drug

• Most common treatment for schizophrenia involves the use of antipsychotic drugs
• 2 categories of antipsychotic drugs:

  • atypical
  • typical
• typical = traditional
• atypical = 2nd generation
• Typical Antipsychotics were the first generation of drugs used since the 1950s
• Typical antipsychotics work as dopamine antagonists
• Dopamine antagonists means that they

  block the action of dopamine receptors in the synapses,

  reducing the action of dopamine
• It is thought that schizophrenics produce too much dopamine or have more dopamine receptors than non-schizophrenics
• Dopamine hypothesis


  Dopamine antagonist effect normalises neurotransmission in key areas of the brain, thereby reducing symptoms like hallucinations
• An example of a typical antipsychotics is chlorpromazine
• Chlorpromazine

  • Taken as tablet, syrup or, injection
  • Tablets administered daily
  • Dosage gradually increased to 400-800 mg
• Chlorpromazine has a sedation effect

  • used to calm individuals
  • especially in hospitals when people are first admitted and acting very anxiously which makes them harder to treat
• Atypical antipsychotics have been used since the 1970s
• Atypical antipsychotics were developed to improve upon the effectiveness of typical antipsychotics and to minimise the side effects
• Atypical block dopamine receptors, but only temporarily. Then, they rapidly dissociate to allow normal dopamine transmission.
• 3 key differences of atypical from typical:

  • Low risk of extrapyramidal side effects
  • Beneficial effect on negative symptoms & cognitive impairment
  • Suitable for treatment - resistant patients
• Examples of atypical drugs:

  • Clozapine
  • Risperidone
• Both typical and atypical antipsychotics have proven efficacy in the treatment of the positive symptoms of schizophrenia
• Claims for the efficacy of atypical antipsychotics in the treatment of negative symptoms and cognitive impairment is less well established.
• When was clozapine developed?

  In the 1960s
• When was clozapine first trialed?

  In the early 1970s
• Why was clozapine withdrawn in the 1970s?

  Due to deaths from a blood condition called agranulocytosis
• When was clozapine remarketed for schizophrenia treatment?

  In the 1980s
• Why is clozapine used today?

  For schizophrenia when other treatments fail
• What is required when using clozapine today?

  Regular blood tests to monitor agranulocytosis
• Why is clozapine not available as an injection?

  Due to its potentially fatal side effects
• What is the typical daily dosage of clozapine?

  300 to 450 mg
• How does clozapine work in the brain?

  It binds to dopamine, serotonin, and glutamate receptors
• What additional effects does clozapine have?

  Improves mood, reduces depression and anxiety, and may improve cognitive functioning.
• Why is clozapine prescribed to high-risk suicide individuals?

  For its mood-enhancing effects
• What percentage of people with schizophrenia attempt suicide?

  30 to 50%
• When was risperidone developed?

  In the 1990s
• What was the purpose of developing risperidone?

  To produce a drug as effective as clozapine
• What forms can risperidone be taken in?

  Tablets, syrup, or injection
• How long does the injection form of risperidone last?

  About two weeks
• How is the dosage of risperidone typically adjusted?

  A small dose is gradually increased
• What is the typical daily dose range for risperidone?

  4-8 mg
• What is the maximum dosage of risperidone?

  12 mg
• How does risperidone work in the brain?

  It binds to dopamine and serotonin receptors
• How does risperidone differ from clozapine in its action on dopamine receptors?

  Risperidone binds more strongly to dopamine receptors