Schizophrenia Flashcards
What are the usual ages of onset in men and women?
20-28 years in men
26-32 years in women
How is schizophrenia diagnosed?
Questionnaires
What may be seen on a brain scan of a patient with schizophrenia?
Ventricular dilation - possibly due to loss of brain tissue
What are the risk factors for schizophrenia?
Genetics - number of susceptible genes usually affecting synaptic function
Environmental - Prenatal problems, obstetric complications, urban/city births, stressful events, drug abuse
When do schizophrenia symptoms usually start to appear?
When a number of risk thresholds have been crossed
What are the positive symptoms of schizophrenia?
“Added”
Hallucinations, delusions, disorganised speech
From increase in dopamine in mesolimbic pathway
What are the negative symptoms of schizophrenia?
“Taken away”
Decreased emotions, motivation and interests
Less thoughts, speech, pleasure
Thought to do with the cortex
What are the potential cognitive deficits of schizophrenia?
Lack of attention
Loss of working and verbal memory
Loss of executive function
What is the dopamine theory for schizophrenia?
Increased dopamine in subcortical pathways leads to psychosis
D2 receptors are inhibitory, increased dopamine increases inhibition leading to psychosis
What is the downside of using D2 antagonists for psychosis?
Dopamine level remains the same so if antagonist is withdrawn, psychosis comes back
What is the glutamate theory for schizophrenia?
Glutamate activates NMDA receptors which activates GABA neurones
Glutamate stimulates dopamine neurones, GABA action modulates release
Hypofunction of NMDA receptors results in lack of GABA so increased dopamine
What could be causes of NMDA hypofunction?
Genetic and non-genetic factors in early development
Phencyclidine
What would be tried first for schizophrenia treatment?
CBT - Before or synergistic with antipsychotic treatment
Arts therapy may be tried for negative symptoms
How should antipsychotic trialling work?
Try optimal dose for 4-6 weeks
Advise patient they may take 2-3 weeks to work and not to stop taking
What may be a side effect of the dopamine increase and what should be done to treat it?
Prolactin increase
Give aripiprazole or a dopamine agonist or use alternative antipsychotic
What are the QT wave limits for patients using antipsychotics?
440ms for men
470ms for women
When may depot formulations be used?
Patient preference
If issues with compliance
Why should caffeine and smoking be avoided when using antipsychotics?
Smoking induces CYP1A2
Caffeine competitively inhibits CYP1A2
What is the MoA for typical antipsychotics?
High affinity for D2 receptor - antagonist
What is the MoA for atypical antipsychotics?
High affinity for serotonin (5-HT2) receptors but also acts as antagonist at D2 receptors
What is the main difference in efficacy of typical and atypical antipsychotics?
Atypical antipsychotics may also have an effect on negative symptoms due to 5-HT2 action
What are the main side effects of typical antipsychotics?
Motor control impairments: Muscle spasms Pseudo-parkinsonism Restlessness Lip smacking or chewing Tongue protrusion
When may anticholinergics be used with typical antipsychotics?
Muscle spasms and pseudo-parkinsonism
Give some examples of typical antipsychotics
Haloperidol Chlorpromazine Trifluoperazine Perphenazine Flupenthixol Zuclopenthixol Sulpiride
What are the main side effects of atypical antipsychotics?
Metabolic side effects: Increased weight Increased blood glucose Increased lipid levels Agranulocytosis
Give some examples of atypical antipsychotics
Quetiapine Olanzapine Clozapine Asenapine Risperidone Paliperidone Lurasidone Amisulpride Aripiprazole
What are the brands of clozapine available?
Denzapine
Clozaril
Zaponex
What are the monitoring requirements for clozapine?
WBC checks weekly for 18/52, fortnightly for weeks 18-52 and every 4 weeks after a year
BP
Pulse
Temperature
What is the traffic light system for clozapine?
Green - Within normal levels, continue as normal
Amber - WBC 3.0-3.5 x10^9 or neutrophils 1.5-2.0 x 10^9, continue but monitor twice a week
Red - Below min amber levels, stop clozapine and monitor for infection signs
How should clozapine be initiated?
Start at 12.5mg and slowly titrate up to max 300mg daily
If more than 300mg needed increase by 50-100mg weekly
What are the clozapine dose targets in male and female non-smokers and smokers?
250mg/day female non-smokers
350mg/day male non-smokers
450mg/day female smokers
550mg/day male smokers
