The Food and Drug Administration approved Movantik, or naloxegol, tablets for the treatment of opioid-induced constipation in adult patients with chronic, non-cancer pain. Millions of patients take opioids for relief from chronic pain, but one undesirable side effect of opioids is that they bind to mu-receptors in the gastrointestinal tract and can lead to constipation. When Europe’s equivalent of the FDA agreed to review the drug’s application for approval last year, AstraZeneca paid Nektar $25million.