Dyspepsia And GORD Flashcards
What are 8 GI disorders??
1) GORD
2) PUD (gastric and duodenal)
3) IBD
4) Nausea
5) Emesis
6) IBS
7) Diarrhoea
8) Constipation
What are the main sites for therapeutic intervention in GI systems?
1) mouth
2) oesophagus
3) stomach
4) liver
5) pancreas
6) SI
7) LI
4 diseases of the mouth…
A) oral ulceration
B) Stomatitis
C) Leukoplakia
D) Dysphagia
What is Oral ulceration?
Break in oral epithelium which exposes the nerve endings in the connective tissue. Caused by chemical or physical injuries, infections, drugs, malignancy, systemic diseases.
What is stomatitis?
Inflammation of lining of soft-tissues in the mouth. Caused by poor oral hygiene, drugs, allergies, poorly fitted dentures, heat burns, infections
What is leukoplakia?
Painless white patches at side of tongue or cheeks
What is dysphagia?
Difficulty with swallowing
Role of the upper oesophageal sphinctus?
- Prevents air entering oesophagus
- prevents oesophagopharyngeal reflux
What does the lower oesophageal sphinctus do?
Prevents gastroesophageal reflux.
High intraluminal pressure keeps the sphinctus closed until food needs to be moved into the stomach
List 3 diseases of the oesophagus
GORD Hiatal hernia Motility disorders: *achalasia, *hypercontraction, *hypocontraction, *oesophageal spasm (uncoordinated contractions)
What is achlasia?
Inadequate lower oesophageal sphinctus relaxation
Factors that increase chances of getting GORD are:
1) obesity
2) eating spicy/acidic/fatty foods
3) medication
4) smoking
5) Barrett’s oesophagus
What is “Barrett’s Oesophagus”?
When the oesophagus is in a pre-malignant state
What is dyspepsia?
Group of symptoms that arise from the upper GI tract e.g. heartburn, eructation, abdominal discomfort, nausea.
What is peptic ulceration?
A benign lesion of the gastric/duodenal mucosa at the site where the mucosa is exposed to acid and pepsin!
Severe cases of peptic ulcers can lead o what?
Haemorrhage
Perforation
Damage of adjacent organs
Melena (black, tarry stools from bleeding)
What causes GORD
Exposure of the unprotected epithelium of the oesophagus to acid!
What are the three types of GORD??
1) non-erosive reflux disease (heartburn)
2) erosive oesophagitis (acute inflammatory response)
3) Barrett’s oesophagus (cancer risk)
What age group does peptic ulcer affect?
All but rare in children
Wha age group does gastric ulcers peak in?
55-66 years
What age group does duodenal ulcers peak in?
25 - 75 years
What age group are likely to have peptic ulcers that relate to gastric cancer??
> 45 years
Who has a greater risk of developing peptic ulcers, males or females??
Males have twice as more chance of developing peptic ulcers than females
Which do women get more commonly, gastric or duodenal ulcers?
Gastric
Two factors that enhance the formation of peptic ulcers from a stimulus are…??
1) excessive acid production
2) intrinsic defect in the mucosal barrier
What causes gastric ulceration?
Gastric ulcers are produced in response to inflammation of parietal cells
Wha causes duodenal ulcers to form?
High acid/low bicarbonate production
What are the two types of peptic ulceration?
Gastric and duodenal ulceration
What are three examples of stimulus that can cause gastric ulceration?
1) gastric and duodenal infection by H.pylori
2) long term use of NSAIDs
3) Stress ulcers
How do NSAIDs cause peptic ulcers?
They block COX enzymes, this inhibits prostaglandin production. Therefore, too much acid will be produced as PGE2 (a type of prostaglandin) would usually inhibit stomach acid secretion.
Why are gastric ulcers associated with normal/decreased acid secretions?
Because they’re caused by damage to the whole gastric area. The mucosa is thinned (atrophic gastritis) so it’s less able to secrete acid, hence acidity of mucosa increases.
Why are duodenal ulcers associated with increased acid secretion?
Gastric inflammation is elevated in the antral/pyloric region, so the gastric body region (the acid secreting area) is fine. More gastrin is released so more HCl is secreted.
What is H.pylori?
Helicobacter pylori: a bacterium that causes peptic ulcers.
How does H.pylori cause peptic ulceration?
1) Infects lower part of stomach (antrum)
2) Inflames gastric mucosa (aka gastritis and is often symptomatic)
3) Forms gastric/duodenal ulcers, which could bleed or perforate (forms a hole in stomach lining).
