A high school student in the US state of Virginia thought she was taking medication that her friend had procured to treat pain and anxiety. Instead, the pill she took was fentanyl, a synthetic opioid that killed her almost instantly. "You're being poisoned by that because you don't know that that's what you're getting. And kids, people, adults, they're dying from it," shares Makayla Cox's mother at her house in Virginia Beach. Deaths are rising especially quickly among young people, who obtain counterfeit prescription drugs through social media, explains Ray Donovan, chief of operations at the US Drug Enforcement Agency (DEA). IMAGES AND SOUNDBITES