GI Drugs

Question 1

Antacids and Alginates Example

Answer 1

Gavsicon

Question 2

Antacids and Alginates mechanism of action

Answer 2

Antacids buffer stomach acid by increasing the pH and alginic acid increases stomach content viscosity and reduces reflex

Question 3

Antacids and Alginates ADRs

Answer 3

Antacids such as aluminium salts cuase constipation

Antacids such as magnesium salts cause diarrhoea

Question 4

Antacids and Alginates Drug interactions

Answer 4

Can reduce absorption of many drugs so doses should be separated

Increases urine alkalinity which increases aspiin excretion

Question 5

Antacids and Alginates contra-indications

Answer 5

Patients with renal failure

Patients with diabetes mellitus

Question 6

Muscarinic receptor antagonist example

Answer 6

Hyoscine hydrobromide

Question 7

Muscarinic receptor Antagonists mechanism of action

Answer 7

Competitively blocks muscarinic acetylcholine receptors in the vestibular nuclei and at the chemoreceptor trigger zone

Question 8

Muscarinic receptor Antagonists ADR

Answer 8

Sedation

Memory problems

Glaucoma

Dry mouth

Constipation

Question 9

Muscarinic receptor Antagonists indications

Answer 9

Motion sickness

Question 10

H2 receptor antagonists example

Answer 10

Ranitidine

Question 11

H2 receptor antagonists mechanism of action

Answer 11

Inhibition of histmine 2 receptors which decreases acid secretion

Question 12

H2 receptor antagonist ADR

Answer 12

Diarrhoea

Headache

However usually well tolerated

Question 13

H2 receptor antagonist contra-indications

Answer 13

It may mask symptoms of gastro-oesophageal cancer

Renal impairment

Question 14

Proton pump inhibitor examples

Answer 14

Lansoprazole

Omeprazole

Question 15

Proton pump inhibitor mechanism of action

Answer 15

They irreversibly inhibit H+ / K+ ATPase in gatsric parietal cells and significantly decreases gastric acid secretions

Question 16

Antacids and alginates indications

Answer 16

GORD

Indigestion

Question 17

H2 receptor antagonists inidcation

Answer 17

Gastric ulcers

Duodenal ulcers

Indigestion

GORD

Question 18

Proton pump inhibitor ADRs

Answer 18

Abdominal pain

Constipation

Diarrhoea

Headache

Dizziness

Confusion and drowsiness

Question 19

Proton pump inhibitor drug interactions

Answer 19

Omeprazole is a CYP inhibitor

Decreases clopidogrel action

Increases effects of warfarin and phenytoin

Question 20

Proton pump inhibitor indications

Answer 20

H.pylori eradication

Gastric ulcers

Duodenal ulcers

GORD

Question 21

Opoid receptor agonist ( anti motility ) examples

Answer 21

Loperamide

Codeine

Morphine

Question 22

Opoid receptor agonist ( anti motility ) indications

Answer 22

Diarrhoea

Faecal incontinence

Question 23

Opoid receptor agonist ( anti motility ) mechanism of action

Answer 23

Binds to µ and δ receptors. This decreases tone of longitudinal and circular smooth muscle. It also reduces peristalsis but increases segmental contractions.
There is decreased colonic mass movement by supressing the gastrocolic reflex.

Question 24

Opiod receptor agonist ( anti-motility ) ADRs

Answer 24

Paralytic ileus

Nausea and vomiting

Sedation

Addiction

Question 25

Opiod receptor agonist ( anti - motility ) drug interactions

Answer 25

Other pain medications

Question 26

Osmotic laxatives examples

Answer 26

Lactulose Movicol Cosmocol

Question 27

Osmotic laxatives mechanism of action

Answer 27

Increase the amount of water in the large bowel Lactulose - draw fluid in Macrogols - retain water they came in with

Question 28

Osmotic laxative indications

Answer 28

Constipation

Question 29

Osmotic laxatives ADRs

Answer 29

Electrolyte imbalance Flatulence Nausea Vomiting

Question 30

Stimulant laxatives indication

Answer 30

Constipation

Question 31

Stimulant laxative examples

Answer 31

Bisacodyl Senna - over the counter Docusate sodium

Question 32

Stimulant laxatives mechanism of action

Answer 32

Increases intestinal motility

Question 33

Stimulant laxatives ADRs

Answer 33

Nausea Vomiting

Question 34

Bulk forming laxatives examples

Answer 34

Ispaghula husk Methylcellulose

Question 35

Bulk forming laxatives mechanism of action

Answer 35

Increase faecal mass stimulating peristalsis

Question 36

Bulk forming laxatives indications

Answer 36

Constipation

Question 37

Bulk forming laxatives ADRs

Answer 37

Abdominal distension

Question 38

Bulk forming laxatives cautions

Answer 38

Adequate fluid intake should be maintained to avoid obstructions