Drugs Used in GI Dysfunction

Question 1

What are the important H2 antagonists used in the treatment of stomach dysfunction? Suffix?

Answer 1

“itidine”

Cimetidine, Ranitidine, Famotidine

Question 2

What is the MOA of cimetidine?

Answer 2

suppress secretary responses to food stimulation by indirectly inhibiting the actions of the proton pump

also, partially antagonizes HCl secretion caused by vagal or gastrin induced release of histamine from ECL like cells

Question 3

Uses of H2 antagonists?

Answer 3

PUD
Gastroesophageal reflux disease (GERD)
Zollinger-Ellison syndrome

Question 4

What are the S/E of cimetidine?

Answer 4

similar to azoles

blocks P450> dec androgens> gynecomastia and decreased libido

Question 5

Name the PPIs? Suffix?

Answer 5

“prazoles”

Omeprazole

Question 6

MOA of PPIs?

Answer 6

direct inhibitors of the proton pump (K+/H+) anti port in the gastric parietal cell

Question 7

What are the uses for PPIs?

Answer 7

Effective in GERD and Zollinger Ellison syndrome

Eradication regimen for H.pylori

Question 8

Which is more effective in treating gastric ulcers? PPIs or H2 antagonists?

Answer 8

PPIs

Question 9

What is the MOA of misoprostol?

Answer 9

PGE1 analog which is cytoprotective > mucus and bicarbonate secretion and dec HCl secretion

Question 10

What is the MOA of sucralfate?

Answer 10

polymerizes on GI luminal surface to form a protective gel-like coating of ulcer beds (requires acidic pH)

Question 11

What are the uses of sucralfate?

Answer 11

improve healing and decrease ulcer recurrence

Question 12

MOA bismuth subsalicylate?

Answer 12

Like sucralfate binds selectively to ulcer, coating it and protecting it from acid and pepsin

Question 13

Use of Bismuth subsalicylate as a triple therapy? Which drugs is it commonly used with?

Answer 13

combined with metronidazole and tetracylcline (BMT) regimen to eradicate H pylori

Question 14

Name the antacids?

Answer 14

Al (OH)3 aluminum hydroxide, Mg(OH)2 magnesium hydroxide, CaCO3 calcium carbonate

Question 15

S/E of antacids?

Answer 15

constipation (Al+++), diarrhea (Mg++) rebound hyperacidity

Question 16

What are some receptors in the CTZ targeted for antiemetic effects ?

Answer 16

D2
5HT3
CB1

Question 17

Describe the absorption of antacids with quinidine?

Answer 17

quinidine is a weak base so oral absorption would increase

Question 18

Describe absorption of antacids with tetracyclines?

Answer 18

tetracylines chelate polyvalent cations so it would decrease absorption

Question 19

Describe the dual action opioids have on emesis?

Answer 19

opioids dec emesis by activating receptors that dec. pain transmission and inc. emesis by activating receptors in the CTZ

Question 20

What are the 5HT3 antagonists? Suffix?

Answer 20

“setrons”

ondansetron

Question 21

What DA antagonists are used for emesis? Do they have other indications?

Answer 21

prochlorperazine, metoclopramide

Also used in cancer chemotherapy; also pro kinetic in GERD

Question 22

Cannaboids used for anti emetic action?

Answer 22

dronabinol

Question 23

NK1 receptor antagonists work?

Answer 23

NK1 receptors act by releasing substance P and concurrently activate vomiting center so you are blocking this pathway

Question 24

How does mesalamine work to treat CD and UC?

Answer 24

(5-ASA) acts as anti- inflammatory agent

Question 25

What are some immunosuprressive agents used for moderate to severe CD and UC?

Answer 25

corticosteroids, cyclosporine, anti-TNF alpha drugs