TREATMENTS FOR SCHIZOPHRENIA

Drugs known as ANTIPSYCHOTICS or NEUROLEPTICS

(often incorrectly known as the "major tranquillisers")

DRUG:- CLOZAPINE

What is it used for ?

Clozapine is an 'antipsychotic' or 'neuroleptic' drug, used to treat the symptoms of schizophrenia in people who have not done well on at least two other similar drugs e.g. not responded or who have had bad side effects. See the links page for some good sources of information on schizophrenia.

How does it work ?

There are many naturally occurring chemical messengers ("neurotransmitters") in the brain. Two of these are called dopamine and serotonin. Dopamine is the chemical messenger in the brain mainly involved with thinking, emotions and behaviour. In schizophrenia, this dopamine may be overactive and helps to produce some of the symptoms of the illness. The main effect that clozapine has is to block some dopamine and serotonin receptors in the brain, reducing the effect of having too much dopamine. This reduces the symptoms caused by having too much dopamine. For a more detailed explanation, click here. The action of clozapine may also be related to several other neurotransmitters in the brain.

How should I take it ?

Clozapine tablets should be swallowed whole with at least half a glass of water whilst sitting or standing. This is to make sure that they reach the stomach and do not stick in the throat.

When should I take it ?

Take your clozapine as directed on the medicine label. Try to take it at regular times each day. Taking it at mealtimes may make it easier to remember as there is no problem about taking clozapine with or after food. If the instructions say to take them once a day this is usually at bedtime as they may make you feel drowsy at first. They are not, however, sleeping tablets.

How long will it take to work ?

Some effects of clozapine appear soon after taking it, for example the drowsiness. The most important action, however, to help control the symptoms of your illness may take several months or even up to a year of regular medication to become fully effective. In the same way, if your dose or treatment is changed it may take an equally long time before you notice the effects of such a change.

How long will I need to keep taking it for ?

This should be discussed with your doctor as people respond differently. You will probably, however, need to continue your treatment for several years. Long term treatment should be reviewed every three to six months, or sooner if there are problems. It is likely that you will benefit from clozapine by taking it for many years.

Is it addictive ?

Clozapine is not addictive. For further discussion, click here.

Can I stop taking it suddenly ?

It is unwise to stop taking clozapine suddenly, even if you feel better. Your symptoms can return if treatment is stopped too early. This may occur some weeks or even many months after the drug has been stopped. If the clozapine has had an effect on your blood it might be important to stop the tablets suddenly. Your doctor will discuss this with you.

What should I do if I forget to take it ?

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 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.

Will it make me drowsy ?

Clozapine may make you feel drowsy or sleepy. You should not drive (see below) or operate machinery until you know how it affects you. You should be careful as it may affect your reaction times or reflexes. Clozapine is not, however, a sleeping tablet, although if you take it at night it may help you get to sleep. If this drowsiness does not wear off, discuss this with your doctor. It may be possible to change your doses round to help this.

Will it cause me to put on weight ?

When you start clozapine you may begin to put on some weight. This weight gain tends to stop after a time but this can be a problem with clozapine. It is thought that clozapine causes an increase in appetite, which then makes you eat more and then put on weight. It is not possible to know what the effect on your own weight may be because each person will be affected differently. Unfortunately, many of the other drugs for this illness seem to have this effect too, but some seem better than others. If you do start to put on weight or have problems with your weight, you should tell your doctor. He or she may be able to change your clozapine dose to reduce this effect. Your doctor can also arrange for you to see a dietician for advice. Any weight you put on can be controlled while you are still taking this drug, with expert advice about diet. Make sure your doctor knows about this if it causes you distress.

Will it affect my sex life?

Drugs can affect desire (libido), arousal (erection) and orgasmic ability. Unlike many other antipsychotic drugs, clozapine has not been reported to have major a major adverse effect on the three stages, except by causing drowsiness. However, if this happens, you should discuss this with your doctor, as a change in dose may help minimise the problem.

Can I drink alcohol while I am taking this ?

You should avoid alcohol while taking clozapine as it may make you feel more sleepy. This is particularly important if you need 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 they affect my other medication ?

You should have no problems if you take other medications. A few problems can, however, occur. Clozapine should not be taken with some antibiotics e.g. co-trimoxazole ("Septrin" or "Bactrim") and chloramphenicol. It can also "interact" with a few other drugs including some drugs for depression and some anticonvulsants e.g. carbamazepine (Tegretol), although your doctor should know about these. This also does not necessarily mean the drugs can not be used together, just that you may need to follow your doctors instructions very carefully. Make sure your doctor knows about all the medicines you are taking. Some other medicines e.g. some antihistamines (e.g. for hay fever) can make you drowsy. Combined with your clozapine this could make you even drowsier. Ask your pharmacist before buying any medicines over the counter e.g. cimetidine. You should tell your doctor before starting or stopping these or any other drugs.

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

It is not thought that the contraceptive pill is affected by clozapine. With many drugs of this type, a womans periods may be irregular or even disappear. This is less likely with clozapine and so they may reappear or become more regular when starting clozapine.

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:

Clozapine is classified as "B". The current information indicates that clozapine is not a major teratogen (i.e. a drug causing malformations). Some problems have been reported and so you should seek personal advice from your GP, who may then if necessary seek further specialist advice.

Will I need a blood test ?

Clozapine can upset the blood of about two or three people in every hundred people taking it. It can reduce the number of white cells or neutrophils in the blood (neutropenia or agranulocytosis). This then makes it much harder for your body to fight infections. You must therefore have regular blood tests for as long as you are taking this medicine.

Your doctor, pharmacist or nurse will let you know when and where to have the tests. You will need a test before you start clozapine, then every week for the first 18 weeks and then every 2 weeks from then on. If you have then been taking clozapine regularly for a year without any blood problems, it may be possible to only have blood tests every four weeks. The blood is usually posted a central laboratory (e.g. to the CPMS Clozaril Patient Monitoring Service, DCMS Denzapine Clozapine Patient Monitoring Service etc), who then send the results back to the Pharmacy and the Doctor.

You may also need extra blood tests if it is thought possible your blood is being affected. You must not miss these tests. Your doctor and pharmacist will not be able to let you have any more tablets if you do. Remember the rule;- no blood, no tablets.

Can I drive while I am taking it ?

Clozapine can affect your driving in two ways. Firstly, you may feel drowsy and/or suffer from blurred vision at first when taking the drugs. Secondly, clozapine can slow down your reactions or reflexes. This is especially true if you also have a dry mouth, blurred vision, constipation etc. (the so-called "anticholinergic" side effects). Until these effects wear off, or you know how your clozapine affects you, do not drive or operate machinery. You should be careful as clozapine may affect your reaction times or reflexes even though you feel well.

It is against the law to drive, attempt to drive or be in charge of a vehicle when unfit, either through illness or from the side effects of medication. Under UK law, it is the drivers responsibility to let the DVLA and insurance company know if you may be "unfit" to drive. If you do not, and you have an accident, it could effect your insurance cover. 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.