The median effective dose of preemptive gabapentin on postoperative morphine consumption after posterior lumbar spinal fusion

BACKGROUND: A single dose of preemptive gabapentin reduces postoperative pain and postoperative analgesic consumption. However, the optimal dose of preemptive gabapentin remains to be evaluated. METHODS: In this prospective study, we defined the median effective analgesic dose using an up-and-down sequential allocation technique of preemptive gabapentin in 67 patients undergoing elective posterior lumbar spinal fusion. The efficacy of the study drug was assessed by morphine consumption during the first 24 h postoperatively. RESULTS: The median effective analgesic dose (median value and 95% confidence interval) of gabapentin was 21.7 mg/kg (19.9-23.5 mg/kg). CONCLUSION: Given the large dose of gabapentin needed, further powered studies are warranted to assess side effects.