Editing Peripheral neuropathy (section)

==== Opioids ====
A Cochrane review of buprenorphine, fentanyl, hydromorphone, and morphine, all dated between 2015 and 2017, and all for the treatment of neuropathic pain, found that there was insufficient evidence to comment on their efficacy. Conflicts of interest were declared by the authors in this review.<ref name=":6" /><ref name=":7">{{cite journal | vauthors = Cooper TE, Chen J, Wiffen PJ, Derry S, Carr DB, Aldington D, Cole P, Moore RA | title = Morphine for chronic neuropathic pain in adults | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | pages = CD011669 | date = May 2017 | issue = 5 | pmid = 28530786 | pmc = 6481499 | doi = 10.1002/14651858.CD011669.pub2 }}</ref><ref name=":9" /><ref name=":10" /> A 2017 Cochrane review of methadone found very low-quality evidence, three studies of limited quality, of its efficacy and safety. They could not formulate any conclusions about its relative efficacy and safety compared to a placebo.<ref name=":8" />

For tramadol, Cochrane found that there was only modest information about the benefits of its usage for neuropathic pain. Studies were small, had potential risks of bias and apparent benefits increased with risk of bias. Overall the evidence was of low or very low quality and the authors state that it "does not provide a reliable indication of the likely effect".<ref name=":11">{{cite journal | vauthors = Duehmke RM, Derry S, Wiffen PJ, Bell RF, Aldington D, Moore RA | title = Tramadol for neuropathic pain in adults | journal = The Cochrane Database of Systematic Reviews | volume = 2017 | pages = CD003726 | date = June 2017 | issue = 6 | pmid = 28616956 | pmc = 6481580 | doi = 10.1002/14651858.CD003726.pub4 }}</ref> For oxycodone the authors found very low-quality evidence showing its usefulness in treating diabetic neuropathy and postherpetic neuralgia only. One of the four authors declared receiving payments from pharmaceutical companies.<ref name=":12" />

More generally, a large-scale 2013 review found opioids to be more effective for intermediate-term use than short-term use, but couldn't properly assess effectiveness for chronic use because of insufficient data. Most recent guidelines on the pharmacotherapy of neuropathic pain however are in agreement with the results of this review and recommend the use of opioids.<ref>{{cite journal | vauthors = McNicol ED, Midbari A, Eisenberg E | title = Opioids for neuropathic pain | journal = The Cochrane Database of Systematic Reviews | issue = 8 | pages = CD006146 | date = August 2013 | volume = 2019 | pmid = 23986501 | pmc = 6353125 | doi = 10.1002/14651858.CD006146.pub2 }}</ref> A 2017 Cochrane review examining mainly propoxyphene therapy as a treatment for many non-cancer pain syndromes (including neuropathic pain) concluded, "There was no evidence from randomised controlled trials to support or refute the use of opioids to treat chronic non-cancer pain in children and adolescents."<ref>{{cite journal | vauthors = Cooper TE, Fisher E, Gray AL, Krane E, Sethna N, van Tilburg MA, Zernikow B, Wiffen PJ | title = Opioids for chronic non-cancer pain in children and adolescents | journal = The Cochrane Database of Systematic Reviews | volume = 7 | pages = CD012538 | date = July 2017 | issue = 7 | pmid = 28745394 | pmc = 6477875 | doi = 10.1002/14651858.CD012538.pub2 }}</ref>