Single-dose, extended-release epidural morphine (DepoDur) compared to conventional epidural morphine for post-cesarean pain.

Background: A single-dose of neuraxial morphine sulfate provides good post-Cesarean analgesia; however, its efficacy is limited to the first postoperative day. In a recent phase III study, extended-release epidural morphine (EREM) formulation provided more effective, prolonged analgesia after Cesarean delivery, compared to conventional epidural morphine. However, the study protocol did not allow for the use of nonsteroidal antiinflammatory drugs, used various postoperative analgesics, and monitoring and treatment of respiratory depression were not standardized. Our aims in this study were to compare postoperative analgesic consumption, pain scores and side effects of EREM with conventional morphine for the management of post-Cesarean pain in a setting more reflective of current obstetric practice.

Methods: Seventy healthy parturients undergoing elective Cesarean delivery were enrolled in this randomized, double-blind study. Using a combined spinal epidural technique, patients received an intrathecal injection of bupivacaine 12 mg and fentanyl 10 mcg. After closure of the fascia, a single-dose of either conventional morphine 4 mg or EREM 10 mg was administered epidurally. Postoperatively, all patients received ibuprofen 600 mg orally every 6 h. Oral oxycodone and IV morphine were available for breakthrough pain. All patients received pulse oximetry and respiratory monitoring for 48 h post-Cesarean delivery.

Results: Single-dose EREM significantly improved pain scores at rest and during activity. The median (interquartile range) of supplemental opioid medication usage for 48 h post-Cesarean (in milligram-morphine equivalents) decreased from 17 (22) to 10 (17) mg with EREM compared to conventional epidural morphine (P = 0.037). Both drugs were well tolerated with no significant difference in adverse event profiles.

Conclusion: EREM provides superior and prolonged post-Cesarean analgesia compared to conventional epidural morphine with no significant increases in adverse events.