Psychosis Flashcards
State the definition of psychosis.
Clinical state of mind characterised by loss of contact with reality. Patients might experience perceptual disturbances (e.g. hallucinations, delusions).
Negative symptoms -blunting of affect, avolition, alogia.
Social or occupational dysfunction.
Clear sensorium
What is the difference between hallucinations and delusions?
Delusions are fixed unshakeable beliefs.
Hallucinations are perceptions without adequate stimuli.
What are the symptoms of delirium?
Medical emergency
Impaired awareness, confusion, disorientation
Others: restlessness, agitation, hallucinations, aggressiveness, ANS symptoms
List the causes of delirium.
DIMTOP
Drugs, Infections, Metabolic, Trauma, Oxygen, Psychological
Explain the pathogenesis of psychosis.
Dopamine hypothesis of schizophrenia - excessive dopaminergic activity.
Increased dopamine activity at mesolimbic pathway: leads to positive symptoms (hallucinations, delusions, thought disorders)
Nigrostrial pathway: often affect by antipsychotic treatment which can lead to motor side effects (Parkinsonism)
Tuberinfundibular pathway: involved in regulation of prolactin secretion (dopamine blockage can lead to hyperprolactinemia as side effect)
What are the causes of psychosis?
Functional psychosis
- schizophrenia
-bipolar mood disorder
Psychotic disorders due to medial conditions
- medical conditions (epilepsy, Alzheimer’s dementia, HIV, neurosyphilis)
- illicit drugs (cannabis, mantras, cocaine, amphetamines)
-prescription (steroids, antiparkinsonism, atropine)
Other
- postpartum psychosis
Outline the approach to management of psychosis.
Depends on aetiology and onset of psychosis.
Acute:
- goals of therapy is to clam the patient down and achieve containment
-antipsychotic and/or benzodiazepine
Chronic:
- goals of therapy is to prevent relapse of acute psychotic symptoms
- antipsychotic drugs & supportive psychotherapy for patient and family
Name the two main classes of neuroleptics? And what is there mechanism of action?
Classical neuroleptics
- dopamine 2 receptor antagonists
- tendency to cause extra pyramidal side effects
Atypical neuroleptics
- D2 and D3 receptor antagonists
- D2 and serotonin receptor antagonist
What are the indications for neuroleptics?
Primary:
- schizophrenia, mania, organic psychosis
Others:
- nausea + vomiting, intractable hiccups, Tourette’s syndrome, behaviour disorders, anaesthesia
Name of the different classes (with examples) of traditional neuroleptics.
Phenothiazines
- alipathic (chlorpromazine)
- piperazine (fluphenazine, prochloperazine)
- piperidine (thioridazine)
Butyrophenones
- haloperidol, droperidol
Thioxanthenes
- flupenthixol, zuclopenthixol
In which cases is the short acting vs long acting depot preparations injectable performed?
Short acting - acute management
Long acting - preferred if compliance is a problem
List the indications for using chlorpromazine.
Schizophrenia
Mania
Organic psychosis
Transquilization in emergency aggressive behavioural disturbances
What are the contraindications of chlorpromazine?
In coma, severe mental depression, severe liver impairment, significant cardiac disorders, glaucoma, bone marrow depression
Name the oldest neuroleptic of low potency.
Chlorpromazine
What are the adverse effects of chlorpromazine?
EPSEs, sedations, postural hypotension, anticholinergic side effects, epileptogenic, photosensitivity, jaundice, agranulocytosis
Which drug classes does chlorpromazine have drug interactions with?
Anticholinergics
Anti-epileptics
Anti hypertensives
Anti Parkinsonism
CNS depressants
Enzyme inducers
What is onset of action in chlorpromazine? Also mention their half life. `
Onset 30-60 hours after oral ingestion and 15min after injections
At what doses should chlorpromazine be taken?
Initially 25mg TDS but maintenance range 75-300mg
IM 25-50mg be respected 3-4 times in 24 hours as necessary
Name a very potent antipsychotic drug.
Haloperidol
In which patients is haloperidol contraindicated?
In Parkinson’s and patient with history of EPSEs from neuroleptics
What are the adverse effects of haloperidol?
Less anticholinergic, hypotensive, least epileptogenic but increased risk of EPSEs
Which drug does haloperidol have drug interactions with?
Lithium -neurotoxicity
What are the adult doses of haloperidol ?
Initially 0.5 - 5mg 2-3 times daily then reduce to lowest effective dose. Usual maintenance dose is 2-10mg daily
Describe the onset of action of haloperidol . Also mention its half life.
Onset of action - 10 minutes after IM injection
Max 4-6 hours after oral ingestion.
Half life 13-35 hours. Metabolised in liver extensively
