GIT George: drugs+antacids

Question 1

Drug indications involving the GIT

Answer 1

1. Peptic ulcer
2. Laxatives
3. Antidiarrhea
4. Antiemetic

Question 2

2 types of peptic ulcer

Answer 2

1. gastric ulcer

2. duodenal ulcer

Question 3

cause of peptic ulcer

Answer 3

1. excess HCL produced by parietal cells
2. secretion of pepsin in the stomach
3. Helicobacter pylori (especially duodenal ulcer)

Question 4

3 approaches to peptic ulcer tx

Answer 4

1. reduce effect of HCL and pepsin
2. protect base of the ulcer from HCL and pepsin
3. eradicate bacterium involved

Question 5

4 drug classes that reduce the effect of the acid

Answer 5

1. antacids
2. antispasmodics (anticholinergic)
3. Histamine (H2) antagonists
4. Proton pump inhibitors

Question 6

indication for antacids

Answer 6

symptomatic treatment of peptic ulcer to reduce pain associated with the ulcer

Question 7

MOA of antacids

Answer 7

neutralise the effect.

some also inhibit pepsin

Question 8

other uses for antacids (other than peptic ulcer)

Answer 8

oesophageal reflux
dyspepsia (indigestion)
reflux oesophagus
gastritis

Question 9

2 types of antacids

Answer 9

1. non-systemic (do not dissolve and absorbed, do not cause alkalosis)
2. systemic (dissolved and absorbed, may cause alkalosis)

Question 10

5 non-systemic examples

Answer 10

a. MAGNESIUM HYDROXIDE (MILK OF MAGNESIA)
- Causes diarrhoea

b. MAGNESIUM TRISILICATE
- Also adsorbs pepsin
- May cause diarrhoea

c. ALUMINIUM HYDROXIDE
- Also adsorbs pepsin
- Causes constipation

d. CALCIUM CARBONATE
- May cause constipation

e. ALUMINIUM HYDROXIDE/MAGNESIUM HYDROXIDE
- Overcomes constipation or diarrhoea

Question 11

1 systemic example

Answer 11

SODIUM BICARBONATE

Toxicity: Sodium load may pose problems in cardiovascular
Disease Caution: Not wise to use in hypertension, congestive cardiac failure

Question 12

antacids drug interactions

Answer 12

Antacids + Tetracyclines, Digoxin,
Oral Iron, Penicillin,
Chlorpromazine, Cimetidine,]
Indomethacin etc. ]
(ie,Tetracycline etc.)

Form non-absorbable complex & reduce the absorption & effect of other drugs

Question 13

Which product contains non-systemic and systemic antacids?

Answer 13

Gaviscon:

Alginic acid
Magnesium trisilicate
Aluminium hydroxide
Sodium bicarbonate