Cyanide poisoning may result from:1

  • Inhalation: gas Inhalation:
  • Ingestion: liquid and solid Ingestion:
    liquid and solid
  • Dermal exposure: liquid Dermal exposure:

Example of situations with cyanide poisoning

  • Fire smoke
  • CBRN* attack
  • Industrial accident

Mechanism of toxicity


by blocking the peripheral use of oxygen at the cellular level (mitochondria) and then inhibiting the production of ATP2, leading to cellular hypoxia.3

Death and neurologic sequelae

Cyanide is a fast-acting poison. Death can occur within minutes if not treated.4 Individuals who survive cyanide poisoning are at risk for central nervous system dysfunction, such as anoxic encephalopathy. Acute and delayed neurologic manifestations (Parkinson-like syndrome, other movement disorders, neuropsychiatric sequelae) have been reported.5

Mechanism of toxicity
Mechanism of toxicity
*CBRN: Chemical Biological Radiological Nuclear


1 - Reade M. et al; Review article: management of cyanide poisoning 2 - Amizet L. et al., Occupational cyanide poisoning, BMJ Case reports 2011:1-3 3 - Hall AH, Dart R, Bogdan G. Sodium Thiosulfate or hydroxocobalamin for the empiric treatment of cyanide poisoning? Ann Emerg Med. 2007 Jun; 49(6):806-13 4 - Eckstein M, Maniscalco P. Focus on smoke inhalation – the most common cause of acute cyanide poisoning. Prehospital Disaster Med 2006; 21(2 Suppl 2):49-55 5 - Leybell I., Cyanide toxicity, Medscape Updated 30 May 2020. See in website 10/5/2020.