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Flashcards in GI Meds Deck (44)
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1

Proton Pump Inhibitors

Omeprazole

2

Administration of omeprazole

administered as inactive acid-liable pro-drugs that have an enteric coating to protect against rapid destruction in the stomach. Dissolved and absorbed in the intestines.

3

Mechanism of Omeprazole

Absorbed in intestine where it is acid activated and blocks H-K-ATPase irreversibly by forming a covalent bond with SH-groups of H-K_ATPase. ATLEAST 18 HOURS ARE REQUIRED FOR FORMATION OF A NEW ATPASE

4

How often is Omeprazole given?

Once daily, twice is severe GERD, should be given 30 min before meal for peak plasma levels.

5

By what percent does food decrease the bioavailability of Omeprazole?

50%

6

Why does ir take 3-4 days of daily medication for full acid inhibition?

Not all H-pumps are inactivated with the first dose

7

Uses of omeprazole

gastric ulcers, alone or in combo with H. pylori; also used in GERD

DRUG OF CHOICE WITH ZOLLINGER ELLISON SYNDROME

8

T/F: Proton pump inhibitors are superior to H2 receptor antagonists and to mucosal protectants in the healing of NSAID Peptic Ulcers

True

9

WHy should you avoid omeprazole and plavix?

Omeprazole is a moderate CYP2C19 inhibitor, that reduces the pharmacological activity of plavix(clopidogrel). Avoid using concomitantly or 12 hrs apart.

10

Histamine H2-receptor antagonist

Cimetidine

11

Main role of cimetidine

Inhibits fasting secretion of gastric acid with a smaller effect on food stimulated gastric acid secretion. Competetive inhibitor at the parietal cell H2-receptor. ALSO BLUNTS RESPONSES TO GASTRIN AND ACH

12

Uses of cimetidine

gastric ulcers, GERD, and heartburn

13

How safe is cimetidine?

Very safe its is available over the counter

14

Drug interactions of cimetidine

interferes with metabolism of other drugs due to inhibition of cytochrome p450

15

Mucosal Protective agents

Misoprostol, Sucralfate, Bismuth subsalicylate

16

Misoprostol

A stable analog of PGE that bings to the PG receptro and causes a modest inhibition of acid secretion. Cytoprotective.

PROMOTES SECRETION OF MUCUS AND BICARB

17

Uses of misoprostol

prevention of gastric damage due to chronic use of NSAIDs

18

Side effects of Misoprostol

diarrhea and abdominal cramps. DO NOT USE IF PREGNANT- CAN CAUSE ABORTION DUE TO UTERINE CONTRACTION

19

Sucralfate

Complex of Al(OH)3 and sulfated sucrose. Cytoprotective. Coats gastric mucosa and stimulates PGE production.

20

Drug interactions of sucralfate

reduces absorbtion of digoxin, phenytoin

21

Bismuth Subsalicylate

Cytoprotective, may inhibit pepcin activity and increase mucus , prostaglandin and bicarb secretion.

22

Uses of Bismuth Subsalicylate

mild diarrhea, been used in clinical trails for eradication of h. pylori. may also have some antibacterial effect against H. pylori (used to eradicate h. pylori)

People dont like it because of bad taste

23

Adverse effects of bismuth:

patients sensitive to asprin may show sensitivty to salicylate

24

Drugs that stimulate gi motility

Metoclopramide and Erythromycin

25

Metoclopramide

A dopamine D2 receptor agonist that releases Ach from cholinergic neurons in myenteric plexus, enhancing tone and motility in esophagus and stomach stimulating gastric emptying with out stimulating acid secretion

only works on upper gi

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Uses of metoclopramide

GERD, heartburn, disorders of gastric emptying and intractable hiccup

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Adverse effects of metoclopramide

extrapyramidal side efects such as parkinsonism, contraindicated in people with seizure disorders and in mechanical obstruction of GI tract

28

Erythromycin

Stimulates motilin receptors (motilin is a polypeptide hormone that mediates intestinal smooth muscle contraction)

29

Uses of erythromycin

used in diabetic gastrophoresis and in upper gi hemorrhages to promote gastric emptying before endoscopy

30

Anti emetics

5-HT3 receptor antagonist: ondansetron