IC11 Schizophrenia, psychosis (X) Flashcards
(48 cards)
what is the DSM-5 diagnostic criteria for schizophrenia?
- 2 or more +ve/-ve symptoms for ≥1 month
- functional impairment
- continuous signs for ≥6 months
- exclusion of schizoaffective or mood disorder
- disorder NOT due to medical disorder or substance abuse
what are some positive symptoms of schizophrenia?
- delusions
- hallucinations
- disorganized speech & behaviour
- catatonic behaviour (can look like: not responding to other ppl/env, holding their body in unusual position, not speaking, resisting ppl who try to adjust their body, agitation)
what are some negative symptoms of schizophrenia?
- cannot experience pleasure (anhedonia)
- cannot initiate goal-directed activities (avolition)
- monotone speech (little or no change to tone), no change in facial expression, even if talking abt sth upsetting/exciting (affective flattening)
what are some non-pharmacological treatment for schizophrenia?
- cognitive behavioural therapy (CBT)
- electroconvulsive therapy (ECT) for treatment-resistant schizophrenia
- psychosocial rehab to increase adaptive functioning
what are the drugs used to treat schizophrenia?
antipsychotics (thought organizers)
how do they generally work?
in schizophrenia/psychosis, there is elevated DA levels –> therefore, antipsychotics are used to lower DA levels
are medications required long term?
yes; often life-long maintenance therapy
what happens if patient is non-adherent to med / suddenly stop bc they feel better?
high risk of relapse;
relapse will occur only a few weeks after discontinuation as antipsychotics are stored in fat tissue and can slowly be released into the bloodstream when discontinued
what are some methods to overcome antipsychotic non-adherence?
- IM long acting injection (LAI)
- community psychiatric nurse
- patient & caregiver education
what is the treatment algorithm for schizophrenia?
diagnosis –> initiate a single FGA/SGA
if inadequate or no response after adequate trial –> use another FGA/SGA
if still inadequate or no response after adequate trial –> clozapine
why is clozapine reserved only as last line?
due to risk of agranulocytosis that requires frequent FBC monitoring
what is considered an ‘adequate trial’ of antipsychotics?
at least 2-6 weeks at therapeutic dose
clozapine: up to 3m at therapeutic dose
what is the main limiting factor when using antipsychotics?
adverse effects
how can we manage the AEs?
lower dose or switch agent
what are some precautions when initiating antipsychotics?
- CVD (esp QTc prolongation)
- PD
- epilepsy, conditions predisposing to seizures
- depression
- myasthenia gravis
- BPH
- angle-closure glaucoma
- severe respiratory disease
- hx of jaundice
- blood dyscrasias (esp for clozapine)
- elderly with dementia
*refer to notes for detailed explanation - may help to understand and memorise
how can we deal with a schizophrenic patient who is acutely agitated?
give benzos/antipsychotic to calm them down - route of administration depends on whether patient is cooperative or not
if patient is cooperative while agitated, what are the agents available to calm them down?
- PO lorazepam 1-2mg
- PO antipsychotic (haloperidol + pre-treatment ECG, risperidone, quetiapine, olanzapine)
if patient is uncooperative while agitated, what are the agents available to calm them down?
- IM lorazepam 1-2mg
- IM antipsychotic (olanzapine, aripiprazole, haloperidol)
- IM promethazine
- combination (lorazepam/promethazine + haloperidol)
what do we need to take note of when giving these agents?
olanzapine & lorazepam cannot be given within 1h of each other due to risk of cardiorespiratory death
if patient is catatonic, what can we give them?
PO/IM lorazepam
if patient is depressed, what can we give them?
antidepressant
describe PK of oral antipsychotics
- fast onset due to short Tmax
- OD dosing possible due to long half-life for most drugs
what are some drugs whose doses cannot be consolidated to OD dosing and why?
clozapine, quetiapine, chlorpromazine, amisulpride, ziprasidone
due to risk of hypotension & seizures
what does ‘decanoate’ in haloperidol decanoate tell us?
decanoate = esterified with long aliphatic chain = allows antipsychotic to be slowly released into bloodstream over 4 weeks = long acting (LAI)
