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.

In a highly-selected case-series of patients with refractory, opioid-associated constipation, naldemedine was safe and associated to reduced gastric residuals and promoting laxation. In the systematic review and meta-analysis, the use of PAMORAs (mainly methylnaltrexone) was safe and associated with a reduced intolerance to enteral feeding but no difference in the time to laxation.