Biological therapy (SZ) Flashcards
(14 cards)
What type of drugs are used to treat SZ?
-Anti-psychotics
a)What are the 2 types of anti-psychotics and b) what is the difference?
a)
-Typical
-atypical
b)
Typical are traditional older anti-psychotics
Atypical are second generation, newer anti-psychotics
What is an example of a typical anti-psychotic
-Chloropromazine
a) How is chloropromazine taken, B) dosage amount and C) side effects?
a) Chloropromazine can be taken orally with tablets or syrup or can be injected
b) maximum 1000mg but usually 400-800mg per day
c)
What does chloropromazine do that limits symptoms of SZ? (2)
1)antagonists to dopamine and therefore reduce dopamine by blocking dopamine receptor sites in the brain and leveling out dopamine across the brain which reduces hallucinations
2) Sedation effect by effecting histamine receptors which can calm people with SZ who are admitted to hospitals for the first time
What are the 2 examples of atypical drugs?
1) Clozapine
2) Risperidone
a) How is Clozapine taken and B) dosage amount
a) Taken orally
b) Dosage amount = 300-450mg per day
a) Why was the testing of Clozapine withdrawn in the 1970s and b) how is it allowed to be used now
a) A few people died in the trials of Clozapine due to a blood condition called agranulocytosis
b) People taking clozapine now have to have regular blood tests to ensure that do not have agranulocytosis.
How does Clozapine work?
-it binds dopamine receptor sites (same as chloropromazine)
-Also acts on serotonin and glutamate receptors
-It is also mood-enhancing and can reduce depression: significant as 30-50% of people with SZ attempt suicide at some point
A) How is Risperidone taken and b) dosage amount?
a) tablets, syrup and injection (lasting for 2 weeks)
b) 4-8mg and maximum of 12 per day
What receptor sites does risperidone act on?
-Binds dopamine and serotonin receptor sites
Why is it believed that risperidone has less side effects than other anti-psychotics?
-it binds more strongly to dopamine receptor sites than Clozapine
What are the strengths for biological therapy for schizophrenia?
-Evidence for effectiveness: Ben Thornley (2004) reviewed studies comparing the effects of chloropmazine to control conditions. Data from 13 trials with 1121 participants showed that chlropormazine was associated with better overall function and reduced symptom severity than placebo.
-Meltzer concluded that clozapine is more effective than typical anti-psychotics and other atypical anti-psychotics: effective in 30-50% of treatment resistant cases where anti-psychotics have failed
HOWEVER: David Healy (2012) has suggested serious flawas with evidence for effectiveness as only short-term effects are studied and some successful trials have been published multiple times which exaggerates the evidence.
What are the limitations of biological therapy for SZ?
-Serious side effects: Typical anti-psychotics are associated with side effects such as dizziness, sleepiness, agitation and weight gain and long-term can result in tardive dyskinesia, caused by dopamine supersensitivity and results in involuntary facial movements such as lip-smacking. Another serious side effect is neuroleptic malignant syndrome (NMS) believed to be caused by drugs blocking dopamine action in hypothalamus. NMS can result in comas and fatalities
-Mechanism unclear: not knowing how some anti-psychotics work. Understanding of how anti-psychotics work is around dopamine hypothesis. However, dopamine-hypothesis is not a complete explanation for SZ and some parts of the brain have too little dopamin, not too much. Also questions over effectiveness of the drugs and this adds to the argument that if they are ineffective.
