Risperidone

Medication name

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

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

Atypical antipsychotic (AKA second-generation antipsychotic)
Ways to take it

Tablets: 0.25mg, 0.5mg, 1mg, 2mg, 3mg, 4mg, and 6mg strengths
Orodispersible (‘melt in your mouth’) tablets: 0.5mg, 1mg, 2mg, 3mg, and 4mg strength
Liquids: Oral solution (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®

Risperidone is licensed to treat schizophrenia, psychosis and mania.

The doctor may also prescribe it ‘off-label’ to help with ADHD, autism spectrum disorder, OCD, depression, aggression in behaviour disorders, tics and Tourette's syndrome. (N.B. some of these uses are licensed when risperidone is used short-term (six weeks or less) but continued treatment beyond that will be ‘off-label’).

Your doctor should discuss the reasons why they believe this is the right medication for you before you start taking it.

Read our guide to psychosis

About risperidone

There is a naturally occurring chemical messenger ('neurotransmitter') in the brain called dopamine.

Dopamine 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, and its beneficial effects may be related to this as well.

Risperidone and everyday life

It can take four to six weeks for risperidone to have its full effect, but some people get good effects right from the first week.

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 had no good effects after two to three weeks, your doctor may increase the dose or change the medicine.

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, it takes three weeks for the injection to start releasing the risperidone.

This means you will need some other antipsychotic cover. This could be risperidone tablets or your previous antipsychotic.

The injection provides a constant release of risperidone over two weeks, so injections are given every two weeks. The three-week delay in the injection starting to release risperidone only matters when you first start treatment. Think of the injection having a very long fuse wire.

If you were already on some other tablets, you will need to continue with them for those first few weeks on the injection.

If you were not on other tablets, the doctor will probably give you some risperidone tablets until the injection starts to work.

If you were on another depot or long-acting injection, you may have one dose of each, very close together.

Don’t worry – as explained above you will not overdose while you take both types for those first few weeks.

Risperidone use has been linked to high blood sugar and diabetes in some young people. This could be linked to putting on weight.

Watch out for any early signs of diabetes: wanting to drink a lot, going for a wee a lot, feeling less hungry and feeling weak.

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.

A side effect of risperidone may be either weight loss or weight gain.

Weight gain is more common than weight loss.

It is very difficult to know how it will affect each person who takes it. If you start to have problems with your weight while taking risperidone, talk to your doctor or pharmacist about this.

Your doctor should measure your weight regularly when you are taking risperidone.

Most of the weight gain is in the first six to 12 months, and then it levels out.

As you grow you will gain weight naturally, but anything more than that should be watched.

Good practice for doctors suggests this routine for checking the weight of people who start taking antipsychotic medicines like risperidone:

get your weight noted before you start
get your weight checked every week for the first six weeks and then again after three months
get your weight and waist measurement checked at least every six months

You could take these measurements yourself and keep a chart to show your doctor.

If you put on weight, there are other antipsychotic medicines you can try which are less likely to make you put on weight.

Look at ways to try and lose extra unwanted weight.

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.

If you feel like a zombie, and you’ve been taking it for more than a month, you should go back to the doctor and see what else you can do.

With risperidone, some people find it hard to get to sleep. If this happens, you can change the time that you take your risperidone each day (if you are taking tablets or liquid). Take it earlier in the day and see if this makes it easier to get to sleep.

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

Alcohol

You can continue to drink alcohol in moderation while taking risperidone. You might find having the two together makes you very sleepy, so during the first few days it might be best to stop drinking alcohol until you see how the medicine affects you.

If you want to drink alcohol, remember that you might be sleepy and make sure you can get home safely.

Street drugs

Some street drugs can increase levels of dopamine in the brain (e.g. cocaine and ecstasy). 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. For more information, have a look at our drugs and alcohol page.

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.

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.

Risperidone can interact with some other medicines and drugs

Check with your doctor or pharmacist whether risperidone is OK for you to take if you are on any other medicines.

If you have any further questions about this, you should speak to your doctor or pharmacist.

Always talk to the doctor if you are taking other medicines. Tell the pharmacist you are taking risperidone if you buy medicines (including things you put on your skin) for common illnesses.

The ordinary tablets may not be suitable for you if you have problems eating some sugars or dairy (milk-based) foods, as they contain lactose. Some brands of the 2mg strength tablets may also have a colour called ‘Sunset Yellow’ (also known as E110) which causes an allergic reaction in some people.

The orodispersible ('melt in your mouth') tablets may contain aspartame, which can be a problem for people who have a condition called phenylketonuria.

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.

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, until you know how it affects you.

Don't worry - most people drive as normal while taking risperidone.

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 up to £1,000 if you do not tell The DVLA about a medical condition that affects your driving.

