Opioids for neuropathic pain

Abstract

Whether opioids are effective for neuropathic pain has been a matter of controversy for decades. Within limits, it is clear that opioids in general are effective for neuropathic pain. Furthermore, there is no evidence that opioids are any less effective for neuropathic pain than for non-neuropathic pain, no evidence that opioids are less effective for neuropathic pain than are other medications, and no evidence that one opioid is any more effective than another for neuropathic pain. It remains uncertain whether opioids are effective for central pain, although they may have a role. Although some patients appear to enjoy long-term benefits, most studies have been short-term. Opioids have an important role in the treatment of neuropathic pain; however, skillful opioid use balances the benefits with management of side effects and prevention and treatment of abuse and addiction.

Efficacy of mu‐opioid agonists in the treatment of evoked neuropathic pain: Systematic review of randomized controlled trials

“…Yet, the belief that NP is opioid-resistant, as well as concerns over adverse effect profiles and potential for abuse often discourages the use of opioids for NP. Recent systematic reviews (Eisenberg et al, in press;Kalso et al, 2004;Katz and Benoit, 2005) of randomized controlled trials (RCTs) have shown the efficacy of opioids in reducing spontaneous NP. However, little is known about their efficacy for evoked pain.…”

Randomized trial comparing polymer-coated extended-release morphine sulfate to controlled-release oxycodone HCl in moderate to severe nonmalignant pain

“…Opioids comprise the most potent analgesic medications and have a broad range of efficacy 7 . Studies have suggested that patients with nociceptive pain are most responsive to opioids 3 , but that a subset of patients with neuropathic pain also demonstrates good response [8][9][10] . It has been suggested that opioid responsiveness represents a continuum, with extensive overlap in the responsiveness of pain that is mediated by nociceptive, neuropathic and mixed mechanisms 3 .…”

Imaging central pain syndromes

“…Possible other explanations are loss of receptors due to the lesion, transneuronal degeneration, or receptor mechanisms such as receptor internalization or downregulation [62]. These observations of reduced opioid receptor binding in central pain patients may explain the poor response of these patients to opioid treatment [64].…”