Naloxone versus nalbuphine infusion for prophylaxis of epidural morphine-induced pruritus

Anesth Analg. 1996 Mar;82(3):641-7. doi: 10.1097/00000539-199603000-00037.


This randomized, double-blind study compared the efficacy of two mu-receptor antagonists, naloxone and nalbuphine, in the prophylactic management of pruritus in postcesarean section patients receiving epidural morphine. Dosages of study drugs were individualized by the use of a patient self-administration (PSA) device. All 51 patients were healthy women who received a uniform epidural anesthetic and epidural morphine (5 mg). Coded solutions were infused for 24 h, with 5-min PSA lockout times: Group A (n = 17), nalbuphine 2.5 mg/h, PSA nalbuphine 1 mg; Group B (n = 16), naloxone 50 micrograms/hr, PSA saline; Group C (n = 18), naloxone 50 micrograms/h, PSA naloxone 40 micrograms. Patients were assessed for pruritus and pain every 8 h for 24 h. Both naloxone and nalbuphine provided good relief for pruritus; median pain and pruritus scores were in the none-to-mild range (0-3) for all groups at all assessment intervals. The pruritus scores of the PSA saline group were higher during the 16- to 24-h period (P < 0.05) than the scores of either group receiving A-receptor antagonist by PSA. There was evidence of shortening of the duration of analgesia in patients receiving naloxone who required treatment for pruritus after 16 h. Patients who self-administered large doses of nalbuphine over the first 8 h also reported pain scores consistent with reversal of analgesia. The potency ratio for naloxone:nalbuphine for antagonism of the pruritic effects of epidural morphine was approximately 40:1. Intervention to treat either unrelieved pruritus or pain, respectively, was necessary in the following numbers of patients: Group A, 0/1; Group B, 1/1; Group C, 2/2. Prophylactic infusions offer the potential for labor cost savings by minimizing the need for episodic therapeutic interventions to treat pruritus.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Analgesia, Epidural / adverse effects*
  • Analgesia, Obstetrical / adverse effects*
  • Analgesia, Patient-Controlled / instrumentation
  • Analgesics, Opioid / adverse effects*
  • Cesarean Section
  • Cost Savings
  • Double-Blind Method
  • Female
  • Humans
  • Linear Models
  • Morphine / adverse effects*
  • Nalbuphine / therapeutic use*
  • Naloxone / therapeutic use*
  • Narcotic Antagonists / therapeutic use*
  • Pain Measurement
  • Pain, Postoperative / prevention & control
  • Pregnancy
  • Pruritus / economics
  • Pruritus / prevention & control*
  • Receptors, Opioid, mu / antagonists & inhibitors


  • Analgesics, Opioid
  • Narcotic Antagonists
  • Receptors, Opioid, mu
  • Naloxone
  • Morphine
  • Nalbuphine