Diarrhoea

Question 1

Names of Opioid Agonist

Answer 1

Loperamide
Diphenoxylate

Question 2

MOA of Loperamide

Answer 2

Bind to opiate receptor in gut wall

Inhibit release of Ach and prostaglandins, reducing propulsive peristalsis

Raise intestinal transit time, but absorption of drug can be affected too

Question 3

ADR of Loperamide

Answer 3

Does not cross BBB, no CNS effects

Question 4

MOA of Diphenoxylate

Answer 4

Reduce epithelial secretion of fluid and electrolytes

Enhance active absorption by mild action on delta receptors

Question 5

ADR of Diphenoxylate

Answer 5

At higher doses can have CNS effects

Long-term use can cause dependence.

Preparations often include atropine to discourage overdose

Question 6

Example of Lyophilizate of killed Lactobacillus Acidophilus

Answer 6

Lacterol Fort

Question 7

MOA of Lacterol Fort

Answer 7

Contains heat-inactivated L. Acidophilus

Adheres onto surface of intestinal cells and normalize intestinal flora by competitive exclusion

Prevent over-colonization of other micro-organisms by blocking their intestinal adherence”

Question 8

Uses of Lacterol Fort

Answer 8

Use in bacterial or ‘traveller’s diarrhoea’

Question 9

ADR of Lacterol Fort

Answer 9

No systemic absorption, little ADR

Need to maintain hydration

Banned for lactose intolerant people

Question 10

Names of Colloidal Bismuth Compounds

Answer 10

Bismuth subsalicylate

Bismuth subcitrate potassium

Question 11

MOA of Bismuth subsalicylate and Bismuth subcitrate potassium?

Answer 11

Bismuth has antimicrobial effect and binds enterotoxins which helps with traveller’s diarrhoea

Bismuth subsalicylate = Reduces stool frequency and lipidity in acute infectious diarrhoea

Question 12

Uses of Bismuth subsalicylate

Answer 12

Traveller’s diarrhoea

Acute infectious diarrhoea

Question 13

Uses of Bismuth subcitrate potassium

Answer 13

Traveller’s Diarrhoea

Question 14

ADR of Bismuth subsalicylate, Bismuth subcitrate potassium

Answer 14

Harmless blackening of stool - may be confused for GI bleeding

Harmless darkening of tongue

Prolonged use can produce bismuth toxicity causing encephalopathy (rare)

Avoid in patients with renal insufficiency

Bismuth Subsalicylate: can cause salicylate toxicity at high doses

Question 15

MOA of Kaolin / Pectin / Dioctahedral Smectite

Answer 15

Absorbents of bacterial toxins and fluid

Lower stool liquidity and number

Question 16

ADR of Kaolin / Pectin / Dioctahedral Smectite

Answer 16

Constipation

Can bind to and inhibit absorption of other meds

Should not be taken within 2 hours of other meds

No systemic absorption so little ADR

Question 17

Name of Bile Salt-Binding Resins

Answer 17

Cholestyramine

Question 18

MOA of Cholestyramine

Answer 18

Cholestyramine is an anion exchange resin

Non-digestible resins that bind to BA in intestine, and increase excretion of BA in faeces

Question 19

ADR of Cholestyramine

Answer 19

Constipation, bloating, flatulence, abdominal pain

Nausea

Question 20

Name of Somatostatin-like peptides

Answer 20

Octreotide

Question 21

MOA of Octreotide

Answer 21

Synthetic somatostatin analogue

Inhibit GI motility, thus controlling watery diarrhoea

Question 22

Uses of Octreotide

Answer 22

Diarrhoea linked to metastatic carcinoid tumours and vasoactive intestinal peptide (VIP) secreting tumours

Chemotherapy-induced diarrhoea (CID)

Question 23

Drugs for Chronic Diarrhoea

Answer 23

Cholestyramine (Bile Salt-Binding Resins)

Octreotide (Somatostatin-like peptides)

Question 24

Which drug is taken with Atropine which tastes bad to prevent addiction?

Answer 24

Diphenoxylate