Gabapentinoids Associated With Lower Explantation Rate in 203 Patients With Spinal Cord Stimulation for Failed Back Surgery Syndrome

BACKGROUND: Spinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). The effect of neuropathic pain medication use on SCS outcome is poorly understood. OBJECTIVE: To study the effect of gabapentinoid use on SCS outcome measured by trial success, explantation rate and opioid dose reduction during a 2-yr follow-up. METHODS: The study cohort included 203 consecutive FBSS patients who underwent SCS in a single tertiary center during January 1997 to March 2014. Purchase data of gabapentinoids, opioids, tricyclic antidepressants, serotonin and noradrenaline reuptake inhibitors, and benzodiazepines during January 1995 to March 2016 were retrieved from national registries. RESULTS: In multivariate Cox regression analysis, patients using gabapentinoids had significantly fewer explantations during the 2-yr follow-up (hazard ratio [HR] 0.2, 95% CI 0.04-0.81, P = .03). In contrast, patients with opioid use of >40 morphine milligram equivalent before implantation had significantly more explantations (HR 6.7, 95% CI 2.5-18, P < .01). In bivariate logistic regression analysis adjusted for patient specific factors, year of SCS implantation, use of neuropathic pain medication, opioids, and benzodiazepines, patients using gabapentinoids significantly more often discontinued opioids or reduced their dose by more than 50% during the 2-yr follow-up (odds ratio 5.7, 95% CI 1.4-23, P = .015). CONCLUSION: The use of gabapentinoids was associated with a significantly lower spinal cord stimulator explantation rate and a higher chance of opioid discontinuation or >50% dose reduction. This indicates that patients with SCS could benefit from concomitant use of gabapentinoids. Prospective randomized trials are warranted to verify this hypothesis.