Gastrointestinal Pharmacology

Question 1

what is the mechanism of action for H2-blockers

Answer 1

○ Competitive block of H2-R on parietal cells

Question 2

what are the specific agents of H2-blockers

Answer 2

Cimetidine (Tagamet), Ranitidine (Zantac), Famotidine (Pepcid)

Question 3

what is the therapeutic uses for H2-blockers

Answer 3

ulcers

Question 4

what is the mechanism of action of anticholinergics

Answer 4

Block of M-receptors on parietal cells

Question 5

what is the therapeutic use of anticholinergics

Answer 5

ulcers

Question 6

what is the mechanism of action of PPI

Answer 6

H+, K+-ATPase inhibition

Question 7

what are the specific agents of PPI

Answer 7

omeprazole and esomeprazole

Question 8

what are the therapeutic uses of PPI

Answer 8

ulcers
GERD
management of Zollinger-Ellison syndrome

Question 9

what are the mechanism of action of PGE1 analogues

Answer 9

1) Decreased proton pump activity
2) Increased bicarbonate and mucous secretion

Question 10

what is the therapeutic use of prostaglandins

Answer 10

prevention of NSAID-induced ulcer/GI bleed

Question 11

what is the contraindication of PGE1 analogues

Answer 11

pregnancy

Question 12

what are drugs that decreases motility in the GI

Answer 12

• diphenoxylate-atropine
• loperamide

Question 13

what is the mechanism of action of diphenoxylate

Answer 13

Opioid receptor agonist - Inhibits ACH release in enteric system at low doses

Question 14

what is the mechanism of action of atropine

Answer 14

1) Synergistic effect with diphenoxylate to decrease effects of ACH on the gut
2) Anticholinergic side effects discourage abuse potential

Question 15

loperamide is similar to diphenoxylate-atropine, but without the ?

Answer 15

atrropine

Question 16

what drugs increases motility

Answer 16

• laxatives
• metoclopramide
• domperidone
• antinausea

Question 17

what are the 4 main categories of laxatives

Answer 17

○ Bulking agents
○ Osmotic laxatives
○ Chemical stimulants
○ Stool softeners

Question 18

what are bulking agents

Answer 18

Non-absorbed agents that create bulkier stools and draw water into stools

Question 19

what does bulkier stool do

Answer 19

stimulates the bowel

Question 20

what does softer stool do

Answer 20

easier to move

Question 21

what are osmotics laxatives

Answer 21

Results in an increase in osmotic pressure leading to retention of water in intestine, lumen extension, and increased bowel action

Question 22

what are chemical stimulants: laxatives

Answer 22

Irritate the gut to induce peristalsis and increase mucous production

Question 23

what are stool softenenrs: laxatives

Answer 23

Use water or oil to soften stools

Question 24

examples of stool softeners

Answer 24

mineral oil
sodium docusate

Question 25

what is the mechanism of action for anti-nausea/vomiting of metoclopramide

Answer 25

block of central D-receptors

Question 26

what is the mechanism of action for increased motility of metoclopramide

Answer 26

block of peripheral D-receptors (dopamine is inhibited)

Question 27

what are the therapeutic uses of metoclopramide

Answer 27

- GERD - Diabetic gastric stasis - prevention of nausea and vomitting with chemotherapy

Question 28

what are the adverse effects of metoclopramide

Answer 28

diarhea hyperprolactinemia

Question 29

how does hyperprolactinemia happen

Answer 29

blocking dopamine therefore causes increased prolactin

Question 30

what can be used to stimulate milk production in lactating mothers

Answer 30

domperidone

Question 31

what are the two drugs for antinausea

Answer 31

- anticholinergics - D2 blockers

Question 32

what does anticholinergics do

Answer 32

Block cholinergic transmissions between vestibular and vomiting centers in the CNS

Question 33

what are the specific agents of anticholinergics

Answer 33

- scopolamine - promethazine

Question 34

what are the specific agents of D2-blockers

Answer 34

- metoclopramide - domperidone