Gastritis & peptic ulcer Flashcards
What are the 3 agents used to reduce gastric acidity?
- Antacids
- H2-receptor antagonists
- PPIs
What are the 4 weak bases used in antacids?
NaHCO3
CaCO3
Mg(OH)2
Al(OH)3
What benefit does simethicone have when taken with antacids?
Antifoaming activity coalesces bubbles and reduces bloating.
Helps to reduce gastric distention, belching discomfort side effects.
In which patients is long-term antacid use contraindicated in?
Renal insufficiency
Patients on diuretics
What type of antacid causes osmotic diarrhoea?
Mg2+ antacids
What type of antacid causes constipation?
Al3+ antacids
Which type of antacid is most prone to reboud acid secretion?
Ca2+
Which types of antacids cause metabolic alkalosis/Milk-Alkali syndrome?
Na+ & Ca2+
Name 3 H2-receptor antagonists
- Famotidine
- Ranitidine
- Cimetidine
What is the MOA of famotidine?
Competitive inhibitor of H2 receptors on parietal cells; suppresses acid secretion by parietal cells
When is famotidine most effective?
At night
Noctornal acid secretion is mostly due to histamine release
What are the common adverse effects of famotidine & ranitidine?
Think of muscarinic antagonism
Headache
Nausea
Dry mouth
What are the severe adverse effects of famotidine & ranitidine?
Tachycardia
Blood dyscrasia
Blurred vision
MSK pain
blood dyscrasia - imbalance of blood cell types
What are the severe adverse effects of cimetidine?
Mental confusion
Anti-androgenic, inhibits estradiol metabolism, increases serum prolactin
gynaecomastia, impotence, glaactorrhoea
What is the MOA of omeprazole?
Irreversibly inhibits H+/K+-ATPase in parietal cells
IRREVERSIBLE!!!