Peptic ulcer disease and GORD Flashcards
Peptic ulcer
umbrella term for gastric and duodenal ulcers
Alkaline mucus
alklaline ulcer close to surface of epithelial cells which neutralises acid in small area of stomach
Peptic ulcer PROTECTION
- Alkaline mucus
- Tight junctions between epithelial cells
- Replacement of damaged cells every few days
Peptic ulcer CAUSES
- Acid and pepsin
- Heliobacter pylori infection
- Drugs - NSAID use
- Lifestyle factors - alcohol, smoking
- Severe physiologic stress
- Hypersecretory state
- Genetic factors
Impaired mucosal defence
NSAIDs inhibits cyclo-oxygenase stopping production of prostaglandins which weakens mucosal defence
Peptic ulcer SYMPTOMS
- Abdominal discomfort, pain or nausea
Pain (peptic ulcer)
located in epigastrium and usually does not radiate
- burning, gnawing or hunger pains
Gastric ulcer pain
aggravated by meals
Duodenal ulcer pain
relieved by meals
Peptic ulcer DIAGNOSIS
X-ray - taken of abdomen, only shows if >5mm
Endoscopy - patient sedated, lying on side, insert long flexible camera down through mouth into the stomach
H.pylori
95% gastric ulcer
80% duodenal ulcer
infects lower part of stomach (antrum)
causes inflammation of gastric mucosa (gastritis)
H.pylori DIAGNOSIS
serologic evaluation
urea breath test
stool antigen test
Serologic evaluation
presence of H.pylori antibodies
Urea breath test
H.pylori contains large amounts of enzyme urease = urea -> NH3 and CO2
- exhaled breath containing CO2 13 isotope = positive for H.pylori
Stool antigen test
detect antigen release by organism present in stomach = active infection
Failure to eradicate H.pylori
80% of ulcers will reoccur within a year
Histamine
comes from Enterochromaffin like cells
- stimulated by gastrin (hormone) or acetylcholine
Acid in lumen
canaliculi structures have proton pumps on surface - increase surface area and allows parietal cells to secrete acid
Examples of H2 receptor antagonists
cimetidine, ranitidine, nizatidine, famotidine
Parietal cells
- Carbonic anhydrase produces HCO3- and H+
- HCO3- is exchanged for Cl-
- Cl- diffuses into lumen
- H+ is pumped into lumen by H+/K+ ATPase
= acid in lumen
H2 antagonists
act competitvely on H2 receptors on gastric parietal cells
- reduce basal acid secretion by 80%
- can treat both duodenal and gastric ulcers but relapse is common after treatment
Adverse effects of H2 antagonists
diarrhoea
headache
confusion in elderly
gynaecomastia with cimetidine (anti-androgen effect)
Cimetidine
inhibits CYP450
- interactions with WARFARIN, PHENYTOIN and THEOPHYLLINE
Examples of proton pump inhibitors
omeprazole, lansoprazole, pantoprazole, rabeprazole, esomeprazole
