Brown Snake Antivenom

Brown Snake antivenom (equine IgG Fab) can be used to treat envenomation from the brown snakes in Australia, these include the eastern and western brown snake (gwardar), dugite and other Pseudonaja species

Indication:

  • Clinical evidence of envenomation
  • Laboratory evidence of complete or partial venom-induced consumptive coagulopathy (VICC)

Contraindication:

  • No absolute
  • Increased Risk of anaphylaxis in patients previously treated with antivenom or those who are suspected of equine sera allergy

Administration:

  • Place the patient in a monitored area where anaphylaxis can be managed
  • Administer 1 ampoule diluted in 500ml of 0.9% saline IV over 20 minutes (the dose is the same for adults and paediatrics – snakes don’t envenomate less because its a child)
  • Antivenom maybe given as a rapid IV push if the patient is unstable or in cardiac arrest

Adverse drug reactions:

  • Anaphylaxis: Cease antivenom infusion, treat as per anaphylaxis with oxygen, IV fluids and IM adrenaline. Recommence antivenom infusion when anaphylaxis has resolved. Rarely will ongoing administration of adrenaline be required to complete the antivenom infusion.
  • Serum Sickness: A benign and self limiting complication occurs 5-10 days after antivenom, symptoms include fever, rash, arthralgia and myalgia. Oral steroids for 5 days may ameliorate symptoms (e.g. prednisolone 50mg/day in adults and 1mg/kg in children). All patients should be warned about this complication who receive antivenom.

Controversies:

  • Reversal of VICC: Recent evidence would suggest that the antivenom does not hasten the recovery from VICC but may prevent or reverse other manifestations of envenoming
  • The use of Fresh Frozen Plasma or Cryoprecipitate: When used after antivenom has been associated with a quicker recovery of VICC but not with earlier hospital discharge. The use of these products in envenomation has not been well defined and should be used at the recommendation of a toxicologist.

References


toxicology library antidote 700 1

Toxicology Library

ANTIVENOM

Dr Neil Long BMBS FACEM FRCEM FRCPC. Emergency Physician at Burnaby Hospital in Vancouver Emergency. Loves the misery of alpine climbing and working in austere environments. Supporter of FOAMed, toxicology, tropical medicine, sim and ultrasound

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