11. GI drugs Flashcards
A P presents with GORD symptoms. Describe the steps involved in his management.
Step 1 - lifestyle changes
- weight loss
- decrease alcohol, stop smoking
- smaller meals, less acidic food
Step 2 - acid buffers
- ANTACIDS (e.g. Gaviscon): alkaline agents that neutralise effects of stomach acid
- ALGINATES: produce viscous coating that protects stomach and oesophagus from acid
Step 3 - acid production inhibitors
- H2 RECEPTOR ANTAGONISTS (e.g. Ranitidine)
- PPIs (e.g. OMEPRAZOLE, LANSOPRAZOLE)
Step 4 - surgery, e.g. fundoplication
A P presents with GORD symptoms. Name 5 red flags to be aware of.
- weight loss
- haematemesis
- meleana
- abdominal mass
- > 55 age of onset
Describe the MOA of H2 R antagonists.
Block action of histamine at H2 Rs of gastric parietal cells… decreased acid production.
Describe the MOA of PPIs.
Irreversibly inhibit H+/K+ ATPase of gastric parietal cells… significantly decreased acid production.
Are there any ADRs for H2 R antagonists?
Usually minimal, exc. for cimetidine which is associated with:
- diarrhoea
- dizzinesss, headache, confusion, depression
- gynecomastia, impotence
Are there any ADRs for PPIs?
- GI disturbances, e.g. abdo pain, diarrhoea
- increased risk C. difficile colitis (as increased pH)
- increased risk osteoporosis with long term use (pH change affects Ca uptake in small bowel)
A P taking NSAIDs presents with peptic ulcers. How would you manage him?
Step 1 - stop NSAIDs
Step 2 - H2 R anatagonists or PPI 6-8 wks
An H. Pylori +ve P presents with symptoms of peptic ulcers. How would you manage him?
Triple therapy:
- Clarithromycin 500mg BD
- Amoxycillin 1g BD
- Lansoprazole/omeprazole 30mg BD
How is presence of H. pylori tested for?
- Carbon 13 urease breath test
2. Stool Ag test
Which investigation would you perform is a case of suspected Zollinger-Ellison syndrome?
fasting serum gastrin
