GI - Drugs

Question 1

Proton Pump inhibitors

Answer 1

Omeprazole, Esomeprazole, Lansoprazole
most potent to decrease acid
inhibit H/K ATPase irreversible
used for ulcers and GERD
traps in canaliculi where converted to active sulfonamide
P450 metabolism

Question 2

Histamine H2 receptor antagonists

Answer 2

Cimetidine, Ranitidine
decrease basal/nocturnal secretion of acid
renal metabolism
Cimetidine inhibits P450
Blocking histamine decreases cAMP which decreases proton pump

Question 3

Prostaglandins

Answer 3

Misoprostol
PGE1 analog
used to prevent NSAID toxicity
sides: cramping, uterine contractions, inflammatory bowel

Question 4

Sucralfate

Answer 4

sucrose sulfate + Al(OH)3
forms polymer gel in stomach to protect ulcers from pepsin
sides: constipation

Question 5

Antacids

Answer 5

Al(OH)3, Mg(OH)2, CaCO3
carbonates make CO2 - gas
Al causes constipation
Mg causes diarrhea

Question 6

Bismuth Subsalicylate

Answer 6

pepto bismol
used for travelers diarrhea and ulcers
sides: black stool, Reye’s syndrome

Question 7

Anti-nausea/vomiting drugs

Answer 7

Scopolamine (anti-muscarinic)
Dimenhydrinate (anti-H1)
Granisetron/Ondansetron (anti-serotonin)
Metoclopramide (anti-dopamine and anti-serotonin)
Prochlorperazine (anti-dopamine)
Dexamethasone (steroid)

Question 8

Scopolamine

Answer 8

anti-emetic
muscarinic antagonist
transderm
motion sickness

Question 9

Dimenhydrinate

Answer 9

anti-emetic
Histamine H1 blocker
motion sickness

Question 10

Ondansetron / Granisetron

Answer 10

anti-emetic
serotonin 5-T3 antagonist
used for chemo and radiation nausea

Question 11

Prochlorperazine

Answer 11

anti-emetic
dopamine D2 antagonist
general use
side: restlessness

Question 12

Dronabinol

Answer 12

anti-emetic
THC - CB1 agonist
prophylaxis for chemo vomiting

Question 13

Aprepitant

Answer 13

anti-emetic
substance P, NK1 antagonist
used for chemo nausea
CYP metabolism

Question 14

Metoclopramide

Answer 14

Pro-Kinetic (gastric emptying)
D2 antagonist, enhances ACh release
used for diabetic gastroparesis

Question 15

Erythromycin

Answer 15

used for diabetic gastroparesis

pro-kinetic (motilin)

Question 16

Anti-diarrhea

Answer 16

Loperamide (opioid, no CNS)
Diphenoxylate (opioid, some CNS)
Fiber
Antibiotics
Bismuth Subsalicylate
Octreotide (somatostatin for carcinoid)

Question 17

Loperamide

Answer 17

anti-diarrhea
opioid, best agent
poor CNS penetration

Question 18

Diphenoxylate

Answer 18

anti-diarrhea

opioid, can produce CNS effects, given with atropine to reduce abuse

Question 19

Octreotide

Answer 19

anti-diarrhea
somatostatin analog
used for tumor-related secretory diarrhea

Question 20

Anti-Constipation

Answer 20

Fiber
Mg(OH)2 (water retention)
Lactulose (osmotic carbohydrate)
Polyethylene Glycol (PEG) (osmotic)
Ducosate salts (anionic surfactant)
Bisacodyl (causes large intestine mucosa inflammation)
Lubiprostone (activates Cl channels
Methylnaltrexone (opioid antagonist

Question 21

Fiber

Answer 21

water soluble=fermented, vice versa
fermentation increases stool bacteria
nonfermented retains water and increases stool bulk
prokinetic and trophic (for constipation)

Question 22

Inflammatory Bowel Disease Drugs

Answer 22

Prednisone (for mod-severe attacks)
Budesonide (enteric-release steroid for Crohns)
Mesalamine/Olsalazine/Sulfasalazine (prophylaxis mild-mod UC, prodrugs to target colon)
Infliximab (anti-TNFa, used for mod-severe Crohns and UC, warning for resp infxns and NHL)