What two ways can gastric damage by long term NSAIDs use be reduced?
1) Use COX-2 selective inhibitors
2) Use a stable PGE1 analogue e.g. msoprotol
What is misoprotol?
A synthetic prostaglandin - replaces the prostaglandin made by COX1 as NSAIDs block COX1 from creating the naturally occurring prostaglandin.
What process inactivates cyclooxygenase (COX) enzymes when reacted with Aspirin (an NSAID)?
Acetylation
Two ways we treat dyspepsia and gastric disorders?
1) Neutralisation of gastric acid
2) reduce acid secretion
Three things given to neutralise stomach acid?
1) antacids (neutralise HCl)
2) alginates
3) sucralfate (mucosal protection)
The things given to reduces acid secertion?
1) PPI’s
2) H2 Antagonists
3) Prokinetics
what are antacids?
Weak bases that neutralise excess stomach acid to comfort level and reduce foaming to prevent heartburn.
What two things are antacids combined with?
Alginates and Anti-foaming agents
Role of anti-foaming agents?
- reduce surface tension of acid
- to prevent bubbles forming
- which causes the agent to coalesce
- and produce a defoaming action
Two types of antacids?
Systemic and Non-systemic
what are systemic antacids?
antacids used in short-term therapy and have a rapid onset of action.
Negative effect of using systemic antacids?
Prolonged use causes an overload on the kidneys e.g. sodium bicarbonate
What are non-systemic acids?
These remain in the GI tract and are useful in long term therapy.e.g. Calcium/magnesium/aluminium/bicarbonate -based antacids.
Adverse effects of using magnesium hydroxide as an antacid?
laxative properties
Adverse effects of using magnesium antacids during renal failure?
Magnesium excretion is reduced
Adverse effects of using Aluminium hydroxide as an antacid?
causes constipation
Adverse effects of using calcium carbonate as an antacid?
Can cause renal calculi (stones) and constipation. Also carbonates can cause bloating and flatulence.
Adverse effects of using sodium bicarbonate as an antacid?
1) highly soluble and has a short duration.
2) can cause metabolic alkalosis
3) sodium content can cause problems in hypertension or renal insufficiency
What are alginates?
Polysaccharides found in cell walls of brown algae
How do alginates work?
By forming a protective barrier on top of the gastric contents
4 things given to regulate HCl secretion?
1) muscarinic receptor antagonists which block competitively
2) H2 receptor antagonists which block competitively
3) Proton pump inhibitors (PPIs) which block covalently so it’s irreversible
4) NSAIDs which block irreversibly
Why are muscarinic receptor antagonists not usually given?
Because they aren’t selective so can affect muscles of other organs (e.g. heart muscle)
Why are PPIs enterically coated?
To avoid metabolism in stomach and allow GI absorption
Once PPIs are activated, what happens next?
They bind irreversibly to the cysteine molecules on the proton pump which inactivates the pump. However, only active pumps are inhibited. Those in tubulovesicles are inactivate so the PPI can’t bind to them to inactivate them.
What is achlorhydria?? How can we overcome it?
When all gastric acid secretion is blocked. Overcome by body synthesising new proton pumps!
How does H2 antagonists work?
1) Suppress effect of gastrin and Ach on acid secretion
2) also inhibit acid secretion by competitively and reversibly blocking H2 receptors
3) but are less potent than PPIs
Three ways prostaglandin protect the stomach from ulceration??
1) decrease acid secretion
2) stimulate mucin production (protein that strengthens mucosal barrier)
3) stimulate bicarbonate production (neutralise acid)
What is sucralfate?
A complex of aluminium hydroxide and sucrose octasulphate
How do sucralfates work?
1) dissociate in acidic environment to anionic form
2) forms gel complex with mucous and forms a cross-linked viscous polymer
3) acts as acid buffer and impairs H+ diffusion
4) stimulates prostaglandin synthesis and bicarbonate secretion
What are the pharmacokinetics of sucralfates?
1) only a small proportion is absorbed in the gut
2) can cause constipation
3) the absorbed fraction is excreted unchanged by kidneys
What are prokinetics??
They are dopamine receptor antagonists that:
1) enhance gastric motility
2) increase rate of gastric emptying
3) increase gastro-oesophageal tone
Side effects of prokinetics??
1) Fatigue
2) Tremors
3) Parkinsonism
4) Tardive Dyskinesia
5) Severe cardiac events
