Nausea + Emesis

Question 1

Can vomiting without nausea occur?

Answer 1

Yes, but it is less frequent

Question 2

Who is more likely to experience vomiting?

Answer 2

Women over men

Question 3

What does the brainstem “vomiting center” do?

Answer 3

Coordinates vomiting through interactions with cranial nerves 3 + 10

Question 4

What does the vomit center contain?

Answer 4

M1 receptors
H1 receptors
NK1 receptors
5HT receptors

Question 5

What does the nucleus tractus solitarius contain?

Answer 5

M1 receptors
H1 receptors
NK1 receptors
5HT receptors

Question 6

What does the chemoreceptor trigger zone contain?

Answer 6

Chemoreceptors
D2 receptors
NK1 receptors

Question 7

What are the triggers for vomiting?

Answer 7

Intracranial pressure
Motion sickness
Anxiety
Drugs
Toxins
Chemotherapy

Question 8

What is serious morning sickness for pregnancy?

Answer 8

Hyperemesis gravidarum

Question 9

What is the process for treating nausea + vomiting?

Answer 9

1. treat complication regardless of cause = replaces salt, H2O
2. identify + treat underlying cause
3. provide temporary relief for symptoms

Question 10

What is the problem with anti-emetics?

Answer 10

Oral = if patient is being sick, they aren’t ging to keep them down
Injection = needles aren’t accessible at home + low patient acceptability

Question 11

What is the best way to treat CINV?

Answer 11

Preventive treatment
= stop being sick in first place
= deceases chance of being sick in future
= able to give higher dose

Question 12

What are pharmacological treatments for nausea + vomiting?

Answer 12

D2 antagonists
5HT3 antagonists
Antihistamines
Anticholinergics
Pro-motility = metoclopramide

Question 13

What are antihistamines used to treat?

Answer 13

Montion sickness
PONV

Question 14

Describe antihistamines

Answer 14

H1 antagonists

Question 15

What are some examples of antihistamines?

Answer 15

Cyclizine
Diphenhydramine
Meclizine

Question 16

What are the problems with antihistamines?

Answer 16

Cause CNS depression + sedation
= drowsiness

Question 17

What are anticholinergics used to treat?

Answer 17

Motion sickness

Question 18

Describe anticholinergics

Answer 18

Muscarinic acetylcholine receptor antagonists

Question 19

What are the problems with anticholinergics?

Answer 19

Blockage of parasympathetic ANS
= blurred vision, dry mouth, urinary retention

Question 20

What is an example of anticholinergic?

Answer 20

Hyoscine

Question 21

What are dopamine antagonists used to treat?

Answer 21

Drug-induced vomiting + vomiting in GI disorders

Question 22

How do dopamine antagonists work?

Answer 22

Centrally block D2 receptors in CTZ
Exert prokinetic action on oesophagus, stomach + intestine

Question 23

What are some examples of dopamine antagonists?

Answer 23

Metoclopramide (low dose)
Chlorpromazine
Haloperidol

Question 24

What are the problems with dopamine antagonists?

Answer 24

Mimic Parkinson’s disease

Question 25

When is metoclopramide used at high dose?

Answer 25

Chemo = at higher level effect serotonin

Question 26

What does 5HT3 antagonists treat?

Answer 26

PONV CINV

Question 27

What are examples of 5HT3 antagonists?

Answer 27

Ondansetron Granisetron

Question 28

What are the side effects of 5HT3 antagonists?

Answer 28

Constipation Headaches

Question 29

What is an example of prokinetic agent?

Answer 29

Metoclopramide

Question 30

What do prokinetic agents do?

Answer 30

CTZ anti-dopaminergic activity

Question 31

What are problems with prokinetic agents?

Answer 31

Obstructed intestine = can cause colic Increases pressure at lower oesophageal sphincter

Question 32

What are NK1 antagonists?

Answer 32

Aprepitant Antagonise NK1 receptors

Question 33

When are NK1 antagonists used?

Answer 33

Delayed onset nausea associated with chemotherapy

Question 34

When are cannabinoids used?

Answer 34

For patients undergoing cytotoxic chemotherapy, that is unresponsive to other anti-emetics

Question 35

How do cannabinoids work?

Answer 35

Decrease vomiting induced by stimulating CTZ