Alimentary pharmacology

Question 1

What are the 3 main types of medications used in acid suppression?

Answer 1

antacids
H2 receptor antagonists
proton pump inhibitors

Question 2

What are the main 3 types of medications used to affect GI motility?

Answer 2

anti emetics - stop vomiting
anti -spasmodics/anti-muscarinics
anti-motility

Question 3

What medications are used for IBD?

Answer 3

5ASA - aminosalicylates
corticosteroids
immunosuppressants
biologics

Question 4

What 2 types of medications are used to affect intestinal secretions?

Answer 4

bile aid sequestrants

usodeoxycholic acids

Question 5

How do H2 receptor antagonists work?

Answer 5

block histamine receptor to decrease acid production

Question 6

What conditions are H2 receptor antagonists used?

Answer 6

GORD/peptic ulcer disease

Question 7

How do antacids work?

Answer 7

neutralise the acid once it has been produced and are usually taken after the onset of symptoms

Question 8

How do PPI’s work and what is meant by triple therapy?

Answer 8

same as H2 receptor antagonists but work on the proton pump inhibitor with potassium to generate the acid and are used for the same conditions
Used with 2 types of antibiotics for H.pylori infection

Question 9

How do alginates work? Name an example

Answer 9

form a gel viscous layer over the stomach contents to reduce reflux eg gaviscon

Question 10

What are prokinetics, why are they used and how do they work?

Answer 10

increase gut motility and gastric emptying
gastroporesis, GORD and with anti emetics
parasympathetically control smooth muscle and sphincter tone via Ach

Question 11

What are medications which decrease gut motility used for and how do they work?

Answer 11

prevent diarrhoea but can cause constipation
act on opiate receptors to prevent Ach release
decrease smooth muscle contraction and increase anal sphincter tone

Question 12

What are anti-spasmodics used for and what are the 3 types?

Answer 12

reduce IBS, renal colic symptoms and pain
anti-cholinergic muscarinic antagonists
direct smooth muscle relaxants
CCB eg peppermint oil

Question 13

How generally can laxatives work? What are the 4 types?

Answer 13

Increase faecal bulk or draw fluid into the gut lumen

bulk, osmotic, stimulant, softener

Question 14

What are the main issues with laxatives?

Answer 14

obstruction - constipated in IBS
addictive
rout of administration
need for other measures eg fluid intake

Question 15

5ASA - what are the cautions?

Answer 15

renal impairment, salicylate allergy,

can cause GI upset and blood dyscrasia

Question 16

Contraindications of corticosteroids?

Answer 16

osteoporosis and susceptibility to infections

Question 17

Why should you not stop long term steroids abruptly?

Answer 17

Addisonian crisis

Question 18

How do immunosuppressants work and what are some possible side effects?

Answer 18

prevent purine required for DNA syntheisis

bone marrow suppression and organ damage

Question 19

What do biologics prevent the action of?

Answer 19

cytokines in the inflammatory response

Question 20

What other conditions are biologics used in and what are the side effects especially of infliximab?

Answer 20

psoriasis, rheumatoid arthritis

TB, malignancy

Question 21

What is cholestyramine used in and what may it effect?

Answer 21

pruiritis for biliary causes
reduce bile salts and bind to the bilirubin for excretion
can bind to other drugs/fat soluble vitamins

Question 22

What Is ursodeoxycholic acid used for and how do they work?

Answer 22

gallstones and PBC

dissolve non calcified stones and inhibit enzyme involved in cholesterol formation

Question 23

Explain how GI or liver disease can effect ADME

Answer 23

A - pH, gut length, transit time
D - low albumin
M - liver enzymes
E - biliary excretion

Question 24

What are the main medications which cause drug induced diarrhoea?

Answer 24

antimicrobials

Question 25

What are some medications that can cause GI bleed and how can these be overcome?

Answer 25

low dose aspirin, warfarin, NSAIDS
using clopidogrel instead of aspirin for 1st line defence
using NOACs instead of warfarin

Question 26

What is the difference between type A and B ADR in retrospect to hepatotoxicity?

Answer 26

A - dose related, predictable, acute, intrinsic hepatotoxicity
B - unpredictable, happen at any time, not dose related - hypersensitivity reaction - due to drug/metabolite can cause LFT rise –> death but usually hepatitis or cholestasis

Question 27

Risk factors for drug induced liver injury?

Answer 27

age, female, malnourishment, genetics, alcohol

Question 28

What is taken into account with the child-pugh classification?

Answer 28

bilirubin, albumin, PT prolonged, encephalopathy and ascites

Question 29

What does the child pugh classification determine?

Answer 29

cirrhosis mortality and liver transplantation

Question 30

What types of drugs should be taken care with or avoided in liver disease?

Answer 30

hepatotoxic drugs
toxic due to pharmacokinetics eg liver metabolism
worsen non liver aspect of liver disease eg encephalopathy

Question 31

What specific medications should be taken care with in liver disease?

Answer 31

warfarin - clotting factors already low
aspirin/NSAIDS - worsen ascites
opiates - precipitate encephalopathy