GIT

Question 1

Using your knowledge of the physiology of acid secretion in the stomach, discuss why the proton pump inhibitors are the strongest medications for the treatment of gastric ulceration.

Answer 1

There are various stimuli that all result in acid being secreted into the stomach e.g. neurocrine (acetylcholine), paracrine (histamine) and endocrine (gastrin). Proton pump inhibitors are the most effective anti-ulcer medications because they will stop the release of acid into the stomach irrespective of the initiating cause. All other anti-ulcer medications are limited to more specific causes of acid secretion in the stomach.

Question 2

Select the drug that is not an anti-emetic.
a. Prochlorperazine.
b. Metoclopramide.
c. Maropitant.
d. Omeprazole.
e. Ondansetron.

Answer 2

Omeprazole.

Question 3

What are the classes of drugs used to induce emesis?

Answer 3

Emetics

Question 4

What are the classes of drugs used to prevent vomiting?

Answer 4

Anti-emetics

Question 5

What are the drugs that halt diarrhoea called?

Answer 5

Anti-diarrhoeals

Question 6

What are the drugs that promote voluminous stools?

Answer 6

Laxatives

Question 7

What are the drugs that promote gut motility?

Answer 7

Pro-kinetics

Question 8

What are the drugs that ameliorate GI ulcers?

Answer 8

Anti-ulcers

Question 9

What are the drugs that bind toxins?

Answer 9

Toxin binders

Question 10

What is the mechanism of action of Apomorphine?

Answer 10

Dopamine agonist at the emetic centre/CTZ

Question 11

What is the mechanism of action of Xylazine?

Answer 11

Alpha-2 agonist at the CTZ

Question 12

Why prevent vomiting?

Answer 12

To prevent loss of water, pain, electrolytes, and nutrients

Question 13

What is Metoclopramide commonly used for?

Answer 13

Anti-emetic and weak prokinetic

Question 14

What neurotransmitters does Metoclopramide act on?

Answer 14

Dopamine and 5-HT

Question 15

What is the duration of action for Metoclopramide?

Answer 15

Up to 6 hours

Question 16

What type of action does Prochlorperazine have?

Answer 16

Antidopaminergic and antihistaminergic effects

Question 17

What does Ondansetron block?

Answer 17

Serotonin (5-HT3) receptors

Question 18

What is Maropitant’s mechanism of action?

Answer 18

Neurokinin-1 blocker

Question 19

What is the primary concern with using anti-diarrhoeals?

Answer 19

They may mask an underlying disease

Question 20

What is Kaolin used for?

Answer 20

Absorbs toxins and halts diarrhoea

Question 21

What is Loperamide commonly known as?

Answer 21

Imodium

Question 22

What is the purpose of activated charcoal?

Answer 22

Universal antidote that adsorbs various compounds

Question 23

What are the two types of laxatives?

Answer 23

Emollient laxatives and bulk laxatives

Question 24

What is the action of magnesium sulfate?

Answer 24

Osmotic cathartic

Question 25

What is the role of Cisapride?

Answer 25

Prokinetic agent that increases motility

Question 26

What is the mechanism of Hyoscine?

Answer 26

Antimuscarinic that reduces GIT cramping

Question 27

What stimulates stomach acid production?

Answer 27

Gastrin, ACh, histamine

Question 28

What do proton pump inhibitors do?

Answer 28

Inhibit acid secretion irrespective of the cause

Question 29

What is Sucralfate used for?

Answer 29

Forms a paste-like complex that binds to ulcerated areas

Question 30

What is the mechanism of action of Omeprazole?

Answer 30

Proton pump inhibitor

Question 31

Is Omeprazole an anti-emetic?

Answer 31

False, it is an anti-ulcer drug

Question 32

What should be considered before using anti-emetics?

Answer 32

Rule out GIT obstruction

Question 33

What is the potential side effect of Hyoscine?

Answer 33

Ileus, urine retention, tachycardia

Question 34

What is the common use of Docusate sodium?

Answer 34

Surfactant action on stool

Question 35

What are the side effects of laxatives?

Answer 35

Dehydration, electrolyte imbalance

Question 36

What is the effect of opioids in anti-diarrhoeals?

Answer 36

Increased segmental tone and decreased propulsive contraction