Gastrointestinal

Question 1

Hyoscine butylbromide

Answer 1

(Antimuscarinics)

Irritable bowel syndrome (for its antispasmodic effect)

Question 2

(Acetylcysteine)

Answer 2

Paracetamol metabolised into N-acetyl-p-benzoquione imine (NAPQI). NAPQI is hepatotoxic, and detoxified with conjugation with glutathione. Acetylcysteine replenishes glutathione supple in paracetamol poisoning.
Also has antioxidant effects. Also breaks disulphide bonds in mucus to decrease viscosity.

Antidote for paracetamol poisoning
Prevent renal injuring from radiographic contrast
Reduce viscosity of respiratory secretions

Question 3

(Alginates and antacids)

Answer 3

Antacids buffer stomach acids. Alginates increase viscosity of stomach content, preventing reflux.

Question 4

Gaviscon

Answer 4

(Alginates and antacids)
Gatro-oesophageal reflux disease
Dyspepsia

Question 5

Antacids

Answer 5

(Alginates and antacids)
Gatro-oesophageal reflux disease
Dyspepsia

Question 6

(Aminosalicylates)

Answer 6

Mechanism unknown, but has anti-inflammatory and immunosuppressive effects.
✖Aspirin hypersensitivity

Question 7

Mesalazine

Answer 7

(Aminosalicylates)

+ corticosteroids to treat ulcerative colitis

Question 8

Sulfasazine

Answer 8

(Aminosalicylates)

Rheumatoid arthritis

Question 9

(Antiemetics, dopamine D2-receptor antagonist)

Answer 9

Vomiting centre in medulla receives input from chemorecpetor trigger zone, solitary tract nucleus, vestibular system and higher neurological centres. D2 receptor is main receptor in chemoreceptor trigger zone. Dopamine also has pro-kinetic effect in gut, promoting gastric emptying
✖Neonates
✖Cardiac conduction abnormalities
✖Intestinal obstruction/perforation

Question 10

Metoclopramide

Answer 10

(Antiemetics, dopamine D2-receptor antagonist)

Treatment of nausea and vomiting

Question 11

Domperidone

Answer 11

(Antiemetics, dopamine D2-receptor antagonist)

Treatment of nausea and vomiting

Question 12

(Antiemetics, histamine H1-receptor antagonists)

Answer 12

Histamine (H1) and acetylcholine (muscarinic receptors) predominate in vomiting centre as well as communication with vestibular system. Drugs blocking H1 receptors useful in treating nausea and vomiting especially from motion and vertigo.

Question 13

Cyclizine

Answer 13

(Antiemetics, histamine H1-receptor antagonists)

Nausea and vomiting especially due to motion sickness or vertigo

Question 14

Cinnarizine

Answer 14

(Antiemetics, histamine H1-receptor antagonists)

Nausea and vomiting especially due to motion sickness or verticgo

Question 15

Promethazine

Answer 15

(Antiemetics, histamine H1-receptor antagonists)

Nausea and vomiting especially due to motion sickness or vertigo

Question 16

(Antiemetics, serotonin 5-HT3-Receptor antagonists)

Answer 16

High number of serotonin receptors in chemorecptor trigger zone of medulla and in gut, released in response to emetogenic stimuli. Serotonin antagonists effective in nausea and vomiting caused by nausea inducing chemicals and visceral stimulation (e.g. gut infection, radiotherapy)

Question 17

Ondansetron

Answer 17

(Antiemetics, serotonin 5-HT3-Receptor antagonists)

Prophylaxis and treatment of nausea and vomiting

Question 18

Granistron

Answer 18

(Antiemetics, serotonin 5-HT3-Receptor antagonists)

Prophylaxis and treatment of nausea and vomiting

Question 19

(Anti-motility drugs)

Answer 19

Agonist of opioid receptors in gut. Increases non-propulsive contractions but decrease propulsive/peristaltic contractions. Transit of bowel content slowed and anal sphincter tone increased.

