TREATMENTS FOR EPILEPSY

AND TO HELP AS A MOOD STABILISER

DRUGS:- CARBAMAZEPINE AND OXCARBAZEPINE

"Tegretol" tablets come as plain tablets, "sustained release" tablets (Tegretol Retard) and chewable tablets. Carbamazepine is also available as suppositories.

Oxcarbazepine is very similar to carbamazepine, and is dealt with in the text as for carbamazepine, unless otherwise stated.

What is carbamazepine used for ?

Carbamazepine has three main uses;-

1. It can be used to help prevent mood swings e.g. feeling 'high' or 'low', in people who suffer from a bipolar illness (sometimes called manic-depression). There are a number of other drugs which are useful to help stabilise moods.
2. It can be used to help control fits or blackouts.
3. It may be used to relieve the symptoms of trigeminal neuralgia (a painful condition of the face).

Carbamazepine is also used to help a number of other illnesses such as alcohol withdrawal or alcohol dependence, schizophrenia, withdrawal from benzodiazepines etc.

How does carbamazepine work ?

In epilepsy, epileptic seizures (fits or blackouts) happen when an abnormal electrical discharge, like a short circuit causing a spark, occurs in the brain. Carbamazepine makes these discharges less likely to happen. It is not known exactly how carbamazepine works in people with mood problems, but it does seem to help to stabilise the brains activity.

How should I take it ?

Tablets

Tablets should be swallowed with at least half a glass of water whilst sitting or standing so that they reach the stomach and do not stick in the throat.

"Tegretol Retard" tablets should be swallowed whole and not chewed. This tablet is made so that the carbamazepine is released over a long period of time. This can help to reduce side-effects or reduce the number of times a day you need to take this medicine. If you cannot swallow them whole they can be broken, but do not crush chew or dissolve them as this will cause the drug to be released too soon.

"Tegretol Chewtabs" are available which may be chewed or sucked.

Liquids

Your pharmacist should give you a medicine spoon or oral syringe. Use it carefully to make sure that you measure the correct amount. Ask your pharmacist for a medicine spoon if you do not have one. Shake the bottle well before use as the drug can settle to the bottom and cause you to receive a lower dose at the start and too high a dose at the end of the bottle, which could be dangerous.

When should I take my carbamazepine ?

Take the dose as directed on the medicine label. You should take it at regular times each day. "Tegretol Chewtabs" should be taken with or after food. Taking any of the other tablets or liquid at meal times also may make it easier to remember as there is no problem about taking carbamazepine with or after food. If the instructions say to take it once a day this is usually best at bedtime as they may make you drowsy. They are not sleeping tablets though.

If you are taking carbamazepine to help control fits or blackouts, it is particularly important that you take it regularly as directed by your doctor to make sure you are getting the best control. Missing a dose can cause your fits to return.

How long will carbamazepine take to work ?

If you are taking carbamazepine to help control fits or blackouts it should start to work a few weeks after you start taking it. It may take some time for your doctor to get the right dose of carbamazepine for you. The aim is for the amount of medicine in your blood to be high enough to prevent or reduce fits but low enough to give you least side-effects. Do not attempt to make any changes yourself. If you are taking it to help prevent mood swings, it may take several months to reach it's full benefit.

Is carbamazepine addictive ?

Carbamazepine is not addictive. If, however, you are taking it for epilepsy you should not stop taking it suddenly as explained below. For further discussion, click here.

Can I stop taking carbamazepine suddenly ?

Carbamazepine is a "preventative medicine". If you are taking carbamazepine to help control fits or blackouts never stop taking it suddenly or without advice from your doctor as this might mean an increase in your fits. If you are taking it to help prevent mood swings it is also unwise to stop taking your carbamazepine suddenly, even if you feel better. You should not suffer any withdrawal effects. For it to continue working carbamazepine must be taken every day. If you do stop taking it before you are advised to do so by your doctor your symptoms could return.

What should I do if I forget a dose ?

Start again as soon as you remember unless it is almost time for your next dose, then go on as before. Do not try to catch up by taking two or more doses at once as you may get more side-effects. You should tell your doctor about this next time you meet. If you are taking carbamazepine to help control fits or blackouts and you are ill and vomit soon after taking your tablets, you should take that dose again. Missing a dose can cause your fits to return. The amount in your blood may drop below the level needed to control your fits.

