(KGNS) - The White House is warning about deadly new versions of fentanyl spreading across the country, including carfentanil, an elephant tranquilizer up to 100 times stronger than standard fentanyl.

While overdose deaths in Webb County are down, first responders and school officials say the trend is a reminder of how dangerous the drugs remain.

Ricky Heard, with the Laredo Fire Department's Opioid Response Team, said, "All it takes is a small fraction of this drug to get into your system and you stop breathing." Paramedics say it takes one pill to kill and are urging people to pick up Narcan at the pharmacy.