Psychosis Flashcards
define psychosis
clinical state of mind characterised by loss of contact with reality
explain the 2 perceptual disturances that the pt might eperience ?
delusion : are fixed unshakeable beliefs
Hallucinations : are perceptions without adequate stimuli e.g. hearing voices or seeing dead people
what negative symptoms they might experience ?
- blunting of affect
- Avolition (lackk of motivation to complete tasks )
- alogia ( inability to speak because o cognitive impairement ,mental confusion or aphasia)
what to do when pt has delirium with acute confusion and aggression ?
delirium is dengerous more than psychosis because with psychosis the LOC is normal but with delirium they can not maintain normal LOC-> this is a medical emergency
- always look for a cause -> DIMTOP (drugs, infection, metabolic, trauma, oxygen, psychological)
-> OTHER SYMPTOMS :Impaired awareness, confusion, disorientation others (restlessness, agitation and hallucinations, ANS symptoms,aggressiveness )
explain the pathogenesis of psychosis
UNknown
-Dopamine hypothesis of schizophrenia
Excessive dopaminergic activity
- role of dopamine : the dopamine hypothesisi :
-used to explain that the unusual behaviours in psychosis can be largely explained by dopamine function changes in the brain .
name the 2 functional psychotic conditions
-Schizophrenia
-Bipolar mood disorder
what causes pyschotic disorders
- medical conditions such as epilepsy, Alzheimer’s dementia, HIV, neurosyphilis,urimia(renal failure),encephalytis
- drugs :
- Illicit drugs –cannabis, mandrax, cocaine, amphetamines(over the counter ,all diet tablets contain them ),PCP(Phencyclidine aka angel’s dust),psilocybin (magic mashrooms ),alcohol( delirium tremors (happens 36 hours later ),thymine definciency and can cause hypoglycaemia in people with poor diet )
-Prescription drugs- steroids, antiparkinsonism drugs, atropine(anticholinergic ),lithium,all the opiods,Ketamine( used in anesthesia ,excelent analgesic,causes dissociation) - others: e.g. postpartum psychosis
mane the 4 major pathways by which dopamine affects the brain and their function
1.mesolimbic pathway - resiponsibile for the negatve symptoms in Schiezophramia -> hyperactive in Schiezophrania -> hallucinations and delusion
2. Mesocortical pathway -> responsible for the positive symptoms of schizophrenia ->behaviour ( symptoms such as lack of motivation and social withdrawal )->underactive in Schiezo
3. Nigrostrial->coordination of voluntary movement->blocked by typical antipsychotics ->extra[yramidal symptoms (deficiency of Dopamine in this pathway can lead to dystonia and parkinson’s symptoms while excess causes dyskinetic symptoms .
- Tuberoinfindibular- prolactin secretion -> dopamin in this pthway is responsible for inhibition of prolactin secretion from the pituitary gland .
what are the indications for neuroleptics ?
Primary
Schizophrenia
Mania
Organic psychosis
Others
Nausea and vomiting
Intractable hiccups
Tourette’s syndrome
Behaviour disorders
Anaesthesia
explain the approach to management of psychosis
- Depends on : aetiology and onset of the pyschosis
- Acute management (agitated or acutely disturbed pt)
Goals of therapy is to calm pt down and achieve containment.
Antipsychotic and/or benzodiazepine of your choice - Chronic management :
Goal of therapy is to prevent relapse of acute psychotic symptoms i.e. delusions, hallucination so as to maintain functionality
- Antipsychotic drugs
- Supportive psychotherapy for patient and family
what is the difference between classic and atypical neuroleptic drugs ?
dopamine receptors that they target .
- classical neuroleptics : (they have high affirnity except for chlorpromazine and Thioridazine )
Dopamine 2 receptors antagonists ,they have the tendency to cause extrapyramidal side effects .
-Atypical neuroleptics :
D2 and D3 receptors antagonists
and D2 (bind weakly )AND serotonin receptor antagonist(strongly ).
List the traditional neuroleptics (classic neuroleptics )
- Phenothiazines (side chain)
- Aliphatic e.g. chlorpromazine
- Piperazine e.g. prochloperazine, fluphenazine
- Piperidine e.g. thioridazine*(discontinued due to cardiotoxicity), pericyazine. - Butyrophenones
- Haloperidol, droperidol - Thioxanthenes
- Flupenthixol, zuclopenthixol
what is the formulation for typucal neuroleptics ?
- Oral
- Injectable - usually IM injection.
- short acting - acute management
-long acting depot preparations -preferred if compliance a problem.
explain the mechanism of action for typical antipsychotics
Block the D2 and D1 receptors .
This drugs have high affinity (bind strongly on the receptors )
Side effects :
1. D2 receptor antagonism -> affects the nigrostriatal pathway (mostly high affinity drugs than low )-> causes extrapyramidal ( dystonia , akathisia, parkinson sx)
2. Antimuscarinic effects (low>high)->dry mouth , constipation, blurred vision ,urinary retension .
3. Blocks 5-HT2 (5-hydroxytryptamine )receptors ->mood ,digestion ,sexual health ,sleep-wake cycle , Nausea
4. Alpha 1 receptors antagonist (low>high)->orthostatic hypotension
5. Histamine H receptor antagonist (low>high)
-Weight gain and sedation .
what is the potency, duration of onset ,half life and doses for Chlorpromazine?
- potency : low ( this is the oldest neuroleptic of low potency )
- half life : 30 hrs
- duration of onset : 30-60min after oral ingestion and 15min after injection
-Doses : initially 25mg tds but maintenance range 75-300mg.
IM 25-50mg ,can be repeated 3-4 times in 24hrs as necessary
USE THE LOWEST EFFECTIVE DOSE
