Antiemetics - Dr. C PowerPoint

Question 1

What is the leading cause of unanticipated hospital admission following outpatient surgery?

Answer 1

PONV and its complications

Question 2

Without prophylaxis, nausea occurs in what percent of patients who receive general anesthesia? Can be as high as ____% in high risk patients.

Answer 2

40%

As high as 80%.

Question 3

A patient who experiences nausea or who vomits within how many hours of a surgical procedure that required anesthesia meets the criteria for PONV diagnosis

Answer 3

24 hours - anything within 24 hours falls under anesthesia

Question 4

Early PONV is NV within?

Answer 4

6 hours

Question 5

Late PONV is NV between?

Answer 5

6-24 hours

Question 6

PONV can be associated with morbidity due to:

Answer 6

Dehydration, electrolyte abnormalities, wound dehiscence from retching, bleeding, esophageal rupture, airway compromise such as aspiration

Question 7

Is emesis always proceeded by nausea?

Answer 7

No

Question 8

The sequence of events that occur during emesis is controlled by? Which lies in the?

Answer 8

Vomiting center in the medulla oblongata

Question 9

A number of neurotransmitters modulate the activity of the vomiting center what are some of these?

Answer 9

*Serotonin, *dopamine, substance P, ACh, GABA, and cannabinoids

Question 10

Slightly superior or cephalad to the vomiting center is the chemoreceptor trigger zone (CTZ), also known as? This area, detects what in the bloodstream?

Answer 10

Area postrema, detects noxious chemicals in the bloodstream

Question 11

Is the chemoreceptor trigger zone within or outside the blood-brain barrier?

Answer 11

Outside the blood-brain barrier, allowing it to sample more chemical chemicals in the blood

Question 12

A number of transmitters modulate the activity of the vomiting center name them

Answer 12

Serotonin, Dopamine, Substance P GABA, Cannabinoids

Question 13

Patient risk factors that increase risk of PONV

Answer 13

women, nonsmokers, hx of motion sickness, previous episodes of PONV

Question 14

Surgical factors that increase risk of PONV

Answer 14

Long surgical procedures, gynecology, laparoscopic, ENT, breast surgery, plastic surgery, orthopedic surgery

Question 15

Anesthetic factors that increase risk of PONV

Answer 15

Use of inhalational anesthetics, including nitrous, neostigmine and opioids

Question 16

What are the current anti-emetic drug classes?

Answer 16

Corticosteroids
Phenothiazines - (compazine)
Butyrophenes -(droperidol, haloperidol)
Benzamides - (reglan)
Anticholinergics
Antihistamines
5-HT3 Antagonists
NK-1 Antagonists
Benzodiazepines

Question 17

Scopolamine works best a preventing what kind of Nausea and Vomiting

Answer 17

Prevention of motion-induced NV

Question 18

How long is one patch of scopolamine good for

Answer 18

24-72 hours

Question 19

What is the most reported side effect of scopolamine

Answer 19

drying of secretions / dry mouth

Question 20

Due to its anti-dopaminergic activity metoclopramide should be used with caution, if at all in patients with?

Answer 20

Parkinson’s disease, restless, leg syndrome, movement disorders related to dopamine, inhibition, and depression

Question 21

What is akathisia?

Answer 21

Can occur after administration of reglan- feeling of unease and restlessness in lower
extremities can occur following IV administration

Question 22

Adult dose of Reglan

Answer 22

10-20mg IV

Question 23

What is the MOA of metoclopramide (reglan)

Answer 23

Week antiemetic, stimulates the GI tract via cholinergic mechanisms that result in features gastric and small intestinal.

Question 24

If using Midazolam for antiemetic effects - when should it be administered during a case?

Answer 24

Should be administered IV towards the end of the case by infusion in intubated and vented patients in the ICU

Question 25

What is believed to be the MOA of midazolam's antiemetic effects?

Answer 25

Believed to decrease dopamine's emetic effect and decrease the release of serotonin

Question 26

What are three antiemetic drugs in the Butyrophenones class?

