Systematic review and network meta-analysis of the efficacy and safety of lidocaine 700 mg medicated plaster vs. pregabalin

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS.

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids.

AUTHORS' CONCLUSIONS

Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

A Review of Recent Pharmacological Advances in the Management of Diabetes-Associated Peripheral Neuropathy

Diabetic peripheral neuropathy is a common complication of longstanding diabetes mellitus. These neuropathies can present in various forms, and with the increasing prevalence of diabetes mellitus, a subsequent increase in peripheral neuropathy cases has been noted. Peripheral neuropathy has a significant societal and economic burden, with patients requiring concomitant medication and often experiencing a decline in their quality of life. There is currently a wide variety of pharmacological interventions, including serotonin norepinephrine reuptake inhibitors, gapentanoids, sodium channel blockers, and tricyclic antidepressants. These medications will be discussed, as well as their respective efficacies. Recent advances in the treatment of diabetes mellitus with incretin system-modulating drugs, specifically glucagon-like peptide-1 agonists, have been promising, and their potential implication in the treatment of peripheral diabetic neuropathy is discussed in this review.

Pregabalin in patients with post-traumatic peripheral neuropathic pain: A meta-analysis of randomized controlled trials

OBJECTIVE

The aim of the study was to investigate the safety and efficacy of pregabalin versus placebo in post-traumatic peripheral neuropathic pain (PTNP).

METHODS

PubMed, Cochrane Library, Web of Science, and Google Scholar were searched for relevant evidence up to January 2022. The Cochran tool was used to assess the quality of randomized clinical trials (RCTs). Data analysis was performed using Comprehensive Meta-Analysis software.

RESULTS

Three RCTs involving 821 patients were included in the meta-analysis. A significant difference was observed between pregabalin and placebo in terms of the pain score (the standardized mean difference [SMD] = -0.14, 95% CI: 0.28 to -0.006, p = 0.04) and sleep interference (MD = -0.25, 95% CI: -0.39 to -0.11, p = 0.00). There was also a significant difference between pregabalin and placebo regarding somnolence (risk ratio [RR] = 2.78; 95% CI: 1.64-4.71, p = 0.00), dizziness (RR = 4.13; 95% CI: 2.71-6.28, p = 0.00), and disturbance in attention (RR: 2.97; 95% CI: 1.02-8.65, p = 0.04). However, no significant difference was observed between pregabalin and placebo in terms of headache (RR = 1.20; 95% CI: 0.70-2.06, p = 0.50), fatigue (RR = 1.42; 95% CI: 0.82-2.47, p = 0.20), nausea (RR = 1.52; 95% CI: 0.88-2.62, p = 0.13), constipation (RR = 1.84; 95% CI: 0.78-4.29, p = 0.15), and discontinuation (RR = 1.52; 95% CI: 0.45-5.06, p = 0.49).

CONCLUSION

Compared with placebo, pregabalin showed better efficacy in reducing PTNP and improving sleep interference. However, it was associated with higher adverse events. Further RCTs are needed to confirm these findings.

Off-label pharmacological treatment for neuropathic pain: A Delphi study by the Spanish Pain Society Neuropathic Pain Task Force

OBJECTIVES

The use of off-label pharmacotherapies for neuropathic pain (NP) is growing relating to the many unmet needs of patients. However, clinical guidelines fail to address it, and the available evidence is sparse and fragmented. We arranged a formal expert consensus to address this controversial issue and provide some guidance on judicious use.

METHODS

A two-round standard Delphi survey that involved pain clinic specialists with experience in the research and management of NP was done over an ad hoc 40-item questionnaire prepared by the authors. Consensus on each statement was defined as at least either 80% endorsement or rejection after the second round.

RESULTS

Forty-three and thirty-seven panelists participated in the first and second round, respectively. Consensus was reached in 34 out of 40 statements. Endorsed alternatives for unresponsive patients include non-gabapentinoid antiepileptics (oxcarbazepine and eslicarbazepine), venlafaxine, intravenous lidocaine (when doses can be optimized), and some vaporized cannabinoids (under appropriate surveillance). In addition, lacosamide, low-dose naltrexone, propofol, or ketamine could prove beneficial if subjected to more research. Other options were rejected, and there was controversy about the usefulness of topical preparations.

DISCUSSION

For patients who do not respond to standard NP treatments, some other viable pharmacological options can be attempted before advancing to other therapeutic stages. This may help patients who are reluctant to or have some contraindication for interventional therapies.

Painful diabetic peripheral neuropathy: real-world comparison between topical treatment with lidocaine 700 mg medicated plaster and oral treatments

INTRODUCTION

Painful diabetic peripheral neuropathy (PDPN), a common complication of diabetes mellitus, is challenging to treat. Efficacy and tolerability of the topical lidocaine 700 mg medicated plaster (LMP) and well-established first-line oral medications (OM) were compared in refractory PDPN patients.

