evaluation of drug therapies Flashcards
evidence for effectiveness
There is a large body of evidence to support the idea that both typical and atypical antipsychotics are least moderately effective in tackling the symptoms of schizophrenia
what did Ben Thorney et al review ( evidence for effectiveness)
Ben Thorney et al (2003) reviewed studies comparing the effect of chlorpromazine to control conditions in which people with schizophrenia received a placebo so their experiences were identical except for the presence of Chlorpromazine in their medication
what was the data from Ben Thorney et al study
Data from 13 trials - a total of 1121 participants showed that Chlorpromazine was associated with better overall functioning and reduced symptoms severity
Data from 3 trials - with a total of 512 participants showed that the relapse rate was lower when chlorpromazine was taken.
In addition, there is support for the benefits of atypical antipsychotics
what did Herbert Meltzer (2012) conclude after his review ( evidence for effectiveness of atypical antipsychotics)
Clozapine is more effective than typical antipsychotics and other atypical psychotics, and that it is effective in 30 - 50% of treatment-resistant cases where typical antipsychotics have failed
a number of studies have compared the effectiveness of Clozapine and other atypical antipsychotics but results have been inconclusive, perhaps some people respond better to one drug or the other
so essentially, antipsychotics are usually effective and this is a strength
serious side effects
the problem with antipsychotic drugs is the likelihood of side effects ranging from mild to serious and even fatal:
- dizziness
- agitation
- sleepiness
- stiff jaw
- weight gain
- itchy skin
long term use can result in tardive dyskinesia, which id caused by dopamine supersensitivity and manifests as involuntary facial movements
what are the serious side effects of typical antipsychotics
neuroleptic malignant syndrome (NMS) is because the drug blocks dopamine action in the hypothalamus, an area of the brain associated with the regulation of a number of body systems
NMS results in:
-high temps
-delirium
-coma
typical doses of antipsychotics have declined so NMS has become rarer.
Atypical antipsychotics were developed to reduce the frequency of side effects and generally, this has succeeded (Meltzer 2012)
However, side effects still exist and people taking Clozapine have to have regular blood tests to alert doctors to early agranulocytosis
use of antipsychotics depends on the dopamine hypothesis
this is more of a theoretical issue than a practical one
- Our understanding of the mechanism of antipsychotic drugs is strongly tied up with the dopamine hypothesis in its original form
This is the idea that there are higher than usual levels of dopamine activity in the subcortex of the brain
There is, however, a bit of evidence to show that this original dopamine hypothesis is not a complete explanation for schizophrenia and that in fact dopamine levels in parts of brian other than the too high
what does the incomplete explanation for dopamine suggest for drug therapies
it means that is not clear how antipsychotics, which are dopamine antagonists, can help with schizophrenia when they reduce dopamine activity
In fact, our modern understanding of the relationship between dopamine and psychosis suggests that antipsychotics shouldn’t work
This undermines the faith of some people who believe that antipsychotics do in fact work
chemical cosh argument
it is widely believed that antipsychotics have been used in hospital situations to calm people and make them easier for staff to work with, rather than for the benefits to the short-term use of antipsychotics to agitated people is recommended by the National Institute for Health and Clinical Excellence (NICE)
This practice is seen by some as human rights abuse (Moncrieff 2013)
