Schizophrenia medicines

A person having a schizophrenic or psychotic 'episode' may lose contact with reality and experience delusions, hallucinations and disturbances of thought. During such episodes, antipsychotic medicines, as their name suggests, help to minimise or take away these symptoms, and are also used to try to prevent them recurring. Some people will have to take the medicines long term to prevent relapses and to control symptoms.

Medicines used to treat schizophrenia are often known as antipsychotics. They work by helping to restore the brain’s natural chemical balance, reducing the symptoms associated with psychotic episodes. Although these medicines cannot cure the condition, they help many people with schizophrenia to lead relatively normal, productive lives by taking away the distressing, painful symptoms, such as delusions, hallucinations and thought disorders.

Medicines for schizophrenia can be broadly classified into 'older' and 'newer' antipsychotics.

Older medicines for schizophrenia

These were first developed in the 1950s and revolutionised the treatment of schizophrenia, because for the first time, many people affected by it became able to live in the community rather than spending their lives in psychiatric hospitals. Many of these early medicines, or derivatives of them, are still used by doctors today. They include chlorpromazine (e.g. Largactil), fluphenazine (Modecate), haloperidol (Serenace), pericyazine (Neulactil) and trifluoperazine (Stelazine).

All the older antipsychotic medicines work, but they have some important differences between them — the main one being in their potency, that is, the dose of the medicine needed to have an effect. The doctor’s choice will depend on a person’s symptoms, the known side effects of the medicines available, and how well the person is likely to tolerate these side effects.

Some older medicines, such as Modecate, can be given as 'depot injections' to prevent relapse of symptoms. Here, doctors give an injection deep into a muscle, allowing the medicine to be slowly released into the body. The injection may be effective at controlling symptoms for between 2 and 4 weeks once the person is stabilised on the dose.

Newer medicines for schizophrenia

Newer antipsychotics, known as 'atypical' or 'novel' antipsychotics, have been developed in recent years as alternatives to the older medicines. These medicines, which many doctors now prefer to try before the older ones, include amisulpride (e.g. Solian), aripiprazole (Abilify), clozapine (e.g. Clozaril), olanzapine (Zyprexa), paliperidone (Invega), quetiapine (Seroquel), risperidone (e.g. Risperdal), sertindole (Serdolect) and ziprasidone (Zeldox).

Doctors believe that these newer medicines are more effective than the older ones against what are known as the 'negative' symptoms of schizophrenia, such as social withdrawal, loss of motivation and lack of emotional expression. Doctors believe they also have fewer side effects, especially trembling and stiffening of muscles and unusual movements, and are better tolerated than the older traditional medicines.

Clozapine, although it is very effective, is usually reserved for people who have not been helped by other antipsychotic medicines, and is available in Australia only through specific authorised medical practitioners. This is because it has been known to occasionally cause agranulocytosis, a serious blood disorder that causes the number of white blood cells in a person’s body to decrease. As white blood cells fight infection, any drop in their numbers may make a person susceptible to contracting serious infections they would normally be able to resist. To detect this problem early, people taking clozapine need to have regular blood tests. Also, in rare cases, people taking clozapine have developed inflammation of the heart muscle (myocarditis).

Side effects of antipsychotics

Most antipsychotic medicines have side effects. These can include:

  • drowsiness;
  • weight gain;
  • increased risk of diabetes;
  • raised blood cholesterol;
  • loss of menstrual periods;
  • dizziness when standing up;
  • muscles stiffness, trembling or unusual movements;
  • dry mouth; and
  • impotence.

However, not everyone who takes a particular medicine will get the same side effects. Talk to your doctor if you get side effects and they worry you. If weight gain is a problem, your doctor will be able to advise you on diet and exercise which may help.

Long-term maintenance treatment for schizophrenia

Some people may need to take antipsychotic medicine for an extended period, and these are usually people who have a history of repeated episodes of schizophrenia, or ongoing schizophrenia. So-called maintenance treatment can be very helpful in preventing symptoms from returning in these situations.

Tardive dyskinesia

When assessing whether a person would benefit from long-term use of antipsychotic medicines, doctors consider very seriously the risks of that person developing a distressing condition called tardive dyskinesia. Tardive dyskinesia is a disorder of movement characterised by abnormal, uncontrollable movements of the mouth, lips, tongue and jaws. The arms, legs and trunk are also often affected.

This may occur in up to one-third of people who take the older medicines for a long period, and although it is less likely to occur with the newer medicines it may still do so. Unfortunately, there is no known treatment for tardive dyskinesia at present, and it may range from mild to severe. In some people, it may continue even after they stop taking the medicine. If a person does need antipsychotic medicine for a long period, doctors will try to prevent tardive dyskinesia occurring by using the lowest dose of medicine possible.

Last Reviewed: 8 September 2010


1. Royal Australian and New Zealand College of Psychiatrists Clinical Practice Guidelines Team for the Treatment of Schizophrenia and Related Disorders. RANZCP clinical practice guidelines for the treatment of schizophrenia and related disorders. Aust N Z J Psychiatry 2005; 39: 1-30.
2. Schizophrenia and related psychoses [revised Oct 2008]. In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2010 Jul. (accessed 10 Sep 2010).
3. Novartis. Clozaril Prescribing Information. Accessed via eMIMS. Date of TGA approved information: 12/06/2009.
4. Schizophrenia [last review Jun 2008]. In: Merck manual. Whitehouse, NJ: Merck, Sharp and Dohme. (accessed 17 Nov 2010).


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