Pharmacology of Ulcers and Inflammation

Question 1

Symptoms of gastric bleeds

Answer 1

Bleeding/perforation
Inflammation
Irritation and abdominal pain

Question 2

How do ulcers occur?

Answer 2

Mucusal defense becomes overwhelmed by acid and other factors such as H. pylori

Question 3

What protective factors are present at the gastric epithelial layer? (6)

Answer 3

1) Mucosal lining
2) Secretion of HCO3-
3) Mucosal blood flow
4) Protective prostaglandins (PGE2)
5) Epithelial tight junctions
6) Epithelial regeneration

Question 4

What is the role of prostaglandins in gastric protection?

Answer 4

PGE2

1) Receptors on mucosal goblet cells: stimulate secretion of HCO3 (cAMP pathway)
2) Receptors on parietal cells: dampen down acid secretion by blocking secretion stimulated by histamine via the cAMP pathway

Question 5

What is an example of a drug which is pro-ulcerative?

Answer 5

Aspirin

Question 6

Acid stimulators

Answer 6

ACh
Gastrin
Histamine
CCK (cholecystokinin)

Question 7

Treatments for peptic ulcers

Answer 7

Proton pump inhibitors (omeprazole)
H2 antagonists (ranitidine)
Antacids (gaviscon)
Prostaglandin analogues
Mucosal strengtheners (bismuth chelates, sulcralfate)

Antibiotics (H. pylori)

Question 8

Examples of antacids and how they work

Answer 8

Al(OH)3, MgCO3, NaHCO3 (Gaviscon)
- Neutralise acid (cation is not absorbed- Al causes constipation and Mg causes laxation)

• ST effect: As pH increases, more acid is secreted (rebound effect)
• No more than 4 weeks

Question 9

What are prostaglandin analogues? Examples and how they work?

Answer 9

Misoprostol

• mimics effects of endogenous PGE2
• antisecretory and cytoprotective (promotes healing)
• can be used as prophylaxis for elderly requiring NSAIDS

Question 10

What are mucosal strengtheners?

Answer 10

Bismuth chelate: coats ulcer

Sulcralfate: protects ulcer and enhances mucus secretion