treatment of peptic ulcers Flashcards
what do oxyntic cells produce
HCl, pepsinogen, intrinsic factor, mucus
what do pyloric glands secrete
mucus to protect the mucosa
how do oxyntic cells form HCl
hydrogen pottasium pump in the villus like projections of the oxyntic cells
what do ECL cells produce in response to gastrin
histamine
where are ECL cells found
deep in the oxyntic gland
where is gastrin formed
in the antrum of the stomach
what are the two forms of gastrin
G-34 and G-17
17 is more common
what do ECL cells stimulate
HCL release
why is gastric secretion inhibited
- distention of the small bowel
- acid in the upper intesting
- presence of protein breakdown products
- irritation of the mucosa
what hormone opposes gastric secretion
secretin
what is the pathogenesis of an H.pylori infection
H. pylori invades the mucus layer
it secretes urease in order to neutralise the gastric acid
it damages the mucus layer and mucosa leading to inflammation and mucosal cell death
what can H. pylori infection lead to
peptic ulcer disease
gastric carcinoma
MALT lymphoma
what is a MALT lymphoma
B cells become abnormal and grow in an uncontrolled way
affects mucosa associated lymphoid tissue
usually occurs after long term inflammation
strongly associated with H.pylori
what are the symptoms of H. pylori infection
acute infection
nausea, dyspepsia, malaise, halitosis
gastric mucosa is inflammed with neutrophils and inflammatory cells with marked lymphocyte penetration
stomach acid production falls
what affects the outcome of H. pylori infection
pattern of inflammation host response virulence, environmental factors patients age
what are the features of antral predominant gastritis
stimulates G cells increased gastric acid output gastric metaplasia of duodenum colonisation of duodenum duodenal ulceration and cancer
what are the features of pangastritis
G- cell stimulation inflammation prevents acid production decreased gastric acid output gastric atrophy gastric ulceration adenocarcinoma
what are the consequences of helicobacter infection
• Peptic ulcer disease • Distal gastric adenocarcinoma • Primary gastric mucosa associated lymphoic tissue lymphoma (MALT) • Dyspepsia • Atrophic gastritis • Iron deficiency anaemia • Idiopathic thrombocytopaenic purpura
how does the urea breath test work
pts swallow urea labelled with an isotope
bacteria will split the urea into carbon dioxide and ammonia
the carbon dioxide isotope is exhaled and detected
how is damage to the mucosa reduced
diet change
antacids
bismuth salts
how is peptic ulcer disease managed
antibiotics
proton pump inhibitors
H2 blockers
how is H. pylori killed
proton pump inhibitor
ampicillin
clarythromycin or metronidazole
how are antihistamines 2 used to treat peptic ulcers
reduce gastric acid
eg CIMETIDINE
now RANITIDINE is used
what are the features of ranitidine
- Similar indication to cimetidine
- Now available over the counter (OTC)
- Well absorbed orally (50%0
- Half like 2-2.5 hours
- Renal excretion
- Malaise and dizziness
- Liver toxicity
- Increased risk of GI infection
what is omeprazole
proton pump inhibitor
what are the side effects of omeprazole
• Central nervous system: headache (7%), dizziness (2%)
• Respiratory: upper respiratory tract infection (2%), cough
• Gastrointestinal: abdominal pain (5%), diarrhea (4%),
nausea (4%), vomiting (3%), flatulence (3%), acid
regurgitation (2%), constipation (2%)
• Neuromuscular and skeletal: back pain (1%), weakness
(1%)
• Dermatologic: rash (2%)
how is a previous exposure to and penicillin allergy treated
PPi bismuth metronidazole tetracycline alternative antibiotics
what is the second line treatment
alternative regimen or quadruple treatment
how else is infection managed
endoscopy
repeat testing
try not to take NSAIDS
what is the difference between enterochromaffin cells and enterochromaffin like cells (ECL)
enterochromaffin cells release serotonin which causes contraction and is also involved in emesis
ECL cells respond to gastrin released by G-cells by releasing histamine, which will stimulate the parietal cells to produce gastric acid.
what type of gastritis causes low gastric pH
pangastritis
due to inflammation damaging acid production
