Background: Pruritus is a common side effect of intrathecal fentanyl or sufentanil that decreases patient satisfaction and may delay hospital discharge. There are conflicting reports about the efficacy of prophylactic ondansetron in reducing the incidence of pruritus. This meta-analysis aimed to assess the effect of prophylactic ondansetron on the incidence of intrathecal fentanyl- or sufentanil-mediated pruritus and the need for rescue treatment.
Methods: A systematic search on PubMed, Medline, and the Cochrane Central Register of Controlled Trials from January 1, 1994, to January 1, 2014, was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Randomized controlled trials evaluating the efficacy of prophylactic ondansetron on pruritus associated with intrathecal fentanyl or sufentanil were included. The primary outcome was the incidence of pruritus, and the secondary outcome was patients' need for rescue therapy. Sensitivity analyses were conducted to assess the outcomes in obstetric and nonobstetric patients and in patients who received ondansetron before or after intrathecal opioid injection. Analyses used random-effect models.
Results: Six randomized controlled trials involving 555 patients were included. In the overall analysis, prophylactic ondansetron did not significantly decrease the incidence of pruritus, but there was a trend toward reduced rescue medication use (risk ratio [RR], 0.57; 95% confidence interval [CI], 0.35-0.91; I = 0%; P = 0.02). Exploratory subgroups, including nonobstetric surgery patients and patients who received ondansetron before spinal opioid administration, also suggest a trend toward less rescue medication use (RR, 0.47; 95% CI, 0.26-0.85; P = 0.01; and RR, 0.62; 95% CI, 0.38-1.00; P = 0.05).
Conclusions: IV 8 mg prophylactic ondansetron does not decrease the incidence of fentanyl- or sufentanil-mediated pruritus but may decrease the need for pruritus rescue medication, particularly in specific subgroups. Randomized trials are needed to confirm these results.