The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial Multicenter Study
A 14-week, randomized, double-blinded, placebo-controlled monotherapy trial of pregabalin in patients with fibromyalgia.
The purpose of the study was to assess the efficacy and safety of pregabalin monotherapy in patients with fibromyalgia in a randomized, double-blinded, placebo-controlled trial. After 1 week of single-blinded administration of placebo, 750 patients meeting American College of Rheumatology criteria for fibromyalgia were randomly assigned to pregabalin (300 mg/d, 450 mg/d, 600 mg/d) or placebo, administered twice daily for 14 weeks. The primary outcome variable was comparison of end point mean pain scores, derived from daily diary ratings of pain intensity (0 to 10 scale), between each of the pregabalin groups and the placebo group. If positive, additional primary efficacy parameters included the Patient Global Impression of Change (PGIC) and the Fibromyalgia Impact Questionnaire (FIQ) total score. Compared with placebo-treated patients, mean changes in pain scores at the end point in pregabalin-treated patients were significantly greater (P < .001: 300 mg/d, -0.71; 450 mg/d, -0.98; 600 mg/d, -1.00). Compared with placebo, significantly more pregabalin-treated patients reported improvement on PGIC (P < .01 for all 3 pregabalin doses) and significant improvements in total FIQ score for the 450 mg/d (P = .004) and the 600 mg/d (P = .003) doses. Compared with placebo, all 3 doses of pregabalin were associated with significant improvement in sleep. The most commonly reported pregabalin-related adverse events were dizziness and somnolence, which tended to be dose-related. ⋯ This randomized, placebo-controlled trial of 300, 450, and 600 mg/d of pregabalin monotherapy demonstrated that all 3 doses were efficacious for up to 14 weeks for the treatment of fibromyalgia and were well tolerated by most patients. These results provide evidence that pregabalin is an important treatment option for patients with fibromyalgia.
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Randomized Controlled Trial
Acute opioid administration improves work-related exercise performance in patients with chronic back pain.
We studied the impact of acute opioid administration on work-related exercise performance in patients with chronic back pain. A double-blinded, random-order, placebo-controlled, crossover trial was conducted. Subjects were predominantly men (63%), with a mean age of 49 years. Subjects performed a continuous lifting and lowering test to voluntary fatigue at a load equivalent to 33% of their predetermined maximal lifting load twice: Once after receiving a single intravenous dose of 1 mug/kg fentanyl (a narcotic analgesic) and once after saline placebo. Of the 30 subjects undergoing testing, 3 subjects were unable to complete testing due to medication-induced nausea. Subjects lifted on average 29.4 +/- 17.9 kg under the influence of fentanyl versus 25.6 +/- 3.1 kg with placebo (effect size = 0.23). Time to fatigue was higher in the fentanyl group (312 +/- 251.4 vs 231 +/- 199.9 seconds, effect size = 0.40), and these subjects also performed more total work (7004 +/- 5144 vs 4748 +/- 3147 J, effect size = 0.72). Opioid analgesia improves lifting performance in the short term in individuals with chronic back pain. Longer trials of the effectiveness of opioid analgesia as an adjunct to functional restoration programs are recommended. ⋯ This article presents the results of a clinical trial showing that acute opioid administration improves work-related exercise performance in individuals with chronic back pain. Longer trials of the effectiveness of opioid analgesia as an adjunct to functional restoration programs are recommended.