010815 upper GI pharm Flashcards
(44 cards)
what role do prostaglandins play in upper GI?
PGI2 and PGE2 are protective:
decrease gastric acid production
increase mucus production
H+/K+ ATPase pump inhibitors are used for
gastric and duodenal ulcers
GERD
pathological hypersecretory conditions like Zollinger Ellison syndrome
list types of H+/K+ ATP ase pump inhibitors
the zoles
omeprazole
esomeprazole
lansoprazole
how do the H+/K+ ATPase pump inhibitors get targeted to their site of action?
they are prodrugs and only in the acidic gastric secretory canaliculi are they catalyzed to a sulfonamide
MOA of H+/K+ ATPase pump inhibitors
irreversibly inactivate the H+/K+ ATPase pump, so only way for the stomach to overcome it is to make new proton pumps!
metabolism of H+/K+ ATPase pump inhibitors
hepatic P450
side effects of H+/K+ ATPase pump inhibitors
few
chronic use-increased risk of bone fracture, increased risk of infection
MOA of H2 receptor antagonists
competitively bind to histamine H2 receptors on parietal cells. reversible binding.
list H2 receptor antagonists
cimetidine (inhibits P450)
ranitidine
the -dines
can develop tolerance to H2 receptor antagonists: true or false?
true
two main drug mechanisms for decreasing acid
H2 antagonist on parietal cell
proton pump inhibitors on parietal cell
in treating ulcers, what are the possible approaches?
decrease acid
increase protective mechanisms
sucralfate
sucrose sulfate and Al(OH)3
MOA of sucralfate
in stomach acid, forms a polymer gel in the acid environment. adheres to epithelial cells and ulcer craters to protect the ulcer by coating it from pepsin hydrolysis
antacids-list them
Al(OH)3
Mg(OH)2
CaCO3
which antacid produces CO2 as side effect?
CaCO3
which antacid has constipation as side effect? diarrhea?
constipation: Al(OH)3
diarrhea: Mg(OH)2
so Mg and Al are combined in many antacid preps to offset each other
cautions for antacids
avoid concurrent administration of antacids and drugs intended for systemic absorprtion (antacids can change drug absoprtion and elimination because they alter gastric and urinary pH)
bismuth subsalicylate
trivlanet bismuth and salicylate suspended in mix of magnesium aluminum silicate clay
called Pepto bismol
use of bismuth subsalicylate
ulcer
black stools, black tongue side effect comes from?
bismuth subsalicylate
antibiotic for H pylori consists of
multi agent antibiotic therapy (single one is ineffective)
tx strategy for NSAID related mucosal injury
if can’t stop using NSAID:
reduce acid
replace prostaglandins (not used much)
treatment for active ulcers that are non-H pylori and non-NSAID
reduce acid
