Clinical 6.1 Drugs for the bowel

Question 1

What drugs can you use to decrease gastric secretions and give an example of each

Answer 1

PPI: omeprazole
H2 receptor antagonists: ranitadine
Antacids: Magnesium and aluminium salts, NaHCO3, Calcium salts, Alginate

Question 2

What do you have to be careful with when giving H2 receptor antagonists?

Answer 2

drug interactions with cimetidine

Question 3

What are the side effects of PPIs and what do you have to be careful of?

Answer 3

Generally well tolerated but can ave nausea, vomiting, diarrhoea and constipation

May increase the risk of C.difficile

Question 4

How do PPIs have a long lasting effect with a short t1/2?

Answer 4

They are a suicide inhibitor - consume and destroy so the duration of effect relates to the ability of regeneration of the enzymes

Question 5

What is the treatment for H.pylori infection

Answer 5

triple therapy of PPI and two antibiotics (clarithromycin and amoxicillin)

Question 6

What are the drugs that protect the mucosa and how do they work?

Answer 6

Sucralfate (forms a protective barrier at ulcer site)

Misoprostol (prostaglandin E1 analogue which stimulates secretion of gastric mucus and HCO3 in the duodenum)

Question 7

What type and give an example of drugs for motion sickness and gastric irritants

Answer 7

H1 antagonists: promethazine (morning sickness too)

M antagonist: scopolamine

Question 8

What type and give an example of drugs for post operative vomiting

Answer 8

D2 antagonists: Phenothiazines and metoclopramide

Question 9

What type and give an example of drugs for chemotherapy and radiotherapy vomiting

Answer 9

5-HT3 antagonists: ondansatron

NK-1 antagonists: Aprepitant

Question 10

How can you minimise constipation with opioid use and give an example?

Answer 10

Use an opioid receptor antagonist for example oxycodone with naloxone

Question 11

What is an example of an anti diarrhoeal drug and how does it work?

Answer 11

Loperamide (immodium) and codeine which are opioid receptor antagonists

Question 12

What drug classes can be used to UC and Chron’s and give examples

Answer 12

5-aminosalicylic acid derivatives: sulfasalazine
Immunosuppressants: Azathioprine
Glucocorticoids: Prednisolone
TNF-a antagonists: Ifliximab

Question 13

How does sulfasalazine work?

Answer 13

activates PPAR-gamma which decreases inflammation in local bowel mucosa

Question 14

What kind of drug is infliximab?

Answer 14

Monoclonal IgG