Risperidone

Risperidone is medicine that helps with symptoms of some mental health conditions such as:

• schizophrenia (where you may see, hear or feel things that are not there or you believe things that are not true or you feel unusually suspicious or have muddled thoughts)
• mania symptoms of bipolar disorder, where your mood changes between feeling highly excited (mania) and very low (depression)
• aggressive or agitated behaviour in children (over 5 years) or young people with learning disabilities
• aggressive or agitated behaviour in adults with Alzheimer's disease

It's an antipsychotic medicine. It does not cure your condition but it can help the symptoms.

Risperidone is only available on prescription.

It comes as tablets (including tablets that dissolve in your mouth) and a liquid that you drink.

It can also be given as an injection (for schizophrenia only).

• Risperidone works by affecting chemical messengers in the brain (neurotransmitters) like dopamine. It does not cure your condition but it helps to keep your symptoms under control.
• Risperidone does not work straight away. It can take several days or even months for some symptoms to get better.
• Common side effects include feeling sleepy, problems with your movement and headaches.
• It can make you feel more hungry than usual, so you may put on weight.
• It's best not to drink alcohol for the first few days of treatment until you see how the medicine affects you.

Risperidone can be taken by most adults and children aged 5 years old and older.

Risperidone is not suitable for some people. Tell your doctor before starting the medicine if you:

• have ever had an allergic reaction to risperidone or any other medicine
• have a heart problem (including arrhythmia)
• have low blood pressure (hypotension)
• have had a stroke or are at high risk of having a stroke
• have ever had problems controlling the movements of your tongue, mouth and face
• have ever had a rare condition called neuroleptic malignant syndrome (symptoms include a high temperature, muscle stiffness, sweating, anxiety and excess saliva)
• have Parkinson's disease or dementia
• have ever had low levels of white blood cells
• have diabetes or epilepsy
• have ever had a prolonged or painful erection that lasted more than 2 hours
• have problems controlling your body temperature or overheating
• have kidney or liver problems
• have had a blood clot or someone in your family has had blood clots

It's important to take risperidone as your doctor tells you.

Dosage and strength

How much you take will depend on what you're taking it for. Your doctor may change your dose depending on how well risperidone works for you.

If you have problems with your kidneys or liver your doctor may ask you to take a lower dose and increase your dose very slowly.

Standard tablets come as 0.25mg, 0.5mg, 1mg, 2mg, 3mg, 4mg and 6mg strength tablets.

Tablets that dissolve in your mouth (dispersible) come as 1mg, 2mg, 3mg and 4mg strength tablets.

Dose for schizophrenia (under 65 years of age)

You'll usually start on a low dose of 2mg. Your doctor may increase this to 4mg a day on the second day. Most people feel better with daily doses of 4mg to 6mg.

You can take it as a single dose each day or you could take half your dose in the morning and half in the evening.

Dose for schizophrenia (over 65 years of age)

You'll usually start on a low dose of 0.5mg, taken twice a day. Your doctor may increase your dose to 1mg or 2mg, taken twice a day.

Dose for mania (under 65 years of age)

You'll usually start on a low dose of 2mg once a day. Your doctor may change your dose depending on how well risperidone works for you. Most people feel better with doses of 1mg to 6mg, taken once a day.

Dose for mania (over 65 years of age)

You'll usually start on a low dose of 0.5mg, taken twice a day. Your doctor may change your dose slowly to 1mg or 2mg, taken twice a day. This depends on how well risperidone works for you.

Dose for aggressive behaviour (18 years and older)

You'll usually start on a low dose of 0.25mg, taken twice a day. Your doctor may increase your dose slowly to see how well risperidone works for you. Most people feel better with 0.5mg, taken twice a day. Some people may need 1mg twice a day. You may only be given risperidone for a few weeks.

Dose for aggressive behaviour in children (5 to 17 years)

Your child's dose will depend on their weight. It will usually start low and may be increased by a small amount every other day.

Your doctor will tell you how to increase the dose, depending on how well risperidone is working. Your child may only take it for a few weeks.

How to take it

Always follow the instructions in the leaflet that came with your medicine.

You can take this medicine with or without food.

How to take standard tablets

Swallow your tablet with a drink of water.

If you need to take half a tablet for your dose or if you have difficulty swallowing the whole tablet, use the score line on the tablet to break it in half.

How to take tablets that dissolve in your mouth (dispersible)

Make sure your hands are dry. Open the blister pack, remove a tablet and put it on your tongue. The tablet will begin dissolving within seconds.

You can have a drink of water afterwards if you like.

How to take liquid

Your medicine will come with a syringe or dropper (pipette) to help you to measure out the right dose.

Having risperidone injections

Some people with schizophrenia may need to have risperidone as an injection.

You will have an injection every 2 weeks at your GP surgery (or some people will have it while in hospital). The dose will depend on how well risperidone works for you.

What if I forget to take it?

If you miss a dose and usually take risperidone:

• once a day – take the missed dose as soon as you remember unless it's less than 12 hours before the next dose is due. In this case leave out the missed dose and take your next dose as usual
• twice a day – take the missed dose as soon as you remember unless it's less than 8 hours before the next dose is due. In this case leave out the missed dose and take your next dose as usual

Do not take 2 doses at the same time to make up for a forgotten dose.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

Contact your doctor if you miss 2 doses or more. They will tell you what you need to do about taking your risperidone.

