GI: Treatment of GORD + Peptic Ulcers Flashcards
What is the aim of antacids?
To neutralise stomach acid
Name the 2 main examples of antacids
Aluminium hydroxide
Magnesium hydroxide
When are antacids used?
Mild GORD
Dyspepsia
What is the side effect of aluminium based antacids?
Constipation
What is the side effect of magnesium based antacids?
Diarrhoea
What is omeprazole an example of?
A protein pump inhibitor (PPI)
What is the mode of action of proton pump inhibitors?
They block active pumps in the apical membrane (NOT tubulovesicles) preventing pumping of H+ ions
At what pH do PPIs become active?
Inactive and neutral pH and become active in the acidic canaliculus
What are PPI’s used to treat?
GORD
Peptic ulcer disease
H.Pylori eradication therapy
Zollinger Ellison Syndrome
What is zollinger Ellison syndrome?
A gastrin secreting tumour of the pancreas
PPI’s undergo a conformational change in acidic pH to become which molecule?
A sulfenamide
What are the side effects of PPI’s?
Constipation/diarrhoea
Headache
What problem can arise with use of PPIs?
Nocturnal acid breakthrough
What is the mode of action of H2 receptor Antagonists?
Block the action of histamine secreted from enterocromaffin cells to decrease HCL production
In what way do H2 receptor antagonists block H2 receptors?
Competitively and reversibly
Name an example of a H2 receptor antagonist
Ranitidine
What are H2 receptor antagonists used to treat?
GORD
Dyspepsia
Peptic ulcers
What are the side effects of H2 receptor antagonists?
Hypotension
Headache
Constipation/diarrhoea
What are sucralfate and bismuth chelate examples of?
Mucosal strengtheners
What is the mode of action of mucosal strengtheners?
Bind to positively charged ulcer base to form protective mucosal barrier. Requires acidic environment
What are mucosal strengtheners used to treat?
Peptic ulcers
GORD
What is the main side effect of mucosal strengtheners?
Constipation
How do mucosal strengtheners affect: A) Blood flow B) Mucus production C) Bicarbonate production D) Prostaglandin production
Increases them all
What is drug treatment of peptic ulcers aimed at?
Decreased acid secretion
Increase in mucosal resistance
Eradication of H.Pylori
Use of which drugs can cause peptic ulcers?
NSAIDS, e.g. ibuprofen
Aspirin
Which drug can be given to reduce the gastric damage caused by long term NSAID use?
Misoprostol
What type of drug is misoprostol?
A stable PGE1 analogue
