Drugs Affecting Acid Secretion Flashcards
Which cells produce stomach acid?
Parietal cells
Name the 3 types of basolateral receptors on a parietal cell.
H2 receptor
CCK receptor
ACh receptor
What structure inside parietal cells is repsonsible for acid production?
Proton pump/H+K+ATPase in the cannalicular membrane.
Name an H2 receptor antagonist.
Ranitidine
What is the MOA of an H2 receptor antagonist?
Blocks H2 receptor on parietal cell, decreasing acid secretion.
Name 2 proton pump inhibitors.
Omeprazole
Lansoprazole
What is the MOA of proton pump inhibitors?
Bind to active proton pumps and make them inactive, inhibiting H+ secretion into the stomach and therefore inhibiting acid production.
How long do PPIs take to become effective?
2-3 days, as they can only bind to active proton pumps, therefore need to wait for all pumps to be active.
When you stop taking PPIs, why does it take a few days for acid secretion to return to normal?
The pumps need to be re-synthesised.
Name an antacid and what is its MOA?
Aluminium hydroxide
Neutralises HCl in the stomach
Name an alginate, and what is its MOA?
Alginic acid
Forms a viscous layer over exposed mucosa to prevent acid getting in, and prevents reflux.
What is the treatment for GORD?
- improved lifestyle
- antacids/alginates
- H2RA and PPI
What type of drug is gaviscon?
An antacid-alginate combination, can be used for GORD.
What is the treatment for Barrett’s oesophagus?
Lifelong PPIs
What is the treatment for a peptic ulcer?
- give H2RA/PPI for 6 weeks
- also stop any NSAIDs and eradicate H.pylori if present
