Novel opioid antagonists for opioid-induced bowel dysfunction and postoperative ileus. 
Methylnaltrexone and alvimopan are two new and potentially useful agents in the management of opioid-induced bowel dysfunction and prevention of postoperative ileus.  Both agents have promising prokinetic properties and appear to be capable of reversing the effects of opioids on delayed gastrointestinal transit.  This article reviews currently available published literature to provide an overview of the clinical trials and to provide insight for the potential use of these agents for patients requiring opioid based analgesia.  These compounds represent a new class of compounds that may impact the therapeutics for opioid induced bowel dysfunction as well as postoperative ileus.