes or mouth, or sex organs or skin peeling with a fever happen more often to patients of Chinese or Thai family backgrounds
- You can have a genetic test before you take carbamazepine to see if this is likely to happen to you
- It might stop you from getting a serious problem
You will have weight and blood tests while you are taking carbamazepine
- When you start taking carbamazepine, the doctor should weigh you and do some blood tests to check your blood and liver function
- These weight and blood tests should be done again after every 6 months of taking carbamazepine.
- A blood test might also be done every 6 months to check the levels of carbamazepine. If carbamazepine is keeping your mood well and you are not getting side effects then levels are less important. Levels are more likely to be done if you are taking carbamazepine for fits as there is a finer balance to be kept.
Stopping the medication causes the balance of chemicals in the brain to alter
- Once you start taking carbamazepine, the brain adjusts to having its calming effect.
- 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 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
Stopping this medicine quickly, or reducing the dose too much at once, may cause uncomfortable symptoms
- 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.
Some side-effects that do appear should get better after a few days. If they do not, you should go back to your doctor.
Don't stop taking Carbamazepine until you talk to your doctor or you may get withdrawal symptoms as well.