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