biological therapy for schizophrenia Flashcards
what is the most common biological treatment for schizophrenia?
drug therapy
what are the drugs most commonly used to treat scz?
antipsychotics
what are antipsychotics?
drugs used to reduce the intensity of symptoms, in particular the positive symptoms, of psychotic disorders like schizophrenia
what are typical antipsychotics?
the first generation of drugs for schizophrenia and other psychotic disorders, having been used since the 1950s. they work as dopamine antagonists and include chlorpromazine
what is the main typical antipsychotic?
Chlorpromazine
what relationship does chlorpromazine have with dopamine?
it’s a dopamine antagonist
what is the usual dose for chlorpromazine?
800-1000mg
what are dopamine antagonists?
they work by blocking dopamine receptors in the synapses of the brain, reducing the action of dopamine
what does chlorpromazine do?
•sits on the post synaptic receptor sites
•the action potential is reduced, reducing the chance of the neuron firing
•reduces the effect of dopamine, reducing the chance of positive symptoms like hallucinations
how long does it usually take to see side effects from antipsychotics?
a month
limitation of typical antipsychotics: serious side effects!
•can lead to tardive dyskinesia- involuntary facial movements like grimacing, blinking and lip smacking
•dizziness, agitation, sleepiness, stiff jaw, weight gain, itchy skin
•could cause deaths
•treatments can cause harm
what are atypical antipsychotics?
drugs for schizophrenia developed after typical antipsychotics. they typically target a range of neurotransmitters such as serotonin and dopamine.
two examples of atypical antipsychotics
clozapine and risperidone
what is clozapine’s relationship with dopamine?
it is still a dopamine antagonist
how does clozapine work?
•a dopamine antagonist
•clozapine works in a similar way to chlorpromazine yet only binds to the D2 receptor site, reducing the chance of the patient developing tardive dyskinesia
•it unbinds from the receptor after about 3 days and binds to another D2 receptor site, allowing the receptor to still be stimulated
what is the dose for clozapine?
350-450mg
what is a side effect of clozapine?
it can cause a blood disease which has led to some deaths
what is Risperidone?
•given in small doses (3-4mg) , can be a pill or injection
•effective in only a few days
•can treat depressive symptoms (which have a comorbidity of 50%)
-it is more expensive then less effective drugs
evaluation points
+effective
-side effects
-issues of compliance
strength: effective
•drug trials- Thornley
•did a meta- analysis of 13 trials which showed that chlorpromazine was associated with better overall functioning and reduced symptom severity compared to a placebo
•meltzer concluded that clozapine is more effective than typical antipsychotics and other atypical antipsychotics, and that it is effective in 30-50% of treatment-resistant cases where typical antipsychotics have failed
•this means that, as far as we can tell, antipsychotics work
limitation: side effects
•dizziness, agitation, sleepiness, stiff jaw, weight gain, itchy skin
•tardive dyskinesia, involuntary movements such as grimacing, blinking and lip-smacking
•blood disease (possible death)
•heart arythmia
•seizures or fits, sexual dysfunction (erectile, loss of labido)
limitation: issues of compliance
•people would refuse to take the drug due to side effects or the fact that they have paranoid delusions and believe they’re trying to be poisoned
•or they might forget/ not have the capacity to take the drug every day
-> revolving door syndrome, regular relapses
•depot injection, injected into fat above the hip and slowly dissolves over a month.
•these are unethical as you can’t withdraw consent, the patient can’t remove the drug from their body