Answer 26

Droperidol and Haloperidol Barhemsys (Amisulpride)

Question 27

What is the PONV dose for droperidol

Answer 27

0.625-1.25mg

Question 28

What is the PONV dose for haloperidol

Answer 28

0.5-2mg

Question 29

Is droperidol less, the same, or more effective than decadron or zofran?

Answer 29

As effective as both decadron and zofran preventing PONV

Question 30

If using droperidol, when should it be given during the case?

Answer 30

Give at the beginning of the case or as a rescue drug in PACU when all else hasn't worked

Question 31

What population should butyrophenones (droperidol and haloperidol) be used with caution in?

Answer 31

Patients with Parkinson's, restless leg syndrome, or other diseases related to dopaminergic activity. It can cause extrapyramidal symptoms.

Question 32

What is the black box warning for droperidol?

Answer 32

Can prolong QT interval in doses higher than the PONV prophylaxis doses.

Question 33

What is Barhemsys (Amisulpride) MOA?

Answer 33

Selective D2 and D3 receptor antagonist

Question 34

What is Barhemsys (Amisulpride) used for?

Answer 34

approved as a rescue agent for PONV

Question 35

What is the dose of Barhemsys (Amisulpride) ?

Answer 35

recommended dose 5-10mg

Question 36

What patients should you avoid using Barhemsys (Amisulpride) ?

Answer 36

Patients with congenital long QT syndrome

Question 37

Is Barhemsys (Amisulpride) sedating?

Answer 37

advertised as non-sedating

Question 38

Is droperidol sedating?

Answer 38

yes

Question 39

Dose for decadron PONV

Answer 39

4-8mg IV

Question 40

Which pts are at risk for increased perioperative hyperglycemia with a single dose of decadron

Answer 40

Obese and diabetic

Question 41

what dose of droperidol has similar effectiveness as zofran or decadron

Answer 41

1.25mg

Question 42

5-HT3 receptor antagonists can each cause what ecg change

Answer 42

slight prolongation of QTc interval

Question 43

What is the brand name for Dimenhydrinate

Answer 43

Dramamine

Question 44

What is Dimenhydrinate (Dramamine) effective at preventing?

Answer 44

Preventing PONV as well as motion sickness

Question 45

What is the PONV dose of Dimenhydrinate (Dramamine) ?

Answer 45

20mg IV

Question 46

In children, Dimenhydrinate (Dramamine) at what dose can significantly decrease the incidence of vomiting after strabismus surgery

Answer 46

0.5mg/kg IV

Question 47

What is one Neurokinin 1 Receptor Antagonist that can be used for PONV prophylaxis? What dose and when should you give it?

Answer 47

Emend 40mg PO before surgery

Question 48

What is the MOA of Emend?

Answer 48

Substance P and NK-1 receptor antagonists

Question 49

What is believed to be the mechanism behind neurokinin 1 receptor antagonism related to PONV

Answer 49

It is believed to provide antiemetic activity by suppressing their activity at the nucleus of the solitary tract (NST), where vagal afferents from the GI tract converge with inputs from the area postrema (aka chemoreceptor trigger zone) and other regions of that brain that initiate emesis

Question 50

One patch of scopolamine contains how much medication

Answer 50

1.5mg

Question 51

Normal dose of Prochlorperazine (Compazine) for adults

Answer 51

10mg IV

Question 52

Aspiration during GA occurs in ~ 1/? adults and 1/? children

Answer 52

1/8500 adults 1/4400 children

Question 53

What are two situations with an increased risk for aspiration

Answer 53

emergency operations due to full stomachs Bowel obstructions

Question 54

Drugs that increase the pH of gastric contents are called

Answer 54

antacids

Question 55

Drugs that decrease the volume of gastric contents are called

Answer 55

prokinetics

Question 56

How do oral antacids work

Answer 56

Neutralize (remove) hydrogen ions from gastric contents or decrease secretion of hydrogen chloride into the stomach

Question 57

What is the nonparticulate (clear) antacid? What population receives it the most

Answer 57

Sodium Citrate - used in OB

Question 58

What is the benefit of a nonparticulate (clear) antacid?

