Risperidone | Atypical Antipsychotic Side Effects

Medication name

Risperidone ("ris-PER-i-doan")
Brand name

Risperdal ® ("ris-PER-dal")
Medication type

Second-generation antipsychotic (sometimes referred to as an atypical antipsychotic)

Tablets: 250 micrograms , 500 micrograms, 1mg, 2mg, 3mg, 4mg, and 6mg strengths

Orodispersible (‘melt in your mouth’) tablets: 0.5mg, 1mg, 2mg, 3mg, and 4mg strength

Liquids: 1mg/ml – one 5ml spoonful is like a 5mg tablet

Injections: Long-acting injection (LAI) that goes into the muscle and releases risperidone slowly – this is called Risperdal Consta® or Okedi®

If you are 18 or over, risperidone is licensed to treat schizophrenia, psychosis and mania.

If you are five to 18 years old, risperidone is licensed for conduct disorder.

If you are younger than the ages listed above or using it for a different reason, a specialist doctor may still consider this as a treatment option.

A specialist may discuss why they think this is an option for other conditions including OCD, tics in Tourette’s syndrome, severe anxiety, to treat depression in combination with other antidepressant medication, or to manage severe irritability, agitation or feelings of anger.

Read our guide to psychosis

About risperidone

Risperidone is a second-generation antipsychotic (sometimes described as an ‘atypical antipsychotic’).

There is a naturally occurring chemical messenger (or 'neurotransmitter') in the brain called dopamine. This is a chemical messenger in the brain mainly involved with thinking, emotions, behaviour and perception. In some illnesses, there may be too much dopamine, and this causes some of the symptoms of the illness.

Risperidone blocks the effects of dopamine in the brain, resulting in a reduction of the symptoms.

Risperidone also has effects on other neurotransmitters in the brain, such as serotonin. Its beneficial effects may be related to this, including the reduction of movement disorders and symptoms of depression and anxiety.

Risperidone and everyday life

You should start to feel some benefits in the first one to two weeks, but it can take four to six weeks for risperidone to have its full effect. This can vary between individuals and the reason why you are taking risperidone.

You should stay in touch with your doctor to see how it goes over the first few weeks. They might do some tests to check your symptoms.

If you have seen no change in any symptoms after one or two weeks, you should talk to your doctor about your progress. They may recommend increasing the dose or changing your medicine. Don’t increase your dose yourself if you think the medication isn’t working.

Your doctor will start with a low dose, which they will increase slowly to a dose that is effective for you. This may take several days or weeks.

If you are starting on the long-acting injection, you may need to continue taking risperidone orally for a few weeks, but this varies depending on the brand of injection you are prescribed. Your doctor or pharmacist will explain this.

If you have responded well to risperidone and you switch to a long-acting injection instead of tablets or liquid, it is likely you will be prescribed a long-acting injection of a medicine called paliperidone. After you take risperidone, your body changes it to paliperidone, so while it may seem like your medicine has changed, it actually hasn’t.

Risperidone may cause weight loss or weight gain, but weight gain is more common. The risk of weight gain with risperidone is lower compared to other antipsychotic medicine (like olanzapine), but children and young people appear to be more at risk of this side effect compared with adults. You may also be more likely to gain weight if you have not taken this type of medication before.

It is not possible to predict how risperidone will affect each person before they start taking it. Talk to your doctor or pharmacist if you are concerned about your weight (or changes to your weight) while taking risperidone. They can review your medicine with you and look at any changes that could be made to help.

Your doctor will monitor your weight regularly when you are taking risperidone.

Making sure you do enough exercise and eat a healthy diet (with vegetables and fibre) can help you to avoid putting on too much weight.

Mental health conditions like schizophrenia and bipolar disorder can make being active and eating healthily more of a challenge. Talk to your doctor, pharmacist and specialist healthcare team for lifestyle advice and where to get support if this would be helpful.

If you do gain weight, most of this is likely to occur in the first six months of treatment. It is possible you may continue to gain weight after this time, but the rate of weight gain will usually be slower. This can happen even if you are taking a very low dose.

