The Association Between N-methylnaltrexone, a Peripherally Acting Mu-Opioid Receptor Antagonist, and Clinical Outcomes in Patients Undergoing Robotic-Assisted Radical Cystectomy

To assess the impact of N-methylnaltrexone, a peripherally acting mu-opioid receptor antagonist, on the post-operative recovery of patients undergoing robotic-assisted radical cystectomy for bladder cancer. We retrospectively reviewed patients undergoing robotic-assisted radical cystectomy by a single surgeon (KC) prior to (control group) and after (treatment group) the routine use of N-methylnaltrexone. Kaplan–Meier curves and the log-rank test were used to quantify time to flatus, bowel movement, and discharge. Daily mean opioid use, daily pain assessment rating, and episodes of severe pain (7–10/10) were compared. Gastrointestinal-related complications, including ileus, emesis, and/or need for post-op nasogastric tube placement, and 30-day readmissions were also compared between groups. Charge capture data were compared between groups to analyze cost impact. 29 patients each in the control and treatment group met inclusion criteria. Patients receiving N-methylnaltrexone had reduced length of stay compared with no N-methylnaltrexone (median 4 vs. 7 days, p < 0.01). Time to flatus and bowel movement, however, were similar. In a multivariable analysis controlling for possible confounders, however, the improvement in length of stay associated with N-methylnaltrexone use did not reach statistical significance (p = 0.11). Episodes of severe pain and composite gastrointestinal-related complications were reduced in the N-methylnaltrexone group (44.8% vs. 10.3%, p < 0.01). The reduction in length of stay was associated with approximately $10,500 in cost savings per patient. In this study, N-methylnaltrexone was associated with reduced length of stay, fewer episodes of severe pain, and reduced costs. These results provide the impetus for further study.