You may be prosecuted if you are involved in an accident as a result.

Pregnancy

When deciding whether to take risperidone during pregnancy it is important to weigh up how necessary risperidone is to your health against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are.

Remaining well is particularly important during pregnancy and while caring for a baby. Treatment with risperidone in pregnancy may be the best option for both mother and baby.

As with other antipsychotics, taking risperidone may cause your folate levels to become low and a prescribed supplement dose of 5mg daily should be taken.

There is information on over 400 mums who took risperidone and there does not seem to be an increased risk of malformations, miscarriage or diabetes during pregnancy.

Post-natal

If you have taken risperidone close to delivery your baby may have some side effects or such as being irritable, crying or problems feeding and sleeping. These are usually mild and go away in a few days without treatment.

Breastfeeding

Risperidone is passed to the baby through breast milk in small amounts. This could help with any discontinuation symptoms.

You should discuss the risks and benefits of breastfeeding with your midwife or doctor.

Remember that it is important for you to remain well while you are bonding with and looking after your baby. For this reason, it may be best to take medicine for your mental health when breastfeeding.

Make sure that your doctor, nurse, or health visitor checks your baby for any side effects.

If your baby was premature or has health problems, then you will need to be extra careful about taking medicines while breastfeeding. It may be best not to breastfeed if this is the case, but you should discuss this with your doctor or midwife.

Sex

Risperidone can have side effects that affect your sex life, including:

painful erections, or problems getting an erection (getting hard) and ejaculating (coming)
periods may become irregular or stop due to raised prolactin levels. Talk to your doctor and they will be able to do a simple blood test to check if the risperidone is the cause
some bleeding from the vagina, and difficulty reaching orgasm the same way as before
some breast growth and milk flow, regardless of gender
decrease in libido (sex drive)

These effects should pass after the first couple of weeks. If they do not, and this is a problem for you, go back to the doctor and see what else you could try.

Fertility

While taking risperidone it might be more difficult for you to fall pregnant, but this effect is not permanent.

Risperidone can increase the level of a natural hormone called prolactin in the body.

This hormone is produced in high levels to produce milk in breastfeeding mothers and provides some natural contraception.

Prolactin is produced at low levels in men.

This means it may be more difficult to get pregnant if your prolactin levels rise. Do NOT rely on this as an alternative to good contraception.

Talk to your doctor about this if you want to get pregnant, and see below for more information about taking risperidone during pregnancy.

Risperidone is not a banned substance in sport.

Taking risperidone may make you feel tired and dizzy, and affect your eyesight. This could be dangerous in some sports like cycling or driving. It might be best to stop such sports for the first few days, until you know how it affects you.

Don't worry - most people play sports as normal while taking risperidone.

Try not to take risperidone for the first time just before your exams.

Taking risperidone may make you feel tired or make it hard to fall asleep at night. It can also give you headaches or affect your eyesight.

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 to study.

Don't worry - most people take exams as normal while taking risperidone.

Psychosis and schizophrenia themselves can also affect concentration.

Your doctor should know

You need to talk to your doctor or pharmacist before starting treatment with risperidone if any of the following apply to you:

you have any heart problems
you have epilepsy
you have diabetes
you have had a blood clot, or anyone in your family has had one
you have ever had unusual movements of your tongue, mouth or face
you have kidney or liver problems
you or someone in your family has had a stroke or is at risk of a stroke
you have ever had a condition known as neuroleptic malignant syndrome (NMS) whose symptoms include high temperature, muscle stiffness and sweating
you have a condition called porphyria (ask your doctor – if you have it, it should be on your records)
you have ever had an erection that lasted for more than a few hours and was very painful (priapism)

Uses, warnings, safety and side effects of risperidone

Taking risperidone

How long will I need to take risperidone for?

You and your doctor should talk about how long you need to take risperidone.

If you take risperidone for bipolar disorder or schizophrenia, you should think about taking it for a few years, otherwise your old symptoms can come back.

Young people taking risperidone for conduct disorders will usually only take it for six weeks.

You should only take risperidone as agreed with your doctor

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

Make sure that you know your dose. If it is not written on the label, check with your pharmacist or 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 - 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 (melts), 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 (the tannin chemical in tea and cola stops the risperidone from absorbing properly into your body).

If you agree to have the long-acting injection (LAI), a doctor or nurse will inject this into a muscle in your arm or bottom every two weeks. 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.

What should I do if I miss a dose of risperidone?

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 to catch up on missed doses.

Do not take 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 every two weeks.

What will happen if I forget to take my risperidone?

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

Stopping the use of risperidone

Stopping the medication causes the balance of chemicals in the brain to alter.

When you start taking an antipsychotic, your brain adjusts to having lower levels of dopamine around.