Risperidone can also affect the way your body processes sugar. A side effect of risperidone includes high blood sugar and, while not common, has been linked to the development or worsening of diabetes in some young people. This could also be linked to putting on weight.

It is important to watch out for symptoms that might mean your body is having trouble processing sugar. These include wanting to drink a lot, going for a wee a lot, and feeling very weak or tired all the time. If you develop these symptoms, or any other symptoms you are concerned about, it is important to make an appointment with your doctor to discuss this.

If you already have diabetes, taking risperidone may affect your blood sugar levels. Talk to your doctor and check your blood glucose levels regularly if this applies to you. You may have to increase the medication you use for your diabetes.

You may want to let your family and friends know you are taking risperidone so they can support you and help you look out for side effects.

For guidance on this, check out our page on getting support with your medication.

You can feel sleepy in the first few days of taking risperidone. This should get better after the first week or two. With risperidone, some people find it hard to get to sleep. If this happens, try taking it earlier in the day and see if this makes it easier to get to sleep.

Reported side effects of risperidone include strange dreams or nightmares.

Rarely, risperidone can also cause sleep-talking and sleep-walking. Some people have also done other activities while they were asleep, like eating.

If you are on the long-acting injection, talk to your doctor if your sleep is disturbed.

If you have been taking risperidone for more than a month and you continue to feel very sleepy during the day or you are struggling to get to sleep (or your sleep at night is worse), you should go back to your doctor and discuss what changes could be made to help. This may include switching to a different medication.

Alcohol

It may be possible to drink some alcohol in moderation while taking risperidone but the two together might make you feel very sleepy and unsteady on your feet, especially when you first start taking the medication.

During the first few weeks of treatment, it is recommended that you don’t drink alcohol until you know how the medicine affects you.

If you want to drink alcohol, it’s best to only drink small amounts, and have a plan for getting home safely if you go out.

Drinking alcohol every day, or in large amounts, can make your symptoms worse and may mean you won’t get the maximum benefit from your medication.

Street drugs

Some street drugs like cocaine and ecstasy can increase levels of dopamine in the brain. As antipsychotics block the effects of dopamine, the 'high' from street drugs may not be as 'high' as before. You may therefore be tempted to increase the dose of your street drug to make up for it, but this could be dangerous.

Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis.

Some street drugs can make you feel sleepy and this could be made worse with risperidone.

There are many other street drugs, but we don’t know what effect taking them with risperidone will have, so it’s best to be cautious. There is no regulation of street drugs or ‘legal highs’, so even if there are no known issues with the medication you take, the supply you receive might be mixed with other substances that could be dangerous.

Risperidone can produce a false positive test for LSD on a urine drug screen. Talk to your doctor about this if it is a problem for you.

Get more advice on our drugs and alcohol guide.

Risperidone does not mix well with some other medicines, including herbal remedies.

Tell your doctor before you take risperidone if you are taking any other medicines, including things you have bought over the counter and things you put on your skin.

Look at the leaflet inside your medicine box for more information about other medicines that can interact with risperidone. With some medicines your doctor may need to adjust the dose of your medicines if you take them together. Ask a doctor or pharmacist for more information if you have any questions.

There are multiple companies that manufacture this medicine and the non-active ingredients may vary between products and also between the different strengths of tablets that are available. Always let your pharmacist know if you have any food allergies or intolerances, and always check with them if you’re concerned about any of the ingredients in your medication.

The ordinary tablets may not be suitable for you if you have problems eating some sugars or dairy foods, as they contain lactose.
The orodispersible ('melt in your mouth') tablets may contain aspartame, which can be a problem for people who have a condition called phenylketonuria.

If you need to avoid animal products, please note that non-active ingredients used in the production of medicines may sometimes be of animal origin. Ask your pharmacist if you have any questions about the ingredients.

Further information about practical considerations for medicines if you need to avoid animal products can be found on the Vegan Society website.

