Antiemetics, Decontamination Agents and IBD Tx

Question 1

Define nausea

Answer 1

an unpleasant sensory experience of gastric discomfort with an urge to vomit

Question 2

Nausea is associated with _____ gastric motility and ____ tone in the small intestine (manifesting as reverse peristalsis)

Answer 2

decreased; increased

Question 3

Define retching

Answer 3

spasmodic respiratory movements conducted with a closed glottis

Question 4

simultaneous contraction of antrum of the stomach and relaxation of fundus and cardia; repeated herniation of the abdominal esophagus and cardia into the thoracic cavity due to negative pressure

Answer 4

Retching

Question 5

Emesis

Answer 5

Gastric and small intestinal contents are propelled up to and out of the mouth

Question 6

Central emetic stimuli

Answer 6

Fear, anticipation, memory

Question 7

Traditional sensory emetic stimuli

Answer 7

nociception, olfaction, vision, inner ear

Question 8

GI sensory emetic stimuli

Answer 8

stimulate the pharyngeal and gut chemo/mechanoreceptors - Cytotoxic drugs, radiation, bacteria and viruses

Question 9

Blood born emetics

Answer 9

stimulate the CTZ

Question 10

The two CNS centers involved in emesis

Answer 10

1. CTZ

2. Vomiting centre

Question 11

First stage of emesis

Answer 11

preparatory movements to protect the airway (deep breath, close glottis, raise larynx, elevate soft palate)

Question 12

Second stage of Emesis

Answer 12

diaphragm contracts downwards to create negative pressure thorax (open LES)
Abdominal walls contract to elevate intragastric pressure

Question 13

Third stage of emesis

Answer 13

stomach and intestinal contents move into the esophagus

Question 14

Is the CTZ inside or outside of the BBB?

Answer 14

Outside - makes a big difference in therapeutic targets

Question 15

Where is the CTZ located?

Answer 15

Outside the BBB in the area postrema

Question 16

Where is the vomiting centre located?

Answer 16

Medullary reticular formation

Question 17

Name some 5HT3 antagonists

Answer 17

Dolasetron
Granisetron
Ondansetron
Palonosetron

Question 18

MOA of 5HT3 antagonists?

Answer 18

Blockade of peripheral 5HT3 receptors on intestinal vagal afferents

Question 19

Therapeutic use of 5HT3 antagonists?

Answer 19

Primary agents for prevention and treatment of chemo induced nausea and vomiting

Question 20

What is the number one drug prescribed in the ER

Answer 20

Ondansetron

Question 21

SE of 5HT3 antagonists?

Answer 21

Usually tolerated well - mild headache, dizziness, constipation.
Prolonged QT interval

Question 22

Droperidol
Metoclopramide
Phenothiazine
Prochlorperazine
Promethazine

Answer 22

D2 antagonists

Question 23

MOA of D2 antagonists

Answer 23

Blockade of D2 (and muscarinic) receptors in the CTZ
May counteract reverse peristalsis
SEDATION

Question 24

Therapeutic uses of D2 antagonists

Answer 24

Vomiting due to uremia, radiation sickness, cancer chemo, infection, hyperemesis gravidarum, labour

Question 25

SE of D2 antagonists

Answer 25

Somnolence, Dystonia, Parkinsonism, tardive dyskinesia (irreversible) Prolactin release

Question 26

Anti muscarinic agent

Answer 26

Scopalamine

Question 27

MOA of scopalamine

Answer 27

Blockade of muscarinic and dopaminergic receptors in the cerebellum

Question 28

Therapeutic use for scopalamine

Answer 28

Motion sickness

Question 29

Name some H1 antihistamines

Answer 29

dimenhydrinate, diphenhydramine, meclizine

Question 30

MOA of H1 antihistamines

Answer 30

Block H1 and muscarinic receptors in the cerebellum

Question 31

Therapeutic use of H1 antihistamines

Answer 31

motion sickness | hyperemesis gravidarum

Question 32

SE of H1 antihistamines

Answer 32

Somnolence | Anticholinergic

Question 33

Name NK1 antagonist

Answer 33

Aprepitant/Fosaprepitant

Question 34

MOA of NK1 antagonists

Answer 34

Blockade of neurokinin (tachykinin) receptor 1 (intrinsic against substance P) in CNS and GI tract

Question 35

What is the difference of aprepitant and fosaprepitant

Answer 35

Aprepitant (oral) | Fosaprepitant (IV)

Question 36

Therapeutic uses

Answer 36

Prevention of acute and delayed phases of chemo induced nausea and vomiting

Question 37

What is a NK1 antagonist combined with

Answer 37

5HT3 antagonist and dexamethasone

Question 38

Cannabinoids

Answer 38

Dronabinol Nabilone Medical Marijuana

Question 39

MOA of Cannabinoids

Answer 39

Activation of central cannabinoid receptors in CNS

Question 40

Therapeutic use of cannabinoids

Answer 40

Cancer chemo induced nausea nad vomiting

Question 41

Dexamethasone

Answer 41

Corticosteroid

Question 42

Whole bowel irrigation =

Answer 42

polyethelene glycol

Question 43

PEG-electrolyte MOA

Answer 43

Osmotic cathartic before endoscopic procedures - not absorbed and increases H20 retention in the lumen

Question 44

How do the anti-inflammatory agents aminosalicylates work?

Answer 44

Variants of mesalamine (5-ASA) which are poorly absorbed in the GI tract - block PG synthesis by inhibiting COX and reduce inflammation

Question 45

Balsalazide and sulfasalazine MOA

Answer 45

some moiety to 5-ASA - limit action until bacteria break down and release the 5-ASA Topical rather than systemic High concentration or enema/suppository

Question 46

Balsalazide nad sulfasalazine are confined to this region

Answer 46

Large intestine

Question 47

Name three anti TNFa antibodies

Answer 47

Adalimumab Certolizumab Infliximab

Question 48

MOA of TNFa antibodies

Answer 48

INFLIXIMAB and ADALMUMAB are antibodies that bind to both soluble and receptor-bound TNFα, preventing binding of the cytokine to its receptors

Question 49

MOA of certolizumab

Answer 49

is a recombinant antibody consisting of an Fab component conjugated to polyethylene glycol (PEG) i.e., there is no Fc component, therefore no complement activation etc.

Question 50

SE of TNFa abs.

Answer 50

infection, reactivation of TB, delayed infusion rxns. | hepatic reactions, increased risk of T cell lymphoma?

Question 51

Anti a4 subunit of integrin

Answer 51

Natalizumab

Question 52

MOA of Natalizumab

Answer 52

inhibits diapedesis

Question 53

Therapeutics of Natalizumab

Answer 53

MS | IBD

Question 54

SE of Natalizumab

Answer 54

Reactivation of JC virus | PML