Non-Pharmacologic Management
Abstract# 2109 - Gabapentin in the Treatment of Fibromyalgia
Authors: L.M. Arnold et al.
Background: Fibromyalgia (FM) is a disabling disease characterized by persistent, widespread body pain and fatigue. The etiology of FM is unknown and its treatment is difficult. In this study, Arnold and associates investigate the safety and efficacy of gabapentin (GB), an alpha 2 delta ligand, on pain in patients with primary FM.
Methods: In this 12-week double-blinded, randomized trial 150 adults with primary FM were randomized to either GB (N = 75) (i.e., 1200 to 2400 mg/day, administered 3 times daily) or placebo (N = 75). Primary outcome was a 24-hour average pain severity score (0 = no pain versus 10 = pain as bad as you can imagine), assessed by the Brief Pain Inventory (BPI). Secondary outcomes included: the FM Impact Questionnaire, a clinician rated FM rating scale, tender point threshold, Medical Outcomes Study sleep measure, Patient Global Impression of Improvement, and Clinical Global Impression of Severity.
Results: GB patients reported significantly greater improvement on the BPI 24-hour average pain score (p = 0.015: estimated between-group difference = -0.92). Compared to placebo, the GB patients significantly improved on the FM Impact Questionnaire total score (p = 0.012), the clinician rated FM rating scale (p = 0.001), Medical Outcomes Study sleep measure (p = 0.001), Patient Global Impression of Improvement (p = <0.001), and Clinical Global Impression of Severity (p = 0.002). No difference was observed on the tender point threshold (p = 0.11). The GB patients were also more likely to report sedation, lightheadedness, and dizziness.
Conclusions: GB (1200 to 2400mg/day) produced significant improvements of a variety of FM outcomes with few side effects.
Editorial Comments: Because the range of symptom expression is FM is so diverse, its treatment is challenging to health professionals. This double-blind, randomized-controlled trial provides strong evidence that GB significantly improves the constellation of FM symptoms. In particular, compared to controls pain, sleep, clinical and patient ratings were all significantly improved in the GB treated patients. Although most of the measures were questionnaire-based, as opposed to, for example, a sleep study, the results are very encouraging.
Unfortunately, fatigue, a major symptom of FM, was not assessed in this study. Nonetheless, the improvement in self-reported sleep indirectly implies that fatigue might also be remediated via GB. It is important to note that this trial of GB was relatively brief (12-weeks). The intermediate and long-term effects of GB on FM remain to be determined.
