anti emetics

Question 1

ctz is located?

Answer 1

within the area postrema

Question 2

physiology of vomiting?

Answer 2

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Question 3

pre ejection phase?

Answer 3

tasric relaxation, retrograde peristalsis into stomach

Question 4

ejection phase?

Answer 4

abdominal and diaphragmatoc muscle contract, retrograde oesophageal contraction, crural muscles contract, upper oesophageal sphincter dilates

Question 5

ctz agonists?

Answer 5

histamine, muscurinic, dopamine, 5ht3 drugs=cisplatin, opioids, nitrogen mustard, vestibular distress

Question 6

ctz antagonists?

Answer 6

hist - promethasine, musc-atropine, dop-droperidol, 5ht antagonist

Question 7

parvicellular reticular formation?

Answer 7

sub p nk1 antagnoist

Question 8

neurotrasnmitters involved

Answer 8

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Question 9

dopamine antagonists?

Answer 9

Haloperidol, Prochlorperazine,Levomepromazine

Question 10

prokinetic agents?

Answer 10

Metoclopramide, Domperidone

Question 11

antihostamines?

Answer 11

Cyclizine, Levomepromazine

Question 12

anti cholinergics?

Answer 12

Hyoscine hydrobromide,Levomepromazine, Promethazine

Question 13

5ht antagonists?

Answer 13

Ondansetron, Granisetron

Question 14

matoclopramide?

Answer 14

RX: gastric stasis or ileus,gastroenteritis•Predominantly D2 receptorantagonist peripherally andcentrally; 5HT3 at high doses•Acute dystonic reactions inyoung patients, akathisia inelderly patients•Colic in patients withintestinal obstruction

Question 15

domperidone?

Answer 15

Does not cross blood-brainbarrier•Minimal extrapyramidaleffects•Other prokinetics includeerythromycin, cisapride

Question 16

haloperidol?

Answer 16

•RX: opioid or metabolicinduced N & V•Acts on central D2 receptorsat CTZ•Sedation andextrapyramidal reactionscan limit their use

Question 17

cyclizine?

Answer 17

•RX: intestinal obstruction,vestibular causes, motionsickness•H1 receptor antagonist atvomiting centre and vestibularafferent pathway•Dry mouth, sedation, blurredvision, skin irritation if givensubcutaneously

Question 18

hyoscine?

Answer 18

RX: intestinal obstruction,excess secretion, motionsickness•Anticholinergic atvomiting centre and GIT•Dry mouth, urinaryretention, blurred vision,agitation esp. in elderly

Question 19

emetic potential?

Answer 19

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Question 20

substance p?

Answer 20

Neuropeptide, tachykinins•Binds to specific receptors known asneurokinin type 1 or NK1 receptors•New NK1 receptor antagonist, aprepitant, isnow available for use in chemotherapyinduced nausea and vomiting•Enhance the effects of 5HT3 antagonist andcorticosteroids

Question 21

post operative nausea?

Answer 21

Stimulation of CTZ and response to vagalstimulation secondary to gastrointestinaldistension, mucosal irritation and infection•Volatile agents such as isoflurane,enflurane and nitrous oxide are highlyemetogenic•Regional anaesthesia e.g. nerve blocks areless emetogenic than general anaesthesia

Question 22

patient risks for ponv?

Answer 22

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