How does it work?

Pericyazine is a type of medicine called a phenothiazine antipsychotic. It is used in the treatment of various psychiatric illnesses.

Pericyazine is sometimes described as a neuroleptic or a 'major tranquilliser', though this last term is fairly misleading, as this type of medicine is not just a tranquilliser, and any tranquillising effect is not as important as the main way it works in psychiatric illness.

Pericyazine works by blocking a variety of receptors in the brain, particularly dopamine receptors. Dopamine is a natural compound called a neurotransmitter, and is involved in transmitting messages between brain cells. Dopamine is a neurotransmitter known to be involved in regulating mood and behaviour, amongst other things.

Psychotic illness, and particularly schizophrenia, is considered to be caused by overactivity of dopamine in the brain. Pericyazine blocks the receptors that dopamine acts on and this prevents the overactivity of dopamine in the brain. This helps to control psychotic illness.

Pericyazine improves disturbed thoughts, feelings and behaviour in various mental conditions, including schizophrenia and behavioural disorders that involve aggression or severe agitation or excitement. It produces a calming effect and controls aggression, delusions and hallucinations.

Pericyazine is used in the long-term management of psychotic conditions such as schizophrenia. It is also used in the short-term to manage severe anxiety and severely agitated, violent or dangerous behaviour.

What is it used for?

Pericyazine tablets and syrup may be used in adults for the conditions listed below.

• Psychotic illness such as schizophrenia.
• Short-term treatment of agitated, violent or dangerously impulsive behaviour (in combination with other medicines).
• Short-term treatment of severe anxiety (in combination with other medicines).

Pericyazine syrup may also be used to treat schizophrenia and behaviour disorders in children over one year of age.

How do I take it?

• Pericyazine can be taken either with or without food.
• The amount taken and how often varies from person to person, and according to the condition being treated. It is important to follow the instructions given by your doctor. These will be printed on the dispensing label that your pharmacist has put on the packet of medicine.

Warning!

• This medicine may cause drowsiness. If affected do not drive or operate machinery. Alcohol should be avoided because it can make drowsiness worse or cause breathing problems.
• This medicine can occasionally cause your blood pressure to drop when you move from a lying down or sitting position to sitting or standing, especially when you first start taking the medicine, or if you are elderly. This may make you feel dizzy or unsteady. To avoid this try getting up slowly. If you do feel dizzy, sit or lie down until the symptoms pass.
• People with diabetes should monitor their blood sugar levels more closely whilst taking this medicine. This medicine may increase the blood sugar levels in the body.
• If you are elderly, this medicine may cause your body temperature to react abnormally in very hot or very cold weather. Discuss this with your doctor.
• High doses of this medicine may make your skin more sensitive to sunlight than it usually is, so you should avoid exposing your skin to direct sunlight or sunlamps until you know how your skin reacts. If you can't avoid strong sunlight you should use a sunscreen lotion or make sure your skin is protected with clothing.
• Pericyazine can cause rare but serious contact skin sensitisation in people who regularly handle the medicine. For this reason you should avoid any unnecessary contact of the medicine with the skin.
• 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.
• If you have been taking this medicine for a long time, for example to treat schizophrenia, you should not suddenly stop taking it unless your doctor tells you to, even if you feel better and think you don't need it any more. This is because the medicine controls the symptoms of the illness but doesn't actually cure it. This means that if you suddenly stop treatment your symptoms could come back. Stopping the medicine suddenly may also rarely cause withdrawal symptoms such as nausea, vomiting, difficulty sleeping or tremor. When treatment with this medicine is stopped, it should be done gradually, following the instructions given by your doctor.
• Consult your doctor immediately if you experience abnormal body movements, particularly of the face, lips, jaw and tongue, while taking this medicine. These symptoms may be indicative of a rare side effect known as tardive dyskinesia, and your doctor may ask you to stop taking this medicine, or decrease your dose.
• Consult your doctor immediately if you experience the following symptoms while taking this medicine: high fever, sweating, muscle stiffness, faster breathing and drowsiness or sleepiness. These symptoms may be due to a rare side effect known as the neuroleptic malignant syndrome, and your treatment may need to be stopped.

