Psychosis Flashcards
What are positive type 1 symptoms of psychosis?
Auditory hallucinations
Delusions
Thought disorders
Thought broadcasting
What are negative type 2 symptoms of psychosis?
Lack of drive
Social withdrawal
Motor disturbances (catatonia)
What are negative type 2 symptoms of psychosis?
Lack of drive
Social withdrawal
Motor disturbances (catatonia)
What drugs act as agonists to dopamine receptors?
Amphetamines
What drugs act as agonists to serotonin receptors?
LSD
What drugs act as an antagonist to glutamate receptors?
Phencyclidine
Name a drug that antagonises the effect of dopamine
Reserpine
How does reserpine decrease the effect of dopamine?
It removes dopamine from the synaptic vesicles
How will amphetamines affect schizophrenia and Parkinson’s?
Exacerbates schizo
Decreases Parkinson’s
How will reserpine affect schizophrenia and Parkinson’s?
Exacerbates Parkinson’s
Decreases schizo
Which dopamine receptors do amphetamine and reserpine act on?
D2 receptors
List the 5 dopaminergic pathways on the brain
Ventral Tegmental area
Mesocortical
Mesolimbic
Nigro-striatal
Tubero-infundibular
What symptoms of schizo are caused by hyperactivity of the mesolimbic pathway?
Positive symptoms (hallucinations etc)
What symptoms of schizo are caused by hypoactivity of the mesocortical pathway?
Negative symptoms (social withdrawal)
What receptor antagonist will reduce the positive symptoms of schizophrenia?
D2 receptor antagonist
Name 3 types of drug that are typical D2 receptor antagonists
Phenothiazines
Thioxanthines
Butyrophenones
Name 3 drugs that are phenothiazines
Chlorpromazine
Thioridazine
Trifluoperazine
Name a drug that is a thioxanthine
Flupenthixol
Name a drug that is a butyrophenone
Haloperidol
Why is it not beneficial to have a very high D2 affinity receptor antagonist?
It can be so effective that it causes hypokinestic disorder effects!
Name a typical drug that has a very high D2 receptor affinity
Haloperidol
What is the effect of typical D2 antagonists on the mesolimbic pathway?
Neuroleptics prevent hallucinations
What is the effect of typical D2 antagonists affect the nitro-striatal system?
Neuroleptic induce movement disorders
What is the effect of typical D2 antagonists on the tuberoinfundibular system?
Neuroleptics cause hyperprolactinaemia
What is the effect of typical D2 antagonists on the tuberoinfundibular system?
Neuroleptics cause hyperprolactinaemia
What are the extra pyramidal symptoms of typical neuroleptics?
Parkinsonian-like
Dystonia
Tardive dyskinesia
Akathesia
How do typical neuroleptics affect H1 histamine receptors?
They block H1 receptors, act as anti-histamines
What is orthostatic hypertension?
Blockage of alpha 1 receptors:
Dry mouth, glaucoma, constipation, urinary hesitancy
What is neuroleptic malgnant syndrome?
Emergency from use of antipsychotic drugs, muscle rigidity, fever, autonomic dysfunction
What are the autonomic side effects of typical neuroleptics?
Orthostatic hypertension
Aplastic anaemia
Neuroleptic malignant syndrome
What are the autonomic side effects of typical neuroleptics?
Orthostatic hypertension
Aplastic anaemia
Neuroleptic malignant syndrome
Is the nucleus accumbens part of the mesolimbic or mesocortical pathway?
Mesolimbic (positive symptoms)
Does lack of dopamine in the prefrontal cortex cause positive or negative symptoms?
Negative symptoms
Does lack of dopamine in the prefrontal cortex cause positive or negative symptoms?
Negative symptoms
What is the effect of typical neuroleptics on positive schizo symptoms?
Decreases positive symptoms
What is the effect of typical neuroleptics on negative schizo symptoms?
Does not decrease negative symptoms
What is the difference between typical and atypical neuroleptic drugs?
Atypical neuroleptics cause fewer extra pyramidal symptoms
They only occupy 30% of D2 receptors (reduced affinity)
What are the 3 main groups of atypical neuroleptics drugs?
Dibenzazepine
Bensisoxazole
Third generation
Name 3 atypical dibenzazepine neuroleptics
Clozapine
Olanzapine
Quetiapine
Name 2 atypical bensisoxazole neuroleptics
Risperidone
Paliperidone
Name 2 3rd generation neuroleptics
Ziprasidone
Aripiprazole
How does Clozapine, an atypical neuroleptic, affect positive and negative symptoms of schizo?
It decreases the positive and negative symptoms
How do atypical neuroleptics decrease positive and negative symptoms of schizo?
They block serotonin receptors as well as D2 receptors - serotonin blocks the release of dopamine, so less serotonin means that more dopamine is present in parts of the brain that require it
What is an extrapyramidal symptoms of atypical neuroleptics?
Hyperprolactinaemia
How do leuroleptics cause hyperprolactinaemia?
Dopamine in the tuberoinfundibular pathway prevents the production of lactate - D2 antagonists will increase it
What are the autonomic side effects of atypical neuroleptics?
Orthostatic hypertension
Weight gain
Increased glucose and lipid levels (leads to type 2 diabetes)
QT interval prolongation
What specific symptoms does clozapine cause?
Agranulocytosis - no production of granulocytes
Do high affinity neuroleptics have autonomic side effects?
No, low affinity neuroleptics tend to have more autonomic side effects
Is aripiprazole, an atypical neuroleptic, a D2 antagonist or agonist?
Apripiprazole is a partial D2 agonist
How does aripiprazole work?
It is a partial agonist for pre synaptic D2 receptors,
It is a weak antagonist of serotonin receptors - means that at low concentrations of dopamine it agonises, however at high concentrations (such as in schizo), it antagonises by preventing the agonist from working at its full extent. Means there is always a low activity of dopamine at the receptors, only when it is excessively high it actually stops it.
Which are preferred as first line treatment, typicals or atypicals?
Atypicals
Why would aripiprazole be preferred even if it doesn’t completely block dopamine receptors?
Has very little extrapyramidal side effects