If you have problems remembering your doses (as very many people do) ask you pharmacist, doctor or nurse about this. There are some special packs, boxes and devices which can be used to help you remember.

What sort of side-effects might occur ?

Table adapted from UK Psychiatric Pharmacy Group leaflets, with kind permission (www.ukppg.org.uk )

Do not be worried by this list of side effects. You may get none at all. There are other rare side-effects. If you develop any unusual symptoms ask your doctor about them next time you meet.

It is not thought that this drug has any major long term side-effects if your dose and blood is monitored with care.

Will carbamazepine make me drowsy ?

Carbamazepine may make you feel a bit drowsy or sleepy at first. You should not drive (see below) or operate machinery until you know how it affects you. You should be careful as this may affect your reflexes or reaction times. It is not, however, a sleeping tablet, although if you take it at night it may help you get to sleep.

Will carbamazepine cause me to put on weight ?

Carbamazepine does not usually cause any changes in weight, although in a few people this can happen and can be distressing and difficult to manage. If, however, you do start to have problems with your weight, tell your doctor next time you meet as he or she can arrange for you to see a dietician for advice on how to help manage this.

Will carbamazepine affect my sex life?

Drugs can affect desire (libido), arousal (erection) and orgasmic ability. Carbamazepine has not been reported to have a major adverse effect on these three stages. However, if this does seem to happen, you should discuss this with your doctor, as a change in dose may help minimise any problem.

Can I drink alcohol while I am taking carbamazepine ?

You should avoid alcohol while taking carbamazepine as it may make you feel more sleepy. This is particularly important if you are allowed to drive or operate machinery. You must seek advice on this.

Are there any foods or drinks that I should avoid ?

You should have no problems with any food or drink other than alcohol (see above).

Will carbamazepine affect my other medication ?

Carbamazepine is affected by some other drugs. Conversely, carbamazepine also affects the action of some other drugs. Tell your doctor of any medicines that you may be taking and also before starting or stopping any other drugs. These other drugs include other treatments for epilepsy, some antibiotics, anticoagulants and treatment for depression, schizophrenia, oral contraceptives (see below) and some heart conditions. This does not necessarily mean the drugs can not be used together, just that you may need to follow your doctors instructions very carefully. You should also talk to your pharmacist before buying any medicines over the counter.

If I am taking a contraceptive pill, will this be affected ?

It is important that you let your doctor know if you are taking a contraceptive pill because carbamazepine makes "the pill" less effective. Your doctor may need to change you to a higher dose pill. Even with this change, the contraceptive pill may still be less effective. You may want to think about other methods of contraception e.g. condom or coil. Ask your doctor or visit your local family planning clinic for advice.

What if I want to start a family or discover I'm pregnant?

It is important to consider that there will be a risk to you and your child from taking a medicine during pregnancy but also a possible risk from stopping the medicine e.g. getting ill again. Unfortunately, no decision is risk-free. It will be for you to decide which is the least risk. All we can do here is to help you understand some of the issues, so you can make an informed decision. For your information, major malformations occur "spontaneously" in about 2-4% of all pregnancies, even if no drugs are taken. The main problem with medicines is termed "teratogenicity" i.e. a medicine causing a malformation in the unborn child. A medicine causing teratogenicity is called a "teratogen". Since a baby has completed it's main development between days 17 and 60 of the pregnancy (the so-called "first trimester") these first 2-16 weeks are the main concern. After that, there may be other problems e.g. some medicines may cause slower growth. The infant may also be affected after birth e.g. withdrawal effects are possible with some drugs.

If possible, the best option is to plan in advance. If you think you could become pregnant, discuss this with your doctor and it may be possible to switch to medicines thought to carry least risk, and take other risk-reducing steps e.g. adjusting doses, taking vitamin supplements etc. If you have just discovered you are pregnant, don't panic, but seek advice from your GP within the next few days if possible. He or she may also want to refer you on to someone with more specialist knowledge of your medicine.

Very few medicines have been shown to be completely safe in pregnancy and so no manufacturer or advisor can ever say any medicine is safe. They will usually advise not to take a medicine during pregnancy, unless the benefit is much greater than the risk. In the UK, there is the NTIS (National Teratology Information Service) who offer individual risk assessments. However, their advice should always be used to help you and your doctor decide what is the risk to you and your baby. There is a risk from taking the medicine and a risk should you stop a medicine e.g. you might become ill again and need to go back on the medication again. The advice offered here is just that i.e. advice, but may give you some idea about the possible risks and what (at the time of writing) is known through the medical press.

