Sounds like 'ris-perry-done'

Risperidone is used to treat some types of mental illness such as bipolar disorder and schizophrenia. Find out how to take it safely and possible side effects. Risperidone is also called Risperdal or Ridal.

Type of medicine Also called
  • Belongs to a group of medicines known as antipsychotics 
  • Risperdal®
  • Ridal®
Orodispersible tablets
  • Risperidone-DRLA
Oral liquid
  • Risperdal®
  • Risperon®
  • Risperdal Consta®

What is risperidone?

Risperidone is used to treat some types of mental illness such as schizophrenia and bipolar disorder. It is sometimes used in dementia, for agitation, restlessness, aggression and hallucinations. It has also been used to help with behavior in autism. It does not cure these conditions but is used to help ease the symptoms and help you on your recovery path. It can help improve symptoms such as extreme mood swings of bipolar disorder, the experience of hearing voices (hallucinations), ideas that distress you and don't seem to be based in reality (delusions), and difficulty in thinking clearly (thought disorder). Risperidone belongs to a group of medicines called antipsychotics. Read more about antipsychotic medication.

In New Zealand, risperidone is available as tablets or a liquid solution. It is also available as an injection. The long-acting or depot injection is an option when your symptoms have settled after taking tablets or liquid solution. Read more about depot antipsychotics.


  • The dose of risperidone will be different for different people. Your doctor will usually start you on a low dose and if you need to, will increase your dose slowly. This allows your body to get used to the medicine and reduce side effects.
  • Always take your risperidone exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much risperidone to take, how often to take it and any special instructions.

How to take risperidone

  • Tablets: Take risperidone tablets with a glass of water.
  • Liquid: Risperidone liquid should be measured carefully with the syringe provided. The liquid may be placed in a small cup and mixed with water, orange juice, or low-fat milk. If you mix risperidone with another liquid, make sure all of the liquid is swallowed so that you get the full dose.
  • Orodispersible tablets: To take risperidone orodispersible tablets, place them on your tongue, let them dissolve then swallow.
  • Timing: You can take risperidone with or without food, but if it makes you feel sick (nausea), try taking it with food.
  • Missed dose: If you forget to take your dose, take it as soon as you remember that day. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the amount.
  • Keep taking risperidone regularly. It usually takes a few weeks to start working and it can take several months before you feel the full benefits. Do not stop taking risperidone suddenly as your symptoms may return if stopped too early; speak to your doctor or nurse before stopping.

Precautions before starting risperidone

  • Do you have any heart problems such as an irregular heartbeat or low blood pressure?
  • Do you have Parkinson’s Disease or epilepsy?
  • Have you had depression in the past?
  • Do you have diabetes or problems with high cholesterol?
  • Are you pregnant or breastfeeding?
  • Do you have any problems with your liver or kidneys?
  • Are you taking any other medicines, including medicines you can buy without a prescription, such as herbal and complementary medicines?

If any of these apply, it’s important that you tell your doctor or pharmacist before you start risperidone. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care, that your pharmacist will tell you about.

Precautions while taking risperidone

  • Alcohol: Avoid alcohol while you are taking risperidone, especially when you first start treatment. Drinking alcohol while taking risperidone can cause drowsiness and affect concentration, putting you at risk of falls and other accidents. It can also cause agitation, aggression and forgetfulness. If you do drink alcohol, drink only small amounts and see how you feel. Do not stop taking your medication.
  • Weight: Let your doctor know if you notice that you are putting on a lot of weight, especially when you first start taking risperidone.
  • Blood tests and other monitoring: Risperidone may cause changes in your blood glucose level, your cholesterol level and in your heart function. To keep an eye out for these effects, your doctor will check your physical health. You will have your weight measured regularly. You may also need to have blood tests to check your kidneys, liver, cholesterol and glucose levels. You may also have your blood pressure measured and an ECG test to check your heart rate.
  • Dehydration: It is important to drink plenty of water to keep well hydrated while taking risperidone. If you have been sick with vomiting or diarrhoea, let your doctor know.

What are the side effects of risperidone?

Like all medicines, risperidone can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Feeling sleepy, drowsy or tired
  • It can last a few hours after the dose 
  • Don’t drive or operate machinery
  • Ask your doctor if you can take your medicine at a different time
  • Avoid drinking alcohol
  • Tell your doctor if troublesome
  • Feeling dizzy
  • This usually only happens when you start your medication
  • It should wear off in a few weeks
  • Try not to stand up too quickly. You are at risk of falls
  • If you feel dizzy, don't drive
  • Feeling like your heart is racing
  • Feeling too hot or too cold
  • Bleeding nose
  • Chest infections, or chesty coughs
  • Tell your doctor
  • Weight gain
  • A diet full of vegetables and fibre may help prevent weight gain
  • Limit sugary or fatty foods and exercise regularly
  • Speak with your doctor if you think you are putting on weight
  • Feeling shaky, feeling restless (cannot sit still)
  • Eyes or tongue may move on their own
  • This is a well-known side effect and is not dangerous
  • Tell your doctor if troublesome
  • Headache
  • Try paracetamol.  Check that this can be taken with any other medicines you may take
  • Signs of changes in hormones
    • In women it can affect breasts (including milk being leaked) and irregular or no periods.
    • In men it can cause impotence (trouble maintaining an erect penis) and chest changes.
  • These changes are due to raised levels of a hormone called prolactin, and it can be very distressing
  • Discuss with your doctor
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product


  • Risperidone interacts with many other medicines and herbal supplements, so check with your doctor or pharmacist before starting risperidone or before starting any new medicines.
  • Risperidone may interact with some medicines that are available without a prescription, such as:
    • cold and flu preparations such as Coldrex®, Dimetapp PE®
    • anti-nausea medication such as Buccastem®, Scopoderm®
    • anti-allergy medication (anti-histamines).

Learn more

The following links have more information on risperidone.

Med-ucation medication benefits & side effects Talking Minds, NZ 
Risperon, Risperdal Consta Medsafe Consumer Information Sheets


  1. Risperidone New Zealand Formulary
  2. Antipsychotic drugs New Zealand Formulary
  3. Prescribing atypical antipsychotics in general practice BPAC, 2011
  4. Managing patients with dementia: What is the role of antipsychotics? BPAC, 2013

Additional resources for healthcare professionals

Atypical antipsychotics – safe prescribing – better, but not perfect SafeRx, NZ, 2019
Antipsychotic pearls for general practice Optimising Medicines Bulletin, ADHB
Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the management of schizophrenia and related disorders Vol. 50(5) 410–472 Australian & New Zealand Journal of Psychiatry, 2016
Antipsychotic medications as a treatment of behavioural and psychological symptoms of dementia The Royal Australian & New Zealand College of Psychiatrists, 2016

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 05 Mar 2018