Nov. 21, 2013, 7:06 a.m.
New Hunter research shows anti-venom for bites of the redback spider, one of Australia’s most feared creepy-crawlies, doesn’t work.
Calvary Mater Hospital clinical toxicologist Dr Geoff Isbister ran a four-year study into the effectiveness of the anti-venom, produced by Commonwealth Serum Laboratories (CSL), presenting the research at a major toxicology conference in Dubai on Tuesday night. The anti-venom has been used for more than 50 years.
More than 220 patients in hospitals around Australia were treated for redback bites, with half given the anti-venom and half a placebo.
Dr Isbister said all patients were also administered a ‘‘significant’’ amount of pain relief, but the results showed no difference.
‘‘In terms of their response to pain after two hours, which was the main outcome, they were the same for the two groups,’’ he said.
‘‘Anti-venoms were introduced when there wasn’t such rigorous testing of whether they work like drugs have to be tested now.
‘‘Everyone assumed that it worked, so we sort of did the research backwards, we checked it after it had already been used for 50years.’’
A CSL spokeswoman disputed the findings, saying any suggestion redback anti-venom didn’t work was ‘‘very much at odds with the clinical experience reported by doctors’’.
‘‘We would urge doctors to continue with currently accepted medical practice until the Isbister study has undergone peer review and the findings have been considered against the weight of the opposing evidence,’’ she said.
No one has died from a redback spider bite since the mid-1950s, but between 3000 and 5000 people are bitten in Australia each year.
Dr Isbister said an initial four-year study on easier ways to administer the drug suggested it may be ineffective, prompting another four years of research.
He said the findings meant doctors should not be giving the anti-venom to redback spider bite victims.
‘‘That may take a while as other people read the research and decided what their practice will be,’’ he said.
‘‘There is a small risk of an allergic reaction with the anti-venom, about 4 or 5per cent, so that’s the balance you make, but if the treatment doesn’t work you really don’t want to put someone at risk of having a reaction.’’
He said those suffering a redback spider bite should take painkillers and apply ice to the area.
Head of the Toxinology Department at the Women’s and Children’s Hospital in Adelaide Professor Julian White said the findings did not match with clinical experience.
‘‘Nor does it match with other public studies on this type of anti-venom both in Australia and other parts of the world,’’ Professor White said.
‘‘I would think that most Australian doctors would consider that a single study or study from a single research group would not constitute a reason for changing a well-established treatment and that you would want confirmatory studies from other groups confirming his findings before anyone should be making a recommendation to change such an important treatment.’’