Postherpetic neuralgia: epidemiology, pathophysiology, and pain management pharmacology

The effect of subcutaneous injection of methylprednisolone acetate and lidocaine for refractory postherpetic neuralgia: a prospective, observational study

BACKGROUND

Postherpetic neuralgia (PHN) is the most common and bearable complication of herpes zoster (HZ). This pain may have negative impact on the patient's all aspects of daily life and health-related quality of life (HRQOL). Despite numerous advances in treatment, many patients remain resistant to the current therapy options. It is the first time subcutaneous injection of methylprednisolone acetate and lidocaine has been used to treat refractory PHN. We report the results of this treatment evaluating pain relief and HRQOL improvement in this disorder.

METHODS

A total of 43 patients with refractory PHN was enrolled in the observational study. All patients received daily subcutaneous injection of methylprednisolone acetate and lidocaine for 10 consecutive days. The severity of pain was assessed by using Visual Analog Scale (VAS), and 36-Item Short Form Survey (SF-36) was applied to evaluate HRQOL. Assessment of the pain and HRQOL was carried out at baseline and posttreatment at 4 weeks as well as 6 and 12 months.

RESULTS

At baseline, all patients experienced severe PHN with average VAS scores of 8.44 ± 0.85 (minimum 7; maximum 10). At 4 weeks, 6 months, and 12 months after treatment, the pain had significantly decreased (P < .001), and all subjects showed significant improvement in all eight domains of HRQOL. No major adverse events associated with the subcutaneous injection were observed.

CONCLUSIONS

Our results indicate that subcutaneous injection of methylprednisolone acetate and lidocaine can be an effective and safe treatment for PHN.

Implantable Peripheral Nerve Stimulation for Trigeminal Neuropathic Pain: A Systematic Review and Meta-Analysis

OBJECTIVES

Implantable peripheral nerve stimulation has been increasingly used to treat neuropathic pain. This neuromodulation strategy may be an alternative option for intractable trigeminal neuropathic pain; however, evidence for this treatment approach remains limited. A systematic review was conducted to identify studies of patients that underwent peripheral nerve stimulation implantation for trigeminal neuropathic pain.

MATERIALS AND METHODS

Databases including, PubMed, EMBASE, and Cochrane Library were searched up to October 5, 2020. The primary outcomes were changes in pain scores and response rates of neuromodulation therapy. A random effects model was used for meta-analysis. Subgroup analysis was performed to examine the source of heterogeneity.

RESULTS

Thirteen studies including 221 participants were evaluated. The estimated response rate of neuromodulation treatment was 61.3% (95% CI: 44.4-75.9%, I²  = 70.733%, p < 0.0001) at the last follow-up. The overall reduction in pain scores was 2.363 (95% CI: 1.408-3.319, I²  = 85.723%, p < 0.0001). Subgroup analysis further confirmed that stimulation target (peripheral branch vs. trigeminal ganglion vs. trigeminal nerve root) contributed the heterogeneity across enrolled studies. Better clinical outcome was associated with stimulation of the trigeminal peripheral branch (p < 0.0001).

CONCLUSION

Peripheral nerve stimulation may be a promising approach in the management of trigeminal neuropathic pain, especially for patients intractable to conventional therapy.

Efficacy of repetitive paravertebral block combined with medication in the treatment of zoster-related pain with different courses

Objectives:

To compare the clinical outcomes of repetitive paravertebral block (PVB) combining oral medication in the treatment of zoster-related pain (ZP) with different courses.

Methods:

Sixty-seven patients with ZP were divided into 3 groups based on their course of herpes zoster (HZ). Group I: 24 patients with acute herpetic neuralgia (within one month of disease onset); group II: 22 patients with subacute herpetic neuralgia (disease onset from 1 to 3 months); group III: 21 patients with postherpetic neuralgia (more than 3 months since disease onset). All patients received ultrasound-guided repetitive PVB with oral gabapentin and tramadol sustained-release tablets. The VAS and QS scores and the incidences of hematoma, dizziness, nausea, and drowsiness were compared at 1 day, 3 months, and 6 months after treatment.

Results:

Pain intensity and sleep quality of the 3 groups improved to varying degrees after treatment. The best efficacy was achieved in the acute group, followed by the subacute group, and the poorest efficacy was observed in the chronic group.