Answer 58

They are less likely to cause a foreign body reaction if aspirated, and their mixing in gastric fluid is more complete than particulate antacids

Question 59

What is the dose of sodium citrate? When should it be given?

Answer 59

15-30mL and admin 15-30min before induction of anesthesia

Question 60

What are some complications of Antacid Therapy

Answer 60

Bacterial overgrowth in small intestine UTI Urolithiasis Altered Renal Elimination (reflects increased urinary ph) Acid rebound (unique to calcium-containing antacids) Hypophosphatemia Milk-Alkali Syndrome (hypercalcemia, systemic alkalosis) Drug interactions

Question 61

How do Macrolides work in the GI System

Answer 61

increases lower esophageal sphincter tone, enhances intraduodenal coordination, and promotes emptying of gastric liquids. prokinetic properties

Question 62

What are the most effective drugs available for controlling gastric acidity and volume?

Answer 62

Proton Pump Inhibitors

Question 63

What is the MOA of PPIs?

Question 64

Histamine induces what within the body

Answer 64

Contraction of smooth muscles in the airways Increases the secretion of acid in the stomach Stimulates release of neurotransmitters in the CNS

Question 65

How do Histamine Receptor Antagonists work

Answer 65

bind to receptors on effector cell membranes, to the exclusion of agonist molecules, without themselves activating the receptor (histamine receptor antagonists do not inhibit release of histamine)

Question 66

How are H1 receptor antagonists characterized? What are the differences?

Answer 66

First Generation: Tend to produce sedation Second Generation: Relatively nonsedating

Question 67

How fast do H1 receptor antagonists take to reach peak plasma concentrations

Answer 67

Within 2 hours

Question 69

What are the clinical uses of H1 Receptor Antagonists

Answer 69

-Prevent and relieve symptoms of allergic rhinitis. -Used to treat acute anaphylactic rxns -Diphenhydramine used as a sedative, antipruritic, and antiemetic

Question 70

What CNS effects are associated with H1 Receptor Antagonists?

Answer 70

Somnolence Diminished Alertness Slowed Reaction Time Impairment of cognitive fxn

Question 71

What are some possible cardiac side effects of H1 receptor antagonists?

Answer 71

Tachycardia, prolong QTc, heart block, arrythmias

Question 72

MOA of H2 Receptor Antagonists

Answer 72

Produce selective and reversible inhibition of H2 receptor-mediated secretion of hydrogen ions by parietal cells

Question 73

What are some H2 blockers

Answer 73

Cimetidine Famotidine

Question 74

Cimetidine clearance decreases _____% between the ages of 20 and 70 years old

Answer 74

75%

Question 75

What are the nonspecific Anti Histamine Agents

Answer 75

Nonspecific antihistamines, likely acting on H1 receptors, including diphenhydramine, dimenhydrinate, and promethazine

Question 76

What is the MOA of H2 Blockers

Answer 76

H2-receptor antagonists competitively and selectively inhibit the binding of histamine to H2 receptors, thereby decreasing the intracellular concentrations of cAMP and the subsequent secretion of hydrogen ions by the parietal cells

Question 77

How long before induction of anesthesia should omeprazole be administered

Answer 77

>3 hours before induction

Question 78

What is the usual dose of omeprazole? How long until onset effects occur?

Answer 78

20mg PO Occurs within 2-6 hours

Question 79

How does omeprazole reduce aspiration risks

Answer 79

effectively increases gastric fluid pH and decreases gastric fluid volume

Question 80

What is the only drug approved by the FDA for the tx of diabetic gastroparesis

Answer 80

Metoclopramide

Question 81

IV admin of Reglan may be associated with

Answer 81

hypotension tachycardia bradycardia cardiac dysrhythmias

Question 82

Who should not receive GI prokinetic drugs

Answer 82

A patient with a suspected or known mechanical obstruction to gastric emptying