Biological Therapies: Drug Therapy

• Chlorpromazine

  • As tablets, syrup or injections
  • Maximum 1000mg
  • Acts as dopamine antagonists
  • An effective sedative – calms anxious 1st time patients and syrup absorbs faster than tablets (when Chlorpromazine is used as sedative)
• Dopamine antagonists


  Reduce action of dopamine
• How dopamine antagonists work


  Block dopamine receptors in synapses of brain which reduces symptoms such as hallucinations
• Atypical modern antipsychotics


  Clozapine & Risperidone
• Aims of atypical modern antipsychotics


  • To improve effectiveness of drugs in suppressing the symptoms of psychosis
  • To minimise side effects
• Clozapine

  • Remarketed in 1980s after deaths in 70s
  • More effective than typical but has fatal side effects
  • Lower daily dosage than chlorpromazine (300-450 mg)
  • Prescribed to high-risk suicidal patients due to its mood-enhancing effects
• How Clozapine works


  Binds to dopamine receptors and acts on serotonin and glutamate receptors to improve mood and reduce depression and anxiety
• Risperidone

  • To be more effective than Clozapine without serious side effects
  • As a tablet, syrup or injection lasting up to 2 weeks
  • Small dosage of 4-8mg and maximum 12mg - more effective in smaller doses
  • Fewer side effects than typical antipsychotics
• How Risperidone works


  Binds to dopamine (more strongly than Clozapine) and serotonin receptors
• Thornley 2003 = Chlorpromazine (typical) was associated with better overall functioning, reduced symptom severity and lowered relapse rate
• Meltzer 2012 = Clozapine (atypical) to be more effective than typical and atypical, effective in 30-50% of treatment-resistant cases where typical had failed
• Antipsychotics are reasonably effective, but inconclusive results on effect of both atypical antipsychotics due to fact that some patients respond better to one drug than the other
• Limitation - Long-term use of typical antipsychotics


  Tardive dyskinesia (caused by dopamine super sensitivity), involuntary facial movements and Neuroleptic Malignant Syndrome because drug blocks dopamine action in hypothalamus which results in high temperature, delirium and coma
• Limitation - Overreliance on dopamine hypothesis

  Our theoretical understanding of antipsychotic drugs is tied with original hyperdopaminergic dopamine hypothesis – evidence shows it as incomplete explanation because it's actually due to low levels of DA in other brain regions, therefore antipsychotics cannot explain hypothesis because they're DA antagonists which reduce DA activity, THEREFORE suggests antipsychotics shouldn't work
• Limitation - Chemical cosh

  Used in hospitals to calm patients and make them easier for doctors to work with – Moncrieff 2013 = this is human rights abuse because it would lead to overuse of the antipsychotics which can make patients more prone to fatal side effects, THEREFORE they're not being protected from harm
• tardive dyskinesia

  involuntary movements of face and jaw
• neuroleptic malignant syndrome


  caused by an adverse reaction to antipsychotic drugs