Experiences with

Carbamazepine

Carbamazepine is a medicine used to treat epilepsy.

It can also be taken for nerve pain caused by diabetes (peripheral neuropathy) or if you have a painful condition of the face called trigeminal neuralgia.

Carbamazepine is occasionally used to treat bipolar disorder when other medicines have not worked.

This medicine is only available on prescription. It comes as standard and slow-release tablets, a liquid that you drink and suppositories (medicine that you push gently into your anus).

The brand Carbagen has been discontinued. If you are currently taking Carbagen, contact your doctor for a different brand to be prescribed.

Updated: 28 September 2020

Who can take carbamazepine

Most adults and children aged 1 month and over can take carbamazepine.

Who may not be able to take carbamazepine

Carbamazepine is not suitable for some people. To make sure it's safe for you, tell your doctor before starting to take the medicine if you have:

• ever had an allergic reaction to carbamazepine or any other medicine
• a heart condition
• a rare blood disorder called porphyria
• ever had bone marrow problems
• are pregnant, trying to get pregnant or breastfeeding

Dosage

How much carbamazepine you take will depend on the condition you're taking it for.

You'll usually start on a low dose of 100mg to 200mg, 1 to 4 times a day. This will be increased over several weeks until you get to the dose that is right for you.

The usual total daily dose dose for adults is:

• epilepsy – 800mg to 1,200mg
• nerve pain – 600mg to 800mg
• bipolar disorder – 400mg to 600mg

In children, the dose of carbamazepine will depend on their weight. Your child's doctor will be able to prescribe the right dose for them.

Changes to your dose

To reduce the chance of side effects, your doctor will start you off on a low dose of carbamazepine. They will increase it gradually over a few days or weeks.

Once you find a dose that suits you, it will usually stay the same, unless your condition changes, or your doctor starts you on a new medicine that may affect carbamazepine.

How to take it

If you take carbamazepine up to 4 times a day, try to space your doses evenly through the day. For example, take it first thing in the morning, after lunch, late afternoon and in the evening.

You can take any type of carbamazepine with or without food.

How to take tablets

Swallow the tablets whole with a drink of water.

If you have difficulty swallowing tablets whole, they have a score line across the middle to help you break the tablet in half.

How to take liquid

Shake the bottle before you measure out your dose.

The medicine will come with a plastic syringe or spoon to help you measure out the right dose. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.

How to take suppositories

Read the instructions in the leaflet inside the package. They will explain how to use the suppository.

Take the wrapping off and push a suppository gently into your bottom (anus).

How long to take it for

If you have epilepsy or bipolar disorder, it's likely that once your condition is under control you will still need to take carbamazepine for several years.

If you have nerve pain, once the pain has gone you will need to take carbamazepine for several months to stop it coming back.

If you forget to take it

If you miss a dose of carbamazepine, take the missed dose as soon as you remember unless the next dose is nearly due. In this case, it's better to leave out the missed dose and take your next dose at the usual time.

Do not take 2 doses at the same time to make up for a forgotten dose.

If you have epilepsy, it's important to take this medicine regularly. Missing doses may trigger a seizure.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

Stopping carbamazepine

If you take carbamazepine for epilepsy, you may have seizures once you stop taking it. You can prevent these withdrawal seizures by reducing the dose of your carbamazepine gradually.

However, if you are taking if for bipolar disorder or nerve pain, your condition could get worse for a short time after stopping it.

Do not stop taking carbamazepine unless your doctor tells you to.

Taking too much carbamazepine can lead to serious side effects.

you take more than your prescribed dose of carbamazepine and:

• you are feeling or being sick (nausea or vomiting)
• you feel dizzy or sleepy
• have difficulty talking
• you have blurred vision
• you have stomach pain
• you feel confused, or your normal behaviour changes

Go to 111.nhs.uk or call 111

You or someone with you takes more than their prescribed dose of carbamazepine and:

• has difficulty breathing
• passes out (loses consciousness)

Find your nearest A&E

If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.

Bring the carbamazepine packet or leaflet inside it, any remaining medicine, and any other medicines you take.

Common side effects

These common side effects of carbamazepine may happen in more than 1 in 100 people. They're usually mild and go away by themselves. If they do not go away there are things you can do to help cope with them:

Keep taking the medicine but talk to your pharmacist or doctor if these side effects bother you or do not go away.

Serious side effects

Skin rashes

It's common to get a skin rash with carbamazepine. Most skin rashes are not serious.

Stevens-Johnson syndrome is a rare side effect of carbamazepine. It causes flu-like symptoms, followed by a red or purple rash that spreads and forms blisters. The affected skin eventually dies and peels off.

It's more likely to happen in the first 8 weeks of starting carbamazepine, or when the dose is increased too quickly. It can also happen if carbamazepine is stopped suddenly for a few days and then restarted at the same dose as before, without reducing the dose and then increasing it slowly again.

