June 15, 2009 -- A long-used box jellyfish antivenom is unlikely to actually save lives, suggests new Australian research. And one expert says findings like this mean we need to improve our testing of antivenom effectiveness. A team publishing online in the journal Toxicology Letters say venom from the box jellyfish acts so rapidly that any antivenom is unlikely to be protective. "The box jellyfish is by far the most lethal organism in the world," says clinical toxicologist Geoff Isbister of Menzies School of Health Research in Darwin. He says a sting from a box jellyfish is like "millions of hyperdermic injections of venom" and can cause cardiac arrest and death. Isbister says there has long been a question mark over the clinical effectiveness of CSL's antivenom for the Australian box jellyfish, Chironex fleckeri, which has been used since the 1970s. "There's never been a case where someone could say that antivenom saved a life," said Isbister. Related Content:
He says people given the antivenom have still died, and others have survived with resuscitation, even without the antivenom. Isbister and colleagues found that when CSL antivenom was mixed with venom and injected into the rat, all the toxins in the venom were bound, and the rat did not die. But, says Isbister, in real life, people are exposed to the venom first, before the antivenom. To mimic this situation, the researchers administered the venom first, and found the rat died within 30 seconds to 2 minutes. "The rats died so quickly you couldn't even give them the antivenom fast enough," said Isbister. They even found that when they gave the antivenom first, it did not protect against the venom. Isbister says the findings suggest the antivenom was unlikely to be effective. "Ultimately in the real setting, even giving antivenom after they've been stung is probably not going to work," said Isbister. Isbister said other studies are finding similar limitations with other antivenoms. He says his own research suggests antivenom is ineffective in relieving the pain of redback spider bite. As a result, he and colleagues have started an NHMRC-funded placebo-randomised controlled trial of redback antivenom. Other research on snake antivenom shows it does not help stop bleeding, says Isbister. He says one reason it is important to make sure antivenom is effective in patients is to ensure the benefits outweigh the risks. "Antivenom is not risk free. It can cause anaphylaxis and allergic reactions," said Isbister. CSL says it needs more time to analyze the new research. Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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