Gastrointestinal

Question 1

What drug class is Gaviscon?

Answer 1

Alignate and Antacid

Question 2

What is Gaviscon indicated for?

Answer 2

GORD symptomatic relief

Dyspepsia - short term relief

Question 3

How do antacids work?

Answer 3

Buffer stomach acids

Question 4

How do alignates work?

Answer 4

Increase viscosity of stomach contents

React with stomach acid to form a floating raft which separates contents from gastro-oesophageal junction

Question 5

Name an alternative to Gaviscon?

Answer 5

Peptac

Question 6

What are the side effects of compound alignates?

Answer 6

Magnesium salts
-Diarrhoea
Aluminium salts
-Constipation

Question 7

What are the contraindications of compound alignates?

Answer 7

Not given to infants with thickened milk preparations

Renal failure

Question 8

Important drug interactions of compound alignates?

Answer 8

Antacids can reduce serum concentrations of many drugs e.g. ACEi, Cephalosporins, Digoxin, PPI etc
Need to take at different times to these drugs

Question 9

What drug class is Ranitidine?

Answer 9

Histamine H2 receptor antagonists

Question 10

What are H2 receptor antagonists indicated for?

Answer 10

Peptic Ulcer disease

GORD

Question 11

How do H2 receptor antagonists work?

Answer 11

Reduce gastric acid secretion
Can do this as acid comes in via the proton pump
Histamine among other substances regulates the pump

Question 12

What are the side effects of H2 receptor antagonists?

Answer 12

Few side effects

Question 13

What are the contraindications of H2 receptor antagonists?

Answer 13

Reduce dose in renal impairment

They can disguise symptoms of gastric cancer

Question 14

Important drug interactions of H2 receptor antagonists?

Answer 14

None

Question 15

What drug class is Omeprazole?

Answer 15

PPI

Question 16

What are PPIs indicated for?

Answer 16

Prevention and treatment of Peptic Ulcer Disease
Symptomatic relief of Dyspepsia and GORD
H. Pylori infection

Question 17

How do PPIs work?

Answer 17

Irreversibly inhibit the proton pump of gastric parietal cells almost completely

Question 18

What are the side effects of PPIs?

Answer 18

GI disturbance
Headache
Prolonged treatment hypomagnesaemia

Question 19

What are the contraindications of PPIs?

Answer 19

Can disguise symptoms of gastric cancer

Can increase the risk of a fracture - so Osteoporosis

Question 20

Important drug interactions of PPIs?

Answer 20

Omeprazole acts on P450 and can reduce antiplatelet effect of Clopidogrel

Question 21

What drug class is Loperamide?

Answer 21

Antimotility drug

Question 22

What are Antimotility drugs indicated for?

Answer 22

Diarrhoea

Question 23

How do Antimotility drugs work?

Answer 23

Opioid - (other opiods have similar effects but loperamide has no analgesic effect)
It is an agonist of the opioid receptors in the GI tract
Reduces peristalsis
Increases non-propulsive contractions
Transit of bowel contents is slowed and anal sphincter tone is increased

Question 24

What are the side effects of Antimotility drugs?

Answer 24

GI effects

Question 25

What are the contraindications of Antimotility drugs?

Answer 25

Acute ulcerative colitis C Dif colitis Dysentery - risk of HUS with E. Coli O157

Question 26

Important drug interactions of Antimotility drugs?

Answer 26

None

Question 27

What drug class is Senna?

Answer 27

Stimulant Laxative

Question 28

What are the types (5) of laxatives?

Answer 28

``` Bulk-forming Stimulant Osmotic Lubricant Stool-softener ```

Question 29

What are laxatives indicated for?

Answer 29

Constipation | As suppositories for faecal impaction

Question 30

How do stimulant laxatives work?

Answer 30

Increase water and electrolyte secretion Increase volume of colonic content Stimulating peristalsis

Question 31

What are the side effects of stimulant laxatives?

Answer 31

Abdominal Pain | Cramping

Question 32

What are the contraindications of stimulant laxatives?

Answer 32

Intestinal obstruction can lead to perforation Haemorrhoids - avoid suppository Anal fissure - avoid suppository

Question 33

Important drug interactions of stimulant laxatives?

Answer 33

None

Question 34

What drug class is Mesalazine?

Answer 34

Aminosalicylates

Question 35

What are Aminosalicylates indicated for?

Answer 35

Mesalazine - Ulcerative Colitis | Sulfasalazine - Rheumatoid Arthritis - used as DMARD

Question 36

How do Aminosalicylates work?

Answer 36

Ulcerative Colitis: - Release 5-aminosalicylic acid - anti-inflammatory and immunosuppressive effects

Question 37

What are the side effects of Aminosalicylates?

Answer 37

``` GI upset Headache Leucopenia Thrombocytopenia Renal impairment Oligospermia ```

Question 38

What are the contraindications of Aminosalicylates?

Answer 38

Aspirin hypersensitivity - salicylates like aspirin

Question 39

Important drug interactions of Aminosalicylates?

Answer 39

PPIs increase gastric pH, meaning coating may be broken down prematurely Lactulose lowers stool pH prevents coating being broken down in colon

Question 40

What drug class is Metoclopramide?

Answer 40

Antiemetics (dopamine receptor antagonists)

Question 41

What are dopamine receptor antagonists indicated for?

Answer 41

Prophylaxis and treatment of nausea and vomiting

Question 42

How do dopamine receptor antagonists work?

Answer 42

There is a vomiting centre in the medulla Receives inputs from the chemoreceptor trigger zone (CTZ) Dopamine receptor is the main one in the CTZ Antagonists don't trigger this Also have a prokinetic effect - promote gastric emptying

Question 43

What are the side effects of dopamine receptor antagonists?

Answer 43

Diarrhoea | Can induce extrapyramidal syndromes - movement abnormalities

Question 44

What are the contraindications of dopamine receptor antagonists?

Answer 44

Children Young adults GI obstruction due to prokinetic effect Perforation

Question 45

Important drug interactions of dopamine receptor antagonists?

Answer 45

Antipsychotics have similar effect with extrapyramidal syndromes, so combining is bad Not combined with dopaminergic agents in Parkinson's

Question 46

What type of antiemetic is cyclizine?

Answer 46

Histamine

Question 47

Side effects with cyclizine?

Answer 47

Drowsiness | Dry throat and mouth due to anticholinergic effects