Conclusion:

The efficacy of ultrasound-guided repetitive PVB with oral medication varied with the courses of HZ. The shorter the time since onset, the better the efficacy. This combined treatment showed better efficacy in patients at the acute and subacute stages and significantly improved their pain and sleep quality, while demonstrating limited pain relief in chronic patients.

Pilot Analyses of Interferon Subtype Expression Profiles in Patients with Herpes Zoster or Postherpetic Neuralgia

Postherpetic neuralgia (PHN) is a painful neuropathic complication resulting from herpes zoster (HZ). The pain manifests in peripheral nerves infected by herpesviruses, mostly from reactivation of latent varicella zoster virus. Mechanistic descriptions suggest that PHN develops because of disrupted immune system signaling and inflammation or peripheral nerve damage; however, the pathophysiology is not clear. It is difficult to predict/prevent PHN manifestations of HZ patients due to the lack of accurate diagnostics. In this study, sera from healthy controls, HZ patients, and PHN patients were subjected to an interferon (IFN) expression profile (IEP) study. The corresponding cDNAs were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using primer pairs against a panel of 21 different IFN subtypes. The results showed that distinct IEPs were observed among HZ and PHN cohorts in comparison to the healthy controls. Together, this pilot study suggested that the IEP study may be used as a molecular tool for diagnosis of PHN and assist in designing new PHN therapeutic protocols.

Ultrasound-Guided Continuous Thoracic Paravertebral Infusion of Methylene Blue in the Treatment of Postherpetic Neuralgia: A Prospective, Randomized, Controlled Study

Introduction

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster. Methylene blue (MB) is an inhibitor of nitric oxide synthesis with potentially analgesic and anti-inflammatory properties. Studies have demonstrated that thoracic paravertebral single MB injection is effective in treating chronic pain. However, there are rare reports of the efficacy of continuous thoracic paravertebral infusion of MB for pain management in PHN patients. The purpose of this study was to evaluate the therapeutic effects of continuous thoracic paravertebral infusion of MB on PHN.

Methods

A total of 104 PHN patients were randomly divided into two groups: the control group (continuous thoracic paravertebral infusion of 5% lidocaine in a total volume of 300 ml) and the MB group (continuous thoracic paravertebral infusion of 5% lidocaine plus 0.2% MB in a total volume of 300 ml). All patients were evaluated using the Numerical Rating Scale (NRS), Insomnia Severity Index (ISI), Patient Health Questionnaire-9 (PHQ-9), 36-Item Short-Form Health Survey (SF-36), and medication doses before and after the procedure. The effective treatment rate and adverse complications were recorded 6 months after the procedure.

Results

In both groups, the NRS scores, ISI scores, PHQ-9 scores, and rescue medication dosages were significantly decreased at different time points after treatment compared to baseline, while the SF-36 scores were evidently improved at different time points after treatment compared to baseline. Compared with the control group, the MB group had significantly reduced NRS scores, ISI scores, PHQ-9 scores, and rescue medication dosages at each observation time point. Furthermore, the SF-36 scores in the MB group were significantly higher than those in the control group at each observation time point. The total effective treatment rate of the MB group was higher than that of the control group 6 months after the procedure. No severe adverse complications were observed in either group.

Conclusions

Ultrasound-guided continuous thoracic paravertebral infusion with MB is a safe and effective therapy for PHN. Continuous infusion with MB can significantly reduce pain intensity, improve pain-related depression, increase quality of life, and decrease the amount of rescue medicine with no serious adverse complications.

Effectiveness of CT-guided epidural infiltration of steroids and local anesthetics for acute and chronic herpes zoster neuralgia

PURPOSE

The purpose of this study was to evaluate the effectiveness and complication rate of computed tomography (CT)-guided epidural injection of steroids and local anesthetics for pain relief in patients with neuralgia due to acute or chronic herpes zoster (HZ).

MATERIALS AND METHODS

A prospective study was conducted from April 2017 to February 2019 including patients with HZ neuralgia (HZN) at any stage (acute or chronic, the latter being defined as pain lasting more than 3 months and also called post herpetic neuralgia [PHN]). The sensory ganglion of the affected dermatome and/or the affected sensory nerve was targeted under CT-guidance and local injection of a mixture of two vials of methylprednisolone 40mg/mL and 2mL of Lidocaine 1% was performed. Using a visual analogue scale (VAS, 0 to 10), pain was assessed prior to the procedure, and at day 7, 1 month, 3 months and 6 months. Adverse effects were graded according to the Society of Interventional Radiology classification.

