GI Meds + Intro to Vasopressors - Final Wrapup Flashcards
What are the Nausea & Vomiting Pathways?
Medulla
Chemoreceptor Trigger Zone
Vestibular Neural Pathway
Reflex & Midbrain Afferent Pathway
What is considered Early PONV?
2-6 Hrs
What is considered Late PONV?
6 - 24 Hrs
What is Considered Delayed PONV?
> 24 Hrs.
What is the population most at risk for PONV?
Non Smoking Female who is younger than 50 years old w/ a PONV hx.
How do risk factors relate to incidence of PONV?
Each risk factor = 20%
No risk factors = 10%
Which drugs can cause PONV?
Anesthetic Gas, N2O, and Opioids
What are the PONV risk factors for Kids?
> 3 years old
Strabismus Surgery
Surgery > 30 Min
Family Hx
What are some Anesthesia Considerations to reduce PONV?
Use Propofol
Regional Anesthesia
NSAIDs over Opiates
Should Neostigmine be reduced due to it’s PONV side effect?
No, Not Recommended
What do you do if PONV pretreatment does not work?
Try medication w/ different MOA
Which meds are recommended for Post Discharge N/V?
Dexamethasone
Scopolamine Patch
&
Rescue Meds
(Zofran, Phenergan)
Which meds are more effective when given BEFORE Induction?
Dexamethasone
Scopolamine Patch
Aprepitant
Amisulpride (Barhemsys)
Out of Zofran, Droperidol, and Dexamethasone, which drug is most effective for PONV?
All Equally Effective
Which drugs are classified as 5HT3 Antagonists?
5HT3 = Serotonin
Drugs that end in -setron
How are 5HT3 metabolized?
CYP450
What is the Half Life of Ondansetron?
4 Hrs
What is the Half Life of Granisetron?
9 - 11 Hrs
What is the Half Life of Dolasetron?
Prodrug
7 - 9 Hrs
What is the Half Life of Palonosetron?
40 Hrs
What are the Side Effects of 5HT3 Antagonists?
Generally Mild
QTc Prolongation
How might Dexamethasone work?
- Glutocorticoid Receptors in brain reduce emetic activity
- ↓Prostaglandin Synthesis to reduce GI contraction
- ↓Serotonin Activity
- ↓Anti-Inflammatory & Pain Effects
- ↑ Endorphins
- Augments other Antiemetics
What are the Side Effects of Dexamethasone?
- Low Risk for Single Dose
- Long Term use:
- Impaired wound healing
- ↑Glucose
- HTN
- AMS
Which D2 Antagonist is classified as Butyrophenone?
Droperidol
What effects does Droperidol have?
Anti-Emetic
Anti-Histamine
Anti-Serotonergic
Why is Droperidol normally given Post-Operatively vs Pre-Operatively?
Onset: 5-10 min
Peaks @ 1 Hr.
What are the Side Effects of D2 Blockers?
Dysphoria
Hypotension
Extrapyramidal Symptoms
Sedation
QT Prolongation
What is Droperidol’s Black Box Warning?
QT Prolongation & Sudden Cardiac Death
Rare
Must have ECG Monitoring for 3 hours
Which drugs are classified as D2 Phenothiazines?
Promethazine & Prochlorperazine
How do Phenothiazines compare to Butyrophenone D2 blockers?
More Highly Sedating & Highly Antihistaminergic
Also Available in Tabs, Gels, Suppository, Liquid
Which D2 Blocker was recently approved for only PONV?
Amisulpride (Barhemsys)
IV Only
How does Reglan work?
D2 Antagonist tht acts on CTZ for its Antiemetic Effects, mainly used for Gastric Emptying
- Increases Lower Esophageal Sphincter Tone
- Enhances Peristaltic Contractions & Gastric Emptying
- Does NOT alter Hydrogen Ion Secretion
How is Reglan Eliminated?
Liver & Kidneys
Crosses BBB & Placenta
Also Excreted in Breast Milk
What are Side Effects of Reglan?
Abdominal Cramps
Akathesia