MOA OF ANTIEMETICS

Question 1

MOA OF APREPITANT

Answer 1

Blocks the action of Substance P at NK1 receptors in CNS, vagal afferent neurons in the GIT & its GIT paracrine actions

Question 2

WHAT IS APREPITANT USED FOR

Answer 2

Used for the delayed stage of CINV in combination with 5HT3 antagonist and dexamethasone

Question 3

WHAT ARE THE ADRS OF APREPITANT

Answer 3

inhibition of CYP3A4

Question 4

MOA OF Ondansetron, Granisetron, Palonostron

Answer 4

Used for the prevention and treatment of acute CINV
Less effective for management of delayed CINV
Peripheral actions –
abolishes vagal afferent response to 5-HT
Acts at the CTZ
Central actions - acts at the NTS and VC

Question 5

MOA OF METOCLOPRAMIDE

Answer 5

central & peripheral D2-antagonist at low doses, weak 5-HT3 blocker and 5HT4 agonist at higher doses
crosses the BBB - extrapyramidal side-effects
EMA recommendations for use regarding safety

Question 6

MOA OF DOMPERIDONE

Answer 6

Peripheral action only
Acts at the CTZ
Does not cross BBB

Question 7

DEXAMETHASONE MOA

Answer 7

Mechanism of action unknown -may relate to a reduction in prostaglandin levels

Question 8

ADRS OF DEXAETHASONE

Answer 8

insomnia
increased mood changes

Question 9

PROCHLORPERAZINE

Answer 9

mixed pharmacology - act as antagonists at D2 receptors in the CTZ, also acts at M1- and H1-, Adenosine and 5HT receptors