RESULTS

Twenty patients were included. There were 9 men and 11 women with a mean age of 67±13.9 (SD) years (range: 27-83 years). Of these, 14 patients had acute HZN and 6 had PHN. Mean VAS at baseline was 8.1±1.2 (SD) (range: 6-10) with significant decrease (P<0.0001) at day 7 (3.4±3.2 [SD]; range: 0-10), day 30 (3.4±3.2 [SD]; range: 0-9), day 90 (2.9±3.2 [SD]; range: 0-9), and day 180 (2.5±3.1 [SD]; range: 0-9). Infiltrations were significantly more effective on acute HZN than on PHN (P<0.001) and required significantly fewer infiltrations for pain relef (P=0.002). Only one grade A adverse event was reported.

CONCLUSION

Epidural injection of a mixture of steroids and local anesthetics under CT-guidance is effective on HZN with a persisting effect over 6 months.

Open-Label Adhesion Performance Studies of a New Lidocaine Topical System 1.8% versus Lidocaine Patches 5% and Lidocaine Medicated Plaster 5% in Healthy Subjects

Purpose

The primary objective was to evaluate adhesion performance of the lidocaine topical system 1.8% for 12 hours in healthy human subjects in three studies: as a single product (Study 1) and versus other lidocaine topical products (lidocaine patch 5% and lidocaine medicated plaster 5% [Study 2] and generic lidocaine patch 5% [Study 3]). Safety of the lidocaine topical system 1.8%, with a skin irritation focus, was a secondary objective.

Patients and Methods

All three studies were open-label, randomized, Phase 1 adhesion performance studies in healthy adult volunteers (N=125). Lidocaine topical products were applied for 12 hours per test, per study arm. Adhesion of all test products was scored at 0, 3, 6, 9, and 12 hours post-application. Skin irritation was scored after product removal or when a product detached.

Results

Overall, the majority (≥75%) of subjects treated with the lidocaine topical system 1.8% demonstrated ≥90% adhesion (FDA adhesion score 0) throughout the 12-hour administration period versus 13.6% of subjects treated with lidocaine patch 5%, 15.9% of subjects treated with lidocaine medicated plaster 5%, and 0% of subjects treated with the generic lidocaine patch 5%. There were no complete detachments with the lidocaine topical system 1.8%, whereas 4.5% of lidocaine patch 5% and lidocaine medicated plaster 5% detached, and 29% of generic lidocaine patch 5% detached. Minimal skin irritation was observed with each lidocaine topical product.

Conclusion

Across three studies, lidocaine topical system 1.8% demonstrated superior adhesion performance versus the three other products tested. Skin irritation was minimal across products and studies.

Clinicaltrials.gov

NCT04312750, NCT04320173, NCT04319926.

The adjuvanted recombinant zoster vaccine is efficacious and safe in Asian adults ≥ 50 years of age: a sub-cohort analysis of the ZOE-50 and ZOE-70 randomized trials

In two large clinical trials (ZOE-50 [NCT01165177] and ZOE-70 [NCT01165229]), two doses of the adjuvanted recombinant zoster vaccine (RZV) demonstrated >90% efficacy (VE) against herpes zoster (HZ) in adults ≥50 years of age (YOA). This post-hoc analysis assessed the VE against HZ and postherpetic neuralgia (PHN), in participants from Asian study sites enrolled in ZOE-50/70. Reactogenicity and safety were also assessed. Participants ≥50 YOA were randomized 1:1 to receive 2 doses of either RZV or placebo, 2 months apart. VE was evaluated for a median follow-up of 4 years post-vaccination overall and by age in the ZOE-50 Asian population ≥50 YOA and in the pooled ZOE-50/70 Asian population ≥70 YOA. Of the 2,729 participants included in the ZOE-50 Asian population ≥50 YOA, 3 RZV and 66 placebo recipients reported a confirmed HZ episode. Overall VE was 95.6% (95% confidence interval [CI]: 86.4–99.1) against HZ and 100% (95% CI: 35.44–100) against PHN. In the pooled ZOE-50/70 Asian population ≥70 YOA, 4 RZV and 75 placebo recipients out of the 2,723 participants reported a confirmed HZ episode. Overall VE was 94.7% (95% CI: 85.9–98.6) against HZ and 89.8% (95% CI: 28.39–99.77) against PHN. Pain and myalgia were the most frequent solicited local and general adverse events, respectively, in both populations. No safety concern was identified during the study periods. RZV is highly efficacious against HZ and PHN and has an acceptable safety profile in Asian populations ≥50 YOA, similar to what was observed in the general ZOE-50/70 populations.

Trademark statement: Shingrix is a trademark owned by or licensed to the GSK group of companies.

Nonprescription Products of Internet Retailers for the Prevention and Management of Herpes Zoster and Postherpetic Neuralgia: Analysis of Consumer Reviews on Amazon

BACKGROUND

Herpes zoster affects approximately 1 million people annually in the United States, with postherpetic neuralgia as the most common complication. The frequent prescription of opioids as the first-line medication for herpes zoster or postherpetic neuralgia contributes to the increasing health care costs of their treatment. Despite the advent of internet retailers providing alternative products for the prevention and management these conditions, there are limited studies on the availability, ingredients, and consumer preference for the products.

OBJECTIVE

This study used the internet retailer Amazon to determine the availability of products for the management of herpes zoster and postherpetic neuralgia, and assessed consumer preference based on listed ingredients.

METHODS

The internet retailer Amazon was used to perform a search for products related to "shingles" in September 2020. Top products sorted by reviews and ratings were determined to be either shingles-specific (including "shingles" in either the product title or description) or shingles-nonspecific. Analysis of price, rating, type of vehicle, and ingredients was performed. The types of vehicles, ingredients, and percentages of positive and negative reviews related to "shingles" of the product groups were analyzed with a two-tailed two-sample proportions Z-test to assess the difference between shingles-specific and shingles-nonspecific products. Statistical significance was judged at P<.05.

RESULTS

The top 131 products among over 3000 products retrieved were determined based on a rating of 4 or more stars after searching for the term "shingles" on Amazon. Forty-six of the 131 products (35.1%) were shingles-specific. Shingles-nonspecific products were more likely to have positive reviews mentioning "shingles" (P=.005). Vehicles, balms (P=.02), and salves (P=.04) were more likely to be shingles-specific, whereas tablets or capsules (P=.002) were more likely to be shingles-nonspecific. Among the ingredients analyzed, aloe vera was the top-ranked ingredient, included in 29 of the 131 total products (22.1%). Aloe vera (P=.01), lemon balm (P<.001), vitamin E (P=.03), and peppermint oil (P=.008) were more likely to be included in the shingles-specific products, whereas magnesium (P=.01) was more likely to be included in shingles-nonspecific products.

CONCLUSIONS

There is an abundance of products and ingredients being used for the management and treatment of shingles with certain ingredients preferred by consumers. There is a discrepancy between approved ingredients and the ingredients preferred by consumers. Furthermore, there are insufficient studies on ingredients used by consumers on internet retailers such as Amazon, and future studies can focus on the effectiveness of popular ingredients to decrease misinformation on the internet.

Intravenous Administration of Vitamin C in the Treatment of Herpes Zoster-Associated Pain: Two Case Reports and Literature Review

Background

Herpes zoster (HZ) is an acute inflammatory neurocutaneous disease caused by the reactivation of varicella-zoster virus. It is estimated that the incidence of postherpetic neuralgia following HZ is 10–20%. The leading risk factors of the prognosis are aging and immunity dysfunction. Vitamin C plays a pivoted role in enhancing white blood cell function. Epidemiological evidence and clinical studies have indicated an association between pain and suboptimal vitamin C status. At present, vitamin C has been used as an additional option in the treatment of HZ-associated pain. Despite the current controversy, case reports and randomized controlled studies have indicated that both acute- and postherpetic neuralgia can be dramatically alleviated following intravenous vitamin C infusions. Case Presentation. Two patients (male aged 72 and female 78 years) with HZ did not respond well to antiviral therapy and analgesics. Skin lesions in the right groin and front thigh healed after early antiviral therapy, but the outbreak of pain persisted in the male patient. The female patient presented to our clinic with clusters of rashes in the right forehead with severe edema of her right upper eyelid. Because nerve blockade could not be conducted for both patients, intravenous infusion of vitamin C was applied and resulted in an immediate remission of the breakthrough pain in the male patient and cutaneous lesions in the female patient.

Conclusions

The use of vitamin C appears to be an emerging treatment alternative for attenuating HZ and PHN pain. Hence, we recommend the addition of concomitant use of intravenously administered vitamin C into therapeutic strategies in the treatment of HZ-associated pain, especially for therapy-resistant cases. Furthermore, animal studies are required to determine analgesic mechanisms of vitamin C, and more randomized clinical trials are essential to further determine the optimal dose and timing of administration of vitamin C.

Acupuncture therapy for treating postherpetic neuralgia: A protocol for an overview of systematic reviews and meta-analysis

BACKGROUND

Postherpetic neuralgia (PHN) is the most common complication and sequela of herpes zoster (HZ) that greatly affects the life and emotional experience of patients. Acupuncture therapy has been confirmed as an effective and safe treatment for PHN. Several systematic reviews (SRs) and meta-analysis (MAs) have reported the evidence of acupuncture therapy for treating PHN. However, the evidence has not been systematically synthesized. This overview aims to synthesize and assess the reliability of evidence generated from these SRs and MAs of acupuncture therapy for PHN.

METHODS

We will conduct a systematic search of the China Biology Medicine (CBM), VIP database, Wangfang database, China National Knowledge Infrastructure (CNKI), Pubmed, Cochrane Library, Excerpt Medical Database (Embase), and Web of Science to identify eligible SRs and MAs, from their inception to October 31, 2020. We will use Assessment of Multiple Systematic Reviews-2 (AMSTAR2) for methodological quality assessment, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for report quality assessment, Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) for the quality of evidence assessment, and ROBIS for the bias assessment. Our reviewers will conduct systematic reviews, qualification evaluation, data extraction, methodological quality, and evidence quality screening in pairs. The outcomes include pain intensity, Quality of life (QoL), Hamilton Anxiety Scale (HAMA), Global impression, and adverse events. All the extracted data will be provided in tabular form to summarize characteristics of each review. The evidence will be a narrative synthesis of the type and content of the intervention and the results reported.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSIONS

This overview will provide comprehensive evidence of acupuncture therapy for patients with PHN.

ETHICS AND DISSEMINATION

This review will not involve private information of participants, so the ethical approval will not be required. The results will be disseminated in a peer-reviewed journal or conference presentation. Important protocol modifications will be updated on PROSPERO.

PROSPERO REGISTRATION NUMBER

CRD42020178738.

Supraorbital Nerve Radiofrequency for Severe Neuralgia Caused by Herpes Zoster Ophthalmicus

Background

Radiofrequency of the Gasserian ganglion can be used for ophthalmic herpetic neuralgia (OHN), but it is associated with complications. This study aimed to use the supraorbital nerve for computed tomography- (CT-) guided radiofrequency thermocoagulation to treat refractory OHN.

Methods

This was a retrospective case series study of patients with simple or combined OHN treated at our hospital between 06/2012 and 06/2018. The numerical rating score (NRS), spontaneous pain, allodynia, gabapentin dosage, paracetamol/oxycodone dosage, patient global impression of change (PGIC) score, Barrow numbness score, postoperative 360-day recurrence rate, and complications were recorded before the operation and at 1, 30, 90, 180, and 360 days after the operation.

Results

Compared with baseline, the NRS was decreased, and PGIC was increased at postoperative 1, 30, 90, 180, and 360 days, and the gabapentin and paracetamol oxycodone doses at postoperative 30, 90, 180, and 360 days were decreased (all P < 0.001). Compared with 1 day after the operation, numbness was decreased at 30, 90, 180, and 360 days after the operation (P < 0.001). Compared with baseline, the number of patients with allodynia at each time point after the operation was decreased (P < 0.001), but without a difference for spontaneous pain (P=0.407). No subjects showed drooping eyelid, corneal ulcers, eyeball damage, decreased vision, and other severe complications.

Conclusion

CT-guided supraorbital nerve radiofrequency thermocoagulation for the treatment of OHN can effectively relieve pain and reduce the dose of analgesics, without any serious complication. This study suggests that this technique is feasible and applicable to clinical practice.

