Biological therapies for schizophrenia; drug therapy Flashcards
What can antipsychotics be in the form of?
Tablets, syrups or injections
What are the two types of antipsychotics?
Typical
Atypical
How often are antipsychotics generally taken?
every 2 weeks
When were Typical antipsychotics developed?
1950’s
What is Chlorpromazine?
Type of typical antipsychotic
What are the dosages of chlorpromazine?
Start on 400mg and can go up to 1000mg
What is the link to chlorpromazine?
The dopamine hypothesis
How does chlorpromazine work?
- Acts as an antagonist in the dopamine system
- They block receptors in the synapse and reduce dopamine action
- Reduces hallucinations
What are antagonists?
They are chemicals which reduce the action of neurotransmitters
How is chlorpromazine a sedative?
It has an effect on histamine receptors but not sure exactly how they sedate patients but extremely fast and effective
When were atypical antipsychotics developed?
1970’s
What are the two types of atypical antipsychotics?
Risperidone
Clozapine
Why was clozapine withdrawn in 1970’s?
Patients died from the drug causing blood condition agranulocytosis
Why was clozapine reintroduced in 1980’s?
It was a better treatment than typical antipsychotics
What measures are taken since clozapine was reintroduced?
Regular blood tests
Not injected
How does clozapine work?
Binds to dopamine receptors and also acts on serotonin levels and glutamate receptors
Who is clozapine prescribed to and why?
Those with high suicide risk
They improve mood and reduce anxiety and depression
When was risperidone developed?
1990’s
What does risperidone do?
Binds to dopamine and serotonin receptors more strongly than clozapine and therefore it is effective in much smaller doses and can reduce side effects
What did Thornley et al (2003) find?
Reviewed studies into effects of chlorpromazine and compared to control group with placebo.
1121 patients over 13 trials
Overall, drug associated with better functioning and reduced severity
Relapse rates were lower
What did Meltzer (2012) find?
Clozapine was more effective than typical, better than other atypical. Effective in 30-50% of treatments.
Inconclusive studies with risperidone, overall antipsychotic drugs are effective in schizophrenia
What do the use of antipsychotics depend on?
The dopamine hypothesis
It is not a complete explanation
Unclear how dopamine antagonists can help if they reduce dopamine
What did Healy (2012) find?
Some successful trials had data published multiple times, exaggerates the positive effects
Just because it is calming, doesn’t mean reduction in psychosis
What are the side effects of using typical antipsychotics?
Dizziness agitation sleeplessness weight gain stiff jaw itchy skin