Anti-Nausa and Anti-Emetic Drugs

Question 1

What are the serotonin receptor antagonists?

Answer 1

Dolasetron
Granisetron
Ondansetron
Palonosetron

Question 2

What is the common suffix for serotonin receptor antagonists?

Answer 2

-setron

Question 3

What specific receptors do serotonin antagonists act on?

Answer 3

5-HT3

Question 4

What is the is the downstream effect of serotonin receptor inhibition?

Answer 4

block serotonin type 3 receptors at vagal nerve terminals and block signal transmission to chemoreceptor trigger zone

Question 5

What is the potential toxic effect of 5HT3 antagonists?

Answer 5

dose-dependent QT prolongation

*Dolasetron has highest risk

Question 6

What 5HT3 antagonists would you use for delayed chemotherapy induced N/V as a single dose?

Answer 6

Palonosetron

sustained-release formulation of Granisetron

Question 7

What are the neurokinin receptor antagonists?

Answer 7

Aprepitant
Fosaprepitant
Netupitant
Fosnetupitant
Rolapitant

Question 8

What does the prefix “fos” represent?

Answer 8

Pro-drug

Question 9

What is the common suffix of neurokinin receptor antagonists?

Answer 9

-pitant

Question 10

What specific receptors do neurokinin antagonists act on?

Answer 10

NK1

Question 11

What is the anti-emetic classification of 5HT3 antagonists?

Answer 11

strong anti-emetics

Question 12

What is the anti-emetic classification of NK1 antagonists?

Answer 12

moderate anti-emetics

Question 13

What is the downstream effect of NK1 antagonists?

Answer 13

blockade of NK1 receptors in the chemoreceptor trigger zone

blockade of NK1 receptors on vagal terminals in gut

Question 14

Are NK1 antagonists used for chemotherapy induced N/V?

Answer 14

Yes but they are most effective in combination with 5HT3 antagonists and glucocorticoid

Question 15

What is given for prophylaxis post-op N/V?

Answer 15

aprepitant

Question 16

What are the possible adverse effects of NK1 antagonists?

Answer 16

GI (dyspepsia/constipation/diarrhea)

CNS (dizziness/fatigue/somnolence)

Question 17

What do you need to check before giving NK1 antagonists?

Answer 17

mild CYP450 inhibition so need to check for drug interactions

Question 18

What are the histamine receptor antagonists?

Answer 18

Diphenhydramine 
Dimenhydrinate
Hydroxyzine 
Promethazine
Meclizine
Cyclizine
Doxylamine + B6

Question 19

What is the anti-emetic classification of histamine receptor antagonists?

Answer 19

weak anti-emetics

Question 20

What specific receptors do histamine antagonists act on?

Answer 20

H1

Question 21

What is the downstream effects of H1 antagonists?

Answer 21

blockade of H1 receptors in vomiting center and vestibular system

anticholinergic properties at the level of the chemoreceptor trigger zone

Question 22

What are the adverse effects of H1 antagonists?

Answer 22

*classic anticholinergic effects*
drowsiness
dry mouth
constipation
urinary retention
blurred vision

Question 23

What is given for N/V of pregnancy?

Answer 23

doxylamine + B6

Question 24

What are given for motion sickness/vertigo?

Answer 24

meclizine
cyclazine
scopolamine

Question 25

What are the dopamine receptor antagonists?

Answer 25

chlorpromazine perphenazine prochlorperazine metoclopramide

Question 26

What is the anti-emetic classification of dopamine antagonists?

Answer 26

weak to moderate anti-emetics

Question 27

What specific receptors do dopamine antagonists act on?

Answer 27

D2

Question 28

What is the downstream effect of D2 antagonists?

Answer 28

blockade of D2 in CTZ | varying levels of anticholinergic properties

Question 29

What is special about the downstream effect of metoclopramide?

Answer 29

also stimulates ACh actions in GI | enhances GI motility and increases LES tone

Question 30

What are the adverse effects D2 antagonists?

Answer 30

``` *classic anticholinergic effects* drowsiness dry mouth constipation urinary retention blurred vision ``` arrythmias and extrapyramidal SE's are possible with large doses!

Question 31

What is used for gastroparesis/dysmotility?

Answer 31

meoclopramide

Question 32

What is the muscarinic receptor antagonist?

Answer 32

scopolamine

Question 33

What is the anti-emetic classification of muscarinic receptor antagonists?

Answer 33

weak anti-emetic

Question 34

How is scopolamine administered?

Answer 34

transdermal via 72 hr patch

Question 35

What specific receptors do muscarinic antagonists act on?

Answer 35

M1

Question 36

What is the downstream effect of M1 receptors?

Answer 36

block of Ach-stimulated muscarinic receptors in neural pathways from the vestibular nuclei and reticular formation

Question 37

What are the adverse effects M1 antagonists?

Answer 37

``` *classic anticholinergic effects* drowsiness dry mouth constipation urinary retention blurred vision ```

Question 38

What can be given for end-of-life care for excessive secretions?

Answer 38

scopolamine

Question 39

What are the cannabinoid receptor agonists?

Answer 39

Dronabinol | Nabilone

Question 40

What is the antiemetic classification of cannabinoid receptor agonists?

Answer 40

strong anti-emetic

Question 41

What is the downstream effect of CB agonists?

Answer 41

Stimulates CB1 and CB2 receptors in the CTZ Exert signal transduction effects through GPCRs resulting in decreased excitability of neurons – minimizes 5HT3 release from vagal nerve

Question 42

When would you use CB agonists?

Answer 42

Chemo induced N/V for treatment resistant scenarios

Question 43

What is another beneficial effect of CB agonists?

Answer 43

appetite stimulation

Question 44

What are some "adverse" effects of CB agonists?

Answer 44

``` Euphoria ;) Vertigo Sedation Impaired cognition/memory Altered perception of reality/hallucinations Xerstomia Increased HR/BP ```

Question 45

What is the classic high-emetogenic regimen?

Answer 45

NK1 antagonist 5HT3 antagonist Corticosteroid (dexamethasone) *may increased to 4 drug regimen with D2 antagonist or CB agonist*

Question 46

What is the classic moderate-emetogenic regimen?

Answer 46

5HT3 antagonist corticosteroid (dexamethasone) *may increased to 3 drug regiment with NK1 antagonist or CB agonist*

Question 47

What is the classic low-emetogenic regimen?

Answer 47

corticosteroid OR 5HT3 antagonist OR metoclopramide OR prochlorperazine

Question 48

What is the classic minimal-emetogenic regimen?

Answer 48

No prophylaxis therapy recommended

Question 49

What is the stepped-therapy for pregnancy N/V?

Answer 49

1. B6 OR H1 antagonist + B6 OR 5HT3 antagonist 2. D2 antagonist 3. Steroid or different D2 antagonist