Taking risperidone may make you feel tired or dizzy and may affect your eyesight when you start taking it.

This could affect you if you drive a car, ride a bike, or do anything else that needs a lot of focus. It might be best to stop doing these things for the first few days or weeks, until you know how it affects you.

Most people drive as normal while taking risperidone. If you are worried about this or have any concerns you would like to discuss, speak to your doctor or pharmacist.

You must tell The DVLA (Driver and Vehicle Licensing Agency) if you have bipolar disorder, schizophrenia, schizoaffective disorder or other mental health conditions that could affect your driving. You can be fined if you do not tell The DVLA about a medical condition that affects your driving and may be prosecuted if you are involved in an accident as a result.

Pregnancy

If you become pregnant while you are on risperidone, you should carry on taking it and make an appointment to see your doctor as soon as possible. They can discuss the benefits and risks of continuing risperidone and help you to make a decision that is best for you and your baby.

They may refer you to a specialist perinatal mental health team to support you with this decision.

You can find out more information about taking risperidone during pregnancy at Bumps (Best Use of Medicines in Pregnancy).

Untreated illness can also be harmful to you and your developing baby, so decisions about stopping or avoiding medication when you are pregnant need to be discussed carefully with your doctor. If you and your doctor agree that it is best for you to continue taking risperidone while pregnant, you should tell your midwife. If you are planning to get pregnant, it is recommended that you take folic acid while you are trying for a baby and during pregnancy. It is safe to take this together with risperidone.

A rare side effect of taking risperidone is that it can increase your chance of getting blood clots. Let your doctor know if you’re taking risperidone and they might suggest a medicine to prevent this.

Post-natal

If risperidone is taking in the last few months of pregnancy, it can cause some symptoms in newborn babies. These are usually mild and last a short amount of time. Speak to your doctor or midwife if your baby is restless, has feeding or breathing problems or is very sleepy.

Breastfeeding

Risperidone is passed to the baby in breastmilk in small amounts.
If your baby was born early, then breastfeeding while you are taking risperidone may not be recommended. Talk to your midwife and doctor about feeding options.

If you breastfeed while taking risperidone, seek urgent medical advice if your baby becomes restless, very sleepy or develops feeding problems.

Sex

Risperidone can have side effects that affect your sex life. These include:

painful erections, or problems getting an erection and ejaculating
irregular or stopped periods
some bleeding from the vagina, and problems reaching orgasm
some breast growth and milk flow, regardless of gender
lower sex drive

In rare cases, risperidone can cause a long-lasting and painful erection, called priapism. If this happens to you, go to a hospital for medical treatment.

Untreated illness can have a negative effect on your sex life, so if risperidone helps you to recover, positive effects can include improving your desire, experience and enjoyment of sex as your mood lifts and you become interested in life and relationships again.

Fertility

There is currently no evidence to suggest that risperidone will affect your fertility.

It can increase a naturally occurring hormone in your body called prolactin. If you have raised levels of prolactin this can impact your fertility, no matter your gender. For people who menstruate, it may cause your periods to stop or become irregular. This can make getting pregnant harder.

Let your doctor know if you’re planning on getting pregnant and taking quetiapine. They can monitor your prolactin levels.

Risperidone is not a banned substance in sport.

Most people play sports as normal while taking risperidone. However, it may affect your ability to play sports that require a lot of focus. It might be best to stop these sports for the first few days until you know how it affects you or the effects get better.

If you have any concerns, discuss this with your doctor.

Risperidone may affect your concentration, give you blurred eyesight and make you feel dizzy and tired. Psychosis and schizophrenia themselves can also affect concentration.

Ideally it’s best not to take risperidone for the first time just before your exams.

It is not possible to predict how the medication will make you feel, and if you do get any side effects, these are more likely to occur when you first start taking risperidone.

You should talk to your doctor about any future exams if you are starting risperidone. You might decide together to delay starting it until you have done them.

If they are more than a month away, however, you might find that it is better to start risperidone to improve your motivation and ability to study.

