Perineural injection of etanercept as a treatment for postamputation pain

Background: The inflammatory cytokine tumor necrosis factor-alpha has been shown to play a pivotal role in the development and maintenance of a wide variety of neuropathic pain conditions. Not surprisingly, systemic treatment with drugs that block tumor necrosis factor have been demonstrated to alleviate pain and pain-related behaviors in clinical and preclinical studies, respectively. Despite evidence that local administration of this drug class may be more efficacious than systemic administration, there are no clinical studies to support or refute this assertion. Objective: To report results on the use of perineural etanercept in 6 traumatic amputees with postamputation pain. Methods: The authors treated 6 soldiers with residual limb and phantom pain with a series of perineural etanercept injections. Results: Five of the six patients reported significant improvements in residual limb pain at rest and with activity, phantom limb pain, functional capacity, and psychologic well-being 3 months after injections. The one soldier who failed therapy was the only patient who presented with pain greater than I year in duration. At the reduced doses administered, no adverse effects were observed. Discussion: These findings support preclinical evidence that the local administration of tumor necrosis factor inhibitors may prove to be a safe and effective treatment for challenging pain conditions.