Efficacy and Safety of Add-on Mirogabalin to NSAIDs in Lumbar Spinal Stenosis with Peripheral Neuropathic Pain: A Randomized, Open-Label Study

Efficacy and Safety of Mirogabalin in Patients with Neuropathic Pain Due to Cervical Spondylotic Radiculopathy: Miro-Cens, A Randomized, Controlled, Interventional Study

INTRODUCTION

There are few studies of pharmacotherapy of neuropathic pain in cervical spondylotic radiculopathy (CSR). Miro-Cens aimed to examine the efficacy and safety of mirogabalin for treating pain in patients with CSR on non-steroidal anti-inflammatory drugs (NSAIDs), compared with NSAIDs alone.

METHODS

Miro-Cens was a 12-week, multicenter, randomized, controlled, open-label, interventional study in Japan. Eligible patients with CSR having upper limb pain (visual analog scale score ≥ 40 mm) were randomly assigned in a 1:1 ratio to the mirogabalin add-on to NSAIDs group and the NSAIDs alone group. The primary endpoint was the change in the weekly average numerical rating scale (NRS) score for upper limb pain from baseline at Week 12.

RESULTS

The mirogabalin add-on group and NSAIDs alone group included 72 and 70 patients, respectively. The mirogabalin add-on group had a significantly greater reduction in the NRS score for upper limb pain than the NSAIDs alone group: estimated changes from baseline at Week 12, - 2.63 [95% confidence interval (CI) - 3.14, - 2.11] in the mirogabalin add-on group; - 1.07 (- 1.62, - 0.53) in the NSAIDs alone group; intergroup difference, - 1.55 (- 2.31, - 0.80; p < 0.001). The responder rate on the NRS score at Week 12 was significantly higher in the mirogabalin add-on group than in the NSAIDs alone group: ≥ 30% improvement, 71.7% vs. 39.6%; ≥ 50% improvement, 58.3% vs. 22.6% (both p < 0.001). The frequent treatment-emergent adverse drug reactions in the mirogabalin add-on group were the known ones (somnolence and dizziness), with most being mild or moderate in severity.

CONCLUSION

In patients with CSR, combination therapy with mirogabalin and NSAIDs significantly improved neuropathic pain compared with NSAID monotherapy. No new safety concerns were identified, although caution should be exercised regarding somnolence and dizziness. These findings suggest that concomitant use of mirogabalin with NSAIDs could be tolerable and a novel treatment option for CSR patients with insufficient analgesic effects on NSAIDs.

TRIAL REGISTRATION NUMBER

jRCTs031210629.

Safety and Efficacy of Mirogabalin in Lumbar Spinal Stenosis Patients with Peripheral Neuropathic Pain on NSAIDs: Post Hoc Analysis of the MiroTAS Study

INTRODUCTION

The primary analysis of the MiroTAS study in patients with lumbar spinal stenosis (LSS) taking non-steroidal anti-inflammatory drugs showed that mirogabalin add-on therapy further improved pain and quality of life (QOL) without new safety concerns.

METHODS

This post hoc analysis of the MiroTAS study examined the timing of onset of mirogabalin-related adverse drug reactions (mrADRs) (composite of somnolence, dizziness, edema, and peripheral edema), factors affecting safety and efficacy, and the relationships between baseline numbness severity (by spine painDETECT questionnaire [SPDQ] score), EQ-5D-5L scores, leg pain improvement (by visual analogue scale [VAS]), and patient satisfaction (by Patient Global Impression of Change [PGIC] scores).

RESULTS

Among 110 patients, there were no significant differences in the incidence rates of mrADRs by patient characteristics. The mrADRs occurred mainly after the first administration and uptitration period of mirogabalin. EQ-5D-5L scores significantly improved from baseline to week 12 in patients with mrADRs vs those without (difference 0.0767; p = 0.0304 by t test). The proportion of patients with PGIC scores ≤ 3 at week 12 was numerically higher in patients with mrADRs vs those without. There were no differences in the percentage of patients with reduced leg pain by VAS score (improvement ≥ 20 mm) at week 12 by patient characteristics except for spondylolysis/spondylolisthesis as a complication. Baseline SPDQ numbness scores were positively correlated with improvement in EQ-5D-5L at week 12 (Spearman's rank correlation coefficient 0.2811, p = 0.0092).

