Adjunctive Use of Gabapentinoids Increases Opioid Consumption Following 1- to 3-Level Anterior Lumbar Interbody Fusion with Posterior Fixation: A Propensity-Score Matched Analysis.

Study design: Retrospective cohort.

Objective: To evaluate the impact of adjunctive gabapentinoid therapy on postoperative opioid consumption following 1-3 levels anterior lumbar interbody fusion (ALIF) with posterior fixation.

Summary of background data: Gabapentin and pregabalin are analogues of the inhibitory neurotransmitter Gamma-Aminobutyric Acid (GABA) and are frequently employed as adjuncts in multimodal anesthesia strategies for managing acute pain. However, the opioid-sparing effect of gabapentinoids in the context of spine surgery has yet to be consistently demonstrated.

Methods: The PearlDiver Database was queried from 2010 to 2021 for patients who underwent primary 1-3 levels ALIF with posterior fixation. Patients with opioid or gabapentinoid use within 6 months prior to index surgery were excluded. Patients with both gabapentinoid and opioid treatment were propensity score-matched to patients with opioid-only treatment.

Results: The propensity score-matching resulted in two equal groups of 2,617 patients with and without adjunctive gabapentinoid treatment for pain management. Adjunctive use of gabapentinoids was associated with a modest 2.9% reduction in average Morphine Milligram Equivalent (MME) per day (Standardized Mean Difference (SMD) -1.33, 95% Confidence Interval (CI) [-2.657, -0.002], P=0.050). However, this was accompanied by a 37.1% increase in the total duration of opioid prescriptions (SMD 94.97, 95% CI [56.976, 132.967], P<0.001) and a 41.7% increase in total MME consumption per patient (SMD 4817.23, 95% CI [1864.410, 7770.044], P=0.001). Additionally, gabapentinoid use was associated with an increased risk of readmission due to pain (Relative Risk (RR) 1.10, 95% CI [1.002, 1.212], P=0.050) and the development of drug abuse (RR 1.37, 95% CI [1.016, 1.833], P=0.046).

Conclusion: Despite the modest daily opioid-sparing effect observed, adjunctive gabapentinoid treatment appears to increase total opioid consumption due to prolonged opioid use and may compromise pain management in the context of ALIF with posterior fixation.