[21] Gastro-Oesophageal Reflux Disease Flashcards
What is GORD?
A long-term condition where the stomach contents come back up into the oesophagus, resulting in symptoms or complications
What is GORD caused by?
The failure of the lower oesophageal sphincter
What prevents reflux in healthy individuals?
The Angle of His, which is the angle at which the oesophagus enters the stomach, creates a valve that prevents duodenal bile, enzymes, and stomach acid from travelling back into the oesophagus
What does duodenal bile, enzymes, and stomach acid cause when they come into contact with the oesophagus?
Burning and inflammation
What are the risk factors for the development of GORD?
- Lower oesophageal sphincter hypotension
- Hiatus hernia
- Oesophageal dysmotility
- Obesity
- Gastric acid hypersecretion
- Delayed gastric emptying
- Smoking
- Alcohol
- Pregnancy
- Drugs, including tricyclics, anticholinergics, and nitrates
- Helicobacter Pylori
What are the symptoms of GORD?
- Heartburn
- Belching
- Acid brash
- Waterbrash
- Odynophagia
- Noctural asthma
- Chronic cough
- Laryngitis
What is acid brash?
Acid or bile regurgitation
What is waterbrash?
Increased salivation
How may GORD be investigated?
- Endoscopy
- 24 hour oesophageal pH monitoring, with or without manometry
- H. Pylori testing
When is endoscopy used to investigate GORD?
If dysphagia, or if over 55 years old with alarming symptoms
When is 24 hour oesophageal pH monitoring used to investigate GORD?
When endoscopy is normal
What are the management options in GORD?
- Lifestyle
- Drugs
- Surgery
What is involved in the lifestyle management of GORD
- Weight loss
- Smoking cessation
- Small, regular meals
- Reduce certain foods and drinks
- Avoid eating <3hours before bed
- Raise bed head
What foods and drinks should be reduced in GORD?
- Alcohol
- Citrus fruits
- Tomatoes
- Onions
- Fizzy drinks
- Spicy foods
- Things containing caffeine
- Chocolate
What drugs are used in the management of GORD?
- Antacids
- PPIs
- Histamine blockers
What are the types of antacids used in GORD?
- Simple antacids
- Compound antacids
Give an example of a simple antacid
Aluminium hydroxide
What course of PPI should patients with GORD be given initially?
Offer people with GORD a full-dose PPI for 4-8 weeks
What should be done if symptoms reoccur after initial treatment with PPI in GORD?
Offer PPI at lowest possible dose to control symptoms
When should a histamine blocker be added in the management of GORD?
For refractory symptoms
What drugs should be avoided in GORD?
- Drugs affecting oesophageal motility
- Drugs that damage mucosa
Give 3 examples of drugs that affect oesophageal motility
- Nitrates
- Anticholinergics
- Calcium channel blockers
Give 3 examples of drugs that can damage the oesophageal mucosa
- NSAIDs
- Potassium salts
- Bisphosphonates
What are antacids?
Weak bases that react with gastric acid to form water and a salt to diminish gastric acidity
What effects do antacids have on pepsin activity?
They reduce it
Why do antacids reduce pepsin activity?
Because pepsin is inactive at a pH greater than 4
What is aluminium hydroxide used for?
- Symptomatic relief of GORD and peptic ulcer disease
- May promote healing of duodenal ulcers
What are the adverse effects of aluminium hydroxide?
- Tends to cause constipation
- Can sometimes cause hyperphosphataemai
What can happen to aluminium hydroxide in renal impairment?
Absorption of the cations from antacids, in this case Mg2+, can cause accumulation in renal impairment.
This is not normally a problem in patients with normal renal function
When can the sodium content of antacids be an important consideration?
In patients with hypertension or congestive heart failure
How do compound alginates work in GORD?
They form a raft floating on the surface of the stomach contents, and therefore reduce reflux and protect the oesophageal mucosa
Where are compound alginates used?
In dyspepsia and GORD
What are the side effects of compound alginates?
- Stomach distention
- Nausea
What effect might taking compound alginates at the same time as other medications have?
