Treatment of Gastric and Duodenal Ulcers (20.02.2020) Flashcards
Acute gastric/duodenal ulcer symptoms
- Epigastric pain
- burning sensation that occurs after meals
What are the most important tests for ulcers?
- Carbon-urea breath test – positive (suggests H. pylori presence)
- Stool antigen test – positive -> confirms H. Pylori
Diagnosis = H Pylori positive peptic ulcer
Pathophysiology of H. pylori
- Dissolves mucus layer (in small portions) -> urease enzyme
- Causes epithelial cell death (exotoxins, inflammation)
- Increased acidity -> peptic ulcer
can cause upper GI blood loss
Treatment of an acute H Pylori positive peptic ulcer (first line)
- Amoxicillin & Clarithromycin/Metronidazole – Antibiotics that are most effective against that bacterium
- Proton Pump Inhibitor (PPI) – reduces acid production (7d)
Helicobacter pylori
- causes mucous layer to dissolve
- Gram negative, motile, microaerophilic bacterium
- Resides in human GI tract – exclusively colonising gastric-type epithelium
- generally it is a commensal bacterium, found in many people
How does H pylori cause ulcers?
- Increased gastric acid formation – increased gastrin or decreased somatostatin
- Gastric metaplasia – cell transformation due to excessive acid exposure
- Downregulation of defence factors - decreased epidermal growth factor & decreased bicarbonate production
- The Urease enzyme is very problematic, a product damages epithelial cells, evokes immune response
- certain virulent strains produce cytotoxins
=> does several different things, multi front attack on the gastric epithelium
Virulence of H. pylori
- Urease – catalyses urea into ammonium chloride & monochloramine -> damage epithelial cells
- Urease – antigenic -> evokes immune response
- Certain virulent strains produce CagA (antigenic) or VacA (cytotoxic) – more intense tissue inflammation
Presentation of chronic ulcers
- Epigastric pain
- burning sensation
Had an ulcer before
Treatment of chronic peptic ulcers
- Antibiotics for H Pylori (amoxicillin & clarithromycin/metronidazole)
- Consider quinolone, tetracycline, bismuth (peptobsimol), sucralfate -> alkalating agents, create a less acidic environment in the stomach, increase pH
- Proton Pump Inhibitor (omeprazole) – 4-12 weeks
Triple therapy with AB, PPI and maybe bismuth/sucralfate or AB other option that first ones
Proton pump
H+-K+-ATPase (proton pump)
- Expressed on secretory vesicles within parietal cells
- increased [Ca2+]ic -> increased cAMP -> translocation of secretory vesicles to parietal cell apical surface -> H+ secretion
(- cAMP is directly linked to Gs proteins)
In ulcers: Increased activity of proton pump – increased H+ secretion -> reduction gastric pH
=> treat with PPIs
Are most ulcers H pylori positive or negative?
positive
What is the second most common cause of ulcers?
NSAID use
Presentation of a H. pylori negative ulcer
Epigastric pain
burning sensation
INVESTIGATIONS and diagnosis of a Hp negative ulcer
Carbon-urea breath test – negative
Stool antigen test – negative
NSAID use – positive
NSAIDS and ulcers
- Directly cytotoxic
- Reduces mucus production
- Increases likelihood of bleeding
- Increased acidity -> peptic ulcer
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