Impact of oral naloxegol vs subcutaneous methylnaltrexone in treatment of opioid-induced constipation in the hospital setting

Abstract Purpose Peripherally acting μ-opioid receptor antagonists (PAMORAs) are indicated to treat laxative-refractory opioid-induced constipation (OIC). While several PAMORAs exist, no head-to-head comparative data are available. This study evaluated the efficacy, safety, and cost of oral naloxegol vs subcutaneous methylnaltrexone for OIC in the hospital. Methods In this multicenter retrospective chart review, patients who received oral naloxegol or subcutaneous methylnaltrexone as an inpatient were included if they were at least 18 years old, were still admitted to the hospital 48 hours after the first PAMORA dose, and either had an outpatient opioid prescription or received at least 30 morphine milligram equivalents in the 24 hours before the first PAMORA dose. The primary outcome was achievement of a bowel movement (BM) within 48 hours of the first dose. Secondary outcomes included a BM in 24 hours, time to the first BM, antimotility agent use, PAMORA cost per patient, and use of a second PAMORA due to failure of the first agent. Results A total of 330 patients were included with 2:1 allocation (220 patients receiving methylnaltrexone vs 110 patients receiving naloxegol). Baseline characteristics were similar between the groups, except for body mass index and weight. Naloxegol met a prespecified noninferiority margin of 15% in production of a BM within 48 hours (risk difference, –4.6%; 90% confidence interval, –13.6% to 4.5%; P = 0.028). Achievement of a BM within 24 hours and time to first BM were also noninferior. Antimotility agent use was higher with naloxegol, naloxegol cost $193.16 less per patient, and 2 patients switched from naloxegol to methylnaltrexone. Conclusion Oral naloxegol may be an effective, cost-efficient alternative to subcutaneous methylnaltrexone for treatment of OIC in the hospital setting.