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Cyanide antidote Pregnancy: Use in emergency — fetal safety secondary to maternal survival.

Hydroxocobalamin (Cyanokit)

Brand names: Cyanokit

Adult dose

Dose: 5 g IV over 15 minutes (initial dose); repeat if necessary
Route: IV infusion (over 15 minutes)
Frequency: Initial 5 g; repeat 5 g if needed; third dose 5 g if cardiac arrest
Max: 15 g total
Suspected cyanide poisoning (smoke inhalation, chemical attack, industrial exposure): 5 g IV over 15 min immediately. If inadequate response or cardiac arrest: 5 g IV over 15 min (max 15 g total). Co-administered with sodium thiosulphate 12.5 g IV in some protocols.

Paediatric dose

Dose: 70 mg/kg
Route: IV
Frequency: Initial dose; repeat if needed
Max: 5 g
Concentration: 25 mg/ml
70 mg/kg IV over 15 minutes. May repeat once or twice (max 3 doses). Paediatric cyanide poisoning — contact NPIS.

Dose adjustments

Renal

No dose adjustment required in emergency.

Hepatic

No dose adjustment required in emergency.

Paediatric weight-based calculator

70 mg/kg IV over 15 minutes. May repeat once or twice (max 3 doses). Paediatric cyanide poisoning — contact NPIS.

Clinical pearls

  • Red discolouration will affect all co-oximetry readings and many laboratory tests — take samples BEFORE giving
  • Preferred over dicobalt edetate (UK) and sodium nitrite/thiosulphate as safer and more effective
  • Binds cyanide to form cyanocobalamin (excreted in urine) — directly detoxifies
  • Contact NPIS for management guidance in all cyanide poisoning cases
  • Store at room temperature (refrigeration not required)

Contraindications

  • Hypersensitivity to hydroxocobalamin (relative — emergency use outweighs risk)

Side effects

  • Red discolouration of skin, urine, and mucous membranes (harmless but alarming — warn staff)
  • Hypertension (transient)
  • Chromaturia (red urine for up to 5 weeks)
  • Skin acne-form reactions
  • Interference with co-oximetry and many blood tests (red colour)

Interactions

  • Sodium thiosulphate — compatible and may be co-administered
  • Sodium nitrite — do not mix in same infusion (chemical interaction)

Monitoring

  • BP and HR
  • Carboxyhaemoglobin and methaemoglobin levels
  • Neurological status
  • Lactate

Reference: BNFc; BNF; TOXBASE; NPIS; Cyanokit SPC. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways