Volume 184 - Issue 8
High rate of immediate systemic hypersensitivity reactions to tiger snake antivenom
Authors: Geoffrey K Isbister, Alan Tankel, Julian White, Mark Little, Simon G Brown, David J Spain, Chris F Gavaghan and Bart J Currie
Med J Aust 2006; 184 (8): 419-420. || doi: 10.5694/j.1326-5377.2006.tb00297.x
Published online: 17 April 2006
Published online: 17 April 2006
To the Editor: During a national multicentre study of snake bites — the Australian Snakebite Project (ASP), involving over 40 hospitals — we have recently noted a high rate of early allergic reactions following the administration of tiger snake antivenom in Australia. People with suspected or definite snake envenoming are recruited to ASP, and laboratory and clinical data and serial blood samples are collected to measure venom and antivenom concentrations.
From 1 November 2005 to 31 January 2006, 14 patients who had been given tiger snake antivenom (CSL Limited, Parkville, VIC) were recruited. These patients are briefly described in the Box, and include bites from several different groups of snakes. Of the 14 patients, 11 exhibited immediate systemic hypersensitivity reactions to antivenom infusion. Reactions were mild in five patients, moderate in three, and severe in three, according to the grading system by Brown.1 The six patients in the moderate and severe groups fulfilled the criteria for anaphylaxis according to a recent consensus definition.2 All patients required specific treatment in addition to ceasing antivenom therapy, and nine were treated with adrenalin. Antivenom was recommenced in all patients at a slower rate, although an adrenalin infusion was required in four of these and repeat doses of intramuscular or subcutaneous adrenalin in another four while the antivenom infusion continued.
Over the same period, there were seven administrations of brown snake antivenom (over 30 vials of antivenom) reported to ASP without any hypersensitivity reactions.
There has been a previous report of allergic reactions to tiger snake antivenom in a single hospital,3 and we are concerned that there may be a particular problem with tiger snake antivenom. The reaction rate in this series is similar to reported rates in parts of the world where high reaction rates have been attributed to relatively impure antivenom preparations.4,5 The reactions here were traced to at least four different batches of tiger snake antivenom.
We have informed CSL of this high rate of reactions and the antivenom batch numbers, and we have encouraged the treating doctors to make formal reports of each adverse reaction to CSL and the Adverse Drug Reactions Advisory Committee.
Health care professionals treating patients with tiger snake antivenom need to be aware of the possible higher risk of anaphylaxis with tiger snake antivenom and be prepared to treat with adrenalin. Recommendations for the diagnosis and treatment of anaphylaxis have recently been reviewed.6 However, this current problem with CSL tiger snake antivenom should not cause health professionals to reduce or cease its use. In all patients described here, control of the adverse reaction and continuation of antivenom was possible. The rapid identification of this problem over a short period was only possible because of our large multicentre collaborative study, and supports such studies for recognising uncommon envenoming syndromes.
Fourteen patients administered tiger snake antivenom for snake envenoming
Competing interests
Julian White is employed by the Women’s and Children’s Hospital, Adelaide, which is paid by CSL Ltd to provide a clinical toxinology service for users of CSL antivenom and venom detection products.
References
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- Sampson HA, Munoz-Furlong A, Campbell R, et al. Second symposium on the definition and management of anaphylaxis: summary report. J Allergy Clin Immunol 2006. In press. 0_i1091984
- Tankel AS. Anaphylaxis associated with the same batch of tiger-snake antivenom. Med J Aust 2001; 174: 608-610. 0_i1091986
- Gawarammana IB, Kularatne SAM, Dissanayake WP, et al. Parallel infusion of hydrocortisone ± chlorpheniramine bolus injection to prevent acute adverse reactions to antivenom for snakebites: a randomised, double-blind, placebo-controlled study. Med J Aust 2004; 180: 20-23. 0_i1091988
- Lalloo DG, Theakston RD. Snake antivenoms. J Toxicol Clin Toxicol 2003; 41: 277-290. 0_i1091990
- Brown SGA. Anaphylaxis: clinical concepts and research priorities. Emerg Med Australas 2006. In press. 0_i1091992