Most people take exams as normal while taking risperidone. If you are worried that taking risperidone might make studying for or taking your exams harder, discuss this with your doctor.

Information and safety considerations

Your doctor will consider any other medical conditions or symptoms you have before recommending a medicine for you.

Your medicine will come with a ‘patient information leaflet’. It’s important that you read this information. Speak to your pharmacist if:

you’re not given a leaflet
you don’t understand the information
you need it in a different format or language
you’re concerned about something you’ve read

The information leaflet also includes a list of warnings and precautions to consider before you take the medicine. If you think that any of these apply to you and are concerned that your doctor is not already aware of them, check with your doctor or pharmacist before you start to take your medication (or as soon as possible if you are already taking it).

Uses, warnings, safety and side effects

Taking risperidone

Your doctor will advise you on how long it is best to keep taking your medication. This may vary depending on what you’re taking it for and how many times you’ve been unwell.

For psychosis or schizophrenia, if you have had one episode of illness, then it is best for you to keep taking risperidone for at least two years to reduce the chances of becoming ill again. If you have had more than one episode of illness, then a period of at least five years is recommended.

If you are taking risperidone to treat bipolar mania or bipolar depression, then you will need to discuss long-term medicines for your bipolar disorder with your doctor. This is to help stop the illness coming back.

For bipolar disorder, it is important to remain on medicines in the long term because every time you become ill, there is more chance of you becoming ill again. Risperidone can be used as a long-term medicine, but there are other choices too, and lithium is still thought to be the best long-term medicine for bipolar disorder. You should discuss your options with your doctor.

For schizoaffective disorder, it is probably best to keep taking the risperidone for several years to reduce the chances of the illness coming back. We know less about schizoaffective disorder, but it has some similarities to bipolar disorder and some similarities to schizophrenia.

Depression is usually treated with an antidepressant medicine, and risperidone is sometimes added to an antidepressant for more severe depression. For people with severe depression, it is best to continue the antidepressant medicine for at least two years to stop the illness from coming back. The doctor is likely to recommend continuing risperidone for the same length of time.

If you are taking risperidone to help with tics associated with Tourette Syndrome you may continue to take this for many years if it is helping. Your doctor will review your medication regularly with you. Tics will naturally ‘wax and wane’, which means they get better and worse over time. This may make it harder to tell if your medication is still working well or not. It might be helpful to keep a diary.

If you are taking risperidone to help with feelings and emotions like severe agitation, irritability or aggression, your doctor will review your medication with your regularly.

Your doctor should review your progress on this medication at least once a year.

You will get most benefit from your risperidone if you take it every day at the dose prescribed by your doctor.

Risperidone is usually taken once or twice a day. You will start with a low dose, which will be increased slowly to a dose that is effective for you. This may take several days or weeks.

It doesn’t matter what time you take it each day, but you should choose a time that you can always remember and get into a routine. This could be a mealtime or when you brush your teeth.

Risperidone can be taken with or without food.

For the normal coated tablets, swallow them whole with a drink of water – if you chew them, they taste bitter. You can break them into two pieces at the line on the tablet if you have trouble swallowing them as one piece.

For the orodispersible tablets, put it on your tongue and let it dissolve there and then swallow it. You can wash down with water if needed.

You can dilute the oral solution with any other non-alcoholic drink if it makes it nicer to take, apart from a cup of tea or a glass of cola as the tannin chemical in tea and cola stops the risperidone from absorbing properly into your body.

If you receive your medicine by injection, a doctor or nurse will administer the risperidone injection into a muscle in your arm or bottom. This provides a long-lasting dose of risperidone, lasting for two or four weeks. If you have just switched to the injection, you may need to take tablets alongside this while the dose builds up. The good thing about this is that you don’t have to remember to take your medicine every day. It is slowly working in your body all the time between injections. The injection should switch between the left side (arm or buttock) and the right side (arm or buttock) so that it’s not given in the same place all the time.

If you remember later during the day, take it as soon as possible.