CONCLUSIONS

Mirogabalin was not related to specific patient characteristics regarding the onset of mrADRs and was effective for LSS regardless of patient characteristics. Caution is needed regarding the onset of mrADRs after first administration and uptitration of mirogabalin, but these may not reduce QOL or patient satisfaction. Patients with high numbness scores may be more likely to benefit from treatment with mirogabalin in terms of QOL.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCTs021200007).

Impact of Intra-Articular Diclofenac Etalhyaluronate on Pain and Osteoarthritic Changes in Advanced and End-Stage Hip Osteoarthritis

Diclofenac etalhyaluronate combines the sustained-release properties of diclofenac with the therapeutic benefits of hyaluronic acid, providing extended analgesic effects for osteoarthritis management. This study investigated the effects of diclofenac etalhyaluronate and subsequent osteoarthritic changes in rat models of advanced and end-stage osteoarthritis. Monosodium iodoacetate (0.5 or 2.0 mg) was injected directly into the right hip joint of rats (n = 8 rats/group) using a posterior approach to induce osteoarthritis. Four weeks after monosodium iodoacetate administration, diclofenac etalhyaluronate (0.25 mg/25 µL) or 25 µL saline was administered in the same way. Pain behavior, number of microglia in the dorsal horn of the spinal cord, radiological features on microcomputed tomography, and histology of the hip joint were evaluated. Administration of diclofenac etalhyaluronate increased the pain threshold and reduced the number of microglia in the dorsal horn of the spinal cord in both models. However, radiological and histological examinations did not detect significant arthritic changes in either group that received diclofenac etalhyaluronate. Intra-articular administration, therefore, contributes to pain relief and improvement of central sensitization in advanced and end-stage osteoarthritis of the hip without subsequent progression of osteoarthritis. These findings highlight the potential of intra-articular administration of diclofenac etalhyaluronate as a conservative treatment option for advanced and end-stage hip osteoarthritis, particularly for patients who may be unsuitable for surgery or have limited response to oral nonsteroidal anti-inflammatory drugs.

Adverse events, including fractures, among older patients receiving mirogabalin versus pregabalin: A retrospective cohort study using a large claims database in Japan

BACKGROUND

Mirogabalin has a mechanism similar to that of pregabalin in the treatment of neuropathic pain. However, it remains unclear whether these drugs differ in terms of serious side effects, such as fall-related fractures, in older patients. This study aimed to investigate whether mirogabalin is associated with a decrease in adverse events, including fall-related fractures, compared with pregabalin.

METHODS

We performed a retrospective cohort study using the DeSC database, a large administrative claims database in Japan. This study included 130,244 patients ≥65 years taking mirogabalin or pregabalin between April 2019 and May 2021. The primary outcome was defined as the occurrence of fractures or switching to other medications and was compared between those receiving mirogabalin and pregabalin using Kaplan-Meier curves and multivariable Cox proportional hazards models. A sensitivity analysis was performed regarding patients who received mirogabalin or pregabalin without other analgesic medications at the initial dose.

RESULTS

During a median follow-up of 2.8 months, 29,686 (22.8%) and 100,558 (77.2%) received mirogabalin and pregabalin, respectively. The rates of the outcome in the mirogabalin and pregabalin groups were 50.1 and 42.8 per 100 person-years. Cox regression analysis showed that mirogabalin was associated with a lower risk of the outcome (hazard ratio, 0.93; 95% confidence interval, 0.87-1.00). However, sensitivity analysis did not demonstrate a difference in the outcome between the mirogabalin and pregabalin groups without other analgesic medications (hazard ratio, 0.93; 95% confidence interval, 0.86-1.01).

