Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HNNS > HNS51 Anti-psychotics > Flashcards

HNS51 Anti-psychotics Flashcards

1
Q

Antidepressants vs Antipsychotics

A

NOT interchangeable
Depressive disorders: ↓ NT level
Psychosis: ↑ Dopamine level (or ↑ D2 receptors)

Antidepressant: treat depressive disorder, elevate mood
Antipsychotics: manage psychosis (E.g. Schizophrenia, Bipolar disorder) (delusions, hallucinations, disordered thoughts)
—> Block dopamine action (reward-driven learning)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Psychosis

A

Mental health problem —> stop person from thinking clearly, telling difference between reality and their imagination and acting in a normal way

  • NOT a disease
  • Spectrum of symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Symptoms of Psychosis

A
  1. Hallucinations (幻覺)
    - perceive something not exist in reality
    - all 5 senses can occur: sight, touch, taste, small, sound
  2. Delusions (妄想)
    - believe things that are not true when examined rationally
  3. Confused and disturbed thought
    - rapid and constant speech
    - random content of speech (switch topics in the middle of sentence)
    - train of thoughts suddenly stop —> abrupt pause in conversation / activity
    - difficulty in concentration on activities
    - talk to themselves
  4. Lack of insight / self-awareness
    - unaware that they are acting strangely / have hallucinations / delusions
    - able to recognise behaviours of others but not themselves
    - ∴ affected individuals often would not seek medical help themselves, rely on outside to tell them they are abnormal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Positive and Negative symptoms of Psychosis

A

Positive signs:

  • Hallucinations
  • Delusions
  • Confused and disturbed thought
  • Agitation

Negative signs:

  • Lack of drive / initiative
  • Social withdrawal / Depression
  • Apathy
  • Lack of emotional response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Causes of Psychosis

A
  1. Psychological conditions (e.g. mental illness)
  2. General medical conditions
  3. Substance abuse (e.g. alcohol, drugs)
  4. Others (genetics, brain structural changes, hormonal / sleep pattern)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Psychological conditions

A
  1. ***Schizophrenia (repeated episodes of psychosis)
  2. ***Bipolar disorder (mood swing, depression followed by manic (energetic, impulsive, happy))
  3. Severe stress / anxiety
  4. Lack of sleep
  5. Severe depression (extreme sadness for prolonged period)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

General medical conditions

A
  1. Metabolic disorders
    - Vitamin B deficiency (e.g. Thiamine, B12)
    - etc.
  2. Brain diseases
    - Stroke
    - Tumour
    - etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Substance abuse

A

Drugs known to trigger psychotic episodes:

  1. Cocaine (significantly ↑ dopamine level)
  2. Amphetamine
  3. Methamphetamine
  4. Mephedrone
  5. MDMA (Ecstasy)
  6. Cannabis (regular cannabis users 40% more likely to develop psychotic illness)
  7. LSD
  8. Psilocybin (magic mushroom)
  9. Ketamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Prevalence of Psychosis

A
  • More common than people think
  • 1 in 100: >=1 episode of psychosis at some point in life
  • Most cases develop during older teens (>15) / during adulthood
  • Cases under 15 are rare
  • Male > Female

Hong Kong:

  • ~200,000 patients
  • 1300 new cases each year
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Treatment of Psychosis

A
  1. Antipsychotics (relieve symptoms of psychosis, but unable to cure)
  2. Psychological therapy - address underlying cause
  3. Social support
  4. Family therapy
  5. Self-help groups
  • Some may need antipsychotics for short period, some life-long
  • Severe cases: may need hospital admission / psychiatric unit —> prevent hurting themselves / others
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Complications of Psychosis

A
  1. More likely to have drug / alcohol problems
  2. Higher risk of suicide (1 in 25)
  3. Hurt / Kill others
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Antipsychotics formulation

A
  • Oral / Injection
  • Slow-release / Rapid-disintegrating

Slow-release:

  • long-acting
  • one injection every 2-6 weeks
  • for patients unable to adhere to daily regimens

Rapid-disintegrating:

