Antiemetic and antinausea drugs

Question 1

What is nausea?

Answer 1

A sensation often leading to the urge to vomit

Question 2

What is emesis

Answer 2

Forcible emptying of gastric and occasionally intestinal contents

Question 3

What is responsible for initiating the physiological events leading to nausea and vomiting?

Answer 3

Vomiting Centre (VC)

Question 4

What sends signals to the VC

Answer 4

Chemoreceptor Trigger zone (CTZ)

Question 5

What happens when the VC and CTZ are stimulated and where are they located?

Answer 5

The vomiting reflex occurs
Both located in the brain

Question 6

What are the three types of nausea and vomiting?

Answer 6

Chemotherapy induced
Postoperative
General

Question 7

What are the 3 pathways that send signals to the CTZ

Answer 7

Labyrinth (inner ear)
GI tract
Cerebral cortex

Question 8

What are the 7 types of antiemetics and antinausea drugs

Answer 8

Anticholinergics
Antihistamines
Antidopaminergic
Neurokinin agonists
Prokinetic drugs
Serotonin blockers
Tetrahydrocannabinoids

Question 9

What is the MOA of anticholinergic drugs and what is an example

Answer 9

Bind to and block ach receptors in the labyrinth therefore blocking transmission of stimuli to the CTZ and VC
Scopolamine

Question 10

What is the MOA of antihistamines drugs and what is 2 examples?

Answer 10

Inhibit ach by binding to H1 receptors
Prevent cholinergic stimulation in vestibular and reticular areas
Dimenhydrinate
Diphenhydramine

Question 11

What is the MOA of antidopaminergic drugs and what is an example

Answer 11

Block dopamine receptors in the CTZ
Prochlorperazine

Question 12

What is the MOA of neurokinin receptor antagonists and what is an example

Answer 12

Inhibit substance P/neurokinin 1 receptors in the brain stem
Used in conjunction with serotonin blockers and glucocorticoids
Used primarily for chemo-induced emesis
Aprepitant

Question 13

What is the MOA of prokinetic drugs and what is an example

Answer 13

Block dopamine receptors in the CTZ resulting in the CTZ becoming desensitized to impulses from the GI
Also stimulates peristalsis in the GI tract
Metoclopramide

Question 14

What can happen as a result of long term use of metoclopramide

Answer 14

Irreversible tardive dyskinesia

Question 15

What is the MOA of serotonin blocks and what is an example

Answer 15

Block serotonin receptors in the GI tract, CTZ and vomiting center
Used primarily for chemo-induced and post op nausea and vomiting
Ondansetron

Question 16

What is the MOA of THC and what is an example

Answer 16

Alters mood and body’s perception of its surroundings, which may help relieve nausea and vomiting
Medical marijuana

Question 17

What is doxylamine succinate and Pyridoxine HCL and what is the combination called

Answer 17

An antinausea drug used for morning sickness with pregnancy
Diclectin

Question 18

What is an herbal product used for nausea and vomiting and what are its interactions, adverse effects?

Answer 18

Ginger
Increased absorption of oral medications
Increased bleeding risk with anticoagulants
Anorexia, nausea, vomiting and skin reactions

Question 19

Many of these drugs can cause severe ________

Answer 19

Drowsiness

Question 20

What can happen when antinausea and antiemetics are taken with alcohol

Answer 20

Severe CNS depression

Question 21

Antiemetics are often given _________ before chemotherapy begins

Answer 21

30 to 60 minutes