Antipsychotic medicines are used to treat some types of mental distress or disorders.

On this page, you can find the following information: 

What are antipsychotic medicines?

Antipsychotic medicines are used to treat some types of mental illnesses such as schizophrenia, bipolar disorder (previously known as manic depression), or very severe depression

If other treatments have failed, they may also be used to treat delirium, dementia, eating disorders, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), short-term severe anxiety and rarely attention-deficit hyperactivity disorder (ADHD). There is not as much evidence for the use of antipsychotic medicines for these conditions.

Antipsychotics do not cure these conditions. They are used to help ease the symptoms and help you on your recovery path. They 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). 

Most antipsychotic medicines are tablets, capsules or liquid which are taken every day. Some antipsychotic medicines such as olanzapine and risperidone are 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.

For more information about psychosis, antipsychotic medicines and the common concerns about them, see Talking Minds, NZ.

The following video gives more information about psychosis and antipsychotic medicines.

(Werry Workforce)

Examples of antipsychotic medicines

Antipsychotic medicines are divided into 2 main groups – typical antipsychotics and atypical antipsychotics.

Typical antipsychotics

These are also called first-generation antipsychotics and are the older type antipsychotics. In the past, these were commonly used but now doctors usually prescribe the newer antipsychotics called atypical antipsychotics.

Examples of typical antipsychotics are zuclopenthixol, flupenthixol, haloperidol, chlorpromazine and fluphenazine.

Atypical antipsychotics

These are also called second-generation antipsychotics and are the newer type antipsychotics. Examples of atypical antipsychotics are amisulpride, aripiprazole, clozapine, olanzapine, quetiapine, risperidone, paliperidone and ziprasidone.

How do antipsychotic medicines work?

Antipsychotics affect the action of chemicals in the brain called neurotransmitters. These are chemicals which brain cells need to communicate with each other.

  • Dopamine is the main neurotransmitter affected by antipsychotic medicines. If parts of the dopamine system become overactive, it is thought that this may cause hallucinations, delusions and thought disorder. Dopamine is also involved in muscle movements. 
  • Most antipsychotics also affect other neurotransmitters such as serotonin and noradrenaline, which are both thought to be involved in regulating mood.

Taking antipsychotic medicines will not change your personality and antipsychotic medicines are not addictive. When starting an antipsychotic medicine, give it time to start working properly.

Choosing antipsychotic medication

The antipsychotic medicine you are prescribed will depend on the severity and nature of your illness, other medical conditions you may have, your response to medication and other things – for example, if you need your medicines in a different form such as an injection instead of pills.

  • Different people respond differently to antipsychotic medication, so finding the one that is best for you may be a process of 'trial and error', where you may have to try a few before you find the antipsychotic medication that is right for you. It can take time to find the right type and dose of medication to manage your symptoms.
  • Also, different antipsychotic medication may have different side effects. When deciding on the best medication for you, it is important to discuss with your doctor what the possible side effects are and how they may impact your lifestyle.

The following resource provides more information about things to think about when choosing antipsychotic medication. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Precautions before starting antipsychotic medications

  • Do you have any heart problems such as an irregular heartbeat or low blood pressure?
  • Do you have Parkinson’s Disease or epilepsy?
  • Do you have diabetes or problems with high cholesterol?
  • Are you pregnant or breastfeeding?
  • 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. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

How long will I need to take antipsychotic medication for?

How long you need to take antipsychotic medication for depends on your symptoms. Some people need to keep taking it long term. For example, for psychosis:

  • If you have only had one psychotic episode and you have recovered well, you would normally need to continue treatment for 1–2 years after recovery.
  • If you have another psychotic episode, you may need to take antipsychotic medication for longer, up to 5 years. This is because the risk of symptoms recurring (relapse) is high for the first few years after a psychotic episode.
  • People who have had several psychotic episodes may need to keep taking antipsychotic medication for most of their life. For other conditions, the length of time you need antipsychotic medication might be different.

What if the medication doesn’t work for me?

If your symptoms are not improving, talk to your doctor about other options. There may be other medicines you can try, or other forms of medicine (such as a depot injection). Most people will only need to take one antipsychotic medication, but some people may need several.

What are the side effects of antipsychotic medications?

Like any type of medication, antipsychotics can cause side effects. Usually, these wear off with time as your body adjusts to the medication. Not everyone has the same side effects with the same medication – and some people have none. Possible side effects of some antipsychotic medications include:

  • dry mouth
  • low blood pressure
  • sexual problems
  • tiredness
  • loss of periods in women
  • dizziness
  • stiffness or trembling in muscles
  • constipation
  • changes in body temperature
  • difficulty sleeping 
  • weight gain.

Also see Talking Minds, NZ , a NZ based website that has an interactive tool that enables you to explore and compare different medications so you and your healthcare team can decide which medication is best for you.

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

What can I do to reduce side effects?

Sometimes, but not always, simple things can help to reduce side effects such as:

  • changing the dose of medication, or changing to another antipsychotic; talk to your doctor about this
  • changing the time of day you take your medication – for example, if your medication makes your feel sleepy, taking it at night may help
  • if your experience dry mouth, sugar-free lollies or mouth spray may help ease this
  • if you experience constipation, ask your doctor about taking laxatives or making changes to your diet
  • diet changes and an exercise program may help with weight gain
  • limit or avoid alcohol, because alcohol will increase the risk of drowsiness. Do not drive if you feel drowsy or tired.    

Always talk to your doctor about any side effects you have and any questions you have about the medication. Do not stop taking your medication without talking to your doctor first, it is important to reduce doses gradually to avoid relapse and withdrawal symptoms.

Blood tests and other monitoring

Some antipsychotics may cause changes in your blood sugar 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. If you are taking clozapine, you will need blood tests often. You may also have your blood pressure measured and an ECG test to check your heart rate.   

Learn more

The following websites provide more information about antipsychotic medication. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Antipsychotic medication The Royal Australian & New Zealand College of Psychiatrists
Antipsychotic Medicines Patient Info, UK
Antipsychotic Medication SANE Australia


  1. Antipsychotic medication The Royal Australian & New Zealand College of Psychiatrists
  2. Antipsychotics Royal College of Psychiatrists, UK
  3. Antipsychotic drugs New Zealand Formulary

Additional resources for healthcare professionals

Antipsychotic online switching tool Australian Prescriber 2022
Webinar – prescribing antipsychotics in primary care
 Goodfellow Unit, NZ, 2017
Atypical antipsychotics – safe prescribing – better but not perfect SafeRx, NZ, 2019
Antipsychotic pearls for general practice Optimising Medicines Bulletin, NZ, 2014
Prescribing atypical antipsychotics in general practice BPAC, NZ, 2011
Managing patients with dementia – what is the role of antipsychotics? BPAC, NZ, 2013

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 09 Feb 2018