Can a pill save snake bite victims?

Doctors have long searched for a snakebite pill that can provide the necessary antidote to prolong life when and where it is needed most. Now, experiments with an existing drug that treats heavy metal poisoning is stoking that dream; Given orally, the drug saved or prolonged the lives of mice injected with lethal doses of viper venom, the researchers report.

Snakebites kill tens of thousands of people each year and leave many more with damaged limbs, in part because of the difficulty in obtaining fast and effective treatment. These bites often occur in remote locations, so many snakebite victims may have to travel hours or even days before reaching a medical facility equipped to provide life-saving antivenin intravenously.

Biomedical scientists in England set out to find something portable and easy to administer that could counteract some of the most widespread and dangerous poison toxins: snake venom metalloproteins, an important component in blood poisoning venoms such as many vipers, these toxins cause a host of problems, including massive internal bleeding and tissue damage around the bite site.

Toxins, however, have an Achilles heel, they rely on zinc ions to function; Drugs used to treat heavy metal poisoning bind to loose metal ions, so the researchers wondered if those drugs might also remove toxins from zinc. One in particular, a compound called unithiol, did just that.

The researchers administered the drug in liquid form orally, 15 minutes after the venom injection, delayed the death of the mice compared to mice that did not receive the drug and even improved the survival of some mice. For example, of five mice injected with West African carpet viper venom and given the drug, two lived and three lived for 12 to 21 hours, while those not given the drug died in four. hours.

Rapidly administered oral unithiol worked as well as a delayed snakebite treatment, and even better when combined with it, the researchers found. Unithiol also prevented local tissue damage at the venom injection site, suggesting that the drug could help prevent disability as well as save lives.

The team plans to conduct a safety trial in sub-Saharan Africa, one of the areas where snakebites take a heavy toll, before administering the pill to actual snakebite victims, the safety trial is needed to reveal unanticipated side effects in an untested population.