Cyanide Poisoning

Basics

Description

  • Toxicity through inhalation, GI tract absorption, or injection
  • Intracellular toxin that inhibits aerobic metabolism through inhibition of oxidative phosphorylation:
    • Leads to decreased O2 utilization and ATP production
  • Intrinsic detoxification:
    • Rhodanese: Hepatic mitochondrial enzyme responsible for the metabolism:
      • Combines cyanide (CN) with sulfur (rate-limiting step) covalently (irreversible) to form less toxic and water-soluble thiocyanate (T-CN)
      • Rate of CN removal requires adequate bioavailability of sulfur compounds (thiosulfate [TS])

Etiology

  • Fires:
    • Combustion byproduct of natural and synthetic products
  • Industry:
    • Metal plating, microchip manufacturing
    • Chemical synthesis
    • Plastic manufacturing
    • Pesticides
  • Solvents:
    • Artificial nail remover (Acetonitrile)
    • Metal polishes
  • Byproduct of nitroprusside metabolism (nonenzymatic):
  • Amygdalin (converted by intestinal flora to CN), CN-containing plants (apricot and peach pits, apple and pear seeds, and cassava)
  • Jewelry making

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