Taipan Antivenom

Taipan antivenom (equine IgG Fab) can be used to treat envenomation from the Taipan snakes in Australia and Papua New Guinea, these include the Costal Taipan, Papuan Taipan and the small-scaled or fierce snake

Indication:

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

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)
• Can be given as a rapid IV push if the patient is haemodynamically 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 and Top Tips:

• Taipan antivenom halts the progression of paralysis but established neurotoxicity is not reversed, also recent evidence suggests that the antivenom does not hasten the recovery of VICC but may prevent/reverse other manifestations of envenomation.
• One ampoule of Polyvalent antivenom may be used instead but at increased risk for anaphylaxis
• 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

• Tox Library – Taipan snakes
• Brown SGA, Caruso N, Borland M et al. Clotting factor replacement and recovery for snake venom-induced consumptive coagulopathy. Intensive Care Medicine 2009; 35(9):1532-1538
• Isbister GK, Buckley NA, Page CB et al. A randomised controlled trial of fresh frozen plasma for treating venom-induced consumption coagulopathy in cases of Australian snakebite (ASP-18). Journal of Thrombosis and Haemostats 2013; 11:1310-1318
• Isbister GK, Brown SG, MacDonald E et al. Current use of Australian snake antivenoms and frequency of immediate-type hypersensitivity reactions and anaphylaxis.  Medical Journal of Australia 2008; 188:473-476.
• Isbister GK, Duffull SB, Brown SGA. Failure of antivenom to improve recovery in Australian snakebite coagulopathy. Quarterly Journal of Medicine 2009; 102(8):563-568
• White J. A clinician’s guide to Australian venomous bites and stings: Incorporating the updated CSL antivenom handbook. Melbourne: CSL Ltd, 2012.