If you stop taking the antipsychotic suddenly, the balance starts to change again, and your brain can take a while to adapt to this change. You could get your old symptoms back. You could also get some symptoms from the change, which are called withdrawal symptoms, although these are mild and rare with risperidone.

You will probably get your old symptoms back if you stop risperidone suddenly.

If you are thinking of stopping or want to stop, talk to your doctor and they can help.

They will reduce and stop the risperidone slowly so that any problems (like your old symptoms coming back) can be picked up quickly.

It is better to agree stopping with a doctor who will reduce your dose gradually. This will be done over a few weeks.

Warnings and safety

Safety headlines

If you have taken more risperidone than the dosage recommended by the doctor who prescribed it to you, you must get medical help immediately – even if you do not feel any different.

Risperidone can sometimes cause serious side effects. Tell your doctor immediately if you experience unusual movements (mainly of the face or tongue).

Go to hospital immediately if you think you may have developed a blood clot (symptoms are usually swelling, pain and redness in the leg); a clot may travel through blood vessels to the lungs causing chest pain and difficulty breathing.

Also go to hospital if you develop a combination of fever, faster breathing, sweating, muscle stiffness or drowsiness; and tell them that you are taking risperidone.

Very rarely risperidone can cause severe allergic reactions. Go to hospital if you have difficulty breathing or swelling of your face or throat.

In rare cases, risperidone can cause a long-lasting and painful erection (called priapism). If this happens, you will need to be treated in hospital.

Risperidone is not addictive, but stopping it suddenly can cause problems such as difficulty sleeping, feeling or being sick, sweating, and uncontrollable muscle movements. See you doctor if you want to stop, or if you are having these effects.

You might feel sleepy in the first few days after taking risperidone. Do not drive a car, ride a bike or operate machines until you see how this affects you.

If you are pregnant, or thinking of becoming pregnant, please read the ‘pregnancy, post-natal and breastfeeding’ section under the 'Side Effects' tab, because risperidone may affect the developing baby.

When to go to the hospital

If you have taken more risperidone than the dosage recommended by the doctor who prescribed it to you, you must get medical help immediately – even if you do not feel any different. Go to A&E. Take your medicine with you to show to the doctors. Tell them how much you have taken. Get a friend or family member to go with you, if you can, just in case you feel ill on the way.

You might get any of the following signs:

feeling sleepy or tired
unusual body movements you can’t control
problems standing and walking
feeling dizzy (due to low blood pressure)
uneven heartbeat
seizures (fits)

Go to a doctor or hospital straight away if you get any of the following symptoms:

swelling, pain, and redness in the leg, which may lead to chest pain and difficulty breathing. This might be a blood clot
a sudden change in your mental state, or difficulty with your memory
sudden weakness or numbness of your face, arms or legs, especially on one side, or slurred speech, even for a short period of time. This may be a stroke
fever, muscle stiffness, sweating or a loss of consciousness (a problem called neuroleptic malignant syndrome)
if you get a painful erection that lasts more than a couple of hours (priapism)
movements of the tongue, mouth and face that you cannot control – this could be a condition called tardive dyskinesia. You do not need to go to hospital but see your doctor as soon as possible
seizures/convulsions (fits)

Side effects of risperidone

Some side effects that appear should disappear or get better after a few days. If they do not, you should go back to your doctor.

Don't stop taking risperidone until you talk to your doctor or you may get withdrawal symptoms as well.

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

headache - speak to your pharmacist about treatments to help
dizziness or low blood pressure - try not to stand up too quickly or sit or lie down if you're feeling dizzy
movement problems, sometimes called extra-pyramidal side effects (EPSEs). This is a medical term that includes many symptoms relating to movement. Symptoms include: muscle stiffness or tightness; jerks when bending your arms and legs; your movements might feel a bit robotic; shakiness in your hands and legs; and feeling restless all the time and needing to move around. If you develop EPSEs, your doctor may decrease your dose or give you other treatments to help

Common side effects of taking risperidone (affecting up to 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
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. 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. Speak to your pharmacist or doctor for advice on healthy foods
heartburn, abdominal (gut) pain or discomfort
higher level of a hormone called prolactin. This can cause periods to 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

Although this list of side effects can look scary, some people won’t get any side effects at all. Speak to your pharmacist or doctor if you think you are having side effects from risperidone.

There are other side effects that you can get when taking this medicine – we have only included the most common ones here. Please look at the leaflet inside your medicine box, or ask a doctor or pharmacist, if you want to know whether you are getting a side effect from your medicine.

If you do get a side effect, please think about reporting it via the Yellow Card Scheme.

Do not stop taking the tablets until you talk to your doctor, or you may get withdrawal symptoms as well.

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)