If you forget to take it by your next dose, just take the next dose at the correct time. Do not try and catch up on missed doses by taking a double dose.

If you miss your appointment for your injection, contact your doctor straight away to make another appointment. It is very important to have the injection regularly.

If you forget to take your tablets for a few days, or you miss an injection, you may start getting your old symptoms back or get withdrawal symptoms. You should talk to your doctor about this.

Regularly forgetting to take your medication can increase the risk of you becoming ill again and may mean that your symptoms could be worse if you become unwell again.

If you are struggling to remember to take your medication regularly as prescribed by your doctor, speak to your pharmacist and doctor for advice to help you.

Stopping risperidone too soon after you have recovered may increase your risk of becoming unwell again. Discuss stopping your medication with your doctor. Planning and support are important to stopping risperidone successfully.

Risperidone is not addictive, but if stopped suddenly, or the dose you are taking is reduced too much at once, you may experience withdrawal symptoms. These are caused by the receptors and levels of chemical transmitters in your brain readjusting after you reduce or stop your medication. Your brain can take a while to adapt to this change.

Some of the symptoms you get may be like symptoms you had when you were unwell, so understandably, you might feel anxious or upset that your illness could be returning.

Withdrawal symptoms usually start within a few days of stopping (or sometimes reducing) your medication. A wide range of symptoms have been reported. You may experience a few or a range of these:

difficulty getting to sleep or disturbed sleep
low mood, feeling anxious or agitated or restless
dizziness or light-headedness
headaches
reduced concentration or feeling confused
feeling sick or being sick, diarrhoea
flu-like symptoms
tense or jerky muscles and slow movements
uncontrollable movement of face or body
hallucinations, intrusive thoughts (you may experience these even if your medication wasn’t prescribed to treat psychosis)

It is not possible to predict if you will experience withdrawal symptoms or how bad they will be if you do experience them. If you do experience symptoms, they are usually mild and don’t last long, but for some these could be severe enough to make you feel very unwell and last longer (two to three months or more). Arrange an appointment with your doctor to discuss your symptoms and seek advice if you are concerned or unable to tolerate them.

You can stop taking risperidone safely with your doctor’s help. Planning a gradual withdrawal together can help to minimise or prevent the withdrawal symptoms you experience.

Warnings and safety

If you have taken more than the dose prescribed by your doctor, contact NHS 111 immediately to ask for advice, or ask a family member or friend to do this for you. This is important even if you don’t feel any different.

NHS 111 can give you advice and direct you to the best place to get more help if you need it.

If you have taken too much medication on purpose, or if after taking this you quickly feel unwell, call 999 or get someone to take you to A&E straight away. This includes any of the following signs:

feeling sleepy or tired
feeling or being sick
unusual body movements you can’t control
problems standing and walking
feeling dizzy (due to low blood pressure)
uneven heartbeat
seizures or fits
a painful erection (priapism) that lasts more than two hours

If you need to go to A&E, do not travel alone or drive yourself there. Get your parent, family member or friend to go with you to support you and keep you safe on the way. If someone is not able to drive you there, call for an ambulance. Take your medication with you and tell doctors how much you have taken.

Serious side effects

Risperidone can sometimes cause serious side effects.

Stop taking risperidone and go to a hospital straight away if you get any of the following symptoms:

difficulty breathing
an allergic reaction or allergy (including symptoms such as swelling of your face, eyelids, lips, tongue or throat so that you cannot swallow or breathe, or really bad itching of the skin with raised lumps)
fever, faster breathing, muscle stiffness, drowsiness, sweating or reduced consciousness (these symptoms could be caused by neuroleptic malignant syndrome)
swelling, pain and redness in the leg (this could be a blood clot and may travel through blood vessels to the lungs causing chest pain and difficulty breathing)
a painful erection (priapism) that lasts more than two hours

Get your parent, family member or friend to take you or go with you to support you and keep you safe on the way. If someone is not able to drive you there, call for an ambulance. Take your medication with you.

