Science More: Health Reuters Health Drugs Fentanyl A legal drug that's 50 times more powerful than heroin blamed for an 'alarming' spike in fatal overdoses Read more: http://www.businessinsider.com/r-powerful-opioid-fentanyl-blamed-for-spike-in-us-drug-overdoses-2015-3#ixzz3UwKSjwii

here