Abstract

Background: The aim of this study is to investigate the effect of a single dose of gabapentin, 1200 mg and one hour before surgery on postoperative pain in opioid-dependent patients undergoing lower extremity orthopedic surgeries.
Methods: In this randomized double-blind clinical trial, 64 opioid-dependent patients, candidates of elective lower extremity orthopedic surgery at Chamran Hospital, Shiraz, Southern Iran, were recruited and randomly assigned to intervention (G) - 1200 mg single oral dose of gabapentin an hour before surgery - and placebo (P) groups. Twenty four hour pain intensity (NRS) after surgery at 2, 4, 6, 12, 18, and 24 hour post-operative, time to the first request for analgesic and total amount of prescribed morphine were measured. The side effects of gabapentin and morphine were recorded at the mentioned time intervals. The patients’ global satisfaction of the pain management was also assessed.
Results: The patients in group G requested analgesic significantly later than the patients in group P (p=0.003). In the first postoperative hour group G received significantly lower amounts of morphine (p=0.038). Otherwise, no significant difference was detected between the two groups regarding the pain intensity and the amount of administered morphine. The frequency of drug-related side effects and the patients' global satisfaction were not significantly different in the two groups of the study.
Conclusions: Oral gabapentin (1200 mg single bolus) can reduce the need for morphine and pain intensity only shortly (about an hour) after the operation in opioid-dependent patients undergoing orthopedic lower-extremity surgeries.

Keywords: Postoperative pain; Opioid-dependency; Gabapentin