Extended-release epidural morphine (EREM; DepoDur) is distinguished from conventional epidural morphine (e.g., Astramorph, Duramorph) by its unique delivery system called DepoFoam, which consists of multiple microscopic, liposomal particles (Pasero & McCaffery, 2005b; Pasero, Quinn, Portenoy, McCaffery, & Rizos, 2011). The liposomes contain aqueous chambers that encapsulate preservative-free morphine (Carvalho et al., 2005). After an epidural injection, the liposomes slowly release morphine over a period of 48 hours by erosion or reorganization of the lipid membranes (Heitz & Viscusi, 2009). Primary advantages of this formulation are that it allows up to 48 hours of pain relief without the use of an indwelling catheter, which can pose a risk of infection, impede mobility, and raise concerns about postoperative anticoagulant therapy (Pasero & McCaffery, 2005b; Viscusi et al., 2005). Further, problems with infusion device programming errors are eliminated with this approach.