PAPER 3 - SCHIZOPHRENIA - drug therapy Flashcards
1
Q
what are antipsychotic drugs?
A
drugs used to reduce symptoms of schizophrenia
2
Q
what are atypical antipsychotics?
A
- carry a low risk of extra pyrimidal side effects
- have beneficial effect on negative symptoms and cognitive impairment
- suitable for treatment-resistant patients
- e.g. clozapine, resperadine
3
Q
what are typical antipsychotics?
A
- dopamine antagonists as they bind to DA receptors but do not stimulate dopamine receptors so reduce symptoms of SZ e.g chlorpromazine
4
Q
how are antipsychotic drugs used to treat psychosis?
A
- may be used in short or long term
- used to treat people who experience a loss of contact with reality e.g. through hallucinations/delusions
5
Q
what are antagonists?
A
chemicals that reduce action of a neurotransmitter (e.g. dopamine)
6
Q
how do typical antipsychotics work?
A
- acts as an antagonist in the dopamine system, so dopamine antagonists work by blocking dopamine receptors in the synapses of the brain
- dopamine may build up at the start of the drug therapy, but then production is reduced which reduces symptoms
7
Q
what is the sedation effect?
A
- an effect of chlorpromazine
- sedative effects are thought to be due to its effect on histamine receptors
- chlorpromazine often used for its calming effects on other conditions and may be used on first admittance to hospital when patients are very anxious
8
Q
what suuporting evidence for effectiveness of antipsychotics is there?
A
- supports effectiveness - lots of evidence
- a researcher reviewed studies comparing the effects of chlorpromazine to control conditions
- data from 13 trials, and total of 1121 participants showed chlorpromazine was associated with better overall functioning and reduced symptom severity compared to placebo
- there is also evidence for benefits of atypical antipsychotics
- researchers found clozapine more effective than typical antipsychotics (effective in 30-50% of treatment-resistant cases where typical antipsychotics have failed
9
Q
what criticising evidence is there for the effectiveness of antipsychotics?
A
- researchers found serious flaws with evidence for effectiveness
- most studies are short term effects only and some successful trials have had their data published multiple times, emphasising the size of the evidence base for positive effects
- antipsychotics have powerful calming effects, its easy to demonstrate that they have some positive effects on on people with SZ - this is not the same as saying they really reduce severity of psychosis
10
Q
how is “serious side effects” a limitation for antipsychotics?
A
- negative side effects include: gaining weight, dizziness, agitation, stiff jaw, sleepiness, and itchy skin
- long term use can result in tardive dyskinesia, caused by dopamine supersensitivity and causes involuntary facial movements
- most serious side effect is neuroleptic malignant syndrome (when the drug blocks dopamine action in hypothalamus) and can result in delirium and coma, and can be fatal
- frequencies range from less than 0.1% to just over 2%
11
Q
how is “mechanisms unclear” a limitation for antipsychotics?
A
- we dont know why they work
- understanding is strongly ties up with original dopamine hypothesis (the idea that symptoms of SZ are linked to high levels of dopamine activity in the sub-cortex of the brain
- however we now know the original DA hypothesis is not complete, and that levels of dopamine in other parts of the brain are too low, this means antipsychotics shouldn’t work
- adds to argument of effectiveness
12
Q
why might people think antipsychotics are unethical?
A
- its believed that antipsychotics are used in hospitals to calm SZ patients to make it easier for the staff rather than benefits to the patients themselves
- HOWEVER, calming distressed people with hallucinations and delusions almost certainly makes them feel better and allows them to engage with other treatments (e.g. CBT) and services 9e.g. meeting with social worker)
