Naloxone Versus Methylnaltrexone for Opioid-Induced Constipation in Critically Ill Patients

Abstract

Background: Opioid-induced constipation (OIC) may occur in up to 81% of critically ill patients and can lead to many complications. Opioid antagonists are a reasonable approach and may be used for managing OIC. Objective: The purpose of this study was to assess the efficacy of enteral naloxone (NLX) versus subcutaneous methylnaltrexone (MNTX) for the management of OIC in critically ill patients. Methods: A retrospective analysis was conducted on adult patients who received NLX or MNTX and a continuous opioid infusion for at least 48 hours. The primary end point was time to resolution of constipation, defined as hours to first bowel movement (BM) after the first dose of an opioid antagonist. Reversal of analgesia was assessed by comparing the total number of morphine milligram equivalents (MME) 24 hours preopioid and postopioid antagonist administration. Univariate and multivariate analyses were conducted to assess treatment response within 48 hours. Results: Baseline characteristics were similar between patients receiving NTX (n = 89) and MNTX (n = 71). However, the time to the first BM with NLX was 18 hours compared with 41 hours with MNTX ( P = 0.004). There was no difference in MME requirements 24 hours pre/post NLX or MNTX administration. Naloxone administration was identified as a statistically significant predictor of BM within 48 hours (odds ratio [OR] = 2.68 [1.33-5.38]). Conclusion and Relevance: The time to first BM was shorter with enteral NLX. Both NLX and MNTX appear to be effective for the management of OIC without causing reversal of analgesia. Future controlled, prospective trials comparing these agents are warranted.

Peripherally‐active mu‐opioid receptor antagonists for constipation in critically ill patients receiving opioids: A case‐series and a systematic review and meta‐analysis of the literature

“…The final selection included 9 papers: two randomized controlled trials, 19,20 one prospective case‐series, 21 three retrospective case‐series 22–24 and three case reports 25–27 …”

“…The final selection included 9 papers: two randomized controlled trials, 19,20 one prospective case-series, 21 three retrospective case-series [22][23][24] and three case reports. [25][26][27] Tables 3 and 4 report the study characteristics and the main outcomes.…”

“…The first possible reason might depend on a higher efficacy of naldemedine itself as compared to other PAMORAs. As a matter of fact, our case-series is, to the best of our knowledge, the first study to assess the effect of naldemedine, whereas the other studies have investigated the use of methylnaltrexone 19,[21][22][23][24][25][26] or naloxegol. 20 As shown in the chronic pain literature, it is likely that naldemedine is more effective than other PAMORAs to treat OIC.…”

Naloxegol versus Methylnaltrexone for Opioid-Induced Constipation in Critically Ill Patients

“…In 2022, a retrospective evaluation by Habeeb et al 11 showed a faster time to BM with naloxone than MNTX (18 vs 41 hours). In keeping with studies by Merchan et al and Habeeb et al, the median time to BM and number of BMs in 72 hours were also investigated in this study.…”