Dyspepsia Flashcards
What is Dyspepsia?
Indigestion
What is GORD?
Gastro-Oesophageal Reflux Disease
Leads to Oesophagitis
What can cause GORD?
Obesity
Pregnancy
Drug-induced
What is Peptic Ulceration?
Damage to lining of alimentary tract
Gastric/Duodenal
Erosion, damage, bleeding
What is Zollinger-Ellison syndrome?
Gastrin secreting tumour of D-cells (pancreas)
What is Gastritis?
Inflammation of the stomach
What effect can NSAIDs/oral steroids have on the alimentary tract?
Damage ie. ulceration
What are the signs/symptoms of Peptic Ulceration?
Epigastric pain, precisely located Hunger pain (relieved by eating) Night pain (relieved by food, milk, antacids) Warterbrash Nausea/vomiting (esp. blood)
What is the most common cause of duodenal/gastric ulcers?
H. pylori (G-) infection
80-90% Duodenal
70% Gastric
What is the pathogenesis of ulcers due to H. pylori infection?
Infection leads to chronic inflammation leads to gastric damage leads to ulceration
What tests are available for H. pylori infection?
Urea breath test - pt given 13C urea, bacterial ureases convert it to 13CO2, exhaled
H. pylori antigens/antibodies (blood, saliva, stool)
What are the warning signs for serious alimentary disease?
Age >45 Weight loss Anaemia Dysphagia Haematemesis Melaena Upper abdominal masses
What factors increase acid secretion?
Histamine (H2 receptors)
Gastrin (CCK receptors)
AcH (M3 receptors, parietal cells)
What factors decrease acid secretion?
Prostaglandins (E2/I2) - also cyytoprotective (bicarbonate/mucus release)
What are the goals of treatment for Dyspepsia?
Symptomatic relief
What are the main methods of treatment for Dyspepsia?
Lifestyle changes (avoid causative drugs, foods, prop up in bed, remove belts)
Suppression of acid release
Mucosal protection
What is required for long term cure of Dyspepsia?
Suppression of acid release
Allows natural healing AND H. pylori infection
What is a further negative effect of H. pylori infection?
Development of gastric carcinomas
What are the most common antacids?
Sodium bicarbonate
Magensium/Aluminium Hydroxide
How do antacids work?
Alkaline bases, react w/ acid to produce salt and water - RAISE pH
What are alginates?
A type of anti-dyspepsia medication often combined with antacids
How do alginates work?
Alginic acid combines w/ saliva
Forms viscous foam, floats on gastric contents
Protects oesophagus during reflux
How do Histamine H2 antagonists work?
Antagonise H2 receptors
H2 receptors coupled via adenylyl cyclase - increase cAMP - activates proton pump
Give examples of Histamine H2 antagonists
Cimetidine
Ranitidine
Famotidine
Which Histamine H2 antagonist is more complicated to treat with?
Cimetidine - inhibits CP450, many drug interactions -Oral anticoagulants -Phenytoin -Carbamazepine -TCAs RANITIDINE FAVOURED
How do Proton Pump Inhibitors work?
Irreversible inhibition of the proton pump
Give examples of Proton Pump Inhibitors
Omeprazole
Pantoprazole
Lansoprazole
What negative effects can treatment with PPIs have?
Inhibit H+ secretion >90% - leads to achlorhydria
Increased risk of Campylobacter infection
What are prokinetic drugs?
Drugs that cause gastric emptying
Give examples of prokinetic drugs
Domperidone - closure of oesophageal sphincter, opens lower sphincter
Metocloperamide - increases gastric motility/emptying
What is Metocloperamide combined with?
Analgesics, accelerates absorption
What is the most effective treatment for H. pylori eradication?
Antibiotic (2 from Metronidazole, Amoxicillin, Clarithromycin)
PPI/H2 antagonist
TRIPLE THERAPY for 1 wk
PPI alone for ulcer healing
What is Bismuth Chelate?
Antacid that kills H. pylori
How does Bismuth Chelate work?
Kills H. pylori
Coats ulcer
Absorbs pepsin
Increases prostaglandin production AND HCO3- secretion
What is the treatment for Dyspepsia in the absence of H. pylori infection?
Staged approach
What is stage 1 Dyspepsia treatment?
Antacid OR Alginate/Antacid
What is stage 2 Dyspepsia treatment?
H2 antagonist
What is stage 3 Dyspepsia treatment?
PPI
How do NSAIDs/oral steroids have their ulcerogenic effect?
Inhibit prostaglandin production
- NSAIDs inhibit COX
- Steroids inhibit PLA2
What are COX enzymes?
Cyclooxygenases
What are the two isoforms of COX enzymes?
COX-1 - physiological form, gastric protection
COX-2 - pathological, inflammation
What is Celecoxib?
COX-2 selective inhibitor, fewer GI side effects
How can GI damage be minimized?
Prophylaxis w/ PPI
H2 antagonists less effective, give w/ Misoprostol
What is Misoprostol?
Stable PGE1 analogue
How does Misoprostol work?
Acts on prostanoid receptors, inhibits gastric H+ secretion
