Drugs-GERD PUD

Question 1

name three cell types and the substances they secrete that bind to parietal cells and promote acid secretion

Answer 1

gatsrin cell (gastrin), nerves/neurons (acetylcholine), ECL cell (histamine)

Question 2

parietal cells contain this, also known as a “proton pump” which is the final step before acid release

Answer 2

H/K ATPase

Question 3

H2 receptor agonists work by?

Answer 3

mimicking histamine and reversibly competing with it to block binding to H2 receptors (histamine receptors) on basolateral membrane of parietal cells -> suppressed basal and stimulated acid output

Question 4

example of H2 receptor agonist

Answer 4

cimetidine

Question 5

side effects of H2 receptor agonists

Answer 5

headache, diarrhea, thrombocytopenia

Question 6

H2 receptor agonists are now OTC, but were instrumental in treatment of ____

Answer 6

ulcers

Question 7

mechanism of action of proton pump inhibitors

Answer 7

irreversibly bind (covalent) to and inhibit H/K-ATPase within luminal membrane of gastric parietal cells -> elimination of almost all acid output

Question 8

PPIs are _____, and thus require activation in acid environment within ______ of parietal cells

Answer 8

prodrugs; secretory canaliculi

Question 9

PPI indications

Answer 9

GERD, peptic ulcer dz (PUD), Zollinger-Ellison syndrome

Question 10

side effects of PPIs

Answer 10

minimal; HA, diarrhea, nausea

Question 11

MoA of sucralfate

Answer 11

extensive cross-linking and polymerization produces viscous, sticky gel that adheres to epithelial cells and ulcer craters, inhibiting pepsin-mediated hydrolysis of mucosal proteins

Question 12

why can’t sucralfate be given with omeprazole?

Answer 12

requires acid environment to function and impairs absorption of other drugs

Question 13

sucralfate is an old-fashioned tx for?

Answer 13

ulcers

Question 14

MoA of misoprostol

Answer 14

prostaglandin E1 analog binds EP3 receptor of parietal cells to decrease intracellular cAMP

Question 15

misoprostol was originally prescribed for ____ but is no longer prescribed due to?

Answer 15

peptic ulcer disease; severe side effects (diarrhea, abdominal cramping)

Question 16

how is misoprostol “cytoprotective”?

Answer 16

it repletes prostaglandin that has decreased, stimulating mucus and bicarb production

Question 17

for what is misoprostol sometimes prescribed today?

Answer 17

in combination with NSAIDS to block ulcer development through cytoprotection

Question 18

MoA of antacids

Answer 18

X(OH) directly neutralize gastric HCl (“buffer” acid)

Question 19

examples of antacids

Answer 19

maylox, mylanta, tums, pepto

Question 20

side effects of antacids

Answer 20

diarrhea, constipation, “milk-alkali syndrome”

Question 21

what is “milk-alkali syndrome”?

Answer 21

the combination of milk and CaCO3 leads to hypercalcemia and can cause renal failure in patients that consume sufficient quantities of them together