Prediction of Individual Analgesic Response to Intravenous Lidocaine in Painful Diabetic Peripheral Neuropathy: A Randomized, Placebo-controlled, Crossover Trial

Intravenous Lidocaine for the Management of Chronic Pain: A Narrative Review of Randomized Clinical Trials

Background

Chronic pain remains a serious health problem with significant impact on morbidity and well-being. Available treatments have only resulted in relatively modest efficacy. Thus, novel therapeutic treatments with different mechanisms have recently generated empirical interest. Lidocaine is postulated to provide anti-inflammatory and anti-nociceptive effect through its action at the N-methyl-D-aspartate (NMDA) and voltage gated calcium receptors. Emerging research indicates that lidocaine could be a reasonable alternative for treating chronic pain.

Objective

Considering the evidence surrounding lidocaine's potential as a therapeutic modality for chronic pain, we conducted a narrative review on the evidence of lidocaine's therapeutic effects in chronic pain.

Methods

A review of the PubMed, and Google scholar databases was undertaken in May 2022 to identify completed studies that investigated the effectiveness of lidocaine in the treatment of chronic pain from database inception to June 2022.

Results

A total of 25 studies were included in the narrative review. Findings on available studies suggest that intravenous infusion of lidocaine is an emerging and promising option that may alleviate pain in some clinical populations. Our narrative synthesis showed that evidence for intravenous lidocaine is currently mixed for a variety of chronic pain syndromes. Findings indicate that evidence for efficacy is limited for: CRPS, and cancer pain. However, there is good evidence supporting the efficacy of intravenous lidocaine as augmentation in chronic post-surgical pain.

Conclusion

Lidocaine may be a promising pharmacologic solution for chronic pain. Future investigation is warranted on elucidating the neurobiological mechanisms of lidocaine in attenuating pain signaling pathways.

Personalized treatment of neuropathic pain: Where are we now?

BACKGROUND

The treatment of neuropathic pain remains a major unmet need that the development of personalized and refined treatment strategies may contribute to address.

DATABASE

In this narrative review, we summarize the various approaches based on objective biomarkers or clinical markers that could be used.

RESULTS

In principle, the validation of objective biomarkers would be the most robust approach. However, although promising results have been reported demonstrating a potential value of genomics, anatomical or functional markers, the clinical validation of these markers has only just begun. Thus, most of the strategies documented to date have been based on the development of clinical markers. In particular, many studies have suggested that the identification of specific subgroups of patients presenting with specific combinations of symptoms and signs would be a relevant approach. Two main approaches have been used to identify relevant sensory profiles: quantitative sensory testing and specific patients reported outcomes based on description of pain qualities.

CONCLUSION

We discuss here the advantages and limitations of these approaches, which are not mutually exclusive.

SIGNIFICANCE

Recent data indicate that various new treatment strategies based on predictive biological and/or clinical markers could be helpful to better personalized and therefore improve the management of neuropathic pain.

Neuropathic Pain and Spinal Cord Injury: Management, Phenotypes, and Biomarkers

Chronic neuropathic pain after a spinal cord injury (SCI) continues to be a complex condition that is difficult to manage due to multiple underlying pathophysiological mechanisms and the association with psychosocial factors. Determining the individual contribution of each of these factors is currently not a realistic goal; however, focusing on the primary mechanisms may be more feasible. One approach used to uncover underlying mechanisms includes phenotyping using pain symptoms and somatosensory function. However, this approach does not consider cognitive and psychosocial mechanisms that may also significantly contribute to the pain experience and impact treatment outcomes. Indeed, clinical experience supports that a combination of self-management, non-pharmacological, and pharmacological approaches is needed to optimally manage pain in this population. This article will provide a broad updated summary integrating the clinical aspects of SCI-related neuropathic pain, potential pain mechanisms, evidence-based treatment recommendations, neuropathic pain phenotypes and brain biomarkers, psychosocial factors, and progress regarding how defining neuropathic pain phenotypes and other surrogate measures in the neuropathic pain field may lead to targeted treatments for neuropathic pain after SCI.

Towards prevention of diabetic peripheral neuropathy: clinical presentation, pathogenesis, and new treatments

Diabetic peripheral neuropathy (DPN) occurs in up to half of individuals with type 1 or type 2 diabetes. DPN results from the distal-to-proximal loss of peripheral nerve function, leading to physical disability and sometimes pain, with the consequent lowering of quality of life. Early diagnosis improves clinical outcomes, but many patients still develop neuropathy. Hyperglycaemia is a risk factor and glycaemic control prevents DPN development in type 1 diabetes. However, glycaemic control has modest or no benefit in individuals with type 2 diabetes, probably because they usually have comorbidities. Among them, the metabolic syndrome is a major risk factor for DPN. The pathophysiology of DPN is complex, but mechanisms converge on a unifying theme of bioenergetic failure in the peripheral nerves due to their unique anatomy. Current clinical management focuses on controlling diabetes, the metabolic syndrome, and pain, but remains suboptimal for most patients. Thus, research is ongoing to improve early diagnosis and prognosis, to identify molecular mechanisms that could lead to therapeutic targets, and to investigate lifestyle interventions to improve clinical outcomes.

Lidocaine Ameliorates Diabetic Peripheral Neuropathy in Streptozotocin-Induced Diabetic Rats through Modulating the c-Jun Signaling Pathway

As one of the common complications of diabetes mellitus (DM), Diabetic Peripheral Neuropathy (DPN) threatens human lives seriously. Emerging evidences have confirmed the protective effects of lidocaine on DPN. However, the possible role and underlying mechanisms of lidocaine in DPN have not been clarified. In this study, the potential role of lidocaine in DPN is explored, and the possible mechanisms are investigated. The rat DPN model is constructed through administration of streptozotocin (STZ, 60 mg/kg). All rats are randomly divided into four groups, including the control group, DPN group, lidocaine (3.78 mg/time) group, and lidocaine combined with the SP600125 (15 mg/kg) group. Mechanical threshold, thermal latency, and blood glucose of rats before and after treatment are detected, and Nerve Conduction Velocity (NCV) is assessed. Moreover, qRT-PCR and western blot assays are carried out to determine the expressions of the c-Jun signaling pathway. The experimental results demonstrate that lidocaine remarkably downregulates the mRNA and protein expressions of the c-Jun signaling pathway in serum and DRGs induced with DPN. Besides, lidocaine combined with SP600125 can obtain better effects than lidocaine alone. It is clearly evident that lidocaine has a certain therapeutic effect on DPN.