Single-dose extended-release epidural morphine for pain after hip arthroplasty

This randomized, double-blind study compared the safety and efficacy of a new single-dose extended-release epidural morphine (EREM) formulation for postoperative pain following hip arthroplasty. Patients were administered a single dose of EREM (10, 20, or 30 mg, n = 93) or a single epidural dose of placebo (n = 27) before surgery and general anesthesia. Following surgery, patients had access to fentanyl with the use of intravenous patient-controlled analgesia. Postoperative fentanyl use, time to first postoperative fentanyl use, pain intensity at rest and with activity, patient ratings of pain control, and adverse events were recorded. Compared with placebo-treated patients, single-dose EREM patients used less total supplemental fentanyl (p < or = 0.049), had a longer time to first fentanyl use (p < 0.001), and were less likely to use any supplemental fentanyl (p < or = 0.042). EREM-treated patients reported lower pain intensity for up to 48 hours postdose compared with placebo-treated patients. Single-dose EREM was effective for postoperative pain relief for up to 48 hours following hip arthroplasty, with a safety and tolerability profile consistent with that of other epidurally administered opioids.