GI pharm + motility Flashcards
Cholinergic agonists
Stimulate gut motility through vagus
Cholinergic antagonists
Reduce gut motility
Treatment for peptic acid disease
Antacids
Omeprazole
Ranitidine
Types of motility
Myogenic = ICC, constant level of electrical activity
Enteric plexus = both with and without CNS, lots of neurotransmitters, regulate over short and long distances
MMC = migrating motility complex, ‘housekeeping’ waves of contractility
Intestinal reflexes = rate of gastric emptying controlled by contents of stomach and duodenum
Anti-emetics
Treatment for vomiting and nausea
Also increase motility
Dopamine, serotonin, cholinergic antagonists (toxic vomiting), histamine antagonist for travel vomiting
Laxatives
Bulk and osmotic
Bulk = plant extracts, bulky bolus that cannot be digested
Osmotic = more fluid in lumen, contain poorly absorbed solutes
Anti-diarrhoeal drugs
Opiates = codeine, loperamide, bind to receptors on myenteric plexus (inhibit ACh release presynaptic) Kaolin = absorbent drugs
Parasympathomimetics
Increase motility, activate cholinergic receptors
Sphincters
Allow stomach and large intestine to act as reservoirs
Prevent reflux
Segmental activity
Gall bladder motility
Activated by CCK
causes of peptic acid disease
oesophageal reflux
peptic ulcer
antacids for peptic acid disease
alkaline salts used widely for reflux
aluminium/magnesium hydroxide
usually effective for reducing mild symptoms occasionally
suppression of acid secretions, for peptic acid disease
peptic ulcers or significant oesophageal damage
acid secretion stimulated by histamine also ACh/gastrin
proton pump inhibitor = omeprazole
histamine antagonist = ranitidine
causes of peptic acid disease
oesophageal reflux
peptic ulcer
antacids for peptic acid disease
alkaline salts used widely for reflux
aluminium/magnesium hydroxide
usually effective for reducing mild symptoms occasionally
