Opioids: Pruritus

Basic, Clinical Sciences: Anesthesia Procedures, Methods, and Techniques

Opioid receptor antagonists, such as naloxone, nalmefene, and naltrexone are effective in treating opioid-induced pruritus. At high doses, they may result in undesirable reversal of the analgesic effect of opioids. Mixed opioid receptor antagonists-agonists such as nalbuphine or butorphanol may be effective as well. Additionally, dopamine D2 receptor antagonists (droperidol and alizaperide), serotonin 5-HT3 receptor antagonists (ondansetron), and propofol are also useful in treating opioid-induced pruritus.

The occurrence of pruritis is reported to be 10-50% following IV administration of opioids and 20-100% after neuraxial administration.

  • Systemic:

  • Caused by nonimmunologic release of histamine from mast cells in tissue.

  • Usually treated with H1 blockers (i.e. diphenhydramine)

  • Neuraxial:

  • Mediated centrally by mu-opioid receptor (MOR) signaling in superficial/deep dorsal horn neurons and medulla oblongata

  • Because NA opioids do NOT produce itching by release of histamine, H1 blockers (i.e. diphenhydramine) have little to no effect on centrally induced itching. It may produce a sedative effect, which could be helpful; however, treat NA pruritis with the following instead:

  • Nalbuphine bolus or infusion (mu receptor agonist-antagonist) – highly effective but may cause sedation

  • Naloxone infusion (mu receptor antagonist) – highly effective but caution at higher infusion rate (>2mcg/kg/h) due to possible reversal of analgesia

  • Ondansetron (5-HT3 antagonist) – studies with mixed results

  • Others in decreasing order of effectiveness: droperidol > propofol > alizapride


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Answered correctly


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Fan Ye, MD and Brittany Aeschlimann, MD