  • dissolve rapidly in minimal amount of saliva
  • avoid swallowing
  • for patients suspected of concealing tablets in mouth then disposing —> making non-adherence impossible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

***Classification of Antipsychotics

A

Typical antipsychotics (High affinity for ***D2 receptors):

  • ***Chlorpromazine
  • ***Haloperidol
  • ***Sulpiride
  • Perphenazine
  • Fluphenazine
  • Thioridazine
  • Trifluoperazine

Atypical antipsychotics (High affinity for ***Serotonin 5HT2 receptors):

  • ***Aripiprazole
  • ***Clozapine
  • ***Olanzapine
  • ***Quetiapine
  • ***Risperidone
  • Ziprasidone

Both only alleviate symptoms, not cure schizophrenia / bipolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Typical antipsychotics (1st generation)

A
  • much cheaper
  • Effective against ***Positive signs but NOT Negative signs

MOA:
- Block D2 receptors —> block action of Dopamine

(- D1 neuron: stimulate Direct pathway (D1 receptor) —> promote movement
- D2 neuron: inhibit Indirect pathway (D2 receptor) —> promote movement)

(Block D2 receptor in Striatum
—> block action of D2 neuron (Substantia nigra) on Striatum
—> less inhibition of Indirect pathway
—> inhibit movement)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Dopamine hypothesis

A

Dopamine:

  • NT
  • associated with how we feel something significant, important, interesting
  • **excessive Dopamine —> **interrupt specific pathways responsible for memory, emotion, social behaviour, self-awareness

Hypothesis is based on these observations:

  1. Many antipsychotic drugs block Dopamine receptors (esp. D2 receptors)
  2. Dopamine agonists (e.g. Amphetamine, Levodopa) exacerbate psychosis
  3. Increased density of dopamine receptors detected in certain brain regions in untreated schizophrenics

Hypothesis not perfect:

  • antipsychotics only effective in most patients but not all
  • some drugs have higher affinity for other receptors e.g. 5HT2 receptor than D2 receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Dopamine receptors

A

5 different dopamine receptors identified (D1-D5)

D1, D5: Activation of adenylate cyclase —> ↑ cAMP production (—> ↑ downstream signals)
D2, D3, D4: Inhibition of adenylate cyclase —> ↓ cAMP production (—> ↓ downstream signals)

D2 most concentrated in:

  1. Cortex
  2. Corpus striatum (Caudate nucleus, Putamen)
  3. Limbic system
  4. Basal ganglia
  5. Pituitary gland
  6. Hypothalamus
17
Q

***3 Major Dopamine pathways in brain

A

**1. Mesolimbic and Mesocortical pathways
(VTA —> Nucleus Accumbens, Amygdala + Hippocampus, Prefrontal cortex)
- **Mental activity + Mood —> blockage of D2 receptors associated with antipsychotic efficacy
- memory
- motivation and emotional response
- reward and desire
- addiction
- hallucinations and schizophrenia

  1. Nigrostriatal pathway (Substantia nigra —> Striatum)
    - motor control
    - Parkinson’s disease
  2. Tuberoinfundibular pathway (Hypothalamus —> Pituitary gland)
    (e. g. Dopamine from Hypothalamus inhibit Prolactin release from Pituitary gland)
    - hormonal regulation
    - maternal behaviour, pregnancy
    - sensory processes
18
Q

***Adverse effects of blockage of D2 receptors

A

Nigrostriatal pathway (Basal ganglia)

  • responsible for Extrapyramidal function (motor system)
  • blockage —> Extrapyramidal symptoms —> tend to develop after several years of antipsychotic therapy (but can appear as early as 6 months)
  1. Acute dystonia (扭麻花)
    - hyperkinetic movement disorder, intermittent, uncoordinated involuntary contractions of muscle of face, tongue, neck, trunk, extremities
    - painful
  2. Akathisia
    - motor restlessness, inability to stay still
  3. Parkinsonism
    - rigidity, tremor
    - cognitive impairment
  4. Tardive dyskinesia
    - repetitive movement of Orofacial structure: tongue protrusion, lip smacking, involuntary repetitive body movements
    - painless

