Effects of epidural naloxone on pruritus induced by epidural morphine: a randomized controlled trial.Int J Obstet Anesth. 2005 Jan; 14(1):22-5.IJ
Epidural morphine produces prolonged analgesia but has many side effects including pruritus. Naloxone is an antagonist that can reverse the side effects of morphine.
We studied the effects of continuously administered epidural naloxone mixed with morphine on side effects and analgesia in a randomized, double blind, two-armed study. Fifty-eight pregnant women undergoing cesarean section were enrolled. All patients received a 4-mg epidural bolus of morphine in the post-anesthetic care unit. After this, patients in group M (n=28) received continuous epidural morphine (6 mg over 48 h) in 0.1% bupivacaine; patients in group N (n=30) received an epidural infusion containing naloxone (1.2 mg over 48 h) and morphine (6 mg over 48 h) in 0.1% bupivacaine. The infusion rate was 2 mL/h.
The incidence (82% versus 47%) and severity of pruritus were lower in group N than group M (P=0.001). There were no significant differences in pain score or in the incidence of nausea, vomiting or urinary disturbance between groups.
Continuous epidural infusion of naloxone combined with morphine is effective in reducing the incidence and severity of pruritus induced by epidural morphine.