PreOp Meds: 5HT3 Antagonists & Ondansetron (Zofran) Flashcards
1
Q
Where is serotonin released from and how does it cause emesis?
A
- Released via chromaffin cells of small intestine → vagal stimulation via 5HT3 receptors
2
Q
Where are the highest concentration of serotonin receptors found?
Where else are they commonly found?
A
- Brain & GI tract
- Kidney, liver, lung, stomach
3
Q
What is the greatest general benefit of 5HT3 antagonists?
What are they not useful for?
A
- Very few side effects
- Not useful for motion sickness
4
Q
What is the E ½ time of Ondansetron? Why is this relevant?
A
- 4 hours: dose must be given so that effect peaks towards end of the case.
5
Q
What is the normal dose of Ondansetron?
A
- 4 - 8 mg IV
6
Q
If side effects are seen with ondansetron, what might be seen?
A
- Slight QT prolongation, headache, diarrhea