23. Drugs Affecting Acid Secretion

Question 1

What are the defensive factors of the gastric mucosa?

Answer 1

Epithelial integrity, cell replication and restitution, mucous membrane barrier, vascular supply.

Question 2

What are the aggressive factors of the gastric mucosa?

Answer 2

Acid, helicobacter pylori, drugs.

Question 3

What are the targets for drugs to act on the parietal cell?

Answer 3

Stimulatory receptors of the baso-lateral membrane, and the proton pump.

Question 4

What are the receptors on the baso-lateral membrane of the parietal cell?

Answer 4

Acetylcholine, cholecystokinine B (CCK-B), histamine 2 receptors.

Question 5

What is the receptor of the apical membrane of the parietal cell?

Answer 5

HK ATPase exchanger - the proton pump.

Question 6

What is the main target for drugs in peptic disorders?

Answer 6

Proton pump.

Question 7

What is the action of PPI?

Answer 7

Blocks the HKATPase on apical membrane of parietal cells. The pump has to be active for it to work on it.

Question 8

When do PPIs have maximum efficacy?

Answer 8

After 2-3 days.

Question 9

Why do patients normally feel immediately better having taken H2 receptor antagonists?

Answer 9

Because they have a short half life so act quickly.

Question 10

What is the dosing of H2 receptor antagonists?

Answer 10

Twice daily.

Question 11

What are the neuroendocrine regulators that act on parietal cells?

Answer 11

Cholecystokinine B, histamine, dopamine, gastrin.

Question 12

What percentage of duodenal ulcer cases have H. pylori infection?

Answer 12

96%.

Question 13

What percentage of gastric ulcer cases have H. pylori infection?

Answer 13

75%.

Question 14

What is the step up ladder used in drugs for peptic disorders?

Answer 14

Anatacids -> alginates -> H2 receptor antagonists -> PPIs.

Question 15

What are the issues with using the H2RA cimetidine?

Answer 15

ADRs: gynaechomastia in men. DDIs: inhibits CYP450 metabolism.

Question 16

Name four H2RA.

Answer 16

Cimetidine, ranitidine, nizatidine, famotidine.

Question 17

Name five PPIs.

Answer 17

Omeprazole, lansoprazole, rabeprazole, pantoprazole, esomeprazole.

Question 18

What are the two goals of GORD treatment?

Answer 18

Symptom control, and healing of the oesophagitis.

Question 19

What are the steps taken in managing GORD in primary care?

Answer 19

Lifestyle, antacids/alginates, H2RA, PPI.

Question 20

What are the steps taken in managing GORD in secondary care?

Answer 20

PPI, H2RA, antacids/alginates, lifestyle.

Question 21

What is the epithelial change in Barrett’s oesophagus?

Answer 21

Squamous to columnar.

Question 22

What are the risks of Barrett’s oesophagus and how can they be avoided?

Answer 22

Cancer and strictures. Use PPIs for life

Question 23

What actions should be taken in the case of peptic ulceration?

Answer 23

Stop NSAIDs, H2RA/PPI for 6 weeks, H pylori eradication.

Question 24

How is H pylori eradicated?

Answer 24

2 antibiotics (clarithromycin + amoxycillin) + full acid blockade with PPI.