16 - Antipsychotics Flashcards
(31 cards)
What is schizophrenia
Disorder of higher cognitive function
What kind of abnormalities in the brain lead to schizophrenia
Structural
Neurochemical
What are some risk factors for schizophrenia (5)
Genes Prenatal factors Early-life stress Drugs Stressful life events
What are the positive symptoms of schizophrenia (3)
Hallucinations
Delusions
Disorganised thought and speech
What are the negative symptoms of schizophrenia (4)
Flattened affect
Alogia
Avolution/apathy
Anhedonia
What are the cognitive symptoms of schizophrenia
Impaired memory
Impaired executive function
What are some physical treatments for schizophrenia
Frontal lobotomy
Electroconvulsion therapy
What are indications of antipsychotics
Treatment of psychosis and symptoms of schizophrenia
Treatment of schizophrenia in ‘treatment resistant patients who fail to respond to other antipsychotic drugs’
What was the first antihistamine
Chlorpromazine
What do antipsychotics antagonist
D2 receptors
What is the correlation between therapeutic efficacy and affinity for D2 receptors
Linear
When is clinical efficacy of D2 drugs achieved
Receptor occupancy up to 80%
What are arguments for ‘excess levels of dopamine increase neurological activity leading to schizophrenia’ 1.
- Amphetamines and other dopamine-releasing drugs induce a state resembling the positive symptoms of schizophrenia
- Antipsychotic drugs antagonise D2 receptors
What are arguments against the ‘excess dopamine’ hypothesis 1.
- No evidence of increased dopamine turnover in schizophrenic brain
- Inconsistent changes in concentrations post-mortem
What are arguments for increased dopamine receptors in schizophrenia 2.
- Increased dopamine receptors are found in schizophrenia brain
- Increased binding and affinity of DA in schizophrenic brain
What are arguments against increased dopamine receptors in schizophrenia 2.
Antipsychotics upregulate DA receptors
What is the dopamine hypothesis of schizophrenia 3.
Elevated presynaptic striatal dopamininergic function is the final common pathway in psychosis
What is the dopamine hypothesis of schizophrenia 4.
GABAergic deficit in hippocampus underlies DA dysregulation in the nucleus accumbens and medial prefrontal cortex
What are some presynaptic DA abnormalities
1) DA levels, synthesis or release are elevated in key brain areas
2) Deficiencies in other neurotransmitters lead to DA dysregulation
3) D2 receptors are supersensitive, blockade reduces overactivity and alleviates psychosis
What do the different dopamine pathways mediate
Mesolimbic - therapeutic
Nigrostriatal - movement side effects
Tuberoinfundibular - endocrine
What are the three major classes of
first generation antipsychotics
- Phenothiazines
- Butyrophenones
- Thioxanthenes
What are major classes of second generation antipsychotics
Diazepines Dibenzothiapines Benzamides Benzisoxazols Quinolinone derivative
Which antipsychotics have better therapeutic efficacy (2)
Atypical antipsychotics
Fewer side effects
Effective in ‘treatment resistant’ patients
What are the receptor actions of atypical antipsychotics
High-affinity of 5HT2 receptors
Moderate affinity for adrenergic and D3 receptors