RESEARCH DESIGN AND METHODS

This is a subgroup analysis of a non-interventional, retrospective 24-week cohort study using anonymized routine medical care data from the German Pain eRegistry. Propensity score matching provided 732 datasets per treatment group. Primary effectiveness endpoint was the absolute change in average 24-hour Pain Intensity Index (0-100 mm) from baseline after 4, 12 and 24 weeks of treatment and over the entire treatment period.

RESULTS

The majority of this multimorbid and polymedicated study population of patients with PDPN had suffered pain for more than a year and presented with a high pain burden despite a median of seven previous analgesic medications. LMP treatment resulted in significant reductions in pain intensity and improvements in daily functioning already after 4 treatment weeks. Effectiveness was maintained over the treatment period even when concomitant analgesics were reduced or discontinued and quality of life improved. Mean change in the primary effectiveness parameter over the 24-week treatment period was -30.2 mm (SE 0.38) and -17.0 mm (SE 0.51) in the LMP and OM groups, respectively. Improvements in all effectiveness parameters were significantly greater under LMP than under OM treatment (p<0.001). Significantly fewer patients under LMP than OM experienced drug-related adverse events (DRAEs; 9.6% vs 61.6%, p<0.001) and discontinued treatment due to DRAEs (4.4% vs 35.8%, p<0.001).

CONCLUSIONS

LMP was effective and well tolerated in routine clinical care of patients with PDPN. The more favorable benefit/risk profile and greater reduction in intake of concomitant analgesics compared with OM suggest LMP as a useful treatment option for PDPN.

TRIAL REGISTRATION NUMBER

EUPAS 32826.

Postsurgical neuropathic pain: lidocaine 700 mg medicated plaster or oral treatments in clinical practice

Aim: To compare the effectiveness and tolerability of the lidocaine 700 mg medicated plaster (LMP) and oral first-line medications (OM) for the treatment of postsurgical neuropathic pain (PSNP) in routine clinical practice. Patients & methods: Data from a noninterventional, retrospective 24-week cohort study in patients with localized peripheral NP refractory to at least one recommended OM using anonymized German Pain eRegistry data were retrieved. A subgroup analysis was conducted on 531 datasets of PSNP patients. Results: Pain relief, improvements in pain-related impairments of daily living and quality of life, and tolerability were significantly greater under LMP than under OM (p < 0.001 for all parameters). Conclusion: These real-world data show the effectiveness and good tolerability of LMP for PSNP treatment in routine clinical practice.

Management of chronic non-cancer pain: a framework

Aim: Since publication of the CDC 2016 Guideline, opioid-related mortality in the USA has doubled and a crisis has developed among the 15-20 million Americans with chronic, moderate-to-severe, noncancer pain. Our aim was to develop a comprehensive alternative approach to management of chronic pain. Methods: Analytic review of the clinical literature. Results: Published science provides a solid framework for the management of chronic non-cancer pain, detailed here, even as it leaves many knowledge gaps, which we fill with insights from clinical experience. Conclusion: There is a sufficient basis in science and in clinical experience to achieve adequate control of chronic pain in nearly all patients in a way that adequately balances benefits and potential harms.

An Insight into Potential Pharmacotherapeutic Agents for Painful Diabetic Neuropathy

Diabetes is the 4th most common disease affecting the world's population. It is accompanied by many complications that deteriorate the quality of life. Painful diabetic neuropathy (PDN) is one of the debilitating consequences of diabetes that effects one-third of diabetic patients. Unfortunately, there is no internationally recommended drug that directly hinders the pathological mechanisms that result in painful diabetic neuropathy. Clinical studies have shown that anticonvulsant and antidepressant therapies have proven fruitful in management of pain associated with PDN. Currently, the FDA approved medications for painful diabetic neuropathies include duloxetine, pregabalin, tapentadol extended release, and capsaicin (for foot PDN only). The FDA has also approved the use of spinal cord stimulation system for the treatment of diabetic neuropathy pain. The drugs recommended by other regulatory bodies include gabapentin, amitriptyline, dextromethorphan, tramadol, venlafaxine, sodium valproate, and 5 % lidocaine patch. These drugs are only partially effective and have adverse effects associated with their use. Treating painful symptoms in diabetic patient can be frustrating not only for the patients but also for health care workers, so additional clinical trials for novel and conventional treatments are required to devise more effective treatment for PDN with minimal side effects. This review gives an insight on the pathways involved in the pathogenesis of PDN and the potential pharmacotherapeutic agents. This will be followed by an overview on the FDA-approved drugs for PDN and commercially available topical analgesic and their effects on painful diabetic neuropathies.

