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Block 7 - GI > GI Pharm > Flashcards

Flashcards in GI Pharm Deck (20):
1

ranitidine

H2 histamine receptor antagonist - competitive inhibitors
used to treat gastric ulcers and associated problems - inhibits secretion of gastric acid

2

Which cells synthesize and store histamine?

ECL cells

3

What are the side effects of ranitidine?

diarrhea, dizziness, muscle pain, skin rash, gynecomastia, CNS effects, drug interxns (p450 inhibition - prolongs life of other drugs)

4

Omeprazole

inhibits H/K ATPase
used to treat gastric ulcers and associated problems - inhibits gastric acid from any agents --> rapid healing!

5

How does omeprazole work?

prodrug requires activation
protonated form inhibits pump - irreversible inhibition via covalent modification of SH groups

6

What is the therapeutic use of antacids?

good for duodenal ulcers, not gastric
treats GER but only symptoms, not dz course

7

Misoprostol

synthetic prostaglandin agonist that inhibits cAMP, increases production of mucus and bicarb
prevents ulcers caused by NSAIDs

8

bethanechol

cholinergic agonist - promotes gastric emptying and GI motility

9

metoclopramide

promotes GI motility
antagonist at dopamine D2 receptors reduces inhibtion
agonist at 5-HT3 and 5-HT4 receptors
can cross BBB
effects more in upper GI tract

10

What can restrict use of metoclopramide?

use >3 mos of high doses can lead to short term or permanent Tardive Tyskinesia

11

lactulose

osmotic laxative - not absorbed and resistant to digestion

12

lubiprostone

treatment of constipation
derivative or PG E1 that activates Cl channels - secretion of Cl with Na leads to more water to soften stools and increase motility

13

diphenoxylate/loperamide

opiate receptor agonists
anti-diarrheal effects w few central effects
act through mu receptors

14

cholestyramine

anion exchange resin
useful in bile-induced diarrhea

15

What can happen with misuse of laxatives?

excessive fluid and electrolyte loss
colonic inertia
steatorrhea
secondary aldosteronism due to volume depletion

16

scopolamine

muscarinic receptor antagonist
antinausea and antiemetic useful in motion sickness

17

ondansetron

5HT3 receptor antagonist
well tolerated - mild side effects headache, constipation, dizziness
antinausea and antiemetic

18

chlorpromazine

dopamine D2 receptor antagonist
antinausea and antiemetic

19

dexamethasone

corticosteroid used for nausea and emesis

20

dronabinol

cannabinoid receptor agonist
side effects so only use if unresponsive to other anti-emetic drugs