Risperidone - Risperdal

Risperidone is prescribed for a variety of problems affecting thoughts, feelings or behaviours. Ask your doctor if you are unsure why it has been prescribed for you.

The most common side-effects are feeling drowsy or dizzy, headache and sleeping problems.

Type of medicine An antipsychotic medicine
Used for Schizophrenia and other psychoses; to ease aggressive or other disruptive behaviours
Also called Risperdal®
Available as Tablet, orodispersible (melt-in-the-mouth) tablet, and oral liquid medicine

Risperidone belongs to a group of medicines called antipsychotics. These medicines work on the balance of chemical substances in the brain.

You may have been prescribed risperidone to relieve the symptoms of schizophrenia or a similar mental health problem affecting your thoughts, feelings or behaviours. These problems are called psychoses. It is also given to treat aggressive behaviour problems in some people where these could become a danger to self or to others.

Risperidone can also be given by injection and there is a separate medicine leaflet for this called Risperidone long-acting injection.

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking risperidone it is important that your doctor knows:

  • If you are pregnant or breast-feeding.
  • If you have a heart condition or blood vessel disease.
  • If you have liver, kidney, or prostate problems.
  • If you have breathing problems.
  • If you have any of the following: epilepsy, depression, Parkinson's disease, glaucoma (raised pressure in your eye) or myasthenia gravis (this is a condition which causes muscle weakness).
  • If you are due to have cataract eye surgery.
  • If you have ever had jaundice (yellowing of your skin or the whites of your eyes) or a blood disorder.
  • If you have porphyria (a rare inherited blood disorder).
  • If you have a tumour on your adrenal gland (a condition called phaeochromocytoma).
  • If you have had an allergic reaction to a medicine.
  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about risperidone and it will also provide you with a full list of the side-effects which you may experience from taking it.
  • Your dose will depend upon the reason you have been prescribed it, so take risperidone exactly as your doctor tells you to. You may be started on a small dose which will then be gradually increased. You will be prescribed one or two doses to take a day. Try to get into the habit of taking your doses at the same times each day, as this will help you to avoid missing any. Risperidone is not affected by food in your stomach so you can take your doses either before or after meals.
  • Most people find it helps to swallow the tablet with a drink of water. If you have any difficulties swallowing, let your doctor know so that you can be prescribed tablets that dissolve in your mouth (called orodispersible tablets) or liquid medicine instead.
  • If you have been given Risperdal® Quicklet tablets, these are made to dissolve in your mouth. Gently peel open the packaging, remove the tablet and place it on your tongue. Allow the tablet to dissolve on your tongue before you swallow.
  • If you have been given liquid medicine, make sure you understand how to use the dose syringe (pipette) to measure out your doses. If you are unsure about this, you can ask your local pharmacist to show you what to do. If you would like to take the medicine added to a little liquid, you can mix it with any non-alcoholic drink except tea.
  • If you forget to take a dose, take it as soon as you remember unless it is nearly time for your next dose, in which case leave out the missed dose. Do not take two doses together to make up for a missed dose.
  • Remember to keep your regular doctor's appointments so that your progress can be checked. If you are taking risperidone long-term, you may need to have some tests from time to time.
  • If you drink alcohol, ask your doctor for advice about drinking while you are on risperidone. Alcohol will increase the chance that you experience side-effects and is unlikely to be recommended for you.
  • If you are having an operation, tell the person carrying out the treatment which medicines you are taking. This is important because risperidone may interfere with any anaesthetic you receive. If you are having cataract surgery, it is particularly important that you tell your surgeon you are on risperidone. This is because an eye problem known as 'floppy iris syndrome' has developed in some people and your doctor will want to advise you about the risk of this.
  • If you buy or take any 'over-the-counter' medicines, check with a pharmacist that they are suitable to take with risperidone.
  • If you have diabetes you may need to check your blood glucose more frequently as risperidone can affect the levels of sugar in your blood. Your doctor will advise you about this.
  • When risperidone has been taken for a while, stopping treatment suddenly can cause problems. If you have been taking it regularly for a year or so, your doctor will probably want you to reduce your dose gradually if this becomes necessary.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with risperidone. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common risperidone side-effects
What can I do if I experience this?
Feeling sick, constipation/diarrhoea, abdominal discomfort, indigestion Stick to simple foods - avoid rich or spicy meals
Feeling dizzy or sleepy, blurred vision If this happens, do not drive or use tools or machines. Do not drink alcohol
Headache and other aches or pains Ask your pharmacist to recommend a suitable painkiller
Feeling shaky or restless, unusual or uncontrollable muscle movements Speak with your doctor as soon as possible about any of these. Your treatment may need adjusting
Increased weight, difficulty sleeping, mood changes, increased blood pressure, coughs and colds, fast heartbeats, skin rash, sexual problems, breast tenderness, production of breast milk, menstrual problems, and dry mouth Discuss these with your doctor if any become troublesome

Important: if you experience symptoms such as muscle stiffness, a very high temperature, feeling confused, a fast heartbeat and sweating, you should contact your doctor immediately. These can be signs of a rare but serious condition known as neuroleptic malignant syndrome.

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Further reading & references

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

Original Author:
Helen Allen
Current Version:
Peer Reviewer:
Dr Adrian Bonsall
Document ID:
3473 (v26)
Last Checked:
16/06/2014
Next Review:
15/06/2017
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