Localized peripheral neuropathic pain: topical treatment with lidocaine 700 mg medicated plaster in routine clinical practice

Aim: To provide real-world evidence for the effectiveness and tolerability of lidocaine 700 mg medicated plaster (LMP) in localized peripheral neuropathic pain (l-PNP) treatment compared with first-line oral medications (OM). Patients & methods: This was a noninterventional, retrospective 6-month cohort study in patients refractory to at least one recommended OM, using anonymized medical care data from the German Pain eRegistry. Treatment groups were matched by propensity scoring, considering seven predefined confounding factors. The primary effectiveness end point was the absolute change in average pain intensity index from baseline at weeks 4, 12 and 24 of treatment and over the treatment period. Results: A total of 3081 datasets were retained per treatment group. LMP provided superior pain reductions and significantly greater improvements in pain-related impairments of daily living and quality of life with significantly better tolerability (p < 0.001 for all parameters) than OM. Conclusion: These real-world data confirm the effectiveness and good tolerability of LMP for l-PNP treatment under routine medical care.

Comparative Benefit-Risk Assessment for Lidocaine 700 mg Medicated Plaster and Pregabalin in Peripheral Neuropathic Pain Following a Structured Framework Approach

Introduction

Peripheral neuropathic pain (PNP) is difficult to treat. Several oral drugs are recommended as first-line treatments. Nevertheless, many patients cannot obtain sufficient pain relief or do not tolerate systemically active treatments. Topical treatments, with a lower risk of systemic side effects such as lidocaine 700 mg medicated plaster, are also recommended in treatment guidelines. This analysis compares the benefit–risk balance of topical 700 mg lidocaine medicated plaster with the benefit–risk balance of oral pregabalin administration for the treatment of PNP following current recommendations on benefit–risk assessment (BRA) methodology.

Methods

The Benefit–Risk Action Team (BRAT) framework was used as structured approach. Selection of key benefits and risks was supported by a patient survey. Published randomized controlled clinical trials were the main source to identify data related to key benefits and risks. The outcome of randomized clinical trials was compared with real-world evidence (RWE) data for consistency.

Results

Identified key benefits were pain reduction and improvement in quality of life. Key risks identified were application site reactions, dizziness, confusion, weight gain, peripheral edema, and blurred vision. Overall, there was similarity in key benefits between the comparators; however, a clear advantage regarding key risks in favor of lidocaine 700 mg medicated plaster was observed. This observation was consistent across data from a direct comparison trial, randomized placebo-controlled trials, as well as data from RWE studies. The low number of randomized controlled trials for lidocaine 700 mg medicated plaster was the main limitation.

Conclusion

Guided by the opinion of patients regarding key benefits and risks deemed important for treatments of peripheral neuropathic pain, our analysis showed that lidocaine 700 mg medicated plaster has a more favorable benefit–risk balance compared to pregabalin (300 and 600 mg daily).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-021-00340-2.

Topical Lidocaine for Chronic Pain Treatment

Topical lidocaine is widely used in current practice for a variety of pain conditions. This literature review shows that its limited absorption and relative lack of systemic adverse events are an attractive analgesic option for a number of vulnerable patients. Topical lidocaine has been approved by health authorities for the treatment of post-herpetic neuralgia in a number of countries, and studies present some degree of evidence of its efficacy and safety in postsurgical pain, diabetic peripheral neuropathy, carpal tunnel syndrome, chronic lower back pain and osteoarthritis. Topical lidocaine may be a great alternative alone or in addition to systemic drugs and non-pharmacological approaches for an optimized pain management and in multimodal analgesia.

Lidocaine 700 mg medicated plaster for postherpetic neuralgia: real-world data from the German Pain e-Registry

Aim: To provide real-world evidence for the effectiveness and tolerability of lidocaine 700 mg medicated plaster (LMP) compared with oral systemic first-line medications (OSM) in postherpetic neuralgia treatment. Patients & methods: Retrospective cohort study in patients refractory to at least one recommended OSM (single drug or a combination of drugs) using anonymized routine medical care data from the German Pain e-Registry. A matched pair approach using propensity score matching was employed. Results: A total of 1711 data sets of postherpetic neuralgia patients were identified per treatment group. The majority (>60%) had experienced pain for more than a year and reported a high burden of pain and reduced quality of life. Six months of LMP treatment provided significantly greater pain reductions, improvements in pain-related impairments and quality of life than OSM treatment (p < 0.001 for all parameters). Drug-related adverse events and treatment discontinuation due to drug-related adverse events also occurred less frequently under LMP treatment (p < 0.001). Conclusion: These real-world data confirm the effectiveness and good tolerability of LMP under routine medical care. The treatment was significantly more effective when compared with first-line oral systemic medications.