Transnasal butorphanol for the treatment of opioid-induced pruritus unresponsive to antihistamines.

Pruritus is a common opioid side effect and can be so severe that opioid therapy must be modified or abandoned. Antihistamines, opioid antagonists, and propofol have been proposed as treatment options, but none is universally effective. The use of intranasal butorphanol, an opioid agonist-antagonist, for pruritus has not been described previously. Six patients complaining of severe opioid-induced pruritus unresponsive to diphenhydramine received 2 mg intranasal butorphanol every 4-6 hr. Scores for pruritus, pain, and sedation were recorded on separate visual analogue scales (VAS). All patients reported significant relief from pruritus 60 min after butorphanol administration (P < 0.001); five patients noted an improvement within 15 min (P < 0.08). Sedation and pain VAS scores were not significantly different from baseline at all time points. These preliminary data demonstrate a substantial effect of intranasal butorphanol on opioid-induced pruritus that has not responded to antihistamines. Prospective controlled studies are needed to validate these findings.