Diarrhoea

Question 1

What are the 6 groups of drugs used to treat diarrhoea?

Answer 1

1. Opoid agonists
2. Colloidal bismuth compounds
3. Intestinal adsorbents
4. Lacteol fort
5. Bile salt-binding resins
6. Somatostatin-like peptides

Question 2

What is first-line for rapid, symptomatic relief of diarrhoea?

Answer 2

Loperamide
Diphenoxylate + atropine

Opoid agonists

Question 3

Which anti-diarrhoeal drug increases risk of cardiac abnormalities on overdose?

Answer 3

Loperamide

Question 4

MOA of opoid agonists?

Answer 4

Agonist of mu opioid receptors in the intestine, decreasing activity of the enteric nervous system and increasing intestinal transit time

Question 5

Which anti-diarrhoeal drug causes harmless blackening of stools & tongue?

Answer 5

Bismuth compounds

Question 6

MOA of bismuth compounds?

Answer 6

Binds to enterotoxins & weak antimicrobial effect against bacteria that cause diarrhoea

Question 7

What benefit does the bismuth subsalicylate formulation have?

Answer 7

Subsalicylate is a NSAID

Inhibits intestinal PGE production & Cl- secretion, reducing stool frequency and liquidity

Question 8

Severe adverse effect of bismuth compounds?

Answer 8

Encephalopathy

Question 9

What patients should avoid taking bismuth compounds?

Answer 9

Renal insufficiency

Question 10

Name 2 examples of intestinal adsorbents

Answer 10

Kaolin
Diosmectite

Question 11

MOA of diosmectite?

Answer 11

Adsorbent of bacteria, toxins & fluid

Decreases stool liquidity and number

Question 12

MOA of lacteol fort?

Answer 12

Adheres onto surface of intestinal cells & normalises the intestinal flora by competitive exclusion, decolonising the harmful organisms

Question 13

Lacteol fort is contraindicated in ________ patients

Answer 13

Lacteol fort is contraindicated in lactose intolerant patients

Question 14

Which groups of patients is colestyramine indicated in?

Answer 14

Patients with diseases of the ileum or surgical resection of the terminal ileum

Question 15

MOA of colestyramine?

Answer 15

Binds & sequesters bile salts, alleviating osmotic diarrhoea caused by excess fecal bile salts

Question 16

Why does resection/disease of the ileum cause diarrhoea?

Answer 16

Bile salts are unable to be reabsorbed by the ileum, causing the osmotically active bile salts to remain in the GIT, hence causing osmotic diarrhoea

Question 17

Name an example of a somatostatin-like peptide

Answer 17

Octreotide

Question 18

MOA of octreotide?

Answer 18

Mimics somatostatin hormone released in the GIT

Inhibits release of various transmitters & hormones, reduces intestinal & pancreatic secretions and slows GI motility

Question 19

What is ocreotide indicated in?

Answer 19

Secretory diarrhoea caused by GI and neuroendocrine tumours

Question 20

Adverse effects of ocreotide?

SGBH

Answer 20

Steatorrhoea due to impaired pancreatic secretion
Gallstones
Bradycardia
Hypothyroidism (in prolonged treatment)
Nausea, abdominal pain, flatulence, diarrhoea

Question 21

What should be the advice given to patients when taking diosmectite & colestyramine?

Answer 21

Avoid oral drugs within 2 hours

Question 22

What are the anti-diarrhoeal drugs indicated for traveller’s diarrhoea?

Answer 22

Opoid agonists (first-line)
Diosmectite
Bismuth compounds
Lacteolfort