Decontamination Agents and Antiemetics Flashcards
What are 3 classes of stimulation that cause vomiting?
Mechanical
Blood born
Higher center
Where are Chemoreception Trigger Zone (CTZ) and Vomiting center located?
CTZ = Oustide of BBB in 4th ventricle
Vomiting Center = IN BBB, medulla
What receptors are present in CTZ?
Serotonin Histamine Muscarinic Opioid Dopamine
What portion/area of the vomiting signal do 5HT inhibitors act on?
5HT receptors in the GI tract
i.e. sensory signalling from vagal afferents
What portion/area of the vomiting signal do DA and opioid inhibitors act on primarily?
CTZ
What portion/area of the vomiting signal do Muscarinic, histamine, NK, and cannabinoid inhibitors act on?
Inside the BBB
- Central Centers
- Vomiting Center
Dolasetron
Granisertron
Ondansetron
Palonosetron MOA and use?
5HT3 R antagonists
Used for chemotherapy anti-emesis
SE of 5HT3 antagonists?
Mild headache, dizziness, constipation
Prolonged QT
Scopolamine MOA and use?
Anti-muscarinic
Motion sickness
How is scopolamine administered?
Trans-dermal patch
Aprepitant/Fosaprepitant MOA and use?
NK1 antagonists (Sub P usually binds)
Used with –serton + dexamethasone to relieve chemotherapy emesis
How are aprepitant and fosaprepitant administered?
aprepitant = Oral fosaprepitant = IV
SE of Aprepitant/Fosaprepitant ?
CYP3A4 metabolism
Dimenhydrinate
Diphenhydramine
Meclizine MOA?
Histamine antagonists, likely due to sedation, possibly acts on H1R in vestibulocerebellar pathway
SE of Dimenhydrinate, Diphenhydramine, Meclizine?
Anticholinergic
Teratogenic
Macrolide interactions
Droperidol Metoclopramide Prochlorperazine Promethazine Thiethylperazine MOA?
DA2 Antagonists
Dronabinol
Nabilone MOA?
Marijonaz
Activated Charcoal MOA?
Large surface area absorbs many drugs and poisons
What DOESN’T charcoal bind?
Iron
Lithium
Potasium
When SHOULDN’t you use activated charcoal?
Poisoning due to corrosive mineral acids or alkalis
Polyetheylene glycol MOA?
Hasten removal or toxins
Ipecac MOA?
Local irritant + CTZ stimulation
