Evaluation of the Efficacy and Safety of ADL5945 for the Treatment of Opioid-induced Constipation in Adults Taking Opioid Therapy for Chronic Noncancer Pain

Morphine and related opioid analgesics are known to slow gastrointestinal (GI) motility and reduce intestinal secretion through their binding to μ opioid receptors (MORs) within the GI tract. The most common symptoms associated with the effects of opioids are constipation and nausea and/or vomiting. Moreover, constipation is a common and distressing side effect of long-term opioid therapy. The primary objective of this study was to compare ADL5945, a MOR antagonist, with placebo in the treatment of opioid-induced constipation (OIC) in adults taking long-term opioid therapy for chronic noncancer pain.