GI

Question 1

Name a systemic antacid

Answer 1

Sodium bicarbonate (NaHCO3)

Question 2

NaHCO3 MOA:

Answer 2

bicarbonate ion is absorbed into the blood and slightly increases pH (alkalosis) + increases stomach pH

Question 3

NaHCO3 indication:

Answer 3

acute, short-term reduction of stomach acid

Question 4

Name 3 problems with NaHCO3:

Answer 4

1) alkalotic urine can increase calcium and phosphate deposition –> kidney stone
2) increase in blood sodium –> HTN exacerbation
3) acid rebound due to feedback regulation

Question 5

Name 3 non-systemic antacids

Answer 5

1) CaCO3
2) Al(OH)3
3) Mg(OH)2
* does not contain bicarb ion so does not affect extracellular or blood pH*

Question 6

Name 2 problems with non-systemic antacids:

Answer 6

1) acid rebound

2) Al + Ca = constipating (may be combined with Mg = laxative)

Question 7

How are muscarinic receptors associated with stomach acid?

Answer 7

Muscarinic Ach receptors in parietal cell stimulate HCl secretion

Question 8

__% to __% of stomach acid needs to be inhibited to get effective control

Answer 8

60-70

Question 9

Name a muscarinic type 1 Ach R blocker

Answer 9

Pirenzipine

Question 10

What are cytoprotectives?

Answer 10

Drugs that protect cells from acidic damage (directly or through mucus stimulation)

Question 11

What are 2 major drugs considered as cytoprotectives?

Answer 11

1) Sucralfate (Al based salt)

2) Misoprostol

Question 12

Sucralfate MOA:

Answer 12

1) Binds to H ions to form paste –> increased pH

2) Binds to degenerating cells to form protective layer over them (artificial mucus)

Question 13

What is 1 problem with sucralfate?

Answer 13

It can inhibit absorption of other drugs (but itself is not absorbed into the bloodstream)

Question 14

Sucralfate DOA:

Answer 14

8-12 hours

Question 15

Misoprostol MOA:

Answer 15

Prostaglandin (PG) analogue that stimulates production of mucosal barrier

Question 16

Name 1 SE of Misoprostol:

Answer 16

Diarrhea

Question 17

Name 3 histamine H2 blockers

Answer 17

1) Cimetidine (Tagamet)
2) Ranitidine (Zantac)
3) Famotidine (Pepcid)

Question 18

Histamine H2 blockers MOA:

Answer 18

Inhibits H2 receptor of parietal cell to decrease HCl production (very specific and no AE on mucosa)

Question 19

Cimetidine results in __% to __% reduction in acidity

Answer 19

50-60

Question 20

Cimetidine DI:

Answer 20

Binds to cyp450

Question 21

Name 1 AE of cimetidine

Answer 21

1) Binds to androgen receptors (may result in gynecomastia, reduced libido, impotence)

Question 22

Cimetidine does not affect bone rigidity!

Answer 22

No effect on osteoporosis

Question 23

Ranitidine results in __% to __% reduction in acidity

Answer 23

65-70%

Question 24

Name 2 advantages ranitidine over cimetidine:

Answer 24

1) Has less DIs (bc only binds to CYP450 at high doses)

2) Does NOT bind to androgen receptors

Question 25

Name 3 advantages Famotidine has over Cimetidine and Ranitidine:

Answer 25

1) More effective 2) Does not bind to CYP450 at all 3) Very few SEs

Question 26

Proton pump inhibitor (PPI) MOA:

Answer 26

1) Inhibits gastric H+/K+ ATPase | 2) Binds to H+ extrusion sites to block release of H+ and Cl-

Question 27

PPI results in __% reduction in acidity

Answer 27

90%

Question 28

PPI indication:

Answer 28

- Rapid reduction of acid (bc does not need to bind to receptors) - GERD

Question 29

If PPI taken chronically, osteoporosis is seen!

