Gastric Pharmacology

Front 1

What are 3 simple lifestyle changes that can significantly help dyspepsia, gastritis, GERD & PUD?

Back 1

- Sleep at an elevated angle

- Do not eat 2-3 hours before bed

- Attain BMI <25

Front 2

Name the prototype proton pump inhibitor.

Back 2

Omeprazole

Front 3

Where are PPIs absorbed?

Back 3

Intestines (so covered with enteric-coating)

Front 4

Where are PPIs secreted?

Back 4

gastric canaliculi

Front 5

What kind of molecule is the pro-drug omeprazole converted to in the acidic environment of the stomach?

Back 5

Sulfenamide

Front 6

To what does the activated PPI bind?

What kind of bond is it?

Back 6

H+/K+ ATPase

Covalent bond

Front 7

What percentage of basal acid secretion is inhibited by PPIs?

Back 7

80-95%

Front 8

On what cells do PPIs act?

Back 8

Parietal cells

Front 9

What enzyme metabolizes Omeprazole?

Back 9

CYP2C19

Front 10

What is the half-life of Omeprazole?

What is the half-life of Omeprazole's therapeutic effects?

Back 10

t1/2 = 1-2 hours

Therapeutic t1/2 = 20 hrs

Front 11

What are the adverse effects of Omeprazole? (4)

Back 11

- Rebound hypersecretion upon withdrawal due to hypergastrinemia

- Increased risk of resp. & GI infection in critically ill

- Decreased B12 absorption

- May alter other drug absorptions

Front 12

In what population is low B12 a concern when prescribing PPIs? (3)

Back 12

- Elderly

- Strict vegetarians

- Alcoholics

Front 13

What effect does omeprazole have on clopidogrel?

Back 13

Decreases absorption

(since pro-drug requires acid environment)

Front 14

How can PPIs be used for ulcers?

Back 14

They help them heal. (Only temporarily needed)

Front 15

Name two prototype competitive H2 antagonists.

Back 15

Ranitidine (Zantac) and Cimetidine (Tagamet)

Front 16

Are H2 antagonists faster than PPIs?

Back 16

Yes

Front 17

By how much do H2 antagonists reduce basal acid secretion of the gastric mucosa?

Back 17

~70%

Front 18

Between H2 antagonists and PPIs, which is more effective?

Back 18

PPIs

Front 19

What happens with long-term use of H2 antagonists?

Does this occur with PPIs?

Back 19

Tachyphylaxis (diminished effect)

No, not with PPIs

Front 20

What is a risk associated with withdrawing from H2 antagonists?

Back 20

Rebound hypersecretion

Front 21

How can H2 antagonists be administered? (3)

Back 21

- PO

- IM

- IV

Front 22

How are H2 antagonists eliminated?

Back 22

Renal excretion

Front 23

What are some adverse effects of H2 antagonists? (3)

Back 23

- Confusion

- Depression

- Hallucinations

Front 24

What are some unique side-effects of cimetidine? (2)

Back 24

- Gynecomastia and impotence in men

- Galactorrhea in women

Front 25

What should be considered when coadministering H2 antagonists with other drugs? (2)

Back 25

- Some drugs require acidic environments for absorption

- H2 antagonists inhibit various CYPs

Front 26

Name an antimuscarinic drug used for reducing stomach acid.

Back 26

Dicyclomine

Front 27

On what muscarinic receptor does dicyclomine act?

Back 27

Any (non-selective)

Front 28

What neurotransmitter does dicyclomine inhibit?

From what cell?

Back 28

Histamine

from ECL cells

Front 29

What salts are available as antacids? (4)

Back 29

- Mg(OH)2

- Al(OH)3

- NaHCO3

- CaCO3

Front 30

What is added to antacids to reduce flatulence and gastric reflux?

Back 30

Simethicone

Front 31

Why is alginic acid added to some antacids?

Back 31

It forms a viscous material that floats to the top of chyme and protects the esophagus from GERD

Front 32

What are the adverse effects of each ion:

Mg?

Al?

Na?

CO3?

HCO3?

Back 32

Mg - diarrhea, CNS depression

Al - constipation, reduced PO4 absorption

Na - HTN

CO3 - flatulence and GERD

HCO3 - alkalosis

Front 33

What drugs may bind to the ions released by antacids? (2)

Back 33

- Tetracycline

- Fluoroquinolone

Front 34

What 3 drugtypes increase protection of gastric cells from acid?

Back 34

- PGE Agonist

- Bismuth subsalicylate

- Sucralfate

Front 35

What is the prototype prostaglandin agonist used for treating gastric disease?

What is its MoA?

Back 35

Misoprostol

methylated-hydroxylated PGE analog

Front 36

What are the adverse effects of misoprostol? (3)

Back 36

- Diarrhea

- Abdominal pain

- Abortifacient (kills fetus)

Front 37

What is the generic name of Pepto-bismol?

What is its MoA?

Back 37

Bismuth salicylate

Physically coating erosions

Front 38

What other effect does bismuth salicylate have besides coating the stomach?

Back 38

Stimulating PGE secretion

Front 39

What does PGE stimulation in the stomach do? (3)

Back 39

- Increases mucus/bicarb production

- Increases bloodflow and epithelial proliferation

- Decreases HCl secretion of parietal cells

Front 40

What are the adverse effects of bismuth salicylate?

Back 40

- Black colored feces and tongue

- Salicylate allergies

Front 41

What is the name of an aluminum hydroxide that has been complexed with sulfated sucrose?

Back 41

Sucralfate

Front 42

What is sucralfate's MoA? (2)

Back 42

In acid, it forms a paste that coats the base of an ulcer to protect gastric cells AND stimulates PGE

Front 43

What are sucralfate's adverse effects? (4)

Back 43

- Constipation

- Leeches other drugs

- Hypophosphatemia

- Huge pill is hard to swallow

Front 44

For how long must antibiotics+PPI combos be prescribed to treat H. pylori infection?

Back 44

10-14 days

Front 45

If initial treatment of H. pylori is ineffective 4 weeks later, what Rx combo is indicated?

Back 45

- Levofloxacin

- Amoxicillin

- PPI

- Bismuth salicylate

Front 46

What combination is used to treat H. pylori if a patient is allergic to penicillin?

Back 46

- Clarithromycin

- Metronidazole

- PPI

- Bismuth salicylate

Front 47

What pain-killer should replace NSAIDs to treat pain and heal NSAID ulcers?

Back 47

COX-2 selective inhibitor

Front 48

Name 3 COX-2 selective inhibitors.

Back 48

- Celecoxib

- Diclofenac

- Meloxicam

Front 49

To heal esophagitis, how long should a patient be on PPIs with lifestyle change?

Back 49

8-weeks

Front 50

How does long-term PPI use differ from short-term?

Back 50

Long-term PPI should be used at the lowest possible dose and as needed

Front 51

Are PPIs safe in pregnant women?

Back 51

Yes (when indicated)

Front 52

For what patients is sucralfate best?

Back 52

Pregnant patients

Front 53

If heartburn is sporadic (stage 1), what treatment is recommended? (3)

Back 53

Lifestyle change, antacids, and H2 inhibitors as needed

Front 54

If heartburn is frequent (stage 2), what treatment is recommended?

Back 54

PPIs as needed

Front 55

If heartburn is constant (stage 3), what treatment is recommended?

Back 55

PPI once or twice daily