Methylnaltrexone for Treatment of Opiate-Induced Constipation in the Intensive Care Unit

Inclusion Criteria: * 18 years of age or older in the ICU * Opioids for analgesia for at least 24 hours. * Opioid-induced constipation with no bowel movement within the last 72 hours. * Women of childbearing potential had negative pregnancy tests. Exclusion Criteria: * Contraindication to use of the GI tract * Diarrhea on admission * Bowel surgery within 8 weeks of admission * Ileostomy or colostomy * Not expected to live or stay more than 3 days in the intensive care unit * Constipation that was not primarily caused by opioids (as determined by the investigator) * No opioid use in the last 24 hours, * Mechanical gastrointestinal obstruction * An indwelling peritoneal catheter * Clinically active diverticular disease * Fecal impaction * Acute surgical abdomen * History of Crohn's disease or ulcerative colitis * On Palliative care * Less than 18 years old * Bowel movement in last 72 hours.