Study objectives: Insomnia, which is very common in patients with chronic low back pain (LBP), has long been viewed as a pain symptom that did not merit specific treatment. Recent data suggest that adding insomnia therapy to pain-targeted treatment should improve outcome; however, this has not been empirically tested in LBP or in any pain condition treated with a standardized pain medication regimen. We sought to test the hypothesis that adding insomnia therapy to pain-targeted treatment might improve sleep and pain in LBP.
Design: Double-blind, placebo-controlled, parallel-group, 1-mo trial.
Setting: Duke University Medical Center Outpatient Sleep Clinic.
Patients: Fifty-two adult volunteers with LBP of at least 3 mo duration who met diagnostic criteria for insomnia (mean age: 42.5 y; 63% females).
Interventions: Subjects were randomized to eszopiclone (ESZ) 3 mg plus naproxen 500 mg BID or matching placebo plus naproxen 500 mg twice a day.
Measurements and results: ESZ SIGNIFICANTLY IMPROVED TOTAL SLEEP TIME (MEAN INCREASE: ESZ, 95 min; placebo, 9 min) (primary outcome) and nearly all sleep measures as well as visual analog scale pain (mean decrease: ESZ, 17 mm; placebo, 2 mm) (primary pain outcome), and depression (mean Hamilton Depression Rating Scale improvement ESZ, 3.8; placebo, 0.4) compared with placebo. Changes in pain ratings were significantly correlated with changes in sleep.
Conclusions: The addition of insomnia-specific therapy to a standardized naproxen pain regimen significantly improves sleep, pain, and depression in patients with chronic low back pain (LBP). The findings indicate the importance of administering both sleep and pain-directed therapies to patients with LBP in clinical practice and provide strong evidence that improving sleep disturbance may improve pain.
Trial registration: clinicaltrials.gov identifier: NCT00365976.
Keywords: eszopiclone; insomnia; low back pain.