Drug therapy

• Typical Antipsychotic

  Chlorpromazine
• What forms can Chlorpromazine come in

  Tablets, Syrups or injection
• Dosage of Chlorpromazine

  Orally: Daily Max 1000mg - initial doses are much smaller and for most people the dosage is gradually increased to a max of 400-800mg
• How does Chlorpromazine work?

  • acts as antagonists in the dopamine system (Antagonists are chemicals which reduce the action of a neurotransmitter)
  • Dopamine antagonist blocks dopamine receptors in the synapses of the brain, reducing the action of dopamine - bind but dont stimulate
  • Initially dopamine levels build up but then reduces
  • According to the dopamine hypothesis - the dopamine antagonist effect normalises neurotransmission in key areas of the brain, reducing symptoms like hallucinations
• When is Chlorpromazine usually used ?

  Chlorpromazine has a sedative effect so is used to calm individuals when they are first admitted to hospital and are very anxious

  (Syrup is absorbed faster than tablets so tend to be given when its used for its sedative properties)
• Atypical Antipsychotic

  Clozapine
• Why was Clozapine developed ?

  Aim in developing newer antipsychotics that improve effectiveness and minimise side effects
• Daily dosage of Clozapine

  300-450mg
• How does Clozapine work ?

  • binds to dopamine receptors in the same way chlorpromazine does, but in addition it acts on serotonin as well
  • this action improves mood and reduces depression and anxiety in patients, may improve cognitive functioning
  • mood enhancing effects means that is is sometimes prescribed when an individual is considered at high risk of suicide
• Limitation- Antipsychotics can do harm as well as good and individuals who experience side effects may avoid continuing treatment = could lead to treatment being ineffective

  • Typical antipsychotics side effects: dizziness, agitation, sleepiness, stiff Jae, weight gain and itchy skin
  • Long term use can result in tardive dyskinesia- caused by dopamine super-sensitivity and causes involuntary facial movement such as grimacing or blinking
• Strength- Evidence to support effectiveness of antipsychotics

  • Ben Thornley et al. (2003) reviewed studies comparing the effects of chlorpromazine to control conditions
  • Data from 13 trials with a total 1121 ppts showed that chlorpromazine was associated with better overall functioning and reduced symptom severity
• Evidence concluding that clozapine is more effective that chlorpromazine

  Herbert Meltzer (2012) review

  Clozapine was effective in 30-50% of treatment-resistant cases where typical antipsychotics failed
• Limitation- It is unclear why the mechanism of the drugs work

  Understanding of the mechanism by which antipsychotic drugs work is strongly tied up with the original dopamine hypothesis

  However we now know that this original dopamine hypothesis is not a complete explanation for schizophrenia

  If the revised dopamine hypothesis is true then most antipsychotics should not work. This means that at least some of the antipsychotics may not be the best treatment to opt for - perhaps some other factor is involved in their apparent success. - are drugs simply supressing symptoms?
• Limitation- are they used inappropriately by professionals to ‘subdued’ patients?- ethics

  It is widely believed that antipsychotics have been used in hospital situations to calm people with schizophrenia and make them easier for staff to work with, rather than for the benefits to the people themselves (Moncrieff 2013).

  Can severely unwell patients give consent to receive medication?
• Counterpoint to ethical issues

  On the other hand, calming people distressed by hallucinations and delusions almost certainly makes them feel better, and allows them to engage with other treatments (such as cognitive behaviour therapy) and services (such as meeting with a social worker to organise accommodation).