Webster LR, et al. - In a 52-week, randomized, double-blind, phase 3 study, researchers evaluated the long-term safety of naldemedine, a peripherally acting µ-opioid receptor antagonist, in patients with opioid-induced constipation and chronic noncancer pain. Researchers noted that patients generally well-tolerated naldemedine for 52 weeks. Naldemedine was not identified to interfere with opioid-mediated analgesia or precipitate opioid withdrawal and was observed to result in significantly increased bowel movement frequency, improved symptomatic burden of opioid-induced constipation, and increased patients' quality of life vs placebo.