Antipsychotics Flashcards
What 4 characteristics are seen in a period of psychosis?
Delusion
Disrupted thought patterns
Hallucination
Lack of self-awareness
What are the 5 main domains of symptoms seen in schizophrenia?
Positive symptoms
Negative symptoms
Cognitive symptoms
Aggressive symptoms
Anxiety/depression
How is Sx diagnosed?
Disturbances to have been longer than 6 months
OR
At least 1 month with 2 of the classic symptoms of delusions, hallucinations, disorganised/catatonic behaviour or negative symptoms
What are the 4 main negative symptoms of Sx?
Affective blunting – reduction in good and bad moods
Anhedonia – lack of joy
Alogia – lack, or paucity, of speech
Avolition – apathy, lack of motivation
What is the main treatment course for Sx?
Combination of pharmacological and psychological therapies
What is the main problem for patients taking antipsychotics?
Adherence
Describe Neuroleptic Malignant Syndrome
Rapid onset of extreme side effects caused by genetic polymorphism of D2 receptors
Presents within the first few weeks of treatment
Fever, autonomic problems, altered consciousness
What is the treatment for Neuroleptic Malignant Syndrome?
Dopamine agonists
Benzodiazepines
Withdrawal of the antipsychotic
What is the mechanism of action of first generation antipsychotics?
Antagonism of D2 receptors
Give 2 examples of first generation antipsychotics
Haloperidol
Chlorpromazine
What other receptors do first-generations act on?
Muscarinic M1
Histamine H1
Alpha-1 adrenergic
What side effects do first generations cause by antagonising M1 receptors?
Dry mouth
Constipation
Blurred vision
What side effects do first generations cause by antagonising H1 receptors?
Sedation
Weight gain
What side effects do first generations cause by antagonising a1 receptors?
Hypotension
Drowsiness
What side effects do first generations cause by antagonising D2 receptors?
Rigidity
Slow movements
Prolactin elevation
What side effects are usually seen in first-generation drugs? (broadly speaking)
Extrapyramidal symptoms
Describe Tardive Dyskinesia
Caused by long term use of first-generations
Leads to involuntary movements of the tongue, twisting/grimacing movements of the face and limbs
Usually irreversible
Give 3 examples of second-generation antipsychotics
Clozapine
Amisulpride
Risperidone
Describe the mechanism of action of second-generation antipsychotics
5HT2 receptor antagonists
What are the benefits/risks seen in second generation?
Lower risk of extrapyramidal symptoms
Higher risk of metabolic side effects
Constipation, weight gain, dizziness and somnolence are side effects caused by which class of drugs and on which receptor?
Antagonism of 5HT receptors
Second-generation antipsychotics
Name the 4 main dopamine pathways
Mesocortical
Mesolimbic
Nigrostriatal
Tuberohypophyseal
Describe the nigrostriatal dopamine pathway
Goes from the substantia nigra (midbrain) to the basal ganglia
Involved in fine tuning and control of motor movements
Describe the Tuberohypophyseal dopamine pathway
Connects the hypothalamus and pituitary gland
Responsible for prolactin release
Describe the mesocortical and mesolimbic dopamine pathway
Start in ventral tegmental and substantia nigra (midbrain), project to nucleus accumbens in basal forebrain
Mesolimbic then goes to limbic system
Mesocortical goes to cortical regions in prefrontal cortex (cognitive function of personality)
Describe Huntington’s disease
Autosomal dominant inherited disorder that results in degeneration of the striatum (caudate nucleus and putamen)
Hyperkinetic disorder
Describe the relationship between dopamine, D2 receptors, and the indirect pathway
Dopamine acting at D2 receptors inhibit the indirect pathway. As this pathway inhibits movement, this results in a net increase of movement
Antagonists of D2 receptors will therefore stop this disinhibition, leading to reduced movement
