Tegretol Retard

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How does it work?

This medicine contains the active ingredient carbamazepine, which is a medicine that is mainly used to treat epilepsy. It works by stabilising electrical activity in the brain. The brain and nerves are made up of many nerve cells that communicate with each other through electrical signals. These signals must be carefully regulated for the brain and nerves to function properly. When abnormally rapid and repetitive electrical signals are released in the brain, the brain becomes over-stimulated and normal function is disturbed. This results in fits or seizures. Carbamazepine prevents epileptic fits by preventing the excessive electrical activity in the brain. It is thought to achieve this by preventing sodium from entering nerve cells when they begin to fire rapid and repetitive electrical signals. A build up of sodium in the nerve cells is necessary for the electrical signal to build up and be passed on to other nerve cells. As carbamazepine prevents this, it helps stabilise the electrical activity in the brain. Preventing the build-up of the electrical signal also prevents the release of a neurotransmitter called glutamate from the nerve cells in the brain. Neurotransmitters are chemicals that are stored in nerve cells and are involved in transmitting messages between the nerve cells. Glutamate is a neurotransmitter that acts as a natural 'nerve-exciting' agent. It is released when electrical signals build up in nerve cells and subsequently excites more nerve cells. It is thought to play a key role in causing epileptic seizures. Reducing the release of glutamate from the nerve cells in the brain is another way in which carbamazepine is thought to help stabilise the electrical activity in the brain and prevent epileptic fits. As carbamazepine stabilises electrical nerve activity, it is also used to treat a condition called trigeminal neuralgia, in which the facial nerves spontaneously send messages of pain to the brain. Carbamazepine prevents the nerve signals being sent inappropriately and relieves the pain of this condition. Lastly, carbamazepine is used as a mood stabiliser for treating people with the psychiatric illness, bipolar affective disorder. It is licensed for preventing episodes of ill health (abnormally high and low mood) in people with bipolar disorder who have not responded to the older mood stabiliser, lithium. It is particularly useful for people who experience multiple mood swings (rapid cycling). Carbamazepine is also used off-license by specialists to control episodes of mania in this illness. It is not fully understood how carbamazepine works as a mood stabiliser, but is thought to be to do with the reduction of glutamate activity in the brain.

What is it used for?

- Generalised tonic-clonic seizures
- Mood stabiliser to prevent episodes of high and low mood in bipolar affective disorder
- Partial seizures
- Severe pain in the lips, gums, cheek, chin or eye caused by a disorder of the nerves in the face (trigeminal neuralgia)
- Treatment of acute manic episodes in bipolar affective disorder (unlicensed use)

Warning!

- This medicine may rarely cause a decrease in the normal amounts of blood cells in the blood. For this reason you should consult your doctor immediately if you experience any of the following symptoms: unexplained bruising or bleeding, purple spots, sore throat, mouth ulcers, high temperature (fever), feeling tired or general illness. Your doctor may want to take a blood test to check your blood cells.
- You should not suddenly stop taking this medicine unless your doctor tells you otherwise.
- This medicine may cause skin rashes and you should consult your doctor if you develop a rash, skin peeling, itching, or other unexplained skin reaction while taking this medicine.
- This medicine can sometimes cause liver problems. Consult your doctor promptly if you develop unexplained itching, yellowing of the skin or eyes, unusually dark urine, nausea and vomiting, abdominal pains, loss of appetite or flu-like symptoms.
- This medicine may cause fatigue and dizziness. You should take care when performing potentially hazardous activites, such as driving or operating machinery, until you know how this medicine affects you and are sure you can perform such activities safely.
- Carbamazepine decreases the blood levels of hormonal contraceptives containing oestrogen and/or progesterone, which may make the contraceptive ineffective or result in breakthrough bleeding. Women taking this medicine who require contraception should be prescribed a contraceptive containing at least 50 micrograms of oestrogen, or use non-hormonal methods of contraception, such as condoms.
- While taking this medicine you should have regular blood tests to allow your doctor to monitor your liver function and the number of blood cells in your blood.
- The Tegretol brand of carbamazepine is available as tablets, chewtabs, liquid and suppositories. Tegretol suppositories are only licensed for use in epilepsy.

Use with caution in

- Elderly people
- History of blood disorders that were caused by any other medication
- History of heart disease
- History of kidney disease
- History of liver disease
- History of previous carbamazepine therapy that was interrupted due to side-effects or allergy
- History of psychotic illness
- Mixed seizures including absence seizures
- Raised pressure in the eye (intraocular pressure), eg glaucoma

Not to be used in

- Allergy to tricyclic antidepressants, eg amitriptyline
- Blockage of an electrical message pathway in the heart (atrioventricular block)
- History of decreased blood cell production by the bone marrow (bone marrow depression)
- Life long inherited blood diseases which can cause a variety of symptoms, including mental health problems (porphyrias)
- People who have taken monoamine-oxidase inhibitor antidepressants (MAOIs) in the last 14 days

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

- It is very important for women with epilepsy to talk to the doctor responsible for their epilepsy treatment before becoming pregnant. Antiepileptic medicines are associated with an increased risk of developmental disorders and malformations in the baby. However, stopping antiepileptic treatment during pregnancy runs the risk of the mother having seizures, which can harm both the mother and the foetus. This risk may be higher than that from continuing the medication. It is important that all the risks and benefits of treatment are weighed up. Seek medical advice from your doctor.
- This medicine passes into breast milk in small amounts. The benefits of breastfeeding should be weighed against any possible risks to the infant. Breast-fed infants should be observed for possible adverse reactions, such as excessive drowsiness, skin rashes or poor weight gain. Discuss this with your doctor.

Label warnings

- Do not stop taking this medication except on your doctor's advice.
- This medication is to be swallowed whole, not chewed.
- This medication may cause drowsiness. If affected do not drive or operate machinery.

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