GI--Pharmacology

Question 1

H2 blockers moa, use?

Answer 1

cimetidine and the other -tidines. reversible block of H2 receptors–>decrease H secretion by parietal cells; used in peptic ulcers/gastritis/mild reflux

Question 2

Cimetidine tox?

Answer 2

potent inhibitor of cyp450, antiandrogenic effects (prolactin relase, gynecomastia, impotence, decreased libido); can cross BBB and cause confusion/dizziness/headaches

Question 3

H2 blockers that decrease renal excretion of creatinine?

Answer 3

cimetidine and ranitidine

Question 4

proton pump inhibitors? moa? use?

Answer 4

-prazoles; irreversible inhibit H/K ATPase in stomach parietal cells; used in PUD/gastritis/reflux/zollinger ellison

Question 5

PPI tox?

Answer 5

increased risk of C diff infection/PNA, hip fractures, decreased serum Mg2+ after prolonged use

Question 6

Bismuth, sulcrafate moa?

Answer 6

binds to ulcer base, provides physical protection and allows HCO3 secretion to re-establish pH gradient in mucous layer; use in ulcer healing and traveler’s diarrhea

Question 7

misoprostol

Answer 7

PGE1 analog; increased production and secretion of gastric mucous barrier; decrease acid production;

Question 8

how to prevent NSAID induced peptic ulcers?

Answer 8

give misoprostol

Question 9

misoprostol uses?

Answer 9

NSAID PUD, maintaining PDA, used to induce labor

Question 10

misoprostol contraindication?

Answer 10

abortifacient, cannot use during pregnancy

Question 11

octreotide moa?

Answer 11

long acting somatostatin analog used in acute variceal bleeds, acromegaly, VIPoma, and carcinoid tumors

Question 12

antacid use can cause:

Answer 12

affect absorption, bioavilability, urinary excretion of other drugs by altering gastric and urinary pH or by delaying emptying; all can cause HYPOkalemia

Question 13

aluminum hydroxide tox?

Answer 13

constipation, hypophosphatemia, proximal muscle weakness, osteodystrophy, seizures

Question 14

calcium carbinate tox?

Answer 14

hypercalcemia, rebound acid increase

Question 15

magnesium hydroxide tox?

Answer 15

diarrhea, hyporeflexia, hypotension, cardiac arrest

Question 16

infliximab moa? uses?

Answer 16

monoclonal antibody to TNF-alpha; used in crohns, UC, RA, ankylosing spondylitis, psoriasis

Question 17

check before infliximab use?

Answer 17

TB; increased risk of infection including reactivation of latent TB

Question 18

Sulfsalazine moa?

Answer 18

combination of sulfapyridine (antibiotic) and 5-ASA (anti-inflammatory); activated by colonic bacteria; used in IBD

Question 19

sulfsalazine tox?

Answer 19

sulfonamide tox, reversible oligospermia

Question 20

ondansetron moa?

Answer 20

5-HT3 antagonist–>deceases vagal stimulation; powerful central acting anti-emetic

Question 21

metoclopramide moa?

Answer 21

D2 receptor antagonist; increases resting tone/contractility/LES tone, motility; Does NOT influence colon transport time

Question 22

metoclopramide tox?

Answer 22

increased parkinsonian effects, interacts with digoxin and diabetic agents; contraindicated in patients with SBO or parkinson disease