Oral gabapentin versus metoclopramide for prevention of intrathecal opioid-induced pruritus.

Abstract

Background: Spinal opioids are frequently coadministered with local anesthetics for analgesia, allowing the use of a lower dose of each agent, thus minimizing side effects. Most opioid-induced side effects, such as nausea, vomiting, and respiratory depression, are usually encountered with systemic use, while pruritus is more common with intrathecal or epidural administration.

Objectives: To compare the action of gabapentin versus metoclopramide in prevention of intrathecal opioid-induced pruritus.

Study design: After ethical committee approval and informed patient' consent, this prospective randomized comparative clinical trial was conducted at Ain Shams University Hospitals on 62 adult patients undergoing elective operations under spinal anesthesia. The subjects were randomly divided into two groups: Group G (received 300 mg of oral gabapentin) and group M (received 10 mg of oral metoclopramide) 2 hours before spinal anesthesia.

Results: The overall incidence of pruritus in both groups was 31.5 percent (48.8 percent in group G and 45.2 percent in group M). There was no statistically significant difference between the two groups. As for the severity, both drugs showed low visual analog scale scores from the first hour after intrathecal fentanyl administration. Gabapentin showed more potency in decreasing the severity of pruritus as only two patients in group G needed rescue treatment compared to five patients in group M (but the difference was of no statistical significance).The overall incidence of nausea was 17.7 percent (22.58 percent in group G and 12.9 percent in group M), while the incidence of vomiting was 11.29 percent (16.13 percent in group G and 6.45 percent in group M). There was no statistically significant difference between the two groups.

Conclusion: Gabapentin is as effective as metoclopramide in prevention of intrathecal opioid-induced pruritus. Moreover, gabapentin proved to be slightly more effective in reducing the severity of pruritus than metoclopramide.