Objective: To evaluate the effectiveness and tolerability of tapentadol prolonged release (PR) for severe, chronic low back pain with a neuropathic component in a subpopulation that achieved adequate pain relief with tapentadol PR 300 mg/day in a randomized, double-blind, phase 3b study.
Methods: Patients with painDETECT "unclear" or "positive" ratings and pain intensity ≥ 6 (11-point NRS-3 [average 3-day pain intensity]) were titrated to tapentadol PR 300 mg/day over 3 weeks. A subpopulation with pain intensity < 4 continued receiving tapentadol PR 300 mg/day during an 8-week, open-label continuation arm. For the primary study population, patients with ≥ 1-point decrease from baseline and pain intensity ≥ 4 were randomized to tapentadol PR 500 mg/day or tapentadol PR 300 mg/day plus pregabalin 300 mg/day during a concurrent 8-week, double-blind comparative period.
Results: From baseline to end of titration and to final evaluation, significant improvements were observed in pain intensity (mean [SD] changes from baseline to: end of titration; - 5.3 [1.78]; final evaluation; - 5.2 [2.39]; both P < 0.0001), neuropathic pain symptoms, and quality-of-life measures in the open-label continuation arm, with greater improvements in this selected subpopulation than in either group in the primary study population. A favorable tolerability profile was observed, with incidences of all individual treatment-emergent adverse events ≤ 5.1% during the continuation period.
Conclusions: A subpopulation of patients with low back pain with a neuropathic component responded very well to tapentadol PR 300 mg/day, with significant improvements in pain intensity, neuropathic pain-related symptoms, and quality of life. Further research is needed to identify factors associated with a very positive treatment response.
Keywords: chronic pain; low back pain; neuropathic pain; tapentadol prolonged release; tolerability.
© 2014 The Authors. Pain Practice published by Wiley periodicals, Inc. on behalf of World Institute of Pain.