Use with caution in

• Elderly people.
• Decreased kidney function.
• Decreased liver function.
• Severe disease affecting the airways or lungs.
• Heart disease, such as heart failure, recent heart attack, very slow heart rate (bradycardia), or irregular heart beats (arrhythmias).
• People with a personal or family history of a type of abnormal heart rhythm, seen on a heart monitoring trace (ECG) as a 'prolonged QT interval'.
• People with risk factors for having a stroke, for example a history of stroke or mini-stroke (TIA), smoking, diabetes, high blood pressure, or a type of irregular heartbeat called atrial fibrillation.
• People with a personal or family history of blood clots (venous thromboembolism), for example in a vein of the leg (deep vein thrombosis) or in the lungs (pulmonary embolism).
• People with other risk factors for getting a blood clot, for example smoking, being overweight, taking the contraceptive pill, being over 40, recent major surgery or being immobile for prolonged periods.
• People with diabetes.
• Epilepsy.
• People with conditions that increase the risk of epilepsy or convulsions, eg brain damage or withdrawal from alcohol.
• Parkinson's disease.
• Abnormal muscle weakness (myasthenia gravis).
• History of closed angle glaucoma.
• Underactive thyroid gland (hypothyroidism).
• Enlarged prostate gland (prostatic hypertrophy).
• Tumour of the adrenal gland (phaeochromocytoma).
• Allergy to other phenothiazine medicines, such as prochlorperazine or trifluoperazine.
• History of sudden drops in the levels of blood cells in the blood (agranulocytosis).
• People with low levels of potassium, magnesium or calcium in their blood (hypokalaemia, hypomagnesaemia or hypocalcaemia).
• People who are not eating properly or are dehydrated.
• People with low fluid volume in their body, eg due to diuretic therapy, kidney dialysis, diarrhoea or vomiting.

Not to be used in

• Pericyazine is not licensed or recommended for treating psychotic illness or behavioural problems that are related to dementia in elderly people, as antipsychotic medicines such as this one have been shown to increase the risk of stroke and death in this group of people.

This medicine should not be used if you are allergic to 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.

• This medicine is not recommended for use during pregnancy unless considered essential by your doctor. Seek further medical advice from your doctor.If you do get pregnant while taking this medicine it is important to consult your doctor straight away for advice. You should not suddenly stop taking this medicine unless your doctor tells you to, as this could cause your symptoms to come back.
• This medicine passes into breast milk. As it could cause drowsiness and potentially other side effects in a nursing infant, it is recommended that women who need treatment with this medicine should not breastfeed. Seek further medical advice from your doctor.

Label warnings

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

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

• Drowsiness.
• A drop in blood pressure that occurs when moving from a lying down or sitting position to sitting or standing, which results in dizziness and lightheadedness (postural hypotension - see warning section above).
• Abnormal movements of the hands, legs, face, neck and tongue, eg tremor, twitching, rigidity (extrapyramidal effects, dyskinesia or dystonia).
• Anxiety, restlessness and agitation (akathisia).
• Dry mouth.
• Difficulty sleeping (insomnia).
• Agitation.
• Nasal congestion.
• Raised blood prolactin level (hyperprolactinaemia). Sometimes this can lead to symptoms such as breast enlargement, production of milk and stopping of menstrual periods.
• Impotence.
• Breathing difficulties or slow, shallow breathing (consult a doctor if you experience this).
• Abnormal heart beats (arrhythmias).
• Jaundice (tell your doctor straight away if you notice any yellowing of your eyes or skin while taking this medicine).
• Skin rashes.
• Increased sensitivity of the skin to UV light (photosensitivity - see warning section above).
• Decrease in the number of white blood cells in the blood (leucopenia - see warning section above).
• Interference with the body's temperature regulation. (This is more common in elderly people and may cause heat stroke in very hot weather or hypothermia in very cold weather).Talk to your doctor or pharmacist about how to avoid these problems.
• Rhythmical involuntary movement of the tongue, face, mouth and jaw, which may sometimes be accompanied by involuntary movements of the arms and legs (tardive dyskinesia). See warning section above.
• High temperature combined with falling levels of consciousness, paleness, sweating and a fast heart beat (neuroleptic malignant syndrome). Requires stopping the medicine and immediate medical treatment - see warning section above.
• Increased blood glucose levels (hyperglycemia).
• Convulsions.
• Blood clot in the leg or the lungs (thromboembolism). Inform your doctor immediately if you get any of the following symptoms while taking this medicine: stabbing pains and/or unusual swelling in one leg, pain on breathing or coughing, coughing up blood or sudden breathlessness.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.

