New antivenom invented for black widow spider bites

Scientists have invented a new antivenom for European black widow spider bites that uses human antibodies to mitigate the effects of the arachnid's painful toxins. 

The new treatment could be superior to existing antidotes, but it will need much more testing before it's available to patients, researchers say.

When European black widows (Latrodectus tredecimguttatus) bite, they inject into their victims a powerful toxin called alpha-latrotoxin. Alpha-latrotoxin attacks the nervous system and can trigger a condition called latrodectism, in which patients experience symptoms such as severe pain, headaches and nausea. If left untreated, these debilitating symptoms can last for several days, but the condition is rarely fatal. 

People who have been bitten by a European black widow are typically prescribed pain relief medications, such as opioids and benzodiazepines, to treat their symptoms. They may also be given an antivenom containing antibodies drawn from horses that have been injected with alpha-latrotoxin and thus developed immunity against it.  

Once injected into the human body, these horse antibodies help strengthen a person's immune response to the venom, countering its effects on the nervous system. However, because the antivenom comes from horses, it may be recognized as "foreign" by the immune system. In a small number of cases, the immune system can consequently go into overdrive, sparking potentially life-threatening allergic reactions and what's known as "serum sickness." 

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The effectiveness of this horse-derived treatment can also vary considerably from one batch of antibodies to the next.