Nausea and Vomiting Flashcards
Where is the chemoreceptor trigger zone located in the brain?
Area postrema, where the is no BBB
What kinds of drugs may stimulate the CTZ to cause vomiting?
Opiates
Emetigenic chemo drugs
Even uremia can do it
Where is the vomiting center of the brain located?
Medulla oblongata
What receptors are present in the vestibular system (whose activation may cause vomiting)?
Histamine (H1)
Acetylcholine
What receptors are present in the CTZ (whose activation may cause vomiting)?
Dopamine (D2)
5-HT3
NK1
List the two dopamine receptor antagonists used to palliate nausea/vomiting
Prochlorperazine
Metoclopramide
Prochlorperazine
MOA
Central dopamine receptor antagonist in the CTZ
Peripherally blocks vagus nerve
Prochlorperazine
Indications
Opioid related nausea and vomiting
GI disorders, inflammation, infection
Prochlorperazine
Adverse Effects
Extrapyramidal effects (Parkinson's-like effects) -AVOID use in Parkinson's patients
Dystonic reaction (kinked neck)
Metoclopramide
MOA
Dopamine receptor antagonist in the CTZ
Promotes motility in upper GI tract by blocking dopamine inhibition of cholinergic smooth muscle
Metoclopramide
Indications
Chemo-induced nausea and vomiting
Upper GI motility effects are good for Diabetic gastroparesis and Gastric stasis
Metoclopramide
Adverse Effects
Etrapyramidal effects
-Tardiev dyskinesia (uncomfortable movements, can’t stop)
Acute dystonic reactions
What is the serotonin receptor antagonist used to palliate nausea/vomiting?
Ondansetron
Ondansetron
MOA
Blocks 5-HT3 receptors in the CTZ and the GI tract
Ondansetron
Indication
Chemo-induced nausea
Radiation-induced nausea
Post-op nausea
