Antiemetic Drugs (84)

Question 1

Brain regions responsible for vomiting reflex

Answer 1

Vomiting center: medulla oblongata, coordinates muscles involved in vomiting

Chemoreceptor trigger zone: medulla oblongata, once stimulated and leads to vomiting reflex

Question 2

Complex mechanism involves several neurotransmitters

Answer 2

-histamine
-ACh
-5 HT
-dopamine
-substance P

Question 3

Most antiemetic drugs are receptor ____

Answer 3

Antagonists
-inhibit neurotransmitter action in vomiting reflex

Question 4

Antiemetic drugs are used in multiple causes of nausea and vomiting such as

Answer 4

-cancer chemotherapy induced
-postoperative with general anesthesia
-motion sickness

Question 5

5 HT antagonists MOA

Answer 5

Block 5 HT3 receptors in CTZ and GI

Question 6

Example of 5 HT antagonists

Answer 6

Ondansetron

Question 7

Dopamine receptor antagonists

Answer 7

Block DA receptors in the CTZ

Question 8

DA receptor antagonists used for other indications

Answer 8

Antipsychotic agents and pro kinetic agents

Question 9

Chlorpromazine

Answer 9

Blocks DA receptors in the CTZ
-more severe vomiting like CINV and radiation therapy

Question 10

Anticholinergic agents MOA

Answer 10

Block ACh receptors in the inner ear labyrinth
-nauseating stimuli to VC
-also block transmission of nauseating stimuli from the reticular formation to the VC

Question 11

Example of Anticholinergic agents

Answer 11

Scopolamine

Question 12

Scopolamine

Answer 12

Used for motion sickness
-patch behind the ear

Question 13

Antihistamine agents MOA

Answer 13

Block H1 receptors
-prevent cholinergic stimulation
-traditional antihistamine

Question 14

Dimenhydrinate

Answer 14

Antihistamine drug

Question 15

Ondansetron AE

Answer 15

Dysrhythmias
-long Q/T

Question 16

DA antagonists AE

Answer 16

Movement disorders

Question 17

Scopolamine AE

Answer 17

Typical Anticholinergic effects

Question 18

Antihistamines AE

Answer 18

Sedation and typical Anticholinergic effects

Question 19

Glucocorticoids indications

Answer 19

Used to suppres cancer chemotherapy N/V
-effective alone and in combination with other antiemetic drugs

Question 20

Aprepitant is a

Answer 20

Substance P/neurokinin 1 receptor antagonist

Question 21

Aprepitant

Answer 21

-Blocks neurokinin 1 type receptors in CTZ
-prevents postoperative and cancer chemotherapy N/V
-prolonged duration of action

Question 22

Tetrahydrocannabinoids

Answer 22

Synthetic derivates of psychoactive substance in marijuana

Question 23

Nabilone, dronabinol

Answer 23

Used for N/V with chemotherapy
-withdrawn in Canada

Question 24

When are antiemetic drugs given when used for chemotherapy

Answer 24

30 min to 3 hours before chemotherapy