What if I take too much?

Taking too much risperidone can cause serious side effects such as:

• feeling sleepy or tired
• unusual body movements
• problems standing and walking
• feeling dizzy
• a fast heartbeat
• a seizure or fit

Like all medicines, risperidone can cause side effects, although not everyone gets them.

Common side effects

These common side effects may affect up to 1 in 10 people. Call your doctor or pharmacist if these side effects bother you or do not go away:

• feeling sleepy in the day or difficulty falling asleep at night
• problems with your movement – difficulty moving, stiff muscles with movements which are difficult to control, a slow shuffling walk, shakes and drooling – this is known as dyskinesia
• headaches
• putting on weight or changes in appetite
• stomach pain
• feeling or being sick (nausea or vomiting)
• constipation
• diarrhoea
• swollen breasts, pain in your breast or leaking breast milk – these can be signs of hormone changes

Serious side effects

Serious side effects are rare and happen in less than 1 in 1,000 people.

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to risperidone.

These are not all the side effects of risperidone. For a full list see the leaflet inside your medicines packet.

What to do about:

• feeling sleepy – do not drive, ride a bike or use tools or machinery if you feel sleepy. As your body gets used to risperidone, this side effect should wear off. If it does not go after a few weeks, speak to your doctor.
• problems with your movement – speak to your doctor if these bother you or do not go away. Your doctor may be able to change your medicine.
• headaches – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if headaches last longer than a week or are severe.
• putting on weight or changes in appetite – try to eat a healthy balanced diet without increasing your portion sizes. Do not snack on foods that contain a lot of calories, such as crisps, cakes, biscuits and sweets. If you feel hungry between meals, eat fruit and vegetables and low-calorie foods. Regular exercise will also help to keep your weight stable.
• stomach pain – try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help. If you are in a lot of pain, speak to your pharmacist or doctor. 
• feeling or being sick – stick to simple meals and do not eat rich or spicy food. It might help to take your risperidone after you've had a meal or snack. If you're being sick, try having small, frequent sips of water or squash to avoid dehydration. Do not take any other medicines to treat vomiting without speaking to a pharmacist or doctor. If you take the combined contraceptive pill or progestogen-only pill and you're being sick , your contraception may not protect you from pregnancy. Check the pill packet for advice.
• constipation – eat more high-fibre foods such as fresh fruit and vegetables and cereals. Try to drink several glasses of water or squash every day. If you can, it may also help to increase your level of exercise. Watch a short video on how to treat constipation.
• diarrhoea – drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor. Speak to a doctor if symptoms get worse or last longer than a week. If you take the combined contraceptive pill or progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
• swollen breasts, pain in your breast or leaking breast milk – speak to your doctor if these side effects last longer than a few days. Your doctor may be able to change your medicine.

Risperidone and pregnancy

Risperidone can be taken during pregnancy, although there is not much information to say how safe it is.

There may be a very small risk to your baby. However, the risk of you becoming unwell if you stop taking your medicine is much greater than the risk of harm to your baby.

For this reason, you will usually be advised to keep taking risperidone in pregnancy. Talk to your doctor about your treatment as soon as possible.

You may be asked to attend a specialist antenatal clinic with a pregnancy specialist (obstetrician) and mental health doctor or nurse.

Do not stop taking your medicine unless your doctor tells you to.

Risperidone and breastfeeding

If your doctor or health visitor says your baby is healthy, you can take risperidone while breastfeeding.

Risperidone passes into breast milk in small amounts and has been linked with side effects in very few breastfed babies. It has been used by many breastfeeding mothers without any problems.

It's important to continue taking risperidone to keep you well. Breastfeeding will also benefit both you and your baby.

If you notice that your baby is not feeding as well as usual, seems unusually sleepy, or seems irritable, or if you have any other concerns about your baby, talk to your health visitor, midwife, pharmacist or doctor as soon as possible.

For more information, read how risperidone can affect you and your baby during pregnancy on the Best Use of Medicines in Pregnancy (BUMPS) website.

There are some medicines that may affect how risperidone works. Tell your doctor or pharmacist if you are taking:

• rifampicin (an antibiotic for treating tuberculosis (TB))
• carbamazepine or phenytoin (medicines for epilepsy)
• itraconazole (a medicine for treating fungal infections)
• medicines that make you feel sleepy such as diazepam (benzodiazepines), morphine or tramadol (opioid painkillers) or chlorphenamine (an antihistamine) – risperidone can increase these sedating effects and make you feel more sleepy
• medicines that cause a slow heartbeat
• medicines to treat high blood pressure
• medicines for Parkinson's disease such as levodopa
• medicines that stimulate the brain such as methylphenidate
• medicines that make you pee more (diuretics) such as furosemide or chlorothiazide

Mixing risperidone with herbal remedies and supplements

There might be a problem taking some herbal remedies and supplements alongside risperidone, especially ones that make you feel sleepy or dizzy. Ask your pharmacist for advice.

While you are taking risperidone, do not take:

• St John's wort, a herbal remedy for depression – it may stop risperidone working as well as it should
• ginkgo biloba – this can increase the side effects of risperidone