Pharmacology

Pharmacology

Core66: Drug-induced adverse reaction: constipation, diarrhea, vomiting

薬剤性有害反応：便秘・下痢・嘔吐

🤢 High-yield / 要点：Drug-induced GI adverse effects often reflect motility changes, mucosal injury, cholinergic effects, or chemoreceptor trigger zone stimulation.

Constipation / 便秘

Main mechanisms / 主な機序

  • Decreased motility
  • Bile acid binding
  • Other direct effects

Drugs causing constipation / 便秘を起こす薬

Mechanism/group Examples
Opioids Morphine, codeine, hydromorphone, oxycodone, diphenoxylate, loperamide
Calcium channel blockers Nifedipine, amlodipine
Smooth muscle antispasmodics Papaverine, drotaverine
Parasympatholytic drugs Atropine, TCAs, antipsychotics, first-generation H1 blockers
Sympathetic stimulants Dobutamine, norepinephrine
5-HT3 antagonists Alosetron
Other Somatostatin, cholestyramine, iron, aluminum hydroxide

Diarrhea / 下痢

Drugs causing diarrhea / 下痢を起こす薬

  • Antibiotics:
    • Carbapenems
    • Broad-spectrum penicillins such as ampicillin
    • Cephalosporins such as cefoperazone, ceftriaxone
    • Clindamycin
    • Co-trimoxazole
    • Tetracyclines
  • Cytotoxic agents:
    • Cyclophosphamide
    • Taxanes
    • Vinca alkaloids
    • Irinotecan
    • 5-FU
  • Cholinergic stimulants:
    • Bethanechol
    • Neostigmine
  • Other drugs:
    • Metformin
    • Colchicine
    • Iron
    • Digoxin
    • Quinidine
    • Lithium
    • Misoprostol
    • Macrolides, especially erythromycin
    • Magnesium hydroxide

Vomiting / 嘔吐

Drugs causing vomiting / 嘔吐を起こす薬

  • Antibiotics:
    • Carbapenems
    • Clindamycin
    • Fluoroquinolones
    • Macrolides such as erythromycin, roxithromycin
    • Co-trimoxazole
    • Nitrofurantoin
    • Metronidazole
  • Chemotherapeutics:
    • Cisplatin
    • Carboplatin
    • Cyclophosphamide
    • Taxanes
    • Vinca alkaloids
    • Methotrexate
  • Antidepressants:
    • SSRIs such as citalopram, paroxetine, sertraline
  • Dopaminergic drugs:
    • L-Dopa
    • Bromocriptine
    • Apomorphine
  • Other:
    • Lithium
    • Morphine, methadone, tramadol
    • Colchicine
    • Digoxin
    • Phenytoin

Remember / 覚え方

  • Opioids and anticholinergics → constipation
  • Antibiotics and chemo → diarrhea
  • Chemo, dopaminergic drugs, opioids → vomiting
  • Clindamycin is high-yield because it can cause both diarrhea and vomiting