Stevens-Johnson syndrome is more common in:

• children
• people who developed a rash with a different epilepsy medicine in the past
• people who are allergic to an antibiotic called trimethoprim
• people also taking a medicine called sodium valproate

To help prevent the chance of you getting a rash that could be confused with Stevens-Johnson syndrome, it's best not to try new medicines or food during the first 3 months of treatment with carbamazepine.

It's also best to not start carbamazepine within 2 weeks of a viral infection, vaccination, or rash caused by something else.

• you get a severe rash with flushing, blisters or ulcers – these can be signs of Stevens-Johnson syndrome

Find your nearest A&E

It's unusual to have serious side effects after taking carbamazepine.

Call a doctor or call 111 straight away if:

• you have unusual bleeding or bruising, mouth sores, infections, a high temperature or sore throat – these can be signs of a blood disorder
• the whites of eyes turn yellow, or your skin turns yellow although this can be less noticeable on brown or black skin – these can be signs of a liver problem
• you have pain in your joints and muscles, a rash across the bridge of your nose and cheeks, and problems breathing – these are signs of lupus (systemic lupus erythematosus)

• you have thoughts of harming or killing yourself – a small number of people taking carbamazepine have had suicidal thoughts

Find your nearest A&E

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to carbamazepine.

Some side effects of carbamazepine can happen over a long time. These include osteoporosis and osteopenia (increasing your risk of breaking a bone).

Your doctor can arrange for tests to check the strength of your bones. Regular exercise and a good diet can also help to keep your bones strong.

Other side effects

These are not all the side effects of carbamazepine. For a full list, check the leaflet inside your medicines packet.

Carbamazepine and pregnancy

Carbamazepine has been linked to an increased risk of problems for your baby if you take it in pregnancy.

You'll usually only be advised to take carbamazepine if your doctor thinks the benefits of the medicine outweigh the risks.

If you take carbamazepine for epilepsy, it's important that this is controlled during pregnancy, as seizures can harm you and your baby. If you become pregnant, keep taking carbamazepine, but talk to your doctor straight away. It is likely that you will need to be seen in a specialist epilepsy clinic, and they may want to change your medicine.

If you're trying to get pregnant or have become pregnant while taking carbamazepine, it's recommended you take a high dose of folic acid (5mg a day). You can get this from your doctor or midwife.

Ideally, it's best to take high dose folic acid for 3 months before you start trying to get pregnant and for the first 12 weeks of pregnancy. Do not worry if you have not taken it before you get pregnant, but start taking it as soon as possible once you know that you are pregnant. It helps your baby to grow normally.

Your baby may need extra monitoring for a few days after they're born. This is because they can sometimes have withdrawal symptoms from carbamazepine.

Carbamazepine and breastfeeding

If your doctor or health visitor says your baby is healthy, it's OK to take carbamazepine while you're breastfeeding.

Carbamazepine does pass into breast milk. Most babies do not get any side effects, but some babies might be more sleepy or not feed as well as usual. Taking other medicines while you're taking carbamazepine may mean your baby gets side effects, although this is still rare.

It's important to keep taking carbamazepine to keep you well. Do not stop taking it without talking to your doctor. Breastfeeding will also benefit both you and your baby.

Talk to your doctor, midwife or health visitor as soon as possible if:

• your baby is not feeding as well as usual
• your baby seems unusually sleepy
• your baby has an upset stomach
• the whites or your baby's eyes turn yellow, or their skin turns yellow (this may be less noticeable on brown or black skin) – this could be a sign of jaundice
• you have any other concerns about your baby

Carbamazepine and fertility

Carbamazepine does not affect female fertility, however, there have been rare reports of problems with male fertility.

Speak to your doctor if you have any concerns.

Cautions with other medicines

There are some medicines that may affect the way carbamazepine works.

Tell your doctor if you're taking any of these medicines:

• medicines to help prevent blood clots such as warfarin, apixaban or rivaroxaban
• antibiotics or antifungals such as clarithromycin, erythromycin or fluconazole
• medicines used for depression or anxiety such as amitriptyline, citalopram or mirtazapine
• ciclosporin, tacrolimus or sirolimus – immunosuppressants used after transplant operations, but also sometimes to treat arthritis or psoriasis
• medicines used to treat HIV or AIDS such as dasubavir or ritonavir
• medicines called monoamine oxidase inhibitors (MAOIs), used to treat depression – these can affect carbamazepine for a few weeks even after you've stopped taking them

Taking carbamazepine with painkillers

Paracetamol and ibuprofen are safe to take with carbamazepine for a short time. Talk to your doctor if you need to take either for more than a few days.

Carbamazepine can make strong painkillers such as tramadol, oxycodone and buprenorphine less effective. Your doctor may recommend increasing your dose if you need to take these medicines.

Mixing carbamazepine with herbal remedies and supplements

Do not take St John's wort, the herbal remedy for depression, while you are being treated with carbamazepine. This is because St John's wort may make carbamazepine less effective.

There's not enough information to say that other herbal remedies or supplements are safe to take with carbamazepine. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

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