Does Preemptive Gabapentin Reduce Morphine Consumption and Remaining Leg Pain After Lumbar Discectomy? A Randomized Double-blind, Placebo-controlled Clinical Trial

Aim: Residual leg pain makes the outcome in lumbar discectomy unfavorable. The aim of this study was to compare gabapentin with placebo in terms of reduced remaining postoperative leg pain and morphine consumption after single level lumbar laminectomy and discectomy. Methods: We conducted a randomized parallel group, double-blind, placebo-controlled clinical trial. Two hundred and six patients were randomly assigned into 2 groups. Each group received preanesthesia identical capsules containing gabapentin or placebo. Similar anesthesia protocol was performed. One hundred thirty patients were excluded secondarily and a total of 76 patients with residual, but less degree postoperative leg pain remained in the study. Postoperative visual analog scale and morphine consumption via patient-controlled analgesia pumps were recorded and statistically compared at 6-hour intervals for 24 hours. Results: No statistical significance was found between the 2 groups in terms of reduced postoperative leg pain or morphine consumption (P > 0/0.05). No clinical evidence to prove synergism between gabapentin and morphine in discectomy patients was found. Conclusions: The results of this clinical trial failed to show that preemptive gabapentin is more effective than placebo with regard to leg pain reduction and morphine consumption during the acute stage after single level lumbar laminectomey and discectomy. However the possibility remains that multiple dose regimens of gabapentin would be beneficial.