It may be helpful to know that in the USA, the FDA (Food and Drug Administration) classifies medicines in pregnancy in five groups:

Carbamazepine and oxcarbazepine are classified as "C", but should probably be classified as "D". There is some evidence of problems e.g. a 1 in 100 chance of spina bifida and a "carbamazepine syndrome". You will need to seek personal advice from an expert, as counselling and screening is recommended. Taking folic acid supplements throughout pregnancy (and possibly before) may reduce this risk. You will also need to consider the risk of relapse if you stop your carbamazepine. If you are taking this medicine for epilepsy, then you will need to also consider the risk of seizures as well. One study over the first few years of life was able to show that carbamazepine did not appear to have an effect on intelligence and speech abilities of children born to mothers who took carbamazepine throughout pregnancy.

Will I need blood tests ?

You may need to have a blood test (or even several) after starting treatment. You may then need a test every six months or so to make sure that the dose of your medication is enough but not too much for you. This is particularly important if you are taking carbamazepine for fits or blackouts. You may also need a test if your dose or tablet is changed or other drugs you are taking are changed.

Can I drive whilst taking carbamazepine ?

Carbamazepine can make you drowsy or sleepy and cause blurred vision or double vision when you first start taking it. You must take care if you are allowed to drive or when operating any type of machinery. It is essential that you report epilepsy as well as sudden disabling attacks of loss or partial loss of consciousness to the 'Driver and Vehicle Licensing Centre' (DVLC). The DVLC will then make a medical assessment of your illness, asking your doctor(s) where necessary. For more information see leaflet 'D100' ('What you need to know about driving licensing') which is available from most post offices, or contact the Driver Enquiry Unit, DVLC, SWANSEA SA6 7JL. (Telephone: 01792 772151 between 8.15 am. to 4.30 pm. on Monday to Friday). You will need to quote your Driver Number whether you write or telephone. Your doctor will be able to advise you, and may wish to access the UK Driver and Vehicle Licensing Agency (DVLA) guidelines website, which has the current DVLA guidelines on anxiety/depression, psychotic disorders, mania and other conditions. If your doctor advises you not to drive, and you continue to do so, the doctor can inform the DVLA directly, as he or she would be lawfully responsible were you to have an accident. Once told, the DVLA may wish to carry out an enquiry, but you are entitled to drive until there a decision is made.

Email your comments or feedback.
Several developments have been as a result of feedback from visitors.

No site can be entirely bias-free. No matter how hard someone tries, training and background will always influence your outlook. We have, however, tried to eliminate bias, and we hope you take these pages in the spirit in which they are provided i.e. a genuine attempt to inform, educate and support.

Information here is based on published data. References include the UK British National Formulary (BNF, published by the British Medical Association and Royal Pharmaceutical Society of Great Britain), Martindale (the extra pharmacopoea, published by RPSGB Pharmaceutical Press), Psychotropic Drug Directory (latest edition), Data Sheet Compendium (UK Manufacturers Data Sheets, published by the Association of British Pharmaceutical Industry), MicroMedex (an independent and extensive CD-ROM based drug information source), UK Psychiatric Pharmacy Group leaflets, Royal College of Psychiatrists advice and guidelines and the current medical literature. Thanks also to all those people who left e-mail comments, suggestions and requests, who have helped shape the site.  

Email your comments or feedback.
Many developments have been as a result of feedback from visitors.

No site can be entirely bias-free. No matter how hard someone tries, training and background will always influence your outlook. We have, however, tried to eliminate bias, and we hope you take these pages in the spirit in which they are provided i.e. a genuine attempt to inform, educate and support.

Information here is based on published data. References include the UK British National Formulary (BNF, published by the British Medical Association and Royal Pharmaceutical Society of Great Britain), Martindale (the extra pharmacopoea, published by RPSGB Pharmaceutical Press), Psychotropic Drug Directory (latest edition), Data Sheet Compendium (UK Manufacturers Data Sheets, published by the Association of British Pharmaceutical Industry), MicroMedex (an independent and extensive CD-ROM based drug information source), UK Psychiatric Pharmacy Group leaflets, Royal College of Psychiatrists advice and guidelines and the current medical literature. Thanks also to all those people who left e-mail comments, suggestions and requests, who have helped shape the site.