GI Meds

Question 1

Proton Pump Inhibitors

Answer 1

Omeprazole

Question 2

Administration of omeprazole

Answer 2

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.

Question 3

Mechanism of Omeprazole

Answer 3

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

Question 4

How often is Omeprazole given?

Answer 4

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

Question 5

By what percent does food decrease the bioavailability of Omeprazole?

Answer 5

50%

Question 6

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

Answer 6

Not all H-pumps are inactivated with the first dose

Question 7

Uses of omeprazole

Answer 7

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

DRUG OF CHOICE WITH ZOLLINGER ELLISON SYNDROME

Question 8

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

Answer 8

True

Question 9

WHy should you avoid omeprazole and plavix?

Answer 9

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

Question 10

Histamine H2-receptor antagonist

Answer 10

Cimetidine

Question 11

Main role of cimetidine

Answer 11

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

Question 12

Uses of cimetidine

Answer 12

gastric ulcers, GERD, and heartburn

Question 13

How safe is cimetidine?

Answer 13

Very safe its is available over the counter

Question 14

Drug interactions of cimetidine

Answer 14

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

Question 15

Mucosal Protective agents

Answer 15

Misoprostol, Sucralfate, Bismuth subsalicylate

Question 16

Misoprostol

Answer 16

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

Question 17

Uses of misoprostol

Answer 17

prevention of gastric damage due to chronic use of NSAIDs

Question 18

Side effects of Misoprostol

Answer 18

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

Question 19

Sucralfate

Answer 19

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

Question 20

Drug interactions of sucralfate

Answer 20

reduces absorbtion of digoxin, phenytoin

Question 21

Bismuth Subsalicylate

Answer 21

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

Question 22

Uses of Bismuth Subsalicylate

Answer 22

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

Question 23

Adverse effects of bismuth:

Answer 23

patients sensitive to asprin may show sensitivty to salicylate

Question 24

Drugs that stimulate gi motility

Answer 24

Metoclopramide and Erythromycin

Question 25

Metoclopramide

Answer 25

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

Question 26

Uses of metoclopramide

Answer 26

GERD, heartburn, disorders of gastric emptying and intractable hiccup

Question 27

Adverse effects of metoclopramide

Answer 27

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

Question 28

Erythromycin

Answer 28

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

Question 29

Uses of erythromycin

Answer 29

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

Question 30

Anti emetics

Answer 30

5-HT3 receptor antagonist: ondansetron

Question 31

odansetron

Answer 31

prevents peripheral and central stimulation of VC by blocking 5-ht3 receptors in stomach, STN and CTZ. has a long half life, given once or twice daily

Question 32

interesting effect of odansetron

Answer 32

increases qt interval but not usaully clinically significant

Question 33

uses of odansetron

Answer 33

effective against chemotherapy and pregnancy induced nausea and vomiting

Question 34

Drugs used in IBD

Answer 34

5-aminosalicylic acid, sulfasalazine (need to supress the inflammatory and immune responses)

Question 35

Glucocorticoids

Answer 35

prednisone and prednisolone (Budesonide is a synthetic analog of prednisone that releases the drug into the distal ileum and colon where it is absorbed)

Question 36

Uses of glucocorticoids

Answer 36

treat moderate to severe FLARES of IBD

Question 37

Purine analogs

Answer 37

Azathioprine and 6- mercaptopurine (immunosuppressants)

Question 38

Adverse effects of purine analogs

Answer 38

nausea vomiting, bone marrow depression and hepatic toxicity

Question 39

Methotrexate

Answer 39

may interfere with inflammatory action of IL 1, increase release of adenosine, stimulates the death of activated t cells

Question 40

Uses of methotrexate

Answer 40

induce and maintain remission of crohns

Question 41

Adverse effects at higher doses with methotrexate

Answer 41

bone marrow depression, megablastic anemia, and alopecia

Question 42

How do you avoid adverse effects of methotrexate

Answer 42

supplement with folate

Question 43

Inflixamab

Answer 43

monoclonal antibody to TNF alpha, inhibits it from binding to receptor.

Question 44

Uses and adverse effects of Inflixamab

Answer 44

uses: UC CD ae: infection due to suppression of inflammatory response