Schizophrenia: biological therapies
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- Created on: 18-03-20 12:01
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- Biological therapies: drug therapies
- The most common treatment is drugs as injections every 2-4 weeks
- Typical anti-psychotics
- Around since the 1950's
- Chlorpromazine
- orally administered to a maximum of 1000mg, but most are 400 to 800mg
- Typical doses have declined over the last 50 years
- Liu and de Haan (2009)
- Typical doses have declined over the last 50 years
- Strong association between chlorpromazine and the dopamine hypothesis
- Act as antagonists by reducing the action of the neurotransmitter by blocking the receptors
- Made to educe symptoms like hallucinations
- Act as antagonists by reducing the action of the neurotransmitter by blocking the receptors
- Also an effective sedative
- Used to relax patients with SZ or other disorders
- orally administered to a maximum of 1000mg, but most are 400 to 800mg
- Other examples
- Haloperidol
- Loxapine
- Atypical anti-psychotics
- Used since the 1970's
- Made to maximise effectiveness, but minimise side effects
- Clozapine
- To be used when others failed as it can in some cases cause a blood disorder called 'Agranulocytosis'
- Must have regular blood tests
- Not available as an injection due to fatal side effects
- Binds to dopamine receptors the same way Chlorpromazine does
- Also acts on serotonin and glutamate receptors
- 300 to 450mg a day
- Prescribed when patients are at high risk of suicide
- Can help reduce depression and anxiety
- Also acts on serotonin and glutamate receptors
- Important as 30 to 50% of sufferers attempt suicide at some point
- Can help reduce depression and anxiety
- To be used when others failed as it can in some cases cause a blood disorder called 'Agranulocytosis'
- Risperidone
- More recently developed
- Like the others i can be a tablet, syrup or injection
- Does are generally 4 to 8mg with a max of 12mg
- Binds dopamine receptors (stronger than clozapine)
- Fewer side effects than most antipsychotics
- Other examples
- Riprasidone
- aripiprazole
- Evaluation
- Evidence for effectiveness
- Thornley et al (2003)
- Compared chlorpromazne to a placebo
- 13 trials with 1121 participants
- Chlorpromazine patients were better functioning and had reduced severity in symptoms
- Evidence from 3 trials with 512 patients also showed lower relapse rates
- Meltzer (2012)
- Concluded that clozapine is more effective than typical and other atypical drugs
- Effective in 30-50% of treatment resistant cases where other drugs failed
- Inconclusive results
- Thornley et al (2003)
- Dependent on the dopamine hypothesis
- More of a theoretical issue than a practical one
- Not a complete explanation
- Levels of dopamine in parts of the brain can be seen as too low than too high
- Modern understanding of the relationship between dopamine and psychosis suggests they shouldn't work
- Undermined people's faith that they work
- Side effects
- Mild to fatal
- Common side effects
- dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin
- Long-term effect can be tardive dyskinesia which causes involuntary facial movement, like lip smacking
- Most serious side effect is called Neuroleptic malignant syndrome (NMS)
- Believed to be caused by a dopamine blockage in the hypothalamus, which regulates body systems
- Results in high temperatures, delirium and comas. Can be fatal
- Frequency range is less than 0.1% to 2%
- Atypicals were developed to reduce side effects
- Meltzer (2012)
- Still exist and are a significant weakness
- problems with the evidence
- Healy (2012)
- Suggested evidence is overstated as it has been published multiple times
- Because of calming effects its easier to say they have a positive effect
- Not denying its effects
- Lots of studies assess only the short term benefits
- Lack studies on long term effects of withdrawal
- Healy (2012)
- Chemical cosh argument
- Used by staff to calm patients rather then to benefit them
- Short term use to calm patients s recommended
- National Institute for Health and Clinical Excellence
- Often can be ethically questionned
- Moncrieff (2013)
- Evidence for effectiveness
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