Painkiller abuse has become the most severe drug epidemic in U.S. history. From 1999 to 2010, opioid painkiller sales quadrupled. Related deaths soared: In 2010, there were more than 16,000 deaths associated with opioid drugs such as Vicodin, Percocet and Oxycontin. But the concerns haven’t stopped the FDA from approving a controversial new painkiller, Zohydro. The surge is driven, says one medical professional, by big pharma and doctors who collaborate with powerful medical corporations, as well as Americans demanding medications that eradicate pain entirely, eschewing assumptions that pain is a natural part of life.