Biological therapy:

• Typical antipsychotics (traditional)


  Been around since the 1950s and include chlorpromazine which can be taken as tablets, syrup or by injection.

  • If taken orally it is administered daily up to a maximum of 1000 mg, although initially doses are much smaller and for most people the dosage is gradually increased to a maximum of 400 to 800 mg
• Dopamine antagonists


  Strong association between the use of typical antipsychotics ie chlorpromazine and the dopamine hypothesis

  • Chlorpromazine work by acting as antagonists (chemicals which reduce the action of a neurotransmitter) in the dopamine system
  • Work by blocking dopamine receptors in the synapses reducing the action of dopamine
  • When beginning taking chlorpromazine dopamine levels build up but then its production is reduced
  • According to the dopamine hypothesis dopamine-antagonist effect normalises neurotransmission in key areas of the brain reducing symptoms like hallucinations
• Sedation effect


  As well as having antipsychotic properties chlorpromazine is also an effective sedative

  • This is believed to be related to its effect on histamine receptors but it is not fully understood how this leads to sedation.
  • Chlorpromazine is often used to calm individuals not only with schizophrenia but also with other conditions
  • This has often been done when patients are first admitted to hospitals and are very anxious
  • Syrup is absorbed faster than tablets so it tends to be given when chlorpromazine is used for its sedative properties.
• Atypical antipsychotics


  Been used since the 1970s

  • The aim in developing newer antipsychotics was to maintain or improve upon the effectiveness of drugs in suppressing the symptoms of psychosis and also minimise the side effects of the drugs used
  • There are a range of atypical antipsychotics and they do not all work in the same way. In fact we do not know how some of them work.
• Atypical antipsychotics:


  Clozapine developed in the 1960s and first trialled in 1970s

  • Withdrawn for a while in 1970s following deaths of some patients from a blood condition
  • 1980s it was discovered to be more effective than typical antipsychotics clozapine was remarketed as a treatment for schizo to be used when other treatments failed
  • Used today and people taking it have regular blood tests to ensure they're not developing agranulocytosis
  • Potentially fatal side effects clozapine is not available as an injection
  • Daily dosage is a little lower than for chlorpromazine 300 to 450 mg a day
• Atypical drugs:


  Clozapine binds to dopamine receptors in the same way that chlorpromazine does, but in addition it acts on serotonin and glutamate receptors

  • Believed that this action helps improve mood and reduce depression in patients and that it may improve cognitive functioning
  • The mood-enhancing effects of clozapine mean that it is sometimes prescribed when an individual is considered at high risk of suicide
  • This is important as 30-50% of people with schizophrenia attempt suicide at some point
• Atypical:


  Risperidone is a more recently developed atypical antipsychotic, having been around since the 1990s.

  • It was developed in an attempt to produce a drug as effective as clozapine but without its serious side effects
  • Like chlorpromazine, risperidone can be taken in the form of tablets, syrup or an injection that lasts for around two weeks
  • In common with other antipsychotics a small dose is initially given and this is built up to a typical daily dose of 4-8 mg and a maximum of 12 mg.
• Atypical:


  Like clozapine, risperidone is believed to bind to dopamine and serotonin receptors.

  • Risperidone binds more strongly to dopamine receptors than clozapine and is therefore effective in much smaller doses than most antipsychotics
  • There is some evidence to suggest that this leads to fewer side effects than other antipsychotics.