L5 Antipsychotics Flashcards
(42 cards)
What are the 5 symptom domains of schizophrenia?
- pos
- neg
- anx/dep
- aggressive
- cognitive
What kind of symptoms are most distressing for an individual with schizophrenia?
Negative symptoms. In contrast, positive phases are characterised by lack of insight (self-awareness of abnormal behaviour)
Examples of positive symptoms of schizophrenia (4)
- Delusions, often paranoid
- Hallucinations eg. exhortatory voices
- Thought disorder including feeling that thoughts are controlled by an outside agency
- Abnormal behaviours eg. stereotypical or aggressive behaviour
What kind of symptoms are most disturbing to others, usually leading to first referral to a psychiatrist and detection of schizophrenia?
Positive symptoms, abnormal behaviours added
Examples of negative symptoms of schizophrenia (2)
- Withdrawal from social contacts
2. Flattening of emotional responses
As the disease progresses, which kind of symptoms generally dominates?
Negative symptoms, normal behaviours subtracted
Why is cognitive dysfunction an important symptom of schizophrenia?
Predicts level of social and vocational functioning and hence, treatment outcome, better than positive symptoms
- Persistent core feature of the disease, not iatrogenic
What are some evidences suggesting that schizophrenia might be a neurodevelopmental disorder?
- Onset in late adolescence/early adulthood is consistent with neurodevelopmental abnormality involving cortio-cortical pathways
- Evidence of enlarged ventricles, abnormalities in laminar organisation of cortical cells
Neurochemical theories (3)
Primarily theories of the positive symptoms
- Dopamine Theory
- 5-HT (Serotonin) Theory
- Glutamate Theory
What is the most important basis for pharmacotherapy of schizophrenia?
All antipsychotic drugs are D2 antagonists - the dopamine theory
What is the dopamine theory?
Amphetamine produces symptoms similar to acute schizophrenia
What are the dopamine pathways of the brain? (4)
- Nigrostriatal
- Mesolimbic
- Mesocorticol
- Tuberoinfundibular
What is the MOA for many of the newer antipsychotics?
5-HT2 antagnosim - the serotonin theory
What is the serotonin theory?
LSD, a 5-HT2 agonist, produces symptoms similar to acute schizophrenia
What is the glutamate theory?
Drugs that block the NMDA receptor channel eg. phencyclidine (PCP) and ketamine, produce symptoms similar to acute schizophrenia
Which typical antipsychotic has a better side effect profile? Chlorpromazine or Haloperidol
Haloperidol
What are the side effects of chlorpromazine?
- M1: dry mouth, constipation, blurred vision
- H1: sedation, weight gain
- a1: postural hypotension, dizziness
What causes the EPS of D2 antagonist drugs?
Action on the extrapyrimidal motor pathways, almost simulating the same deficit as Parkinson’s
Which of dyskinesia/akathisia correlates directly with duration on medication?
Akathisia, not dyskinesia
What is the EPS side effect that occurs in 20-40% of patients on typical antipsychotics?
Tardive dyskinesia and akathisia
Why is tardive dyskinesia and akathisia often irreversible?
Most probably de to upregulation or supersensitivity of dopamine receptors in the nigrostriatal system
What is dyskinesia?
Repetitive and stereotyped involuntary movements of face, tongue, and limbs
What is akathisia?
Involuntary movements and compulsion to act, associated with restlessness, anxiety, and agitation
Examples of typical antipsychotics (4)
Chlorpromazine, haloperidol, trifluoperazine, fluphenazine
