Treating Gastrointestinal Disorders Flashcards
Which factors support the integrity of the gastric mucosa?
Good vascular supply
Mucous membrane barrier
Epithelial integrity
Cell replication and restitution
Which factors threaten the integrity of the gastric mucosa?
Acidic conditions
H pylori
Drugs
Which cells secrete acid into the stomach?
Parietal cells
Which 3 receptors on the parietal cell membrane stimulate acid secretion? Which ligands do they bind to?
ACh Muscarinic receptor- stimulated by vagus nerve
H2 receptor- stimulated by histamine release from ECL cell.
CCK- stimulated by gastrin produced by G cell
Which cell produces somatostatin in response to high levels of stomach acid and inhibits the parietal cell?
D cell
Which factors stimulate the G cell to produce gastrin?
Stretch receptors in stomach wall
Ach muscarinic receptor via vagus nerve
Which cell in the stomach produces pepsinogen via stimulation of CCK receptors from gastrin and vagal stimulation?
Chief cells.
What are the two major classes of drugs used to control acid secretion?
Proton pump inhibitors eg omeprazole
H2 receptor antagonists
What are some key facts about H2 receptor antagonists?
BD dosage
Short half life
Prevent stimulation of parietal cell by H2
What are some key facts about PPIs?
Delayed action as is used dependent and not all of the pumps are active all of the time
Restoration of acid synthesis requires de novo synthesis of receptors
What is the stepwise treatment of GORD/ peptic disease via step up and step down regimens?
Lifestyle- stop NSAIDs, lose weight, reduce alcohol intake
Antacids/alginates- alginates attach to damaged mucosa and prevent further damage
H2RA
PPi
How is H pylori treated?
Clarithromycin 500mg BD, amoxicillin 1gBD, lanzoprazole 30mg BD.
How does H pylori lead to development of peptic ulcer disease?
Causes inflammation of gastric mucosa which leads to duodenal or gastric ulcer.