Question 20

Loperamide

Answer 20

(Anti-motility drugs)

Symptomatic treatment of diarrhoea

Question 21

Codeine phosphate

Answer 21

(Anti-motility drugs)

Symptomatic treatment of diarrhoea

Question 22

(Azathioprine)

Answer 22

Prodrug that is metabolised into active form (6-mercaptopurine) Inhibit synthesis of purines and inhibit DNA and ribonucleic acid replication. Lymphocytes dependant on purine synthesis

Maintenance of Crohn’s disease remission and ulcerative colitis
Rheumatoid arthritis and autoimmune conditions not responding to corticosteroids
Prevent organ rejection

Question 23

(Calcium and vitamin D)

Answer 23

Positive calcium balance via diet or supplements reduce rates of bone loss. In chronic kidney disease impaired phosphate excretion and reduced activation of vitamin D causes hyperphosphataemia and hypocalcemia. Oral calcium binds to phosphate in gut; alfacalcidol provides vitamin D. In hyperkalaemia, calcium raises myocardial threshold potential, reducing risk of arrhythmia
✖Hypercalcaemia

Question 24

Calcium carbonate

Answer 24

(Calcium and vitamin D)
Osteoporosis 
Chronic kidney disease 
Severe hyperkalaemia 
Hypocalcaemia

Question 25

Calcium gluconate

Answer 25

``` (Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia ```

Question 26

Colecalciferol

Answer 26

``` (Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia Vitamin D deficiency ```

Question 27

Alfacalcidol

Answer 27

``` (Calcium and vitamin D) Osteoporosis Chronic kidney disease Severe hyperkalaemia Hypocalcaemia ```

Question 28

(Histamine H2-receptor antagonist)

Answer 28

Histamine receptor antagonists reduces gastric secretion. Proton pumps regulated by histamine. Partially suppresses acid production as there are other means of stimulation. PPIs offer more complete suppression

Question 29

Ranitidine

Answer 29

(Histamine H2-receptor antagonist) Peptic ulcer disease Gastro-duodenal reflux disease and dyspepsia

Question 30

(Osmotic laxatives)

Answer 30

Osmotically active substances are not digested or absorbed. Remains in lumen and hold water. Lactulose in particular reduces ammonia absorption by increasing gut transit and acidifying stool that reduces numbers of ammonia producing bacteria. Useful in liver failure + encephalopathy ✖Intestinal obstruction

Question 31

Lactulose

Answer 31

(Osmotic laxatives) Constipation Bowel preparation Hepatic encephalopathy

Question 32

Macrogol

Answer 32

(Osmotic laxatives) Constipation Bowel preparation

Question 33

Phosphate enema

Answer 33

(Osmotic laxatives) Constipation Bowel preparation

Question 34

(Stimulant laxatives)

Answer 34

Increases water and electrolyte secretion into lumen to stimulate peristalsis ✖Intestinal obstruction

Question 35

Senna

Answer 35

(Stimulant laxatives) | Constipation

Question 36

Glycerol suppositories

Answer 36

(Stimulant laxatives) | Faecal impaction

Question 37

Bisacodyl

Answer 37

(Stimulant laxatives) | Constipation

Question 38

Docusate sodium

Answer 38

(Stimulant laxatives) | Constipation

Question 39

(Proton pump inhibitors)

Answer 39

Irreversibly inhibits H+/K+ ATPase in gastric parietal cells.

Question 40

Lansoprazole

Answer 40

(Proton pump inhibitors) Peptic ulcer disease Symptomatic treatment of dyspepsia and GORD + antibiotic therapy in H. pylori eradication

Question 41

Omeprazole

Answer 41

(Proton pump inhibitors) Peptic ulcer disease Symptomatic treatment of dyspepsia and GORD + antibiotic therapy in H. pylori eradication

Question 42

Pantoprazole

Answer 42

(Proton pump inhibitors) Peptic ulcer disease Symptomatic treatment of dyspepsia and GORD + antibiotic therapy in H. pylori eradication