Drugs List

Question 1

Calcium carbonate and magnesium carbonate

Answer 1

Antacid

Buffers gastric acid, raising pH

Question 2

Aluminium hydroxide and magnesium hydroxide

Answer 2

Antacid

Buffers gastric acid, raising pH

Question 3

Antacids (2)

Answer 3

Calcium carbonate and magnesium carbonate

Aluminium hydroxide and magnesium hydroxide

Buffers gastric acid, raising pH

Question 4

Sodium alginate, sodium bicarbonate, calcium carbonate

Answer 4

Alginate

Anionic polysaccharides

Increase the viscosity of stomach contents by forming a viscous gel upon binding water. Protects the oesophageal mucosa from acid reflux

Question 5

Alginates (1)

Answer 5

Sodium alginate, sodium bicarbonate, calcium carbonate

Anionic polysaccharides

Increase the viscosity of stomach contents by forming a viscous gel upon binding water. Protects the oesophageal mucosa from acid reflux

Question 6

Histamine H2-receptor antagonists (2)

Answer 6

Ranitidine

Cimetidine

Competitively inhibit histamine actions at H2 receptors

Question 7

Ranitidine

Answer 7

Histamine H2-receptor antagonist

Competitively inhibit histamine actions at H2 receptors on parietal cells

Question 8

Cimetidine

Answer 8

Competitively inhibit histamine actions at H2 receptors on parietal cells

Question 9

What else does cimetidine do?

Answer 9

Inhibit cytochrome P450 enzymes (liver)

Question 10

Proton pump inhibitors (2)

Answer 10

Omeprazole

Lansoprazole

Irreversibly inhibit the H+/K+-ATPase pump, the terminal step in the acid secretory pathway.

Question 11

Omeprazole

Answer 11

Proton pump inhibitor

Irreversibly inhibit the H+/K+-ATPase pump, the terminal step in the acid secretory pathway.

Question 12

Lansoprazole

Answer 12

Proton pump inhibitor

Irreversibly inhibit the H+/K+-ATPase pump, the terminal step in the acid secretory pathway.

Question 13

List some characteristics of PPIs

Answer 13

Inactive at neutral pH

Enteric coated tablets - higher doses leads to disproportionate increase in plasma levels

Accumulate in secretory canaliculi of parietal cells - very specific

More effective that H2-receptor antagonists

Question 14

How do NSAIDs impair the renewal of the gastric mucosal barrier?

Answer 14

Inhibit the action of the enzyme COX.

COX converts arachidonic acid into prostaglandin E2

PGE2 stimulates gastric mucus production and inhibits gastric acid production

If PGE2 is inhibited, less mucus is made, less gastric protection, more likely to ulcerate

Question 15

How does H pylori produce gastric ulcers?

Answer 15

Produces and secretes urease, which breaks down urea into CO2 and NH3 (Imonia)

NH3 neutralises gastric acid.

H. pylori penetrates mucus barrier, facilitating acid penetration.

NH3, other bacterial products, and acid damage epithelial cells.

Question 16

List the 4 types of purgatives

Answer 16

Bulk laxatives

Osmotic laxatives

Faecal softeners

Stimulant purgatives

Question 17

Bulk laxatives (2)

Answer 17

Methylcellulose

Isphagula husk

Polysaccharide polymers not broken down by the normal process of digestion

Retain water in the GI lumen, softening and increasing faecal bulk, promote motility

Question 18

Methylcellulose

Answer 18

Bulk laxative

Polysaccharide polymers not broken down by the normal process of digestion

Retain water in the GI lumen, softening and increasing faecal bulk, promote motility

Question 19

Isphagula husk

Answer 19

Bulk laxative

Polysaccharide polymers not broken down by the normal process of digestion

Retain water in the GI lumen, softening and increasing faecal bulk, promote motility

Question 20

What class of drugs are a good first choice in constipation and IBS?

Answer 20

Bulk laxatives

Question 21

Osmotic laxatives (3)

Answer 21

Magnesium sulphate and magnesium hydroxide (saline purgatives)

Macrogols - ethylene glycol

Lactulose - synthetic disaccharide of fructose and galactose (acts like lactose)

Maintain an increased volume of fluid in the GI tract.

Accelerates SI transit resulting in large volume of fluid entering the colon

Distention leads to purgation

Question 22

Magnesium sulphate and magnesium hydroxide

Answer 22

Saline purgative - osmotic laxative

Maintain an increased volume of fluid in the GI tract.

Accelerates SI transit resulting in large volume of fluid entering the colon

Distention leads to purgation

Question 23

Macrogols

Answer 23

Osmotic laxatives

Ethylene glycol

Maintain an increased volume of fluid in the GI tract.

Accelerates SI transit resulting in large volume of fluid entering the colon

Distention leads to purgation

Question 24

Lactulose

Answer 24

Osmotic laxative

synthetic disaccharide of fructose and galactose (acts like lactose)

Maintain an increased volume of fluid in the GI tract.

Accelerates SI transit resulting in large volume of fluid entering the colon

Distention leads to purgation

Question 25

Which drug is useful in treating opioid constipation and chronic constipation?

Answer 25

Lactulose

Question 26

Faecal softeners (2)

Answer 26

Docusate Arachis oil enema Anionic surfactants: lower surface tension at oil-water interface, allowing water or fats to enter the stool. Faecal matter is softened.

Question 27

Docusate

Answer 27

Faecal softener Anionic surfactants: lower surface tension at oil-water interface, allowing water or fats to enter the stool. Faecal matter is softened.

Question 28

Arachis oil enema

Answer 28

Faecal softener Anionic surfactants: lower surface tension at oil-water interface, allowing water or fats to enter the stool. Faecal matter is softened.

Question 29

Stimulant purgatives (2)

Answer 29

Bisacodyl (PR) Stimulates rectal mucosa, resulting in mass movements and defaecation in 15-30 minutes Senna Anthracene combined with sugars. Bacterial action in colon releases free anthracene derivatives which have an effect on the myenteric plexus

Question 30

Bisacodyl

Answer 30

Stimulant purgative Stimulates rectal mucosa, resulting in mass movements and defaecation in 15-30 minutes

Question 31

Senna

Answer 31

Stimulant purgative Anthracene combined with sugars. Bacterial action in colon releases free anthracene derivatives which have an effect on the myenteric plexus

Question 32

Which drug has a direct effect on the myenteric plexus?

Answer 32

Senna

Question 33

Oral rehydration therapy

Answer 33

An isotonic or hypotonic solution of glucose and NaCl

Question 34

Anti-motility agents (2)

Answer 34

Loperamide Codeine Act on mui-opioid receptors in the myenteric plexus Increases tone and rhythmic contractions of colon, but diminishes propulsive activity Contracts pyloric, ileocaecal and anal sphincters

Question 35

Loperamide

Answer 35

Anti-motility agent Act on mui-opioid receptors in the myenteric plexus Increases tone and rhythmic contractions of colon, but diminishes propulsive activity Contracts pyloric, ileocaecal and anal sphincters