TREATMENTS FOR "SIDE EFFECTS"

DRUG GROUP:- ANTICHOLINERGICS or ANTIMUSCARINICS

What are they used for ?

Anticholinergics (or antimuscarinics) are most often used to help control some of the common side-effects which can occur with some antipsychotic (neuroleptics or major tranquillisers) drugs e.g. tremor or shaking, stiffness or movement problems,. These side effects are known as the "Extra-pyramidal side effects" or "Parkinsonian" side effects. The anticholinergic drugs are very effective for this but as these side effects tend to wear off, you may not need to take an anticholinergic drug all the time. These drugs are also used to control the symptoms of Parkinson's Disease itself.

How do they work?

Many of the symptoms of "psychosis" are caused by an over-activity of dopamine in the brain. Dopamine is a naturally occurring chemical messenger ("neurotransmitter") in the brain. Antipsychotic drugs block the action of this dopamine in the brain. However, dopamine is also important in controlling muscle tone or tension. Unfortunately, the antipsychotic drugs also block these muscular actions of dopamine and the tremor, stiffness or movement problems mentioned above then occur due to this imbalance of dopamine in the brain. In people who get these side-effects, the effects of the transmitter 'acetylcholine' are greater than normal. Acetylcholine causes the muscles to become stiffer. Antimuscarinic or anticholinergic drugs block or reduce some of the action of acetylcholine in the brain and so reduces these side-effects. For a more detailed explanation, click here. Some antipsychotics (especially the phenothiazines) also block acetylcholine receptors, which is partly useful in minimising this problem. It is not, however, usually enough to counteract the effects of the antipsychotic on dopamine.

How should I take them ?

Tablets:

The tablets should be swallowed 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.

Liquids:

Your pharmacist should give you a medicine spoon or oral syringe. Use it carefully to make sure you measure the correct amount. Ask your pharmacist for a medicine spoon if you do not have one.

When should I take them ?

Take your medication as directed on the medicine label. These drugs can give you a dry mouth. This can be helped by taking your medicine before food. They may also cause you to feel a bit sick or give you an upset stomach. If this happens it is best to take them after food as this will help. If you have a dry mouth and stomach upset, try taking your medicine after food and then sucking a peppermint, chewing gum or drinking water to help your thirst and stop your mouth getting dry.

Benztropine ("Cogentin") and Biperidin ("Akineton") can both cause you to feel sleepy so if the instructions say to take them once a day this is usually best at bedtime. They are not sleeping tablets. Benzhexol ("Artane"), orphenadrine ("Disipal") and procyclidine ("Kemadrin") can have the opposite effect. You should avoid taking these at night if possible as they may stop you getting off to sleep easily.

How long will they take to work ?

They start to work with an hour or so and the effect lasts for about 8 to 12 hours.

How long will I need to keep taking them for ?

This should be discussed with your doctor as people respond differently. Once the doses of your other drugs have settled down you may not need to take them regularly, only when you need them. If you are having a "depot" injection you may only need these tablets for a few days after your injection.

Are they addictive ?

These drugs are not addictive as such. There have been some reports of people "abusing" them but this is uncommon.

Can I stop taking them suddenly ?

If you are taking them regularly it is best not to stop them suddenly as you symptoms may then get worse. It is best to stop them gradually and you should discuss this with your doctor. If you are only taking them "when required" there is no problem.

What should I do if I forget to take them ?

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 forget some doses and do not notice any difference you may well not need to take them at the moment. Talk about this with your doctor.

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 they make me drowsy ?

These drugs may make you feel a little drowsy. You should not drive (see below) or operate machinery until you know how they affect you. You should be careful as they may affect your reaction times. Benztropine ("Cogentin") and Biperidin ("Akineton") can both cause you to feel sleepy so if the instructions say to take them once a day this is usually best at bedtime. They are not sleeping tablets. Benzhexol ("Artane"), orphenadrine ("Disipal") and procyclidine ("Kemadrin") can have the opposite effect. You should avoid taking these at night if possible as they may stop you getting off to sleep easily.

Will they cause me to put on weight ?

It is not thought that any of the anticholinergics cause any changes in weight. If you do start to have problems with your weight, however, tell your doctor next time you meet as he or she can arrange for you to see a dietician for advice.

Will it affect my sex life?

Drugs can affect desire (libido), arousal (erection) and orgasmic ability. The anticholinergic drugs have not been reported to have a major adverse effect on these three stages. However, if this does happen, 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 these ?

If you are taking benztropine ("Cogentin") or biperidin ("Akineton"), you should avoid alcohol while taking them as it may make you feel more sleepy. If you are taking one of the other anticholinergics and it makes you sleepy, you should also avoid alcohol as the alcohol may make this worse. This is particularly important if you need to drive or operate machinery and 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 although a few problems can occur. Some other drugs, including the tricyclic antidepressants, MAOI's (antidepressants), the phenothiazine antipsychotics (e.g. chlorpromazine, thioridazine, Modecate, trifluoperazine etc.) and some antihistamines also have "antimuscarinic" or "anticholinergic" side-effects. If they are taken with an anticholinergic drug the side-effects can be made worse. Your doctor should know about these, but make sure your doctor knows about all the medicines you are taking. 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. In fact, anticholinergics are usually used to treat the side effects of many of the antipsychotic drugs.

Some other medicines e.g. some antihistamines can make you drowsy. Combined with your anticholinergic this could make you even drowsier. You should tell your doctor before starting or stopping these or any other drugs and consult your pharmacist before buying any medicines over the counter.

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

It is not thought that the contraceptive pill is affected by any of these drugs.

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:

The anticholinergics are all classified as "C". There is no firm evidence of a teratogenic effect, but some problems have been reported and so you should seek personal advice from your GP, who may then if necessary seek further specialist advice.

Can I drive while I am taking them ?

These drugs can affect your driving in two ways. Firstly, you may feel drowsy and/or suffer from blurred vision at first when taking any of these drugs. Secondly, the drugs 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 wear off, or you know how your drug affects you, do not drive or operate machinery. You should be careful as they 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.

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© 2005 Steve Bazire, Norfolk and Waveney Mental Health Partnership NHS Trust Users drug information text originally compiled by Stephen Bazire & Sarah Branch  Comments/Problems email WebMaster

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.