schizophrenia Flashcards
(15 cards)
What are the positive symptoms?
Increase in abnormal active behaviours:
- hallucinations
- delusions
- disordered thoughts
- language
- abnormality
- motor disorder
what are the negative symptoms?
absence of normal active behaviours occur prior to positive symptoms
- affecting blunting
- avolition
- anhedonia
- poverty of speech
- social withdrawal
- neglect of hygiene
what are the cognitive symptoms?
distubance of normal thought process
- poor excecution
- function and decision making
- recognition deficits
- memory problems
- attention deficits
How interactions lead to structural and functional deficits?
genetic predisposition and environmental insult —> neurodevelopment defect —> structural abnormalities —> functional abnormalities
How to treat with typical antipsychotics?
DA related include hormonal and extrapyramidal motor (on target side effects)
pseudoparkinsonism (early Parkinson’s like) eg bradykinesia, tremor
tardive dyskinesia (late Huntington’s like)
other motor effects (akathisia, dystonia)
increased prolactin release – sexual dysfunction
Non-DA (off target side effects)
sedation - antihistamine, anticholinergic (H1 mACh)
hypotension – central adrenergic (alpha 1)
peripheral autonomic – blurred vision, dry mouth, constipation (MACh)
How to treat schizophrenia with atypical antpsychotics?
Relatively low affinity for D2
Benzamides:
Olanzapine, Quetiapine, Risperidone, Ziprasidone, Quitiapine, Aripiprazole
Also Clozapine
Effective against both positive and negative
High affinity at 5HT2
High ratio 5HT2:DA may be desirable
Less side effects than Typical antipsychotics, especially motor effects.
but other side effects
weight gain
diabetes
Whats the role of 5HT in schizophrenia?
- Increased levels in
schizophrenics - LSD - 5HT agonist induces
hallucinations, cognitive
impairment, aggression - 5HT metabolites
(Dimethyltryptamine)
hallucinogenic - many neuroleptics are potent
5HT2 receptor blockers
Whata the role of glutamate?
- Neurodevelopmental change –
glutamate neurones affected - Disordered migration -
abnormal circuits - Neuronal and synaptic loss
- NMDA antagonists e.g.
ketamine, phencyclidine are
psychotomimetic - NMDA receptor knockout -
social withdrawal in mice - Reduced glutamate in CSF of
patients with active
schizophrenia - Loss of cortical glutamate
receptors in post mortem
schizophrenics
How to manage schizophrenia?
Offer an oral antipsychotic drug + psychological therapy
Start low and slowly titrate up to the minimum effective dose
The drug should be given at an optimum dose for 4-6 weeks before it is deemed ineffective
What are first generation antipsychotics and examples?
Act predominantly by blocking dopamine D2 receptors in the brain.
They are more likely to cause a range of side effects
e.g
Phenothiazide derivatives: chlorpromazine, fluphenazine, levomepromazine
Butyrophenones: haloperidol
Thioxanthenes: flupentixol, zuclopenthixol
What are second generation antipsychotics and examples?
Act on a range of receptors in comparison to 1o generation and are generally associated with a lower risk of acute extrapyramidal symptoms (EPS) and tardive dyskinesia (TD);
However, they are associated with other adverse effects such as weight gain and glucose intolerance
e.g
Amisulpride
Aripiprazole
Clozapine
Olanzapine
Quetiapine
Risperidone
How to prescribe antipsychotics for elderly?
Antipsychotic drugs should NOT be used in elderly patients with dementia, unless they are at risk of harming themselves or others, or experiencing agitation, hallucinations or delusions that are causing them severe distress.
The lowest effective dose should be used for the shortest period of time.
Treatment should be reviewed regularly; at least every 6 weeks (earlier for in-patients).
What to consider when prescribing antipsychotics for people with learning disabilities?
A reduction in dose or the discontinuation of long-term antipsychotic treatment;
Review of the patient’s condition after dose reduction or discontinuation of an antipsychotic drug;
Referral to a psychiatrist experienced in working with patients who have learning disabilities and mental health problems;
Annual documentation of the reasons for continuing a prescription if the antipsychotic drug is not reduced in dose or discontinued.
What are extrapyramidal symptoms?
- Parkinsonian symptoms
(including bradykinesia,
tremor) - Dystonia (uncontrolled muscle
spasm in any part of the body) - Akathisia (restlessness) - may
be mistaken for psychotic
agitation - Tardive dyskinesia (abnormal
involuntary movements of lips,
tongue, face, and jaw)- in
some patients it can be
irreversible
What to look out for with clozapine (high risk drug)
Clozapine should be offered if schizophrenia is not controlled despite the sequential use of at least 2 different antipsychotic drugs
MHRA/CHM advice: potentially fatal risk of intestinal obstruction, faecal impaction, and paralytic ileus
MHRA/CHM advice: monitoring blood concentrations for toxicity (blood tests to manage the risk of agranulocytosis), such as when:
a patient stops smoking or switches to an e-cigarette;
concomitant medicines may interact to increase blood clozapine levels;
a patient has pneumonia or other serious infection;
reduced clozapine metabolism is suspected;
toxicity is suspected.
