Drug Therapy Flashcards
What are antipsychotic drugs?
Drugs that are affective in treating the most disturbing forms of psychotic illness, such as schizophrenia are called antipsychotics.
What are typical antipsychotic drugs used for?
Primarily to combat the positive symptoms of schizophrenia such as hallucinations and thought disturbances, products of an overactive dopamine system.
What are atypical antipsychotic drugs used for?
To combat positive symptoms but may also have some beneficial effects on negative symptoms of psychotic illness.
What is an example of a typical antipsychotic drug?
Chlorpromazine
What is an example of an atypical antipsychotic drug?
Clozapine
How do typical antipsychotics work?
The basic mechanism of typical antipsychotic drugs is to reduce the effects of dopamine and thus reduce symptoms of schizophrenia.
Conventional antipsychotics are dopamine antagonists in that they bind to but do not stimulate dopamine receptors, thus blocking their action and reducing delusions and aural hallucinations.
How do atypical antipsychotics work?
Atypical antipsychotic drugs act on the dopamine system but additional act on serotonin systems in the brain that might be involved in schizophrenia.
These drugs temporarily occupy D2 dopamine receptors and then rapidly dissociate to allow normal dopamine transmission.
It is this characteristic of atypical antipsychotics that is thought to be responsible for the lower levels of side-effects compared to typical antipsychotics.
How does a World Health Organisation study support drug therapy?
World Health Organisation 01 reported that relapse rates in schizophrenics after 1 year were 55% with placebos, 25% with chlorpromazine alone(typical antipsychotic drug) and 2-23% with chlorpromazine was combined with family intervention.
This suggests that whilst placebos can have a significant effect, typical antipsychotics have a far superior impact, particularly when combined with psychotherapy of some sort.
How does a meta-analysis by Adams suggest that Drug Therapy isn’t effective treatment for schizophrenia?
Adams conducted a meta-analysis of 50 randomised controlled trials of the use of chlorpromazine for schizophrenia.
In total, they included 5,276 individuals in treatment or placebo groups. Overall, they found that chlorpromazine failed to produce global improve in 76% of patients, and commonly produced adverse side-effects such as sedation, a risk of movement disorders and dizziness.
What is one of the main reasons that drug therapies fail is?
Because side effects cause patients to stop taking their medication.
What are possible side-effects of drug therapy treatment for schizophrenia?
Relatively minor side effects include drowsiness, visual disturbance, dryness of the mouth, changes in weight and depression.
More seriously, they can induce a disorder called tar dive dyskinesia which is irreversible and involves uncontrollable lip and tongue movements and facial tics. Around 24% develop this after taking typical antipsychotics for 7 years.
Clearly there are ethical issues to consider when prescribing these drugs.
What are the potential downsides with using Clozapine (atypical antipsychotic drug)?
Is associated with potentially fatal lowering of the white blood count and its use requires regular blood monitoring. Other side effects include sedation, hyper salivation and weight gain.
How is the biological therapies reductionist, thus a negative of the approach?
Biological therapies are considered to be reductionist, assuming that the disorder is simply biologically causes and ignoring the social and emotional factors surrounding the individual’s condition and how they make sense of their disorder.
How many the biological approach involve publication bias?
Non-significant results are less likely to be published so meta-analyses may over-exaggerate positive findings from research studies.
Drug companies often fund research, they might suppress negative results to protect their profits. The result will be that drug therapy appears more successful than it actually is.
