Anti-psychotics Flashcards
What is schizophrenia and how is it charecterized?
A psychotic disorder that at a miniumum consitists of dellusions and hallucinations
Charecterised by distortions of thinking and perception. It affects the emotionial response to stimuli/situations, becoming inapproprite or blunted
What are the 5 diensions of symptoms shown by Schizophrenic sufferers?
Posititve symptoms
Negitive symptoms
Cognitive symptoms
Agressive symptoms
Depression and anxiety
What is required for a diagnosis of Schizophrenia to be reached?
Disturbance lasting for 6 months or longer with at least one of the classical symptoms, delusions, hallucinations, disorganised or catatonic behavior or negitive symptoms
Name 5 classical symptoms of Schizophrenia
Thought echo/instertion/withdrawal
Delusional perception and control
Hallucinatory voices that comment or discuss the patient in the third person
Though disorders
Influence or passivity
Give 4 ‘negitive’ symptoms of Schozophrenia
Affective blunting = reduced emotional reactivity
Ahedonia = loss of enjoyment or intrest in previously enjoyed activites
Alogia = Loss of the ability to speak
Apathy = Absence or supression of emotion feeling, concern or passion
Give 5 positive symptoms of Schizophrenia
Delusions
Hallucinations
Agitation
Exaggerated/disorganised speech
Exaggerated/disorganised bizzare behavior
What anatomical alreations can be see in Schizophrenia?
Imbalance in transmitter levels are thought to underpin schizophrena (dopamine)
Degeneration occurs within the grey matter - particularly within the medial temporal lobes
Enlarged ventricles and sulci are apparent on scanning as a result
Cerebral blood flow is reduced in the basal ganglia and frontal lobes
What is the target for antipsycotics?
Dopamine receptors
Dopamine antagonists have been proven to calm Schizophrenic patients
What is the major problem with antipsychotics?
Less effect on negitive symptoms
60% of patients still suffer these even when the negitive symptoms are under control
What are the two groups of antipsychotics?
First generation - Classical
Second generation - Atypical
What receptors do first generation antipsychotics act on?
Primarily potent antagonists at the D2 receptor
Also act on Muscaranic, Histamine, and Adrengic receptors
Low efficacy and 30% of patients are non-responders
What are the 4 main groups of first generation antipsychotics?
Phenothiazines
Butyrophenones
Thioxanthines
Dibenzoiazenes
Second generation antipsychotics were initially delveloped to around 5HT and dopamine antagonism, however they have been found to act on other receptors. What are these receptors?
Multiple receptor subtypes of 5HT and Dopamine
Muscarinic, histminergic and aderenergic receptors
May also inhibit reuptake mechanisms
What is the gold standard second generation Antipsychotic?
Clozapine
High efficancy but has the most associated side effects (cardiovascular)
Also causes Agranulocytosis
Generally only used after at least 2 second generation antipsychotics have been shown to be ineffective
Which two second generation antipsychotic drugs are the most effective at tacking negitive symptoms?
Risperidone and Olanzapine
Risaperidone can be classed as both a first and second generation antipsychotic. Why is this?
What other uses/benfits does this drug have?
Shows biphasic activity. Atypical at low doses and more conventional at higher doses.
Used to treat dementia
Can be used in children and adolescents
Name first (2), second (3) and third generation (1) antipsychotics
1st = Chlorpromazine, Haloperidol
2nd = Amisulpride, Risperidone, Clozapine
3rd = Aripiprazole
What are the majority of side effects seen with antipsychotics called?
What are they a result of?
Extrapyramidal symptoms
As a result of altering activity within the nigrostrital pathway
Give examples of 3 extrapyramidal symptoms caused as a side effect of antipsychotics
Dystonias
Akathisia
Parkinsonisms
What are the side effects of antipsychotics?
Extrapyramidal symptoms
Sedation
Seizures
Hypotension
Hypothermia
Hypersensitvity
Weight gain
Why are second generation antipsychotics associated with seeing reduced side effects?
2nd generation antipsychotics have a higher affinity for the mesolimbic and cortical pathways than the nigrostriatal dopaminergic pathways.
What is neuroleptic malignant syndrome?
Describes the side effects associated with the use of antipsychotics in patients with a genetic polymorphism of the D2 receptor
High fever, autonomic problems, and altered consciousness
Where a patient presents with neuroleptic malignant syndrome, how can the side effects caused by the use of antipsychotics be treated?
Dopamine agonists and benzodiazepines can be used following immedate withdrawal of the antipsychotic
What is Tardive dyskinesia?
Disabling invoulentary movements of the face and limbs: tounge protruding, grimacing and twisting of the face and limbs
Only side effect that is irrevesible - spontanelously remitts in 30% of presentations
What causes Tardive dyskinesia?
A result of oxidative neurodegneration caused by increased glutamatergic transmission wich results from a down-regulation of the dopamine system
Caused by prolonged use of classical antipsychotics
What would be the action you would take on presentation of Tardive dyskinesia?
Withdraw the classical antipsychotic
Switch to a atypical antipsychotic
Immediately stop any anticholinergics being used
What dopamine pathway is involved in the pathogenesis of schizophrenia?
Mesolimbic and Mesocortical
Which of the dopamine pathways are used in parkinsonism?
Striatongral
What substances can induce iatrogenic parkinsonism?
Antiemetics
Antiepileptics
Cardiovascular agents
Vestibular Seditives
