Exam 3- Antiemetics And Adjuncts Flashcards
What are the antihistamine receptors?
H1 and H2 receptor antagonists
Where do stimulation of H1 receptors occur?
In GI tract
What does H1 receptors lead to?
Contraction of intestinal smooth muscle
Where does the stimulation of H2 receptors occur?
In parietal cells
What does H2 receptors do?
Increase gastric acid secretion H+
What are H2 blockers used for (5)
- Duodenal and gastric ulcers
- Zollinger Ellison syndrome
- GERD
- IV for critical patients to prevent stress ulcers (stress ulcer prophylaxis)
- Reduce peri-op risk of aspiration pneumonia
What does H2 blockers effect?
pH (acid secretion)
How can H2 be used to reduce aspiration risk? (2)
- Given at bedtime the night before and 2 hours before procedure
- Depends on renal elimination
Are H1 blockers used primarily to prevent aspiration?
NO
What are H2 blockers (4)?
- Ranitidine
- Famotidine
- Nizatidine
- Crimetidine
What is Proton Pump Inhibitor (PPI) and how does it work?
Inhibit acid secretion by binding to the K+ H+ pump
What is PPI used for (3)?
- Duodenal ulcer
- GERD
- Stress ulcer prophylaxis
What are the 3 PPI?
- Pantoprazole
- Lansoprazole
- Omeprazole
What is metoclopramide?
Dopamine receptor antagonist -central
When is metoclopramide used for in chronic therapy?
Primarily for patients with diabetic gastroparesis
Where does metoclopramide elimination occur?
Renal
What do you treat metoclopramide adverse effects with?
Anti muscarinic (or diphenhydramine)
Patent related risk factors (3)
- female
- nonsmoking
- history of PONV or motion sickness
Anesthetic related risk factors (3)
- inhaled anesthetics
- nitrous oxide
- opioids
Surgery related risk factors (2)
- duration
- type of surgery
Each 30 min of surgery relates to what PONV?
Increase risk of 60%
5 neurotransmitter receptors:
- Muscarinic (M1)
- Dopamine (D2)
- Histamine (H1)
- Serotonin (5HT3)
- Neurokinin 1 (NK1) - substance P
6 pharmacological options
- Antimuscarinic
- Dopamine (D2) receptor antagonist
- Antihistamine
- 5HT3 receptor antagonist
- NK1 receptor antagonist
- Corticosteroid
Where and what can the nausea and emesis be triggered by?
Higher cortical centers communicating with the central pattern generator in the medulla
In peri-op the stimulation of what are central stimuli that may cause N&V?
Vestibular system
2 rescue antiemetic:
Use agent of another class
- prochlorperazine
- droperidol
Where are the 5HT3 receptors:
GI tract and CTZ (brain)
When are 5HT3 emesis attributable?
Vagal stimulation in post-op and chemo
When is 5HT3 receptor antagonists useful for?
Prevention and treatment of vomiting near end of surgery or rescue therapy in PACU
Do 5HT3 receptor antagonists have sedative side effects?
NO
What kind of metabolism does 5HT3 receptor antagonists have?
Liver
What is a risk of 5HT3 receptor antagonists?
Prolonged QT
4 5HT3 receptor antagonists?
- Ondansetron
- Granisetron
- Dolasetron
- Palonosetron
Of the 5HT3 receptor antagonists, which has the longest half life?
Palonosetron
Other use for dexamethasone?
Decrease ICP
2 possible risks for dexamethasone?
- Impaired glucose tolerance
2. Risk of wound infection
What is a antimuscarinic?
Scopolamine
Where do D2 receptor block?
CTZ
2 common D2 blockers?
Butyrophenones
Droperidol
Which dopamine blocker is not used in children (4)
Droperidol
Perphenazine
Promethazine
Prochlorperazine
Box warning for droperidol?
QT prolongation risk
Arrhythmia tornadoes de pointe
Adverse effect of dopamine receptor blocker?
Acute dystonic reaction
How do you treat dopamine receptor blockers adverse effects?
Antimuscarinic (or diphenhydramine)
Where do NK1 antagonist inhibition occur?
At both central and peripheral receptors
What is a NK1 receptor antagonist?
Aprepitant
Acupuncture where can help with PONV
Median nerve
