As many as 116 million adults experience chronic pain each year in the United States, and treatment for these individuals often includes opioids.1 However, the use of opioids for chronic pain is controversial, highlighting the need for nonopioid therapies for this patient population.
The potential for intravenous (IV) lidocaine to reduce postoperative pain was first proposed in the literature in 1961.2 Multiple studies conducted since then have demonstrated support for this concept, and other research suggests that IV lidocaine may also be effective in the treatment of chronic pain.
Although there are limited data regarding the proposed mechanisms underlying these effects, findings indicate that IV lidocaine is “eﬀective in the management of some neuropathic pain syndromes by modulating the ectopic neuronal discharges, thus decreasing hyperalgesia and the inﬂammatory response,” according to a paper published in 2017 in Anesthesiology and Pain Medicine.
“This eﬀect is obtained through inhibition of the voltage-gated sodium channels, voltage-gated calcium channels, various potassium channels, N-methyl-D-aspartate receptors, glycine system, and G protein pathways.”
The authors conducted a review of research investigating the safety and efficacy of systemic lidocaine — delivered either intravenously or through a patch (5% lidocaine) — for the prevention and treatment of chronic pain. The literature search included relevant studies published through April 2016. Selected results are described below.
Systemic lidocaine and postherpetic neuralgia (PHN). The 5% lidocaine patch received approval from the US Food and Drug Administration in 1999 for one specific indication — relief of pain in PHN — and studies have demonstrated its safety and efficacy in reducing PHN-related tactile allodynia.4 In some cases, the patch does not cover the entire affected area, suggesting that “the eﬀect of lidocaine patch is most likely achieved through systemic absorption, rather than a local eﬀect,” the authors wrote.
A study reported in Pain in 2007 used functional magnetic resonance imaging to examine brain activity associated with PHN-associated spontaneous pain and how this activity is modulated by treatment with a 5% lidocaine patch.5 Spontaneous PHN pain was found to activate affective and sensory-discriminative areas, and this activity was found to be reduced after 2 and 3 sessions of treatment with the lidocaine 5% patch.
This article originally appeared on Clinical Pain Advisor