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Risperidone long-acting injection

Risperdal Consta

Risperidone long-acting injection will be given to you every two weeks.

The most common side-effects are headache, sleeping problems, feeling anxious or depressed, slowed movements and symptoms of a common cold.

If you ever miss an appointment for an injection, please make another appointment as soon as possible.

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About risperidone long-acting injection

Type of medicine

An antipsychotic medicine

Used for

Schizophrenia and other similar mental health problems in adults

Also called

Risperdal Consta®

Available as

Long-acting intramuscular depot injection

Schizophrenia is a mental health condition that causes disordered ideas, beliefs and experiences. You will have been prescribed risperidone to relieve the symptoms of schizophrenia. Such symptoms include hearing, seeing, or sensing things that are not real, having mistaken beliefs and feeling unusually suspicious. Risperidone works on the balance of chemical substances in your brain to help control these types of symptoms.

Long-acting, or 'depot', injections are used for maintenance once your symptoms have been eased by taking tablets. The injection slowly releases risperidone into your body to stop your symptoms from coming back. You will need to receive the injection regularly, every two weeks. The main advantage of a depot injection is that you do not have to remember to take tablets every day.

For information about taking risperidone tablets every day see our medicine leaflet called Risperidone (Risperdal).

Before having 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 having risperidone injections, it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you have a heart condition or blood vessel disease.

  • If you have liver, kidney or prostate problems.

  • If you have any problems with your breathing.

  • If you have any of the following: epilepsy, depression, Parkinson's disease, raised pressure in your eye (glaucoma) or a condition which causes muscle weakness, called myasthenia gravis.

  • If you have ever had yellowing of your skin or of the whites of your eyes (jaundice) or a blood disorder.

  • If you are scheduled to have eye cataract surgery.

  • If you have a tumour on your adrenal gland (a condition called phaeochromocytoma), or if you have been told you have 'a prolactin-dependent tumour'.

  • If you have a rare inherited blood disorder called porphyria.

  • 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, as well as herbal and complementary medicines.

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How risperidone long-acting injection is given

  • Before you start the treatment, ask to 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 having it.

  • Risperidone injection will be given to you by your doctor or nurse at two-weekly intervals. It is given by injection into a muscle in your buttock or upper arm.

  • You may be asked to continue taking your tablets for a few weeks after you have started the injections. This is because it can take a few weeks before you feel the full effect of the injections.

Getting the most from your treatment

  • Your treatment will require careful monitoring to make sure that you get the best possible benefit from risperidone. Keep your regular doctor's appointments so that you get your injections on time and your progress can be checked. If you miss an appointment for an injection, contact your doctor to arrange for another appointment as soon as possible. This is so that you can be given the injection without any further delay.

  • If you are due to have any dental treatment or an operation, please tell the person carrying out the treatment that you have had a risperidone injection. This is important because it may interfere with any anaesthetic you receive. If you are having cataract surgery, it is particularly important that you tell your surgeon that 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 risks of this.

  • If you buy or take any 'over-the-counter' medicines, check with a pharmacist that they are suitable for you to take with risperidone.

  • If you have diabetes you may need to check your blood glucose more frequently, as risperidone may affect the levels of sugar in your blood. Your doctor will advise you about this.

  • If you drink alcohol, please ask your doctor for advice. Alcohol increases the risk of side-effects from risperidone, so it should be avoided.

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Can risperidone long-acting injection cause problems?

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 long-acting injection. 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.

Very common risperidone long-acting injection side-effects (these affect more than 1 in 10 people)

What can I do if I experience this?

Common cold symptoms, problems sleeping, mood changes, slowed movements

Discuss these with your doctor if any become troublesome


Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know


risperidone long-acting injection side-effects (these affect fewer than 1 in 10 people)

What can I do if I experience this?

Feeling dizzy or sleepy, blurred vision

Do not drive and do not use tools or machines. Do not drink alcohol

Feeling shaky or restless, unusual or uncontrollable muscle movements

Speak with your doctor

Stomach upset, indigestion, stomach discomfort

Stick to simple meals - avoid rich or spicy food

Pain at the site of the injection

This should quickly pass. If the area becomes red, swollen or 'lumpy', let your doctor know

Chest and urinary infections, dry mouth, feeling breathless, changes in your heartbeats, anaemia, toothache, rash, urinary problems, muscle aches and pain, blood pressure changes, weight changes, appetite changes, breast swelling or discomfort, erectile dysfunction, menstrual problems

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, please speak with your doctor or pharmacist for further advice.

Important information about all medicines

Important information about all medicines

If you suspect that you have had an overdose of this medicine, contact your doctor or go to the accident and emergency department of your local hospital.

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

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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