Clinical Pharmacology

Question 1

Name five main drug classes used in the treatment of alimentary disease

Answer 1

• Acid suppression
• Drugs affecting GI motility
• Laxative
• Drugs for IBD
• Drugs affecting intestinal secretions

Question 2

What types of drugs are used for acid suppression?

Answer 2

• Antacids
• H2 receptor antagonists
• Proton pump inhibitors

Question 3

What types of drugs are used for GI motility?

Answer 3

• Anti-emetics
• Anti-muscarinics/ anti-spasmodics
• Anti-motility

Question 4

What drugs are used for IBD?

Answer 4

• Aminosalicylates
• Corticosteroids
• Immunosuppressants
• Biologics

Question 5

What drugs are used that affect intestinal secretions?

Answer 5

• Bile acid sequestrates

* Ursodeoycholic acid

Question 6

How do alginates drugs (i.e. gaviscon) work for acid suppression?

Answer 6

Forms a viscous gel that floats on stomach contents and reduces reflux

Question 7

What is the action of H2 receptor antagonists (i.e. ranitidine) in acid suppression?

Answer 7

Block histamine receptor thereby reducing acid secretion - indicated in GORD/peptic ulcer disease

Question 8

What is the action of proton pump inhibitors (i.e. omeprazole) in acid suppression?

Answer 8

Block proton pump and thereby reduce acid secretion

Question 9

What is the effect of prokinetic agents?

Answer 9

Increase gut motility and gastric emptying

Question 10

Give an example of a prokintetic agent

Answer 10

Domperidone

Question 11

What is the action of drugs which decrease motility?

Answer 11

Opiate receptors in GI tract to decrease ACh release: decrease smooth muscle contraction and increase anal sphincter tone

Question 12

How can anti-spasmodics be used to reduce symptoms due to IBS?

Answer 12

Three mechanisms:
• Anti-cholinergic muscarinic antagonists - Inhibit smooth muscle constriction in the gut wall, producing muscle relaxation and reduction spasm
• Direct smooth muscle relaxants
• Calcium-channel blockers (peppermint oil) reduce calcium required for smooth muscle contraction

Question 13

What are the four types of laxatives?

Answer 13

• Bulk
• Osmotic
• Stimulant
• Softener

Question 14

What are the actions and side effects of aminosalicylates in IBD?

Answer 14

Mechanisms is unclear but is anti-inflammatory

• GI upset
• Blood dyscrasias
• Renal impairment

Question 15

What are the actions and side effects of corticosteroids in IBD?

Answer 15

Anti-Inflammatory effects

• Osteoporosis
• Cushingoid features - weight gain, DM, HT
• Increase susceptibility to infection
• Addisonian crisis with abrupt withdrawal

Question 16

What are the actions of corticosteroids in IBD?

Answer 16

Prevents formations of burins required for DNA synthesis so reduces immune cell proliferation

• Bone marrow suppression
• Azathioprine hypersensitivity
• Organ damage (lung, liver, pancreatitis)

Question 17

What is the action of biologics in IBD?

Answer 17

Prevents action of TNF-alpha (key cytokine inflammatory response) - addresses inflammatory response but not underlying disease process so so course of disease after discontinuation