Antipsychotics Flashcards
What are the 4 key symptoms of a psychotic episode?
- Hallucinations
- Delusions
- Disrupted thought patterns
- Lack of self-awareness
Define schizophrenia.
Defined by the ICD10 as being characterized by distortions of thinking and perception; and of affect (the emotional response to stimuli/situations) inappropriate to the situation or blunted (i.e. reduced)
What is the diagnostic criteria for schizophrenia?
Disturbance lasts for six months or longer, with at least one month of at least two of the classical symptoms:
- Delusions (persecutory nature)
- Hallucinations (any sensory modality but mainly auditory)
- Disorganised/catatonic behaviour
- Negative symptoms
What are the negative symptoms of schizophrenia?
- Affective blunting
- Alogia
- Anhedonia
- Avolition
What are disorganisation syndromes?
Alterations in speech, thought patterning and behaviour commonly including:
- Thought insertion/withdrawal
- Thought echo
- Thought broadcasting
What are the positive symptoms of schizophrenia?
‘Hyper’ types of behaviour e.g. agitation, hallucinations and exaggerated behaviour
What do auditory hallucinations tend to be like in schizophrenic patients?
In the 3rd person like an external voice giving them direction or commenting on their behaviour
What are the classes of antipsychotic drugs?
- 1st generation (classical/typical): DA antagonist
- 2nd generation (atypical): DA antagonist
- 3rd generation: partial DA agonist
What is the only 3rd generation antipsychotic to date?
Aripiprazole
What are the main characteristics of 1st generation anti-psychotics?
Main target = DA D2 receptor
Also = H1, M1 + a1 adrenergic antagonists
Higher risk of neurological side effects
Not as effective at targeting -ve symptoms as +ve
What are the main characteristics of 2nd generation antipsychotics?
Main target = 5HT2 more than D2 receptor
Also = multiple 5HT, DA, M, H + a1 adrenergic receptor subtypes
Higher risk of metabolic (cholinergic) side effects but lower risk of extrapyramidal side effects
Thought to be better at targeting -ve symptoms but no evidence that they are better than 1st generation to date
What are the 4 dopamine (DA) pathways (from inner-outer brain)?
- Tuberohypophyseal
- Nigrostriatal
- Mesolimbic
- Mesocortical
Reduced dopamine (DA) in Parkinson’s disease cause what symptoms?
Reduced movement
Reduced emotions
Dampened personality
What is thought to be the main mechanism for psychosis?
Too much DA in the mesolimbic pathway
What are the main roles of the prefrontal cortex?
Planning Personality \+ve emotions Judgement Reasoning
What are the main roles of the limbic system?
-ve emotions Social recognition Spatial awareness Sensory perception Memory
Give some examples of 1st generation antipsychotic.
4 types:
- Butyrophenones e.g. Haloperidol
- Phenothiazines e.g. Chlorpromazine
- Thioxanthines e.g. Zuclopenthixol
- Dibenzodiazenes e.g. Sulpiride
Give some examples of 2nd generation antipsychotics.
Clozapine
Risperidone
Amisulpride
Aripirazole