CONCLUSIONS

Our analyses suggest that the outcome may be less likely in the mirogabalin group; however, the difference appears to be clinically insignificant. Further studies are warranted to confirm these findings.

Mirogabalin as a novel calcium channel α2δ ligand for the treatment of neuropathic pain: a review of clinical update

Neuropathic pain (NP) is often caused by diabetic neuropathy, chemotherapy, or spinal cord lesions and is associated with significant economic burden and poor quality of life. Sophisticated etiology and pathology recognized different pharmacologic interventions, and hitherto, the reported analgesic efficacy and safety of guideline-recommended drugs are not satisfactory. Overall, this article reviews the mechanism of α2δ ligand, the clinical pharmacokinetics, efficacy, safety and cost-effectiveness of mirogabalin for the treatment of NP, offering clinical perspectives into potential benefits of NP-related syndrome or comorbidities. Mirogabalin, a novel voltage-gated Ca2+ channel (VGCC) α2δ ligand with selective binding affinities to α2δ-1 than α2δ-2 subunit, exhibited a wider safety margin and a relatively lower incidence of adverse events compared with other gabapentinoids. Randomized-controlled trials and open-label studies have demonstrated the efficacy and long-term safety of mirogabalin in Asian patients with diabetic peripheral neuropathic pain (DPNP), postherpetic neuralgia (PHN), and central NP. Analgesic effects of mirogabalin for the single or add-on treatment on chemotherapy-induced peripheral neuropathy and orthopedic disease/postoperation-related NP were also evidenced. To date, mirogabalin is approved for the general indication of NP in Japan, PNP in South Korea, and DPNP in the Chinese Mainland and DPNP, PHN in Taiwan (China). In summary, mirogabalin emerges as a promising option for NP; further research is warranted to refine wider treatment strategies, flexible dosing in real-world setting.

Mirogabalin: a novel gabapentinoid or another false dawn?

PURPOSE OF REVIEW

Mirogabalin is a novel gabapentinoid medication for the treatment of neuropathic pain. The purpose of this review is to discuss current evidence for its use. Gabapentinoids are widely prescribed for neuropathic pain. Mirogabalin offers theoretical advantages over traditional gabapentinoids due to its specificity for the α2δ-1 subunit of voltage-gated calcium channels. It is theorised that this specificity may reduce adverse drug reactions by minimising binding to the α2δ-2 subunit which is responsible for many of the gabapentinoid side effects.

RECENT FINDINGS

Mirogabalin's slower dissociation from the α2δ-1 compared with α2δ-2, and its higher potency may also impart an efficacy benefit over traditional gabapentinoids. These theoretical advantages of mirogabalin remain inconclusive in clinical practice, with mixed evidence regarding mirogabalin versus traditional gabapentinoids. Some studies suggest a reduced side effect profile yet, others fail to demonstrate significant differences. Regarding efficacy, mirogabalin may be superior to placebo for several neuropathic pain syndromes, but evidence of widespread benefit over traditional gabapentinoids is currently lacking.

SUMMARY

Mirogabalin offers theoretical promise, but large, independent studies are required to further assess its performance versus traditional gabapentinoids.

A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled 14-Week Study of Mirogabalin in Chinese Patients with Diabetic Peripheral Neuropathic Pain

INTRODUCTION

There is no approved effective drug for diabetic peripheral neuropathic pain (DPNP) in China. Gabapentinoids including mirogabalin have shown promise, although data in Chinese patients are scarce.

METHODS

This phase 3, multicenter, randomized, double-blind, placebo-controlled trial investigated the efficacy and safety of mirogabalin for treating DPNP in China. Mirogabalin was administered at 5 mg twice daily for the first week and uptitrated to 15 mg twice daily for a total duration of 14 weeks. The primary efficacy endpoint was the change from baseline in weekly average daily pain score (ADPS) at week 14; secondary endpoints included the ADPS responder rate, Short-Form McGill Pain Questionnaire visual analogue scale score, patient global impression of change (PGIC), average daily sleep interference score (ADSIS), EuroQol 5-dimensions 5-levels (EQ-5D-5L), and incidence of treatment-emergent adverse events (TEAEs).

