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Flashcards in Anti-Emetics Deck (11):
1

Vestibular Nucleus Receptors

H1
Ach

2

Vomiting Centre Receptors

Muscarinic
NK1

3

Chemoreceptor Trigger Zone

5HT3
D2
NK1
ENK

4

Stomach

5HT3
DA

5

Serotonin Antagonists

Ondansetron
Prevent activation of VC
Doesn’t affect dopamine receptors, no extra-pyramidal effects
PK: Absorbed well, metabolised by liver
SE: tolerated well

6

Dopamine Antagonists

Domperidone
Competitive D2 antagonist
Inhibit VC and afferent impulses in gut at solitary tract nucleus
SE: Sedation, anticholinergic effects, hypertension, parkinsonism

7

H1 Antagonist

Promethazine
Inhibits neural pathway from VN
May not be primary MOA
Could be sedative effects
SE: Drowsiness, Hypotension, Confusion, Urinary retention

8

Antimuscarinics

Scopolamine
Inhibits muscarinic receptors in Cerebellum
Rapidly and fully distributed in CNS
Particularly effective in motion sickness
SE: Anticholinergic effects when given orally which are reduced transdermally

9

Neurokinin Receptor Antagonists

Aprepitant
Usually given with dexamethasone and 5HT3 antagonist
Prevents acute amd delayed emetic response to chemo e.g. Cisplatin
Blocks action of Substance P on NK1 receptors in CTZ
PK: Metabolised by CYP3A4 and induces it
SE: Constipation, fatigue

10

Cannabinoids

Dronabinol- oral formulation of THC
Cancer chemo- induces emesis refractory
Acts on receptors in CTZ

11

Benzodiazepines

Sedative-hypnotic
Used to control anticipatory nausea and vomiting