Gabapentin versus naproxen in the management of failed back surgery syndrome; a randomized controlled trial.Acta Anaesthesiol Belg 2014; 65(1):31-7AA
Gabapentin is an analogue of the gamma amino butyric acid (GABA), which regulates the conductance of calcium channels. In this study, we compared the efficacy of gabapentin the one of naproxen in the treatment of failed laminectomy syndrome. In this controlled trial, patients who had had elective lumbar discectomy or spinal fusion surgery more than one year ago, and complaining about leg and back pain in spite of different medical therapy were randomly assigned to receive naproxen (control group) or gabapentin. Gabapentin was started at a daily dose of 300 mg. This dose was increased by 300 mg at the end of each week up to a maximum dose of 1800 mg. Naproxen, which was administered at an initial daily dose of 250 mg, was increased similarly to the maximum 1500 mg. Patients were then followed up for the next 6 consecutive months. Back and leg pains were compared between the two groups at 9 consecutive time points, namely 0, 2, 4, 6, 8, 12, 16, 20 and 32 weeks after starting the treatment. The Visual Analog Scale (VAS) score of the back pain was significantly reduced when a 600 mg daily dose of gabapentin was reached (P < 0.001). At a dose of 1800 mg, the decrease in back pain amounted 20.5%. Naproxen-treated patients did not show significant improvement in back pain. Leg pain as similarly assessed by a VAS significantly decreased when a 1200 mg dose of gabapentin was attained (P < 0.008). At 1800 mg, the reduction in VAS was 39.2%. Naproxen-treated patients had a 7.7% pain reduction at 6th week, when using the maximum daily dose of 1500 mg (P < 0.04), but the pain increased thereafter. We conclude that Gabapentin, at a maximum daily dose of 1800 mg, is significantly more efficient than naproxen at treating persistent pain after spinal surgeries.