Butorphanol prevents morphine-induced pruritus without increasing pain and other side effects: a systematic review of...

Pruritus is a frequent adverse event after administration of morphine. Butorphanol has been used to prevent morphine-induced pruritus, but its efficacy is still controversial. The aim of this systematic review was to evaluate the efficacy of using butorphanol to prevent morphine-induced pruritus.

We searched PubMed, Cochrane Library, EMBASE, and China's BioMedical Disc for full reports of randomized controlled trials that compared the use of butorphanol with either placebo or no treatment for preventing morphine-induced pruritus. The number of patients experiencing pruritus or other side effects was analyzed using relative risk (RR) with 95% confidence intervals (CI).

Sixteen trials (795 patients) were analyzed. Continuous intravenous and epidural butorphanol reduced pruritus with RR 0.22 (95% CI 0.10 to 0.45) and RR 0.24 (95% CI 0.16 to 0.36), respectively. Use of epidural butorphanol decreased the number of patients requesting rescue treatment for pruritus (RR 0.57; 95% CI 0.41 to 0.81). Butorphanol decreased postoperative pain intensity at four, eight, and 12 hr with standardized mean differences of -0.29 (95% CI -0.52 to -0.05), -0.30 (95% CI -0.56 to -0.04), and -0.23 (95% CI -0.46 to -0.01), respectively. Epidural but not intravenous butorphanol reduced postoperative nausea and vomiting (PONV) (RR 0.35; 95% CI 0.19 to 0.66). Butorphanol did not increase respiratory depression (RR 0.71; 95% CI 0.31 to 1.63), somnolence (RR 0.71; 95% CI 0.22 to 2.37), or dizziness (RR 2.45; 95% CI 0.35 to 17.14).

Butorphanol administered with morphine may be an effective strategy for preventing morphine-induced pruritus as it decreases pain intensity and PONV without increasing other side effects. Thus, it can be recommended for preventing morphine-induced pruritus during the perioperative period.