Contact your doctor immediately but don't stop taking risperidone, if you get any of the following symptoms:

movements of the tongue, mouth and face that you cannot control (this could be a condition called tardive dyskinesia)
tensing or contraction of muscles that you are not able to control (this could affect any muscle, including your eyes, mouth, tongue or jaw)
any unusual bleeding or bruising
sudden fever, sore throat or mouth ulcers
yellowing of the skin or whites of the eyes (these may be signs of hepatitis)
a sudden change in your mental state, or difficulty with your memory
severe abdominal pain and feeling sick
develop new symptoms which include needing to drink a lot, needing to pee a lot, feeling weak or feeling hungry despite having an increased appetite (these might indicate your body is not processing sugar very well)

If you are unable to contact your doctor, call NHS 111 for urgent advice.

Side effects and your health

Side effects are more common when you first start taking risperidone. Many go away as you continue your medicine. If they don’t get better, or if you are worried by them and they are causing you distress, speak to your doctor or pharmacist about them.

Very common side effects of taking risperidone (affecting more than one in ten people) include:

feeling sleepy, tired, weak or exhausted (this can be worse at the start of treatment and wear off after a few weeks – if you take your dose once daily, you could try taking it just before you go to bed)
headache – speak to your pharmacist about treatments to help
movement problems, sometimes called extra-pyramidal side effects (EPSEs)

EPSEs is a medical term that includes many symptoms relating to movement like muscle stiffness or tightness, jerks when bending your arms and legs, robotic movements, shakiness in your hands and legs, feeling restless all the time and needing to move around. If you develop EPSEs, discuss this with your doctor so that they can review your medicine. You may need a lower dose or a different medicine may be better for you.

Common side effects of taking risperidone (affecting up to one in ten people) include:

nausea (feeling sick) or vomiting (being sick) – try taking your dose with food
diarrhoea (loose poo) – make sure you drink lots of water and speak to your doctor or pharmacist if it continues for more than a few days
constipation (finding it hard to poo) – make sure you drink enough fluids, eat enough fibre (like brown breads, fruit and veg) and do enough exercise, and speak to your pharmacist if this goes on for a few more days than is normal for you
increased appetite, decreased appetite or eating less, weight gain or weight loss – try to eat lots of veg and fibre when you can and speak to your pharmacist or doctor for advice on healthy foods
heartburn, abdominal (gut) pain or discomfort
higher level of a hormone called prolactin

Higher levels of prolactin might not cause any symptoms, but can cause periods to be irregular or stop, or milk to leak from your breasts. It can also cause trouble getting an erection. Speak to you doctor if you get any of these symptoms and they can check your prolactin level with a simple blood test. In the long term, raised prolactin can weaken your bones.

Young people and children aged 5-17 are more likely than adults to get the following side effects:

feeling tired, sleepy, or less focused
headache
increased appetite
vomiting (being sick)
getting cold symptoms like a blocked nose and cough
abdominal (gut) pain
fever
dizziness and shaking
diarrhoea (loose poo) and incontinence (less control over when you wee)

There are other side effects that you can get when taking this medicine. We have only included the most common ones here.

This list of side effects can look scary. You may not experience any of them, but it’s important to be aware of them so you know what to do if they do happen.

Unless your side effects are very severe or distressing, try to continue taking your medication until you can talk to your doctor. Your doctor can make changes to your medication to help if needed.

You should have your weight, blood sugar, blood fats, prolactin level, blood pressure and pulse measured before you start risperidone and regularly during early treatment, then at least every six months (if you are under 18) or once a year (if you are over 18) after that.

A blood test will be required to check your blood sugar, blood fats and prolactin level.

Your doctor might also check your heart with an electrocardiogram (ECG).

They might also check your height and development. If you have periods, they may ask if there have been any changes to the pattern or frequency of these.

It is very important to go for these checks when you are asked to do so. If you are worried or anxious about the monitoring, talk to your doctor, care team or practice nurse about this for advice and support.

You could take some of these measurements at home (e.g. weight) and keep a record of the results to share with your doctor when they review your treatment.