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Flashcards in vomiting Deck (26)
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1
Q

name the 2 physiological trigger for vomiting and how they work

A

5HT
Substance P
Trigger vagus nerve that has specific receptors and sends AP to brain VC

2
Q

what type of drug are ‘setrons’

A

5HT3 receptor antagonists

3
Q

how do 5HT3 receptor antagonists work

A

competitively block the peripheral and central receptors for 5HT3

4
Q

what would setrons be used for

A

chemotherapy and radiation

5
Q

example of 5HT3 antagonist (2)

A

ondansetron, palonosetron

6
Q

how do muscarinic ACh receptor antagonists work?

A

directly inhibit GI movement by antagonising the ACh receptors that would normally be associated with parasympathetic system (i.e. stimulate GI movement)

7
Q

name ACh receptor antagonists (2)

A

hyoscine, scopolamine

8
Q

what are ACH receptor antagonists used for?

A

motion sickness, prophylaxis

9
Q

how do histamine H1 receptor antagonists work?

A

competitively block H1 receptors in the VC and CNS (causing sedation)

10
Q

why would you use H1 receptor antagonists

A

motion sickness, inner ear (vertigo), post operative nausea and vomiting

11
Q

give 2 examples of H1 receptor antagonists

A

clyczizine, cinnarizine

12
Q

why would you give dopamine receptor antagonists?

A

drug induces vomiting and GI disorders

13
Q

what receptors do dopamine antagonists block? and where?

A

centrally block D2 and D3 receptors in the CTZ

14
Q

give 2 examples of dopamine receptor antagonists

A

metoclopramide (causes parkinson like symptoms)

domperidone

15
Q

when would you use NK1 receptor antagonists

A

chemotherapy and used with 5HT3 + dexamethasone (steroid)

16
Q

what does NK stand for?

A

Neurokinin

17
Q

example of NK1 (1)

A

aprepitant

18
Q

what would cannabinoid CB1 receptor antagonists be used for?

A

chemotherapy that is unresponsive to other drugs

19
Q

what receptor does cannabinoid antagonists block

A

CB1

20
Q

how do cannabinoid CB1 receptors act?

A

stop vomiting by agents actin at CTZ

21
Q

CB1 antagonist example

A

nabilone

22
Q

what stimulates CTZ

A

toxins, drugs, vagal afferents

pharyngeal stimulation, gastric/duodenum distension, irritation

23
Q

what stimulates NTS

A

mechanical stimuli eg distention, irritation, pharyngeal stimulation

24
Q

what does CTZ and NTS stand for?

A

chemotrigger receptors zone = CTZ

nucleus tractus solitarius = NTS

25
Q

what histamine receptors are target for anti-emetic and what are target for dyspepsia and PUD?

A

anti-emetic are H1

dyspepsia and PUD are H2

26
Q

histamine H2 blocker example

A

ranitidine