title: A randomized controlled trial of gabapentin for chronic low back pain with and without a radiating component.
abstract: Gabapentin is prescribed for analgesia in chronic low back pain, yet there are no controlled trials supporting this practice. This randomized, 2-arm, 12-week, parallel group study compared gabapentin (forced titration up to 3600 mg daily) with inert placebo. The primary efficacy measure was change in pain intensity from baseline to the last week on treatment measured by the Descriptor Differential Scale; the secondary outcome was disability (Oswestry Disability Index). The intention-to-treat analysis comprised 108 randomized patients with chronic back pain (daily pain for ≥6 months) whose pain did (43%) or did not radiate into the lower extremity. Random effects regression models which did not impute missing scores were used to analyze outcome data. Pain intensity decreased significantly over time (P < 0.0001) with subjects on gabapentin or placebo, reporting reductions of about 30% from baseline, but did not differ significantly between groups (P = 0.423). The same results pertained for disability scores. In responder analyses of those who completed 12 weeks (N = 72), the proportion reporting at least 30% or 50% reduction in pain intensity, or at least "Minimal Improvement" on the Physician Clinical Global Impression of Change did not differ significantly between groups. There were no significant differences in analgesia between participants with radiating (n = 46) and nonradiating (n = 62) pain either within or between treatment arms. There was no significant correlation between gabapentin plasma concentration and pain intensity. Gabapentin appears to be ineffective for analgesia in chronic low back pain with or without a radiating component.
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
authors.forename: J Hampton
authors.initials: JH
authors.lastname: Atkinson
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Scottsdale Healthcare Research Institute, Scottsdale, AZ, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Slater
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Edmund V
authors.initials: EV
authors.lastname: Capparelli
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.
authors.forename: Shetal M
authors.initials: SM
authors.lastname: Patel
authors.affiliation: Computational and Applied Statistics Laboratory, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Tanya
authors.initials: T
authors.lastname: Wolfson
authors.affiliation: Computational and Applied Statistics Laboratory, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Gamst
authors.affiliation: Departments of Mathematics.
authors.forename: Ian S
authors.initials: IS
authors.lastname: Abramson
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Anesthesiology, and.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Wallace
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Funk
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Rutledge
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Wetherell
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Matthews
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Sidney
authors.initials: S
authors.lastname: Zisook
authors.affiliation: VA San Diego Healthcare System, San Diego, CA, USA.|Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Garfin
mesh_terms: D000328:Adult; D000368:Aged; D000588:Amines / Q000627:therapeutic use*; D000700:Analgesics / Q000627:therapeutic use*; D059350:Chronic Pain / Q000188:drug therapy*; D003509:Cyclohexanecarboxylic Acids / Q000627:therapeutic use*; D004185:Disability Evaluation; D004311:Double-Blind Method; D005260:Female; D000077206:Gabapentin; D006801:Humans; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D016896:Treatment Outcome; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use*
chemical_list: D000588:Amines; D000700:Analgesics; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin