Cost-Effectiveness of Treatment Options for Neuropathic Pain: a Systematic Review

The analgesic effect of total saponins of Tribulus terrestris on neuropathic pain was studied based on TLR4/NF-κB pathway

Neuropathic pain (NP) consists of a range of unpleasant sensations attributed to a lesion or a disease of the somatosensory nervous system. It is important to note that the sensations initiated by NP are debilitating and adversely affect quality of life; however, the underlying mechanisms involved in the occurrence and development of this type of pain remain to be determined. Previously data demonstrated that inhibition of TLR4/NF-κB signaling pathway diminished the adverse consequences attributed to NP. Thus, the purpose of this study was to examine whether saponins derived from Tribulus terrestris might exert an analgesic effect on NP in rats using a chronic constriction injury (CCI) involving sciatic nerve. Male rats were randomly divided into Sham, CCI, low 100 mg/kg T. terrestris, high 200 mg/kg T. terrestris, and compared to pregabalin 10 mg/kg, the recognized first line of defense in NP. Three days after surgery, rats were treated with sham control (water) or drugs. The paw mechanical withdrawal threshold (PMWT) and thermal latency (TL) of rats were measured 1 day before operation and 3, 7, and 10 days after. Nissl staining was used to observe the morphology and Western Blot to detect protein expression of NF-κB and TLR4 on the 10th day after operation. ELISA was employed to detect levels of IL-1β, IL-6, and TNF-ɑ in spinal cord. CCI significantly decreased PMWT and TL. In CCI neurons and glial cells in the spinal dorsal horn were deeply stained with swelling and atrophy observed. The protein expression levels of NF-κB and TLR4 in the spinal dorsal horn of the injured side were significantly increased accompanied by elevated levels of inflammatory mediators IL-1β, IL-6, and TNF-ɑ. Treatment with low 100 mg/kg or high 200 mg/kg T. terrestris or pregabalin reduced effects of CCI on PMW, TL, histopathological changes as well as levels of inflammatory cytokines IL-1β and IL-6 associated with inhibition of TLR4/NF-κB pathway. Data suggest that T. terrest exerts an analgesic effect on peripheral NP which involves TLR4/NF-κB pathway inhibition.

Treadmill running on neuropathic pain: via modulation of neuroinflammation

Neuropathic pain is a type of chronic pain caused by an injury or somatosensory nervous system disease. Drugs and exercise could effectively relieve neuropathic pain, but no treatment can completely stop neuropathic pain. The integration of exercise into neuropathic pain management has attracted considerable interest in recent years, and treadmill training is the most used among exercise therapies. Neuropathic pain can be effectively treated if its mechanism is clarified. In recent years, the association between neuroinflammation and neuropathic pain has been explored. Neuroinflammation can trigger proinflammatory cytokines, activate microglia, inhibit descending pain modulatory systems, and promote the overexpression of brain-derived neurotrophic factor, which lead to the generation of neuropathic pain and hypersensitivity. Treadmill exercise can alleviate neuropathic pain mainly by regulating neuroinflammation, including inhibiting the activity of pro-inflammatory factors and over activation of microglia in the dorsal horn, regulating the expression of mu opioid receptor expression in the rostral ventromedial medulla and levels of γ-aminobutyric acid to activate the descending pain modulatory system and the overexpression of brain-derived neurotrophic factor. This article reviews and summarizes research on the effect of treadmill exercise on neuropathic pain and its role in the regulation of neuroinflammation to explore its benefits for neuropathic pain treatment.

Productivity outcomes from chronic pain management interventions in the working age population; a systematic review

ABSTRACT

Productivity loss because of chronic pain in the working age population is a widespread concern internationally. Interventions for chronic pain in working age adults might be expected to achieve enhanced productivity in terms of reduced costs of workers' compensation insurance, reduced disability support, and improved rates of return to work for injured workers. This would require the use of measures of productivity in the evaluation of chronic pain management interventions. The aim of this review was to identify and interpret the productivity outcomes of randomised controlled trials reported by studies that conducted economic evaluations (eg, cost-effectiveness and cost-utility) of chronic pain management interventions in the working age population published from database inception to March 2023. Econlit, Embase, and Pubmed electronic databases were searched, yielding 12 studies that met the selection criteria. All 12 studies used absenteeism to measure productivity, translating return to work measures into indirect costs. Only one study included return to work as a primary outcome. Ten studies found no statistically significant improvements in productivity-related costs. Despite evidence for reduced pain-related disability after pain management interventions, this review suggests that the use of measures for assessing productivity gains is lacking. Including such measures would greatly assist administrators and payers when considering the broader societal benefits of such interventions.

A phenotypic screening platform for chronic pain therapeutics using all-optical electrophysiology

ABSTRACT

Chronic pain associated with osteoarthritis (OA) remains an intractable problem with few effective treatment options. New approaches are needed to model the disease biology and to drive discovery of therapeutics. We present an in vitro model of OA pain, where dorsal root ganglion (DRG) sensory neurons were sensitized by a defined mixture of disease-relevant inflammatory mediators, here called Sensitizing PAin Reagent Composition or SPARC. Osteoarthritis-SPARC components showed synergistic or additive effects when applied in combination and induced pain phenotypes in vivo. To measure the effect of OA-SPARC on neural firing in a scalable format, we used a custom system for high throughput all-optical electrophysiology. This system enabled light-based membrane voltage recordings from hundreds of neurons in parallel with single cell and single action potential resolution and a throughput of up to 500,000 neurons per day. A computational framework was developed to construct a multiparameter OA-SPARC neuronal phenotype and to quantitatively assess phenotype reversal by candidate pharmacology. We screened ∼3000 approved drugs and mechanistically focused compounds, yielding data from over 1.2 million individual neurons with detailed assessment of functional OA-SPARC phenotype rescue and orthogonal "off-target" effects. Analysis of confirmed hits revealed diverse potential analgesic mechanisms including ion channel modulators and other mechanisms including MEK inhibitors and tyrosine kinase modulators. Our results suggest that the Raf-MEK-ERK axis in DRG neurons may integrate the inputs from multiple upstream inflammatory mediators found in osteoarthritis patient joints, and MAPK pathway activation in DRG neurons may contribute to chronic pain in patients with osteoarthritis.

Cognitive-Evaluative Dimension of Pain in Neuropathic Pain Relapse in Sciatica: A Case Report

The cognitive-evaluative (C-E) dimension of pain is commonly observed in patients with a relatively long duration of pain. However, little is known about the effects of pain relapse on the C-E dimension of pain. Moreover, the improvement process of the C-E dimension of pain following treatment is unknown. The objective of this case report was to (a) demonstrate that the C-E dimension was affected in the acute phase of neuropathic pain in cases of pain relapse, and (b) demonstrate the improvement process of the C-E dimension of pain. A woman was diagnosed with low back pain (LBP) and sciatica. The patient had previously experienced symptoms of LBP and sciatica; thus, this episode was a case of pain relapse. At the beginning of rehabilitation, the C-E dimension of pain was present in addition to the sensory-discriminative (S-D) dimension of pain. It was observed that improvement of the C-E dimension of pain was delayed in comparison with that of the S-D dimension of pain. The C-E dimension of pain was observed with pain relapse even though it was in the acute phase of pain. This case provides a novel insight into the C-E dimension of pain. Moreover, the delay in improving the C-E dimension of pain indicates a difference in the improvement process for each pain dimension.

The amino-terminal heptapeptide of the algesic substance P provides analgesic effect in relieving chronic neuropathic pain

Of painful conditions, somatic pain of acute nociceptive origin can be effectively managed clinically, while neuropathic pain of chronic neuropathy origin is difficult to control. For molecules involved in pain sensation, substance P (SP) is algesic, exacerbating painful sensation, while its amino-terminal fragment, heptapeptide SP(1-7), confers biological activities different from its full-length parent neuropeptide precursor. We previously demonstrated SP(1-7) interaction with pain processing to alleviate chronic pain. Here we evaluated SP(1-7) and its C-terminal amidated analogue SP(1-7)amide, together with SP and opioid agonist DAMGO. We tested mouse behaviors of both acute somatic pain in tail-flick latency assay, and neuropathic pain in sciatic nerve injury model of chronic constriction injury (CCI). DAMGO produced dose-dependent analgesia for somatic pain as expected, so did both SP(1-7) and its analogue SP(1-7)amide, while SP yielded the opposite effect of algesia, in a phenomenon we termed 'contrintus', meaning 'opposite from within' to denote that two peptides of the same origin (SP and its metabolic fragment SP(1-7)) produced opposite effects. In CCI model, DAMGO showed a general reduction in allodynia sensitivity for both nerve-injured and normal paws, without selective effect for neuropathic pain, consistent with clinical observation that opioids are less effective for chronic neuropathic pain. On the other hand, both SP(1-7) and SP(1-7)amide displayed dose-dependent anti-allodynia effect that is selective for neuropathic pain. These findings suggest that SP(1-7) and its analogue may be useful for developing pharmaceuticals to treat neuropathic pain.

Cost effectiveness of immune checkpoint inhibitors for treatment of non-small cell lung cancer: A systematic review

Background

Immune checkpoint inhibitors (ICIs) for treatment of non-small cell lung cancer (NSCLC) have been rapidly evolving. ICIs are likely to be more effective but also lead to escalating healthcare costs.

Objectives

The aim of this study was to evaluate the cost effectiveness of immune checkpoint inhibitors (ICIs) for treatment of non-small cell lung cancer (NSCLC).

Methods

We searched the PubMed, Web of Science, and Cochrane Library for studies comparing the cost effectiveness of ICIs for NSCLC. Potential studies identified were independently checked for eligibility by two authors, with disagreement resolved by a third reviewer. Quality of the included studies was evaluated using Consolidated Health Economic Evaluation Reporting Standards checklists.

Results

A total of 22 economic studies were included. Overall reporting of the identified studies largely met CHEERS recommendations. In the first-line setting, for advanced or metastatic NSCLC patients with PD-L1 ≥ 50%, pembrolizumab appeared cost-effective compared with platinum-based chemotherapy in the US and Hong Kong (China), but not in the UK and China. The cost-effectiveness of pembrolizumab versus chemotherapy for first-line treatment of NSCLC in PD-L1 ≥ 1% patients remained obscure. Regardless of PD-L1 expression status, pembrolizumab in combination with chemotherapy could be a cost-effective first-line therapy in the US. On the contrary, addition of atezolizumab to the combination of bevacizumab and chemotherapy was not cost-effective for patients with metastatic non-squamous NSCLC from the US payer perspective. In the second-line setting compared with docetaxel, pembrolizumab was cost-effective; though nivolumab was not cost-effective in the base case, it could be by increased PD-L1 threshold. Results of the cost-effectiveness of atezolizumab second-line treatment remained inconsistent. In addition, the adoption of durvalumab consolidation therapy after chemoradiotherapy could be cost-effective versus no consolidation therapy for patients with stage III NSCLC.

Conclusions

Immunotherapy can be a cost-effective option for treatment of NSCLC in several scenarios. A discount of the agents or the use of PD-L1 expression as a biomarker improves the cost-effectiveness of immunotherapy.

Oral pharmacotherapeutics for the management of peripheral neuropathic pain conditions - a review of clinical trials

INTRODUCTION

Epidemiological studies have shown that 6.9-10% of people suffer from neuropathic pain, a complex painful condition which is often undertreated. Data regarding the effectiveness of treatment options for patients with neuropathic pain is inconsistent, and there is no single treatment option that shows cost-effectiveness across studies.

AREAS COVERED

In this narrative review, the authors present the results of different prospective, randomized controlled trials, systematic reviews and meta-analyses assessing the effects of different oral medications in the management of various peripheral neuropathic pain conditions. The authors discuss the effectiveness of commonly used oral medications such as voltage-gated calcium channels antagonists, voltage-gated sodium channel antagonists, serotonin-norepinephrine reuptake inhibitors, NMDA antagonists, and medications with other mechanisms of action.

EXPERT OPINION

Most of the presented medications were more effective than placebo; however, when compared to each other, none of them were significantly superior. The heterogeneity of the studies looking into different oral neuropathic conditions has been the major issue that prevents us from making stronger recommendations. There are multiple reasons including high placebo responsiveness, improperly treated underlying comorbidities (particularly anxiety and depression), and inter-patient variability. Different sensory phenotypes should also be taken into consideration when designing future clinical trials for neuropathic pain.

ALIAmides Update: Palmitoylethanolamide and Its Formulations on Management of Peripheral Neuropathic Pain

Neuropathic pain results from lesions or diseases of the somatosensory nervous system and it remains largely difficult to treat. Peripheral neuropathic pain originates from injury to the peripheral nervous system (PNS) and manifests as a series of symptoms and complications, including allodynia and hyperalgesia. The aim of this review is to discuss a novel approach on neuropathic pain management, which is based on the knowledge of processes that underlie the development of peripheral neuropathic pain; in particular highlights the role of glia and mast cells in pain and neuroinflammation. ALIAmides (autacoid local injury antagonist amides) represent a group of endogenous bioactive lipids, including palmitoylethanolamide (PEA), which play a central role in numerous biological processes, including pain, inflammation, and lipid metabolism. These compounds are emerging thanks to their anti-inflammatory and anti-hyperalgesic effects, due to the down-regulation of activation of mast cells. Collectively, preclinical and clinical studies support the idea that ALIAmides merit further consideration as therapeutic approach for controlling inflammatory responses, pain, and related peripheral neuropathic pain.