Antipsychotic Drugs

Drugs used to treat schizophrenia and other severe psychiatric disorders

Common drugs

  • Amisulpride

  • Chlorpromazine

  • Clozapine

  • Fluphenazine

  • Haloperidol

  • Olanzapine

  • Pimozide

  • Promazine

  • Quetiapine

  • Risperidone

  • Trifluoperazine

  • Zotepine

Antipsychotic drugs are used to control symptoms such as hallucinations and disturbed patterns of thought in schizophrenia and other psychotic disorders. Some of these drugs are also used to stabilize mood in people with bipolar affective disorder, where episodes of mania tend to alternate with episodes of depression, although people with this condition are also likely to be treated with a mood-stabilizing drug such as lithium. Occasionally, an antipsychotic drug is used to control vomiting or uncontrollable hiccups where other treatments have failed. Antipsychotic drugs may also be prescribed to treat severe anxiety and agitation.

How do they work?

Many antipsychotic drugs block the action of the neurotransmitter (brain chemical) dopamine. This chemical is released in the brain at higher than normal levels in people with psychotic disorders and is believed to play a part in producing symptoms. Some antipsychotic drugs also block the action of serotonin and other chemicals involved in regulating mood.

How are they used?

The type of antipsychotic drug prescribed will depend on factors such as how much sedation is needed and your susceptibility to side effects.

The drugs are usually taken orally, although they may be injected if a person is very agitated. A low dose of the drug is prescribed initially, and the dose is then increased gradually until the symptoms are under control. A depot injection, which is an injection deep into a muscle from which the drug is slowly released, may be used so that you do not have to take the drug every day. Depot injections provide enough of the drug to last up to 4 weeks.

If you have bipolar affective disorder, your doctor may prescribe lithium or another mood-stabilizing drug. These drugs take time before they become fully effective. For this reason, you may initially be given a short course of an antipsychotic drug that acts rapidly to make you feel calmer until the moodstabilizing drug reaches its full effect.

What are the side effects?

Antipsychotics may cause a dry mouth, blurred vision, and dizziness due to lowering of blood pressure, and some may make you feel drowsy. They may also cause restlessness and, rarely, movement disorders such as parkinsonism and tardive dyskinesia (involuntary, rhythmic movements of the face, jaw, and tongue). These side effects tend to disappear when you stop taking the drug although, after a long period of use, some antipsychotic drugs may occasionally cause permanent tardive dyskinesia.

You should never suddenly stop taking any antipsychotic drug without first consulting your doctor. If you need to stop taking the drug, the dose will be reduced gradually by your doctor.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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