FDA sent warning letters to nine online networks operating 53 websites demanding they stop illegally marketing misbranded and unapproved drugs, specifically opioids, the agency announced Tuesday (June 5). FDA Commissioner Scott Gottlieb said firms should take this as a message that FDA will not tolerate such actions, and he added the agency will take “additional steps in the coming months.” As part of FDA's efforts to help stem the opioid crisis, the agency head is taking on social media sites...