GI system

Question 1

Antacids

Answer 1

Aluminium & magnesium hydroxide/calcium carbonate

MoA - gastric acid neutralisation

Indication - dyspepsia, heartburn

Adverse effects - nausea

Question 2

Antacid + alginates

Answer 2

Sodium alginate with sodium bicarbonate

MoA - gastric acid neutralisation

Indication - gastric reflux

Adverse effects - abdo distension

Question 3

H2-receptor antagonists

Answer 3

Famotidine, Cimetidine

MoA - Blockade of gastric H2 histamine receptors

Indications - stomach ulcers

Adverse effects - dizziness

Question 4

Proton-pump inhibitors

Answer 4

Omeprazole, lansoprazole

MoA - blockade of stomach acid transporters

Indication - Stomach and duodenal ulcers, gastric reflux

Adverse effects - headache, diarrhoea

Interactions - warfarin

Question 5

Pancreatic enzymes

Answer 5

Pancreatin

MoA - restoration of pancreatic enzymes

Indication - pancreatic insufficiency - cystic fibrosis, pancreatitis

Question 6

Bulk laxatives

Answer 6

Methylcellulose, Isphagula husk

MoA - Water absorption in intestinal lumen to bulk stools

Indication - constipation

Adverse effects - rare

Question 7

Faecal softener

Answer 7

Docusate, arachis oil

MoA - Stimulates water & electrolyte secretion into intestinal lumen

Indication - constipation

Question 8

Osmotic laxatives

Answer 8

Macrogol (PEG), Lactulose,
Magnesium Sulphate, Magnesium Hydroxide

MoA - Water retention in intestinal lumen

Indication - constipation

Adverse effects - stomach cramps

Interactions - anti epileptics

Question 9

Stimulant laxatives

Answer 9

Bisacodyl, Senna

MoA - Increase intestinal motility

Indication - Constipation

Adverse effects - nausea

Question 10

Opioid anti-motility agents

Answer 10

loperamide, codeine

MoA - Agonist for µ-opioid receptors in myenteric plexus. Blocks intestinal muscarinic receptors

Indication - diarrhoea