GI drugs

Question 2

H2 blockers (4)

Answer 2

Cimetidine, Ranitidine, Famotidine, Nizatidine

Question 3

H2 blockers mechanism

Answer 3

reversible block of histamine H2 receptors leading to decreased H+ secretion by parietal cells

Question 4

H2 blockers clinical use

Answer 4

peptic ulcer gastritis mild reflux

Question 5

Cimetidine toxicity

Answer 5

-potent inhibitor of CYP450 -antiandrogenic effects (prolactin release, gynecomastia, impotence, decreased libido) -crosses BBB (confusion, HA) and placenta

Question 6

Both Cimetidine and Ranitidine can…

Answer 6

decrease renal excretion of creatinine.

Question 7

Proton pump inhibitors (5)

Answer 7

Omeprazole Lansoprazole Esomeprazole Pantoprazole Dexlansoprazole

Question 8

PPI MOA

Answer 8

irreversibly inhibit H+/K+ ATPase in stomach parietal cells

Question 9

Clinical Use of PPIs

Answer 9

-peptic ulcer -gastritis -reflux -ZE syndrome

Question 10

Toxicity of PPIs

Answer 10

-C. diff infxn -pneumonia -hip fractures -decreased magnesium

Question 11

Bismuth and Sucralfate MOA

Answer 11

bind to ulcer base, providing physical protection and allowing HCO3- secretion to reestablish pH gradient in mucous layer

Question 12

Bismuth and Sucralfate Use

Answer 12

increases ulcer healing traveler’s diarrhea

Question 13

Misoprostol mechanism

Answer 13

PGE1 analog that increases the production/secretion of gastric mucous barrier and decreases acid production

Question 14

Misoprostol use

Answer 14

prevention of NSAID-induced peptic ulcers maintenance of PDA induce labor

Question 15

Toxciity of Misoprostol

Answer 15

diarrhea

Question 16

Misoprostol is contraindicated in…

Answer 16

women of childbearing potential because it is an abortifacient.

Question 17

Octreotide MOA

Answer 17

long-acting somatostatin analog

Question 18

Octreotide Use

Answer 18

-acute variceal bleeds -acromegaly -VIPoma -carcinoid tumors

Question 19

Toxicity of Octreotide

Answer 19

nausea cramps steatorrhea

Question 20

Antacid use can affect the…

Answer 20

absorption, bioavailablity or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.

Question 21

All antacids can cause…

Answer 21

hypokalemia.

Question 22

Antacids (3)

Answer 22

1. Aluminum hydroxide 2. Calcium carbonate 3. Magnesium hydroxide

Question 23

Aluminum hydroxide overuse can cause…

Answer 23

constipation and hypophosphatemia, proximal muscle weakness, osteodystrophy and seizures

Question 24

Overuse of calcium carbonate can cause…

Answer 24

hypercalcemia and cause a rebound acid increase.

Question 25

Overuse of magnesium hydroxide can cause...

Answer 25

diarrhea, hyporeflexia, hypotension and cardiac arrest.

Question 26

Osmotic laxatives (4)

Answer 26

1. magnesium hydroxide 2. magnesium citrate 3. polyethylene glycol 4. lactulose

Question 27

Osmotic laxative MOA

Answer 27

provide osmotic load to draw water out

Question 28

Lactulose also helps treat hepatic encephalopathy since...

Answer 28

gut flora degrade it into metabolites (lactic acid and acetic acid) that promote nitrogen excretion as NH4+.

Question 29

Infliximab MOA

Answer 29

monoclonal antibody to TNF-alpha

Question 30

Infliximab clinical use

Answer 30

-Crohn's -UC -RA -ankylosing spondylitis -psoriasis

Question 31

Toxicity of Infliximab

Answer 31

-infection (including reactivation of latent TB)

Question 32

Sulfasalazine MOA

Answer 32

combo of sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory) activated by colonic bacteria

Question 33

Uses of Sulfasalazine

Answer 33

-UC -Crohn's

Question 34

Toxicity of Sulfasalazine

Answer 34

-sulfonamide toxicity -reversible oligospermia

Question 35

Ondansetron

Answer 35

5-HT3 antagonist (decreases vagal stimulation) powerful central-acting antiemetic

Question 36

Metoclopramide MOA

Answer 36

D2 receptor antagonist (increases resting tone, contractility, LES tone and motility)

Question 37

Use of Metoclopramide

Answer 37

-diabetic and post-operative gastroparesis -antiemetic

Question 38

Toxicity of Metoclopramide

Answer 38

-increased parkinsonian effects -interaction with digoxin and diabetic agents

Question 39

Metoclopramide is contraindicated in pts with...

Answer 39

small bowel obstruction or Parkinson disease.