Answer 29

Management: higher doses of Pepcid instead

Question 30

Name 2 drug examples of PPIs:

Answer 30

1) Omeprazole (prilosec) | 2) Esomeprazole (nexium)

Question 31

What are 4 ways to test for a H. pylori infection?

Answer 31

1) Urea breath test 2) Serological 3) Culture 4) Histology

Question 32

Why are H. pylori infections difficult to treat?

Answer 32

Because they are not extensively in contact with the bloodstream

Question 33

Triple therapy for H. pylori tx:

Answer 33

1) PPI- to control acid | 2) + 3) 2 effective ABs to kill HP

Question 34

Quadruple therapy for H. pylori tx:

Answer 34

Same as triple therapy + bismuth to prevent ulcer from growing

Question 35

Name 3 drugs that can contribute to a reduction in lower esophageal sphincter pressure (to allow reflux)

Answer 35

1) B-blockers 2) Ca channel blockers 3) Nicotine

Question 36

Name lifestyle changes that can help tx GERD1

Answer 36

1) Avoid foods such as: caffeine, chocolate, peppermint, alcohol, fatty foods 2) Avoid large meals (esp right before bed) 3) Stop smoking 4) Weight reduction (if overweight)

Question 37

What is ulcerative colitis (UC)?

Answer 37

- Submucosa inflammation | - Ulcerations that may ctsly cover colon's entire surface

Question 38

What are the signs and sx associated with UC?

Answer 38

1) Diarrhea, bleeding, severe pain 2) Nutrition loss, anemia 3) Stiff colon due to scarring --> bursts --> peritonitis

Question 39

What is Crohn's disease (CD)?

Answer 39

- Inflammatory disease that can cover entire digestive system - Inflammation sites can be isolated regions

Question 40

What are signs and sx associated with CD?

Answer 40

- Fistulas may form - Intestinal wall may become breached (infection risk) - Severe skin inflammation - Ulcerations in skin, eye

Question 41

Surgical removal of colon can eliminate UC, but not always CD

Answer 41

Management: - drink extra L of water/day - Vitamin B supplements - no long-acting drugs will work on pts w/o colon

Question 42

Name 3 goals of treatment for UC and CD:

Answer 42

- Treat acute outbreak - Induce and retain remission - Treat complications

Question 43

What is the first-line tx for mild-moderate UC?

Answer 43

5-Amino Salicylic acid, 5-ASA (less useful in severe UC, CD)

Question 44

5-ASA MOA:

Answer 44

- Unknown but does NOT work via COX inhibition bc systemic NSAIDs exacerbate disease - 5-ASA is only released in large intestine in sulfasalzine by bacteria

Question 45

What are steroid-responsive pts?

Answer 45

Pts whose - sx improve over 1-2 weeks - disease remains in remission as steroids are tapered off (seen in 40% of pts)

Question 46

What are steroid-dependent pts?

Answer 46

Pts who - respond to steroids, but experience disease relapse when steroids are tapered off (not remission, just suppressing disease- seen in 30% of pts)

Question 47

What are steroid-unresponsive pts?

Answer 47

Pts who do not respond to steroid tx (seen in 15-20% of pts)

Question 48

GC Indication:

Answer 48

acute tx of mod-severe UC/CD - not useful in maintaining remission

Question 49

GC SEs (4):

Answer 49

1) weight gain 2) stress, emotional responses 3) steroid-dependent diabetes 4) increased infection risk

Question 50

Name 2 opioid related agents used to treat diarrhea

Answer 50

Diphenoxylate (Lomotil), Loperamide (Imodium)

Question 51

Adsorbents MOA:

Answer 51

Coats GI tract wall and adsorbs bacteria/toxins causing diarrhea

Question 52

Name 2 adsorbents:

Answer 52

Pepto-bismol, kaopectate

Question 53

Immunosuppressives

Answer 53

same as immunosuppressive lecture??