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West London NHS Trust > Patients and carers > Treatments and medication > Medication > Antipsychotics


As the name suggests, antipsychotics are used in the treatment of psychotic illnesses. There are two major types – typical antipsychotics (older) and atypical antipsychotics (newer).

They work mainly by blocking the receptors in the brain for a chemical called dopamine. Research has shown that people with schizophrenia and other psychoses have an excessive amount of this in their brains.
Examples of atypical antipsychotics are Olanzapine, Risperidone, Quetiapine and Aripiprazole. Clozapine is an atypical antipsychotic medicine that is used when others don’t seem to work as well. Regular monitoring is necessary because Clozapine can cause a drop in the number of white blood cells.
However, they’re not suitable or effective for everyone, as side effects can affect people differently. In particular, antipsychotics will be monitored closely in people who also have epilepsy, a condition that causes seizures or fits.
People who have cardiovascular disease – conditions that affect the heart, blood vessels, or circulation, such as heart disease – will also be closely monitored.
Antipsychotics can usually reduce feelings of anxiety within a few hours of use, but they may take several days or weeks to reduce psychotic symptoms, such as hallucinations or delusional thoughts.
Antipsychotics can be taken by mouth (orally) or given as an injection, sometimes called ‘depot’. There are several slow-release antipsychotics, where you only need one injection every two to six weeks.

Side effects

Antipsychotics can have side effects, although not everyone will experience them and their severity will differ from person to person.
Side effects can include:

  • drowsiness
  • shaking and trembling
  • weight gain
  • restlessness
  • muscle twitches and spasms – where your muscles shorten tightly and painfully
  • blurred vision
  • dizziness
  • constipation
  • loss of sex drive (libido)
  • dry mouth

Tell your GP or mental health worker if you have side effects that are becoming particularly troublesome. There may be an alternative antipsychotic medicine you can take that causes less side effects.
Never stop taking medication prescribed for you unless advised to do so by a qualified healthcare professional responsible for your care.
Suddenly stopping prescription medication could trigger a return of your symptoms (relapse). When it’s time for you to stop taking your medication, it will be done gradually.

Find out more

For more information and up to date advice about medication, including side effects, visit the Choice and Medication website.
The Royal College of Psychiatrists has published leaflets about medication and mental health problems. You can access the information free of charge on their website