Tuberoinfundibular pathway

  • Dopamine: released from Hypothalamus —> inhibition of prolactin release from Pituitary
  • blockage —> Hyperprolactinemia in both male and female —> Pseudopregancy (False pregnancy)
  1. Hyperprolactinemia
    - Gynecomastia
    - Galactorrhea
    - Loss of libido
    - Sexual dysfunction (no ovulation and menstruation)
  2. Inhibition of GnRH due to prolactin
    - ↓ FSH, LH release —> Hypogonadism, Infertility
19
Q

Summary of SE of Typical antipsychotic

A
  1. Extrapyramidal symptoms
  2. Hyperprolactinemia symptoms
  3. Drowsiness
  4. **Neuroleptic malignant syndrome (NMS)
    - medical emergency
    - **    temperature regulation centre fail by drug
    - body temperature ↑ >40oC
    - 1 in 500
    - develop over 1-3 days of drug use
    - e.g. rigidity, muscle breakdown, tachycardia, elevated BP, dilation of pupil, sweating
20
Q

Atypical antipsychotic (2nd generation)

A
  • Treat **Positive + **Negative signs of psychosis

MOA:

  • Block 5HT2 receptors
  • Affinity for 5HT2 > D2 (quickly dissociate from D2 —> ↓ extrapyramidal, hyperprolactinemia SE)
21
Q

Adverse effects of Atypical antipsychotics

A
  • **Metabolic SE (combined H1 + 5HT2 blockage):
    1. ↑ Risk of high glucose
    2. ↑ Lipids, cholesterol
    3. ↑ Diabetes risk
    4. Severe weight gain
    5. Hypertension, Atherosclerosis

(5HT2 regulate energy intake and expenditure, 5HT2c ↑ appetite)

  • **D2 blockage:
    6. Extrapyramidal effects
    7. Hyperprolactinemia
    8. Neuroleptic malignant syndrome
    9. Sudden death
  • **α1 adrenergic receptor blockage (α1: Vasoconstriction):
    10. Reflex tachycardia
    11. Postural hypotension
  • **Muscarinic receptor blockage (Anticholinergic symptoms):
    12. Dry mouth
    13. Constipation
    14. Urinary retention
    15. Mydriasis
    16. Tachycardia
    17. Hyperthermia
  • **Histaminergic receptors blockage:
    18. Sedation
    19. Slowness
22
Q

Choice of Atypical antipsychotic drugs

A

Prevent Sedation: Aripiprazole
Prevent Weight gain: Aripiprazole
Prevent EPS: Clozapine

23
Q

Withdrawal problems

A
  • Gradual dose reduction when switching to another drug / discontinuation
  • Blockage of Dopaminergic receptor by antipsychotics
    —> ***↑ number and sensitivity of Dopamine receptors
    —> Super-sensitivity psychosis (when withdrawing drug)
  • Withdrawal symptoms:
    1. Psychosis (relapse of underlying disorder)
    2. Tardive dyskinesia
    3. Nausea
    4. Emesis
    5. Anorexia
    6. Anxiety
    7. Agitation
    8. Restlessness
    9. Insomnia
24
Q

Antipsychotic prescribing indication

A

Original target population:
- Schizophrenia
- Bipolar disorder
—> relatively small population

Newer target population:

  • Severe depression (use in combination with antidepressants)
  • Mild mood disorder, Everyday anxiety, Insomnia, Mild emotional discomfort
25
Q

Off-label use of antipsychotics

A

Non-psychotic disorders:

  • agitation
  • various headache conditions
  • anxiety disorder (limited controlled trials, no effect / inconsistent results, no approved use yet)
  • suppress hiccups
  • Alzheimer’s disease
  • depression
  • dementia
  • involuntary motor disorder (Tourette syndrome, Huntington chorea)
  • Autism spectrum disorders (Risperidone approved for treatment of irritability in children and adolescents with autism)

HNNS (58 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions