GI

Question 1

Histamine Receptor Antagonists

Answer 1

MOA: selective, competetive blockade on basolateral side of parietal receptor cells - prevents stimulation of proton pump

Question 2

what are some risk factors with H2RA

Answer 2

anti-adrogenic (gynecomastia, impotence), arrhytias, headache, dizziness, GI upset

Question 3

major interactions with H2RA

Answer 3

caffeine (cimetidine)

St John’s Wart

Question 4

PPI MOA

Answer 4

selective irreversible H/K?ATPase inhibition on luminal side of parietal cells.

• acid-labile: broken down in stomach acid which reduces their absorption.
• secretory activity returns 3-5 days after stopping

Question 5

risk factors with PPIs

and interactions

Answer 5

Mg depletion, osteoporosis, c diff infections, CAP, HA, dizziness, GI
CYP - hepatic impairment
St John’s Wart and Grapefruit

Question 6

Are PPIs or H2RAs better at immediate symptom relief and why?

Answer 6

H2RA are better for immediate relief because their onset is 30-45 minutes rather than 2-3 hours. PPIs also have a commuluative effect if they are taken multiple days in a row

Question 7

What would you prescribe for GERD?

Answer 7

Antacids - acid buffer in lumen
H2RA - competitive antagonism of H2 receptors
PPI - Inhibit H/K/ ATPase pump

Question 8

What site of action do PPIs and H2RAs have in common?

Answer 8

both act on the parietal cell

both inhibit proton pump (H2RA indirectly)

Question 9

tachyphlaxis

Answer 9

rapidly diminishing response to successive doses of a drug, rendering it less effective. The effect is common with drugs acting on the nervous system

Question 10

rx for gas

Answer 10

simethicone: siicone polymer

Alpha- galactosidase: beano

Question 11

what can simethicone interact with?

Answer 11

thyroid medication - can decrease serum concentration

Question 12

Simethicone

Answer 12

inert silicone polymer, de-foaming agent, reduces surface tension of gas bubbles

Question 13

Alpha- galactosidase

Answer 13

mold-derived enzyme that cleaves oligosaccharides before reaching colonic bacteria.

Question 14

A diabetic patient on medications wants a flatulene product, what would you recommend?

Answer 14

simethicone because

alpha-galactosidase is not recommended in diabetic patients and activated charcoal can impact absorption of medications.

Question 15

Stimulant laxatives

Answer 15

senna (ex-lax): anthraquinone stimulates peristalsis by directly acting on mucosa nerve plexus
bisacodyl (dulcolax): irritates smooth muscle causes peristalsis

Question 16

osmotic laxatives

Answer 16

plyethylene glycol 3350 (miralax): water retention in stool increases frequency
magnesium citrate: osmotic retention of fluid in bowel

Question 17

stool softeners

Answer 17

docusate (colace): diocyl dosium sulfosuccinate reduces surface tension of oil water on stool and inhances incorporation of water and oil into stool

Question 18

if a patient was taking senna, what else could you add for persistent constipation?

Answer 18

docusate stool softener

Question 19

bulk laxatives

Answer 19

psyllium (metamucil): absorbs water in intestine and promotes peristalsis and reduces transit time

Question 20

if you are a prescribing opiates, what is important to also give?

Answer 20

laxatives

Question 21

antidiarrheal: opiate like

Answer 21

loperamide (immodium)
Diphnoxylate
Atropine

Question 22

loperamide (immodium)

Answer 22

decreases GI motility acting on circular and longitudinal muscles. Reduces GI secretions

Question 23

Diphnoxylate and Atropine

Answer 23

opiate receptro agonist inhibiting GI activity

also inhibits SLUD

Question 24

what are the actions of antidiarrheal drugs?

Answer 24

act on smooth muscle or inhance chloride channel activity to increase fluid secrtion into intestinal lumen

Question 25

lamotil and imodium have what similar mechanism of action?

Answer 25

decrease GI motility

Question 26

pharmacology for IBD

Answer 26

Corticosteroids/Glucocorticoids Aminsalicylates - most common Immunosuppresants Atibiotcs

Question 27

MOA corticosteroids - Prednisone

Answer 27

modulates protein synthesis leading to reduced migration of plymophonuclear leukocytes and fibroblasts. Prevents/controls inflammation by reversing capilarry permeability

Question 28

MOA Glucocorticoid: budesonide

Answer 28

same as prednisone | interacts with grapefruit and st johns wart

Question 29

Aminosalicylates: Mesalamine MOA

Answer 29

modulates local chemical mediators of inflammatory response and supresses lukotriens, acts as free radical scavenger and inhibits tumor necrosis factor. Most *activity is topical, minimal absorption

Question 30

Aminosalicylates: sulfasalazine MOA

Answer 30

prodrug of mesalamine and bond is cleaved by colonic bacteria. * competetive inhibitor of folate * take a away from meals * sweat, urine, tears turns orange

Question 31

where are azo drugs released?

Answer 31

closer to colon

Question 32

Antimetabolites (immunosuppresants)

Answer 32

azathioprine: - inhibits most rapidly proliferating cells in body. - purine analog/antimetabolite - inhibits purine synthesis and DNA replication, resulting in an anti-proliferative effect and induction of apoptosis of T-cells

Question 33

What is the major interaction with Azathioprine?

Answer 33

ETOH

Question 34

Monoclonal Abs: Tumor necrosis factor (TNF alpha)

Answer 34

Inhibits TNF alpha which is responsibe for induction of proinflammatory cytokines which activate neutrophils and eosinophils adn induce acute phase reactants

Question 35

what is recommended along with TNF alpha

Answer 35

premedication with antihistimines to preventand manage infusion related reactions

Question 36

Anti-TNF alpha: Infliximab

Answer 36

chimeric IgGk that binds both free and membrane bound TNF a: different ab smashed together that contain zone that will attach to ag.

Question 37

Anti-TNF a: Adalimumab (Humira)

Answer 37

``` human mAb (IgG1k) against TNFa more accepted in body because comes from human, not animal. ```

Question 38

Explain cycle of inflammation that happens with IBD

Answer 38

- innate cells produce increased TNF a, interleukins and chemokines - marked expansion of lamina propria with increased CD4 t cells (especially proinflammatory ones) - These secrete increased levels of cytokines and chemokines wich results in more leukocytes - cycle of inflammation

Question 39

Rx for Nausea/Emesis

Answer 39

serotonin antagonists | dopamine antagonists

Question 40

Serotonin Antagonists

Answer 40

Ondansetron: selectively antagonizes serotonin receptors | - hepatic metabolism

Question 41

risk factors with Ondansetron

Answer 41

QT prolongation, HA, fatigue, malaise, diarrhea | interacts with grapefruite and St johns wart

Question 42

If Serotonin antaginsts prevent nausea, what would SSRIs do

Answer 42

induce nausea | as well as decrease depression/anxiety

Question 43

Dopamine antagonists

Answer 43

promethazine | metoclopramide

Question 44

promethazine

Answer 44

blocks postsynaptic dopaminergic receptors in brain and depresses release of hormones (hypothalamic and hypophyseal) - anti-muscarinic and anti histimine activity - hepatic metabolism/CYP

Question 45

Metoclopramide

Answer 45

antagonizes dopamine receptors and blocks serotonin receptors in CNS - prokinetic: enhanced motility and increased gastric emptying

Question 46

what receptors does metoclopramide effect?

Answer 46

D2 | Seratonin

Question 47

where is the emetic center

Answer 47

medulla