RESULTS

Of 393 patients (mirogabalin, n = 196; placebo n = 197), the mean age was 58.2 years (mirogabalin, 58.7 years; placebo, 57.7 years) and 54.2% were male (mirogabalin, 56.1%; placebo, 52.3%). Mirogabalin elicited a greater change from baseline in the weekly ADPS vs. placebo at week 14: least-squares mean difference (95% confidence interval) vs. placebo - 0.39 (- 0.74, - 0.04), p = 0.0301. PGIC, ADSIS, and EQ-5D-5L data reflected significantly better improvements for patients receiving mirogabalin vs. placebo. The incidence of TEAEs was 75.0% and 75.1% in the mirogabalin and placebo groups, respectively. Most TEAEs were mild or moderate, and the incidence of TEAEs leading to treatment discontinuation was 2.6% in the mirogabalin group and 1.5% in the placebo group.

CONCLUSIONS

Although the effect size of mirogabalin was reduced due to the placebo effect, mirogabalin is a safe and effective treatment option for Chinese patients with DPNP.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04094662.

Nonsurgical therapy for lumbar spinal stenosis caused by ligamentum flavum hypertrophy: A review

Lumbar spinal stenosis (LSS) can cause a range of cauda equina symptoms, including lower back and leg pain, numbness, and intermittent claudication. This disease affects approximately 103 million people worldwide, particularly the elderly, and can seriously compromise their health and well-being. Ligamentum flavum hypertrophy (LFH) is one of the main contributing factors to this disease. Surgical treatment is currently recommended for LSS caused by LFH. For patients who do not meet the criteria for surgery, symptom relief can be achieved by using oral nonsteroidal anti-inflammatory drugs (NSAIDs) and epidural steroid injections. Exercise therapy and needle knife can also help to reduce the effects of mechanical stress. However, the effectiveness of these methods varies, and targeting the delay in LF hypertrophy is challenging. Therefore, further research and development of new drugs is necessary to address this issue. Several new drugs, including cyclopamine and N-acetyl-l-cysteine, are currently undergoing testing and may serve as new treatments for LSS caused by LFH.

Post-thoracotomy pain syndrome in the era of minimally invasive thoracic surgery

Post-thoracotomy pain syndrome (PTPS) is defined as pain around the wound that persists for more than 2 months after surgery. Persistent pain not only increases the use of analgesics and their side effects but also causes many social problems, such as decreased activities of daily living, decreased quality of life, and increased medical costs. In particular, thoracic surgery is associated with a higher frequency and severity of chronic pain than is surgery for other diseases. The basic principles of postoperative pain treatment, not limited to thoracic surgery, are multimodal analgesic methods (using combinations of several drugs to minimize opioid use) and around-the-clock treatment (administering analgesics at a fixed time and in sufficient doses). Thoracic surgeons must always be aware of the following three points: acute severe postoperative pain is a major risk factor for chronic pain; neuropathic pain due to intercostal nerve injury is a major cause of postoperative pain after thoracic surgery, and its presence must not be overlooked from the acute stage; and analgesics must be administered in sufficient quantities according to dosage and volume. The frequency of PTPS has decreased compared with that in the standard thoracotomy era because of the development of analgesia and the widespread use of minimally invasive procedures such as thoracoscopic surgery and robot-assisted surgery. However, no consistently effective prevention or treatment strategies for PTPS have yet been established. In this review, we focus on PTPS in the era of minimally invasive surgery and discuss the role of thoracic surgeons in its management.

Efficacy and safety of add-on mirogabalin to conventional therapy for the treatment of peripheral neuropathic pain after thoracic surgery: the multicenter, randomized, open-label ADMIT-NeP study

BACKGROUND

For chronic pain after thoracic surgery, optimal timing of its diagnosis and effective treatment remains unresolved, although several treatment options are currently available. We examined the efficacy and safety of mirogabalin, in combination with conventional pain therapy (nonsteroidal anti-inflammatory drugs and/or acetaminophen), for treating peripheral neuropathic pain (NeP) after thoracic surgery.

METHODS

In this multicenter, randomized, open-label, parallel-group study, patients with peripheral NeP were randomly assigned 1:1 to mirogabalin as add-on to conventional therapy or conventional treatment alone.

RESULTS

Of 131 patients of consent obtained, 128 were randomized (mirogabalin add-on group, 63 patients; conventional treatment group, 65 patients). The least squares mean changes (95% confidence interval [CI]) in Visual Analogue Scale (VAS) score for pain intensity at rest from baseline to Week 8 (primary endpoint) were - 51.3 (- 54.9, - 47.7) mm in the mirogabalin add-on group and - 47.7 (- 51.2, - 44.2) mm in the conventional group (between-group difference: - 3.6 [95% CI: - 8.7, 1.5], P = 0.161). However, in patients with Self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) score (used for the screening of NeP) ≥ 12 at baseline, the greater the S-LANSS score at baseline, the greater the decrease in VAS score in the mirogabalin add-on group, while no such trend was observed in the conventional treatment group (post hoc analysis). This between-group difference in trends was statistically significant (interaction P value = 0.014). Chronic pain was recorded in 7.9% vs. 16.9% of patients (P = 0.171) at Week 12 in the mirogabalin add-on vs. conventional treatment groups, respectively. Regarding activities of daily living (ADL) and quality of life (QOL), changes in Pain Disability Assessment Scale score and the EQ-5D-5L index value from baseline to Week 8 showed significant improvement in the mirogabalin add-on group vs. conventional treatment group (P < 0.001). The most common adverse events (AEs) in the mirogabalin add-on group were dizziness (12.7%), somnolence (7.9%), and urticaria (3.2%). Most AEs were mild or moderate in severity.

CONCLUSIONS

Addition of mirogabalin to conventional therapy did not result in significant improvement in pain intensity based on VAS scores, but did result in significant improvement in ADL and QOL in patients with peripheral NeP after thoracic surgery.

TRIAL REGISTRATION

Japan Registry of Clinical Trials jRCTs071200053 (registered 17/11/2020).

Inhalation of Pelargonium graveolens Essential Oil Alleviates Pain and Related Anxiety and Stress in Patients with Lumbar Spinal Stenosis and Moderate to Severe Pain

Pain in lumbar spinal stenosis (LSS) patients is closely associated with psychological factors, including anxiety, stress, and depression, and is a critical determinant of patient daily functionality and overall quality of life. The present study evaluated the effects of inhalation of Pelargonium graveolens (geranium) essential oil (GEO) on pain and related psychological factors in LSS patients. Fifty-nine patients, categorized as having mild or moderate to severe pain based on pain visual analog scale (VAS) scores, were randomly assigned to inhalation of 1% GEO or placebo control (PC). No significant differences between GEO and PC were observed in patients with mild pain, whereas differences in anxiety-VAS and stress-VAS scores were observed in patients with moderate to severe pain. Anxiety-VAS and stress-VAS scores decreased significantly after GEO but not after PC inhalation. Regardless of the severity of pain, post-intervention pain-VAS scores were significantly lower in the GEO group than in the PC group. In summary, GEO reduced pain and improved anxiety and stress, particularly among patients with moderate to severe pain. These findings suggest that GEO inhalation may have potential as an adjunct therapy for improving pain management and alleviating anxiety and stress in LSS patients with insufficient responses to pharmacological pain control.

Combined Efficacy of Systemically Acting Diclofenac Sodium Patch and Alpha-2-Delta Calcium Channel Ligand in Chronic Low Back Pain: Subanalysis of a Phase III Study

INTRODUCTION

Chronic low back pain often comprises mixed pain types and involves multiple factors. Therefore, we hypothesized that the systemic transdermal formulation of diclofenac sodium (DF systemic patch), which is effective for nociceptive pain, and an α2δ Ca2+ channel ligand, which is effective for neuropathic pain, would have additive effects in the treatment of chronic low back pain.

METHODS

From among participants in a randomized, double-blind, placebo-controlled study of DF systemic patch (75 or 150 mg) applied once daily for 2 weeks in patients with chronic low back pain, we performed a subpopulation analysis of those who were concomitantly treated with an α2δ Ca2+ channel ligand during the study period. The efficacy endpoint was pain intensity score on a visual analog scale (VAS).

RESULTS

The difference (95% confidence interval) in the least square mean pain VAS score between patients in the 150-mg combination group, who were treated with 150-mg DF systemic patch and an α2δ Ca2+ channel ligand (n = 11), and those in the non-combination group, who were treated with placebo patch and α2δ Ca2+ channel ligand (n = 22), was - 15.09 mm (- 26.45, - 3.73). Because the upper limit of the 95% confidence interval was less than zero, this result indicates that the pain VAS score improved more in the 150-mg combination group than in the non-combination group (placebo group).

CONCLUSIONS

The combination of the DF systemic patch and an α2δ Ca2+ channel ligand may be more effective than α2δ Ca2+ channel ligand monotherapy for controlling chronic low back pain.

TRIAL REGISTRATION NUMBERS

JPRN-JapicCTI-205134 and jRCT2080225040.

Naturally Inspired Molecules for Neuropathic Pain Inhibition-Effect of Mirogabalin and Cebranopadol on Mechanical and Thermal Nociceptive Threshold in Mice

BACKGROUND

Neuropathic pain is drug-resistant to available analgesics and therefore novel treatment options for this debilitating clinical condition are urgently needed. Recently, two drug candidates, namely mirogabalin and cebranopadol have become a subject of interest because of their potential utility as analgesics for chronic pain treatment. However, they have not been investigated thoroughly in some types of neuropathic pain, both in humans and experimental animals.

METHODS

This study used the von Frey test, the hot plate test and the two-plate thermal place preference test supported by image analysis and machine learning to assess the effect of intraperitoneal mirogabalin and subcutaneous cebranopadol on mechanical and thermal nociceptive threshold in mouse models of neuropathic pain induced by streptozotocin, paclitaxel and oxaliplatin.

RESULTS

Mirogabalin and cebranopadol effectively attenuated tactile allodynia in models of neuropathic pain induced by streptozotocin and paclitaxel. Cebranopadol was more effective than mirogabalin in this respect. Both drugs also elevated the heat nociceptive threshold in mice. In the oxaliplatin model, cebranopadol and mirogabalin reduced cold-exacerbated pain.

CONCLUSIONS

Since mirogabalin and cebranopadol are effective in animal models of neuropathic pain, they seem to be promising novel therapies for various types of neuropathic pain in patients, in particular those who are resistant to available analgesics.

Efficacy and safety of mirogabalin for chemotherapy-induced peripheral neuropathy: a prospective single-arm trial (MiroCIP study)

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a painful, dose-limiting adverse effect of commonly used chemotherapeutic agents. The purpose of this exploratory study was to evaluate the efficacy and safety of mirogabalin in patients with moderate to severe CIPN during chemotherapy and the effects of 12 weeks' intervention on chemotherapy completion and CIPN severity.

METHODS

Patients experiencing moderate to severe CIPN while undergoing oxaliplatin- or taxane-containing chemotherapy for colorectal, gastric, non-small-cell lung, or breast cancer received mirogabalin at between 5 and 15 mg twice daily. The primary endpoint was change in numeric rating scale (NRS) score for pain from baseline to week 12. Secondary endpoints included NRS scores for tingling and sleep, completion of chemotherapy, severity of CIPN, and quality of life (QOL) scores. The safety endpoint was incidence of adverse events.

