USMLE GI pharm

  1. H2 blockers: names and MOA
    • Cimetidine, ranitidine, etc
    • Reversible block of histamine H2 receptors
    • Decreases secretion by parietal cells
    • Take before eating
  2. H2 blockers: toxicity
    • P450 inhibitor
    • Antiandrogenic
    • Cross BBB (confusion, HA) and placenta
    • Decreased renal excretion of creatinine
  3. PPIs: names
    • omeprazole
    • lansoprazole
  4. PPIs: MOA
    Irreversibly inhibit H/K-ATPase in parietal cells
  5. Bismuth and sucralfate: MOA and use
    • For ulcer healing and traveler's diarrhea
    • Bind to ulcer base providing protection
    • Allow bicarb secretion to reestablish pH gradient in the mucous layer
  6. What is triple therapy of h. pylori ulcers?
    • Metronidazole
    • Amoxicillin (or tetracycline)
    • Bismuth
  7. Misoprostol: MOA
    • PGE1 analog
    • Increases gastric mucous barrier
    • Decreases acid production
  8. Misoprostol: uses
    • Prevent NSAID ulcers
    • Maintaine PDA
    • Induce labor
  9. Misoprostol: toxicity
    • Diarrhea
    • Abortifacient
  10. Muscarinic antagonists: names
    • Pirenzepine
    • propantheline
  11. Muscarinic antagonists for PUD: MOA
    • Block M1 receptors on ECL cells to decrease histamine secretion
    • Block M3 receptors on parietal cells to decrease proton secretion
  12. Muscarinic antagonists: toxicity
    Tachy, dry mouth, difficulty focusing eyes
  13. Antacids: problem
    • They can affect concentrations of other drugs by altering gastric/urinary pH or delaying gastric emptying
    • They can also cause hypokalemia
  14. Antacids: names and problem with overuse
    • Aluminum hydroxide: constipation and hypophosphatemia (--> muscle weakness, osteodystrophy, seizures)
    • Magnesium hydroxide: diarrhea, hyporeflexia, hypotension, cardiac arrest
    • Calcium carbonate: hypercalcemia, rebound acid
  15. Infliximab: MOA
    Monoclonal TNF antibody
  16. Infliximab: uses
    • Crohns
    • Rheumatoid arthritis
  17. Infliximab: toxicity
    • Respiratory infection
    • fever
    • hypotension
  18. Sulfasalazine: MOA
    • Combination of sulfapyridine and 5-aminosalicylic acid
    • Activated by colonic bacteria
  19. Sulfasalazine: toxicity
    • Malaise, nausea
    • Sulfa allergen
    • Reversible oligospermia
  20. Ondansetron: MOA
    • Serotonin antagonist
    • Central-acting antiemetic
  21. Ondansetron: toxicity
    HA, constipation
  22. Metoclopramide: MOA
    • D2 receptor antagonist
    • Increases resting tone, contractility, LES tone, motility
    • Does not influence colon transport time
  23. Metoclopramide: use
    Diabetic and post-surgery gastroparesis
  24. Metoclopramide: toxicity
    • Parkinsonian
    • Interacts with digoxin and diabetic agents
    • Don't use in small bowel obstruction
Author
andresjm
ID
21067
Card Set
USMLE GI pharm
Description
Step 1 pharm for GI from FA 2010
Updated