Medicine & USMLE


Gastrointestinal Pharm
  1. H2 Blockers (Cimetidine, Ranitidine, Famotidine)
  2. Proton Pump Inhibitors (PPIs)
  3. Misoprostol
  4. Orlistat
  5. Antacids
  6. Bismuth & Sucralfate
  7. Octreotide
  8. Diphenoxylate vs. Loperamide
  9. Ondansetron
  10. Metoclopramide
  11. Bulk-forming Laxatives
  12. Senna
  13. Docusate
  14. Aprepitant


Misoprostol is a prostaglandin E1 or PGE1 analogue. Acting on the stomach, misoprostol reduces the secretion of gastric acid, and also increases the secretion of mucus forming the protective lining of the stomach wall. These two actions make it helpful in the prevention and treatment of peptic ulcers, specifically ulcers induced by NSAID use. Next, the action of PGE1 on the cervix and uterus can lead to uterine contractions, which can be used to induce labor or cause abortion. Non-specific adverse effects of misoprostol use include diarrhea and abdominal pain.

Key Points

  • Misoprostol
    • Mechanism
      • Acts as a prostaglandin (PGE1) analog
        • Increases the production and secretion of gastric mucus barrier
        • Decreases acid production
    • Clinical Use:
      • Used for NSAID-induced peptic ulcer prophylaxis
        • NSAIDs block PGE1 production
      • Causes induction of labor
        • PGE1 ripens the cervix and induces labor
    • Adverse effects
      • Causes abortion
        • Used along with mifepristone for abortion
        • Can also be used in the treatment of ectopic pregnancy and gestational choriocarcinoma
      • Causes GI side effects (abdominal pain, diarrhea)