Gastrointestinal Pharmacology

Question 1

Name eight gastrointestinal disorders

Answer 1

Gastrointestinal Reflux Disease
Peptic Ulcer Disease
Duodenal Ulcer
Nausea
Emesis
Irritable Bowel Syndrome 
Diarrhoea
Constipation

Question 2

What do pyloric mucosa cells secrete?

Answer 2

A thick, alkaline-rich mucus: protection

Question 3

What are pylori mucosa cells stimulated by?

Answer 3

Mechanical and chemical irritation and parasympathetic inputs

Question 4

What can protective mucus barrier be damaged by?

Answer 4

Bacterial and viral infection, certain drugs, and aspirin

Question 5

What does too little 5-HT lead to?

Answer 5

Constipation

Question 6

What does too much 5-HT lead to?

Answer 6

Diarrhoea

Question 7

What are precipitating factors of GERD?

Answer 7

Fatty food, alcohol, caffeine
Smoking
Obesity
Pregnancy

Question 8

What are the causes of peptic ulcer disease?

Answer 8

Helicobacter Pylori bacteria (80% cause)

Excess Alcohol

Stress

N.S.A.I.D.s

Question 9

What is begnin PUD?

Answer 9

Normal gastric acid production + mucosal barrier weak

Question 10

What is malignant PUD?

Answer 10

Excessive gastric acid secretion, overwhelms mucosal barrier

Question 11

How is PUD diagnosed?

Answer 11

By barium swallow
Or/and
Upper G.I. endoscopy +/- biopsy

Question 12

What surgery treatments are used for PUD?

Answer 12

Vagotomy: cutting vague nerve
Antrectomy
Pyloroplasty: widening stomach-duodenal passage

Question 13

What are drug treatments of GERD & PUD?

Answer 13

Antacids
H2 Receptor Blockers
Mucosal Protective Agents
Proton Pump Inhibitors
Anti-Cholinergic
Prostaglandin Analogy
Anti-microbial agents

Question 14

What is a systemic antacid?

Answer 14

Sodium bicarbonate

Question 15

What are non systemic antacids?

Answer 15

Aluminium + Magnesium hydroxide combinations

Question 16

What is contraindicated in non systemic antacids?

Answer 16

Patients with impaired renal function

Question 17

What can cause diarrhoea?

Answer 17

Magnesium

Question 18

What can cause constipation?

Answer 18

Constipation

Question 19

What do histamine H2 receptor blockers do?

Answer 19

Competitive inhibition of acid secretion H2 inhibition

Question 20

What do histamine H2 receptor blockers interact with?

Answer 20

CYP450 enzymes: changes effects of other drugs

Question 21

What do proton pump inhibitors do?

Answer 21

Irreversible inhibition of proton pump

Question 22

What are prostaglandins a treatment of?

Answer 22

NSAID- induced injury

Question 23

What are side effects of prostaglandins?

Answer 23

Diarrhoea, cramping pain (30%) and teratogenicity

Question 24

What do anticholinergics do?

Answer 24

block gastric acid secretions effectively at H2 blockers

Question 25

What are side effects of anticholinergics?

Answer 25

Constipation, dry mouth, sedation, buried vision

Question 26

What do sucralfate do?

Answer 26

Prevent/treat PUD as a barrier Sticky polymer in acid pH Adheres to ulcer site

Question 27

What do cheated bismuth do?

Answer 27

Protects ulcer crater & allows healing

Question 28

What are side effects of cheated bismuth?

Answer 28

Constipation

Question 29

What percentage of PUD is caused by H.pylori?

Answer 29

85%

Question 30

What does H.pylori do?

Answer 30

Attach to epithelial cells of stomach & duodenum Damage cells, enzymes & toxins

Question 31

What is Ulcerative colitis and what are the symptoms?

Answer 31

Diffuse mucosal colonic inflammation Bloody diarrhoea, colic, urgency, tenesmus

Question 32

What is Crohns disease and what are the symptoms?

Answer 32

Patchy transmural inflammation | Abdo pain, diarrhoea, weight loss

Question 33

What are treatments of inflammatory bowel disease?

Answer 33

``` Aminosalicylates Corticosteroids Thiopurines Methotrexate Cyclosporin Infliximab ```

Question 34

What do corticosteroids do?

Answer 34

Decrease IL1 transcription, arachidonic acid metabolism

Question 35

What are side effects of corticosteroids?

Answer 35

Cushing's disease-Moon face, mood disturbance, glucose intolerance, osteoporosis

Question 36

What is constipation?

Answer 36

Difficulty in imagining a bowel movement

Question 37

What is a treatment of constipation and what is the problem with this treatment?

Answer 37

Laxatives. Only use if lifestyle modifications fails. Overuse produces a constipation cycle

Question 38

What are the different laxative therapies?

Answer 38

Bulking agents Osmotic laxatives Stimulant drugs Stool softners

Question 39

What do bulk laxatives do?

Answer 39

Increase bowel volume Trigger stretch receptors in wall Initiates peristalsis

Question 40

What are the different saline & osmotic laxatives?

Answer 40

Non digestible sugars & alcohol (lactulose) Salts Polyethylene glycol

Question 41

What are some stool softners?

Answer 41

Docusate sodium Liquid paraffin Glycerin suppositories

Question 42

What do irritant laxatives do?

Answer 42

Increase GI motility + irritates GI mucosa

Question 43

What are causes of diarrhoea?

Answer 43

Toxins | Micro organisms: shigella, salmonella, E.coli, campylobacter, Clostridium difficile

Question 44

What do anti-diarrhoeal drugs do?

Answer 44

Reduce peristaltic- stimulates bowel opioid receptors & allow more time for H20 absorption

Question 45

What do anti-flatulents do?

Answer 45

Changes elasticity of mucus coated gas bubbles making large bubbles break

Question 46

What are invasive treatments of haemorrhoid treatments?

Answer 46

Rubber band ligation Sclerotherapy Laser coagulation Surgical: removal or stapling

Question 47

What are haemorrhoid treatments?

Answer 47

Fibre & water/ exercise | Drugs: hydrocortisone

Question 48

What are some antiemetic drugs?

Answer 48

Muscarinic M1 antagonist Histamine H1/ Dopamine D2 antagonist 5HT3 antagonist

Question 49

What are emetics?

Answer 49

Drugs that cause vomiting

Question 50

What is a haemorrhoid?

Answer 50

swollen blood vessels in or around the anus and rectum