Denzapine

How does it work?

Denzapine tablets contain the active ingredient clozapine, which is a type of medicine known as an atypical antipsychotic. It works in the brain, where it affects a neurotransmitter called dopamine. Neurotransmitters are chemicals that are stored in nerve cells and are involved in transmitting messages between the nerve cells. Dopamine is a neurotransmitter known to be involved in regulating mood and behaviour, amongst other things. Schizophrenia is associated with an overactivity of dopamine in the brain, and this may be associated with the delusions and hallucinations that are a feature of this disease. Clozapine works by blocking the receptors in the brain that dopamine acts on. This prevents the excessive activity of dopamine and helps to control psychotic illness. Clozapine is restricted to treating schizophrenia in people who have not responded to, or are intolerant of, other treatments, as it can cause rare, but serious side effects. It is also used for treating psychotic illness in people with Parkinson's disease where other treatments have not worked. Clozapine is also sometimes used by specialists to treat episodes of mania in people with the psychiatric illness, bipolar affective disorder (manic depression). This is an unlicensed use of the medicine, and it is only used if other medicines have been ineffective at controlling the symptoms.

What is it used for?

Schizophrenia in people for whom other antipsychotic medicines are ineffective or not tolerated

Psychotic disorders in people with Parkinson's disease, in cases where standard treatment has failed

Treatment of manic episodes resistant to standard treatment in bipolar affective disorder (unlicensed use)

Warning!

One side effect of this medicine is that it can occasionally cause a drop in the number of white blood cells in the blood. This may be referred to as neutropenia or agranulocytosis. As this could result in potentially serious infections, you will need to have regular blood tests while you are taking Denzapine, to make sure your blood cells are not affected. These blood tests will be weekly for the first eighteen weeks of treatment, then at least every four weeks for the rest of the time you take the medicine. If your white blood cell count does drop significantly, your treatment will need to be stopped and your blood cells should then recover. If you do get neutropenia or agranulocytosis you will not be able to take this medicine again.

You should tell your doctor immediately if you experience any signs of infection, such as flu-like symptoms, high temperature (fever), sore throat or inflammation of the lining of the mouth (stomatitis), while taking Denzapine. This type of symptom may indicate that your white blood cell count has fallen, and your blood should be tested.

Treatment with this medicine should only be started in people who have had their old antipsychotic dose tapered down and who have a normal blood count. People starting this medicine must be registered with the Denzapine Patient Monitoring Service.

Supply of this medicine is restricted to hospitals and retail pharmacies registered with the Denzapine Patient Monitoring Service. These pharmacies can only provide supplies of the medicine if the patients blood test results are normal. Denzapine cannot be obtained from unregistered pharmacies.

This medicine may very rarely have an effect on the heart. For this reason you should tell your doctor if you experience any increased or abnormal heart rate, chest pain, shortness of breath, unexplained fatigue or swelling in the legs (oedema) while taking this medicine, especially in the first two months of treatment.

This medicine can sometimes cause liver problems. People with pre-existing liver disorders should have regular blood tests to monitor their liver function. Consult your doctor promptly if you develop nausea, vomiting, loss of appetite, itching, yellowing of the skin or eyes or unusually dark urine, so that your liver function can be tested.

Some people may develop constipation, which may become severe, while taking this medicine. Tell your doctor if this happens, as it may need treatment.

This medicine can cause a drop in blood pressure when moving from lying down or sitting to a sitting or standing posisiton, and this may make you feel dizzy or cause you to faint. This is more likely to occur when starting treatment and if you are taking certain other medicines (see below). People with Parkinson's disease who have been prescribed this medicine should have their blood pressure regularly monitored during the first weeks of treatment.

This medicine can cause some people to put on weight. Talk to your doctor about this before you start treatment so that you can discuss strategies, such as diet and exercise, for minimising any weight gain.

This medicine may cause drowsiness. If affected do not drive or operate machinery. Alcohol should be avoided.

The components of tobacco smoke can cause clozapine to be removed from the body faster than normal. This means that if you are a smoker and then give up while you are taking clozapine, your blood level of clozapine may increase. Tell your doctor if you plan to give up smoking while you are taking clozapine.

Drinking caffeine can cause your blood level of clozapine to increase. If you regularly drink caffeine and then suddenly stop for a few days, this may cause your blood level of clozapine to fall below normal. For this reason you should try not to make big changes to your normal caffeine intake while you are taking this medicine.

It is recommended that if treatment with this medicine is stopped, this should be done gradually over one to two weeks. You should not suddenly stop taking this medicine unless your doctor tells you to (for example because of problems with your white blood cells). After stopping treatment your blood will still need to be monitored for a further four weeks.

Use with caution in

Elderly people

Closed angle glaucoma

Diabetes

Enlarged prostate gland

Constipation

People taking medicines that can cause constipation

History of disorders involving the large bowel (colon)

History of lower abdominal surgery

History of bone marrow disorders

History of epilepsy

History of heart disease

Kidney disorders

Liver disorders

Not to be used in

Children under 16 years of age

Low levels of white blood cells in the blood

People taking other medicines that can decrease white blood cell count (see below)

Disorders of the bone marrow

History of a drop in white blood cell count (agranulocytosis/granulocytopenia) caused by clozapine or other medicines (except cancer chemotherapy)

History of a drop in white blood cell count (agranulocytosis/granulocytopenia) with no known cause

People unable to have regular blood tests

Uncontrolled epilepsy

Active liver disease associated with nausea, loss of appetite or jaundice

Worsening liver disease or liver failure

Severe kidney disorders

Severe heart disorders, eg inflammation of the muscular walls of the heart (myocarditis)

Failure of function of part of the gut causing an obstruction (paralytic ileus)

Failure of the blood circulatory system (circulatory collapse)

Unresponsive unconscious states (comatose states)

Reduced awareness, slow reactions or drowsiness due to medicines or illness that reduce activity in the central nervous system

Drug intoxication

Psychosis due to drugs or alcohol

Breastfeeding

Hereditary galactose intolerance

Inherited inability to absorb the sugars glucose and galactose (glucose-galactose malabsorption)

Hereditary Lapp lactase deficiency

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.

The safety of this medicine in pregnancy has not been established and it should only be used during pregnancy if the benefits of treatment outweigh any risks to the foetus. Women who had no periods or irregular periods while taking a previous antipsychotic medicine may find their periods return when they are changed to clozapine. These women should use adequate contraception while taking clozapine. Discuss this with your doctor.

This medicine may pass into breast milk, therefore mothers taking this medicine must not breastfeed. Discuss with your doctor.

Label warnings

Follow the printed instructions you have been given with this medication.

This medication may cause drowsiness. If affected do not drive or operate machinery. Avoid alcoholic drink.

Go To Next Page>>
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care or attention by a qualified practitioner. The materials in this web site cannot and should not be used as a basis for diagnosis or choice of treatment. Conditions for use



© Copyright 1998 - 2004 NetDoctor.co.uk - All rights reserved