May impair the medications absorption, or damage its enteric coating
What secretes gastric acid?
The parietal cells of the gastric mucosa
What stimulates gastric acid secretion from parietal cells?
- Acetylcholine
- Histamine
- Gastrin
How do acetylcholine, histamine, and gastrin stimulate the secretion of gastric acid?
They bind to receptors and stimulate the proton pump to secrete hydrogen ions in exchange for potassium ions in the lumen of the stomach
What is ranitidine?
A copmetitive antagonist of histamine receptors
What effect does ranitidine have?
it inhibits histamine receptors to partially inhibit gastric acid secretion
What is ranitidine particularly effective against?
Noctural acid secretion
How effective are histamine antagonists at inhibiting acid secretion?
They can inhibit greater than 90% of basal, food-stimulated, and noctural secretion of gastric acid after a single dose
Is the action of histamine receptor antagonists fully reversible?
Yes
Why has the use of histamine receptor antagonists decreased?
With the advent of PPIs
What kind of drug is ranitidine?
A long-acting histamine receptor antagonist
What are the side effects of ranitidine?
Minimal side effects, but if present may include;
- Headache
- Dizziness
- Diarrhoea
- Muscular pain
What effect might histamine receptor antagonists have on drugs?
Drugs which depend on acidic medium for gastric absorption, such as ketoconazole, may not be efficiently absorbed if taken with a histamine receptor antagonist
Give 3 examples of PPIs?
- Omeprazole
- Lansoprazole
- Esomeprazole
How do PPIs work?
They bind to the H/K/ATPase enzyme system (proton pump) of the parietal cell which acts to suppress the secretion of the hydrogen ions into the gastric lumen
How effective are PPIs?
At standard doses, they inhibit basal and stimulated gastric acid secretion by more than 90%
In what respects are PPIs superior over histamine receptors?
For suppressing acid production and healing peptic ulcers
What are the indications for the use of PPIs?
- Stress ulcer treatment and prophylaxis
- Treating erosive oesophagitis and active duodenal ulcers
- Long-term treatment of pathologic hypersecretory conditions
- GORD
Gastroprotection with use of drugs such as NSAIDs and aspirin
Give an example of a pathologic hypersecretory condition
Zollinger-Ellison syndrome
When should PPIs be taken for maximum effect?
30 to 60 minutes before breakfast or the largest meal of the day
When should a histamine antagonist be taken if used alongside a PPI?
Well after the PPI
Why should a histamine receptor be taken well after a PPI if both are needed?
Because histamine antagonists reduce the activity of the proton pump, and PPIs require active pumps to be effective
Which PPIs are effective orally?
All
How are PPI metabolites excreted?
In urine and faeces
Are PPIs generally well tolerated?
Yes
What are the adverse effects of PPI?
- Nausea
- Diarrhoea
- Headache
- Increased risk of bone fractures
Why does omeprazole interact with some drugs?
Because of competitive inhibition of CYP450 enzymes
What drugs may omeprazole effect?
It has been shown to inhibit the metabolism of warfarin, phenytoin, diazepam, and cyclosporin
What effect have PPIs been shown to have on clopidogrel?
All PPIs have been shown to decrease the effectiveness of clopidogrel
What are the options for the surgical management of GORD?
- Laparoscopic Nissen fundoplication
- Laparoscopic insertion of a magnetic bead band
- Radiofrequency-induced hypertrophy
What is the aim in the surgical management of GORD?
To increase resting lower oesophageal sphincter pressure
When should surgery be considered in the management of GORD?
If severe GORD where drugs are not working
What symptoms of GORD are less likely to improve with surgery?
Atypical symptoms, such as cough and laryngitis
What are the complications of GORD?
- Oesophagitis
- Ulcers
- Benign strictures
- Iron-deficiency
- Barrett’s oesophagus
What is Barrett’s oesophagus?
Where the distal oesophageal epithelium undergoes metaplasia from squamous to columnar
What % of people with Barrett’s oesophagus progress to oesophageal cancer?
0.1-0.4%/year