RESULTS

Of 58 patients who consented to participation, 52 were eligible and constituted the full analysis set and safety analysis set. From baseline to week 12 (last observation carried forward [LOCF]), NRS score decreased by 30.9%: mean change (95% confidence interval [CI]), - 1.7 (- 2.4 to - 1.0) (p < 0.001). Patients with baseline NRS of ≥ 6 experienced a 44.0% reduction in score from baseline to week 12 (LOCF): mean change (95% CI), - 3.3 (- 5.0 to - 1.5) (p = 0.002). Chemotherapy was discontinued in 18 (34.6%) patients; CIPN led to discontinuation in only 2 (3.8%). There was no notable worsening of CIPN severity in terms of Common Terminology Criteria for Adverse Events grade or Modified Total Neuropathy Score-reduced, although use of pain medications during chemotherapy might cause worsening of CIPN due to underestimation of subjective symptoms. QOL score based on the EuroQol five-dimensional descriptive system did not worsen during the 12 weeks. Thirty-one percent of patients experienced adverse drug reactions, and the most common event was somnolence (13.5%). Serious adverse events and death occurred in 3 patients and 1 patient, respectively; however, they were unrelated to mirogabalin treatment.

CONCLUSIONS

Intervention with mirogabalin during chemotherapy may be effective and safe for cancer patients with moderate to severe CIPN. It can contribute to completion of chemotherapy without worsening of CIPN.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCTs031210101, registered 20/5/2021).

Impact of Lumbar Surgery on Pharmacological Treatment for Patients with Lumbar Spinal Canal Stenosis: A Single-Center Retrospective Study

Treatment for lumbar spinal canal stenosis (LSCS) is mainly classified into conservative and surgical therapies. Among conservative therapies, pharmacological treatment is commonly prescribed for LSCS. Meanwhile, surgical treatment is the last option for LSCS. This study aimed to examine the impact of lumbar surgery on pharmacological treatment for patients with LSCS. Consecutive patients aged ≥ 40 years who underwent lumbar surgery for LSCS were identified. A total of 142 patients were retrospectively reviewed for preoperative and 6-month and 1-year postoperative LSCS medications. The results showed that the number of LSCS medications significantly decreased after lumbar surgery. The proportion of the patients taking non-steroidal anti-inflammatory drugs, pregabalin/mirogabalin, opioids, prostaglandin E1 analogs, and neurotropin was significantly decreased after lumbar surgery, but that of the patients taking mecobalamin, acetaminophen, and serotonin-noradrenalin reuptake inhibitors was not significantly changed. Additionally, around 15% of the participants showed an increase in LSCS medications even after lumbar surgery. Multivariable analysis revealed that individuals without improvements in walking ability (RR: 2.7, 95% CI: 1.3-5.9) or social life (RR: 2.3, 95% CI: 1.1-5.0) had a greater risk of a postoperative increase in LSCS medications. The study results may provide physicians with beneficial information on treatment for LSCS.

Diagnosis and Management of Neuropathic Pain in Spine Diseases

Neuropathic pain is generally defined as a non-physiological pain experience caused by damage to the nervous system. It can occur spontaneously, as a reaction to a given stimulus, or independently of its action, leading to unusual pain sensations usually referred to as firing, burning or throbbing. In the course of spine disorders, pain symptoms commonly occur. According to available epidemiological studies, a neuropathic component of pain is often present in patients with spinal diseases, with a frequency ranging from 36% to 55% of patients. Distinguishing between chronic nociceptive pain and neuropathic pain very often remains a challenge. Consequently, neuropathic pain is often underdiagnosed in patients with spinal diseases. In reference to current guidelines for the treatment of neuropathic pain, gabapentin, serotonin and norepinephrine reuptake inhibitors and tricyclic antidepressants constitute first-line therapeutic agents. However, long-term pharmacologic treatment often leads to developing tolerance and resistance to used medications. Therefore, in recent years, a plethora of therapeutic methods for neuropathic pain have been developed and investigated to improve clinical outcomes. In this review, we briefly summarized current knowledge about the pathophysiology and diagnosis of neuropathic pain. Moreover, we described the most effective treatment approaches for neuropathic pain and discussed their relevance in the treatment of spinal pain.