There may be an increased risk of drowsiness, sedation and breathing problems if pericyazine is taken with any of the following, which can also cause drowsiness:

• alcohol
• barbiturates, eg amobarbital, phenobarbital
• benzodiazepines, eg diazepam, temazepam
• sedating antihistamines, eg chlorphenamine, hydroxyzine
• sleeping tablets, eg zopiclone
• strong opioid painkillers, eg morphine, codeine
• tricyclic antidepressants, eg amitriptyline.

There may be an increase in side effects such as dry mouth, constipation, confusion or heat stroke (in hot and humid conditions) if pericyazine is taken with other medicines that have anticholinergic effects, including the following:

• anticholinergic medicines for Parkinson's symptoms, eg procyclidine
• antihistamines, eg brompheniramine, chlorphenamine
• other antipsychotic medicines
• certain antisickness medicines, eg promethazine, meclozine, cyclizine
• antispasmodic medicines, eg hyoscine
• medicines for urinary incontinence, eg oxybutynin, flavoxate, tolterodine, propiverine, trospium
• MAOI antidepressants, eg phenelzine
• muscle relaxants, eg baclofen
• tricyclic antidepressants, eg amitriptyline.

Anticholinergic medicines such as procyclidine, which are sometimes used to treat the Parkinson-like side effects of pericyazine, may oppose the antipsychotic effect of this medicine.

Medicines that increase the risk of a type of abnormal heart rhythm, seen as a 'prolonged QT interval' on an ECG, should be avoided in combination with pericyazine. These medicines include the following:

• antiarrhythmics (medicines to treat abnormal heart beats), eg amiodarone, procainamide, disopyramide, sotalol
• the antihistamines astemizole, mizolastine or terfenadine
• arsenic trioxide
• atomoxetine
• certain antidepressants, eg amitriptyline, imipramine, maprotiline
• certain antimalarials, eg halofantrine, chloroquine, quinine, mefloquine, Riamet
• certain other antipsychotics, eg thioridazine, haloperidol, sertindole, pimozide
• cisapride
• dronedarone
• droperidol
• intravenous erythromycin or pentamidine
• methadone
• moxifloxacin
• saquinavir.

There may also be an increased risk of a prolonged QT interval if medicines that can alter the levels of salts such as potassium or magnesium in the blood, eg diuretics such as furosemide, are taken in combination with pericyazine.

Pericyazine may enhance the blood pressure-lowering effects of certain medicines used to treat high blood pressure (antihypertensives). If you are taking medicines for high blood pressure you should tell your doctor if you feel dizzy or faint after starting treatment with this medicine, as your blood pressure medicines may need adjusting.

Pericyazine may oppose the effect of anticonvulsant medicines used to treat epilepsy.

Pericyazine may increase blood sugar levels and disturb the control of diabetes. People with diabetes may need an adjustment in the dose of their antidiabetic medication.

Pericyazine may oppose the effects of dopamine agonists used to treat Parkinson's disease, eg levodopa, apomorphine, bromocriptine, cabergoline, pergolide, ropinirole, rotigotine.

Pericyazine should be used with caution in people taking lithium, as this combination may have an increased risk of side effects.

Antacids for indigestion may potentially reduce the absorption of this medicine from the gut and so could make it less effective. To avoid a possible interaction, you should avoid taking antacids within two to three hours of taking this medicine.

Other medicines containing the same active ingredient

Pericyazine tablets and syrup are only available generically, ie without a brand name.