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LETTER TO EDITOR
Year : 2019  |  Volume : 25  |  Issue : 4  |  Page : 594--595

Lidocaine 5% patch in localized neuropathic pain

Abhijit S Nair, Srinivasa Shyam Prasad Mantha, Mohammad Azharuddin, Basanth Kumar Rayani 
 Department of Anaesthesiology, Basavatarakam Indo-American Cancer Hospital and Research Institute, Hyderabad, Telangana, India

Correspondence Address:
Abhijit S Nair
Department of Anaesthesiology, Basavatarakam Indo-American Cancer Hospital and Research Institute, Hyderabad - 500 034, Telangana
India




How to cite this article:
Nair AS, Mantha SS, Azharuddin M, Rayani BK. Lidocaine 5% patch in localized neuropathic pain.Indian J Palliat Care 2019;25:594-595


How to cite this URL:
Nair AS, Mantha SS, Azharuddin M, Rayani BK. Lidocaine 5% patch in localized neuropathic pain. Indian J Palliat Care [serial online] 2019 [cited 2019 Dec 13 ];25:594-595
Available from: http://www.jpalliativecare.com/text.asp?2019/25/4/594/268889


Full Text



Sir,

The International Association for the Study of Pain has defined neuropathic pain (NP) as “pain caused by a lesion or disease of the somatosensory nervous system.”[1] Pathophysiology of NP involves both peripheral and central mechanisms. Localized NP is a distinct entity which is seen in a lot of conditions. Localized NP is characterized by consistent and circumscribed areas of pain associated with negative or positive sensory signs and/or spontaneous symptoms characteristic of NP.[2] It could be due to infectious, metabolic, postoperative, nerve entrapment or compression, and chemotherapy induced.[3] [Table 1] shows the situations causing commonly encountered localized NP. In this condition, there is neuronal hyperexcitability due to plastic changes in afferent nociceptive fibers from peripheral and central nerves. There is also central sensitization and hyperexcitation of spinal nociceptive neurons leading to increase in spontaneous discharge along with impairment of modulatory descending inhibitory controls. Routinely used medications for NP such as antidepressants, antiepileptics, and opioids usually do not provide effective relief in localized NP. On the other hand, patients suffer with unwanted adverse effects due to the use of above-mentioned medications, especially elderly patients and patients with medical comorbidities. In resistant situations, 5% lidocaine and 8% capsaicin transdermal patches have been used successfully. Although lidocaine 5% patch has been used in many localized NP, 8% capsaicin has been found beneficial only in postherpetic neuralgia (PHN) and NP due to HIV.[4]{Table 1}

When used as a patch, lidocaine nonselectively blocks sensory afferents of small damaged pain fibers, thus reducing ectopic discharge and signal propagation. Lidocaine patch does not lead to a sensory block due to blockade of Na+ channels present on large myelinated Aβ sensory fibers. The patch has a negligible or no systemic absorption after application (3%–5%) usually gets systemically absorbed which is negligible. Till date, local anesthesia systemic toxicity has not been reported with lidocaine patch. Therefore, dose adjustment is not required in patient with mild-to-moderate renal and hepatic impairments. Commonly encountered adverse effects with routinely used chronic NP medications such as sedation, constipation, and cognitive dysfunction can totally be avoided with the use of patches. Some patients do complain erythema, itching, burning, and edema at the site of application, but it is self-limiting and resolves once the patch is removed. The patch should be preferably avoided in infected, atrophic, and injured skin. Long-term use of 5% lidocaine patch has been established, especially in patients with PHN, postoperative pain, and in complex regional pain syndrome-1 (up to 3–5 years).[5]

Although lidocaine patch has shown efficacy in certain category of patients, there is no robust evidence from good quality randomized controlled studies to justify the use of lidocaine patch to treat all categories of localized NP.[6] Right now, the use of patch is not recommended in pregnancy and children.

To conclude, the lidocaine patch is a reasonable alternative in patients with localized NP as mentioned earlier. It is devoid of adverse effects which are observed with routinely used oral medications, is safe, well tolerated, and can be used for a long duration. It can be used along with other systemic medications also.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1International Association for the Study of Pain. IASP Taxonomy. Pain Terms. Neuropathic Pain. Available from: http://www.iasp pain.org/Taxonomy#Neuropathicpain. [Last accessed on 2017 Dec 14].
2Mick G, Baron R, Finnerup NB, Hans G, Kern KU, Brett B, et al. What is localized neuropathic pain? A first proposal to characterize and define a widely used term. Pain Manag 2012;2:71-7.
3Pickering G, Martin E, Tiberghien F, Delorme C, Mick G. Localized neuropathic pain: An expert consensus on local treatments. Drug Des Devel Ther 2017;11:2709-18.
4Laklouk M, Baranidharan G. Profile of the capsaicin 8% patch for the management of neuropathic pain associated with postherpetic neuralgia: Safety, efficacy, and patient acceptability. Patient Prefer Adherence 2016;10:1913-8.
5Wilhelm IR, Tzabazis A, Likar R, Sittl R, Griessinger N. Long-term treatment of neuropathic pain with a 5% lidocaine medicated plaster. Eur J Anaesthesiol 2010;27:169-73.
6Derry S, Wiffen PJ, Moore RA, Quinlan J. Topical lidocaine for neuropathic pain in adults. Cochrane Database Syst Rev 2014;(7):CD010958.