Long-term effect of oxycodone/naloxone on the management of postoperative pain after hysterectomy: a randomized prospective study

BACKGROUND: The analgesic efficacy of oxycodone prolonged-release (PR) combined with naloxone PR (OXN) in postoperative pain management is recognized, however, few studies have examined the efficacy of OXN on pain relief and bowel function following hysterectomy. This study compared the effect of OXN vs. standard treatment for postoperative pain management and bowel function following hysterectomy. METHODS: This randomized prospective study included 83 women who underwent laparoscopic/laparotomic hysterectomy. General anesthesia was induced by propofol (1.5-2 mg/kg), fentanyl (50-100 mu g) and rocuronium (0.6-1 mg/kg) and maintained with sevoflurane (MAC 0.8-1) and fentanyl (1-2 mu g/kg). Intraoperative analgesia was performed with ketorolac (30 mg), paracetamol (1 g) and morphine (0.1 mg/kg). Postoperative analgesia in the control group (N.=41) included morphine (0.2-0.4 mg/kg/day), whereas the OXN (N. =42) group only received ox-ycodone (10 mg)/naloxone (5 mg) for the first 48 hours. As rescue analgesic, both groups received paracetamol (3 mg). Bowel Function Index (BFI) and pain numeric rating scales (NRS) were measured at day 0, 1, 2, 3, 5 and 7. whereas vital parameters, rescue medication and side effects were recorded for the first three days only. RESULTS: Bowel function indices were significantly improved in OXN-treated patients at all time points compared to morphine-treated patients. Mean static pain NRS was significantly decreased at day 2 and day 3 and dynamic pain NRS at day 3 in the OXN group. Side effects, rescue analgesic and antiemctics were more frequent in the control group. CONCLUSIONS: Improved pain control, bowel function and reduced side effects were observed with OXN compared to morphine in patients who underwent hysterectomy.