Prophylactic vaccination with a live-attenuated herpes zoster vaccine in lung transplant candidates

BACKGROUND

Herpes zoster (HZ) is caused by the reactivation of varicella-zoster virus (VZV). Patients with lung transplants are at high risk for HZ owing to their immunocompromised status and the need for lifelong immunosuppression. In this study, patients on the waiting list for lung transplantation were vaccinated by a live-attenuated HZ vaccine (Zostavax, Merck Sharp & Dohme), and the safety and immunogenicity of this vaccine were studied.

METHODS

In total, 105 patients with end-stage pulmonary disease (ESPD) were enrolled (68 participants received 1 dose of Zostavax and 37 participants were enrolled as unvaccinated controls). Among them, 43 patients underwent lung transplantation and were followed up for further analysis. VZV immunoglobulin G antibody titers and VZV-specific cell-mediated immunity (CMI) on multiple time points before and after vaccination and before and after transplantation were measured.

RESULTS

Immune response to Zostavax was higher in younger patients, highest within 3 months after vaccination, and not influenced by gender or type of ESPD. Age, cytomegalovirus serostatus, and immunity to VZV at baseline impacted the subsequent immune response to the vaccine. Short-term immunosuppressant treatment had strong effects on VZV CMI levels, which returned to a high level at 6 months after transplantation in vaccinated patients. Zostavax did not impact infection or rejection rate after transplantation.

CONCLUSIONS

Zostavax was safe and induced a robust humoral and cellular response for patients awaiting lung transplantation regardless of the type of ESPD. Patients younger than the recommended vaccination age of over 50 years showed a strong response and could also benefit from pre-transplant immunization.

Human Papillomavirus, Herpes Zoster, and Hepatitis B Vaccinations in Immunocompromised Patients: An Update for Pharmacists

PURPOSE

Current evidence regarding efficacy and safety of human papillomavirus 9-valent (9vHPV), recombinant zoster (RZV), and CpG-adjuvanted recombinant hepatitis B (HepB-CpG) vaccines in adults with human immunodeficiency virus, inflammatory bowel disease, solid organ transplant, and allogeneic hematopoietic stem cell transplant is reviewed.

SUMMARY

Patients immunocompromised due to underlying disease or treatment are at increased risk for infections; however, insufficient understanding of various vaccines' efficacy, safety, indications, and contraindications in this population has led to suboptimal vaccination rates. The Infectious Disease Society of America (IDSA) published guidelines on vaccines in immunocompromised populations in 2013. Since then, several advances have been made including an expanded indication with 9vHPV for use in males and females 9 to 45 years old, and the introduction of new vaccines for herpes zoster (RZV) and hepatitis B (HepB-CpG). Pharmacists are instrumental to vaccination efforts and may benefit from a review of recent vaccine updates.

CONCLUSION

The 9vHPV can be used in men and women ages 9 to 45 years old regardless of immune status. RZV safety and efficacy in several immunocompromised populations has been demonstrated; however, manufacturers and major societies have yet to update their recommendations. HepB-CpG may be used in most immunocompromised patients yet remains under-utilized.

Predicting Postherpetic Neuralgia in Patients with Herpes Zoster by Machine Learning: A Retrospective Study

Introduction

Postherpetic neuralgia (PHN) is a neuropathic pain secondary to shingles. Studies have shown that early pain intervention can reduce the incidence or intensity of PHN. The aim of this study was to predict whether a patient with acute herpetic neuralgia will develop PHN and to help clinicians make better decisions.

Method

Five hundred two patients with shingles were reviewed and classified according to whether they had PHN. The risk factors associated with PHN were determined by univariate analysis. Logistic regression and random forest algorithms were used to do machine learning, and then the prediction accuracies of the two algorithms were compared, choosing the superior one to predict the next 60 new cases.

Results

Age, NRS score, rash site, Charlson comorbidity index (CCI) score, antiviral therapy and immunosuppression were found related to the occurrence of PHN. The NRS score was the most closely related factor with an importance of 0.31. As for accuracy, the random forest was 96.24%, better than that of logistic regression in which the accuracy was 92.83%. Then, the random forest model was used to predict 60 newly diagnosed patients with herpes zoster, and the accuracy rate was 88.33% with a 95% confidence interval (CI) of 77.43–95.18%.

Conclusions

This study provides an idea and a method in which, by analyzing the data of previous cases, we can develop a predictive model to predict whether patients with shingles will develop PHN.

Autologous fat grafting seems to alleviate postherpetic neuralgia - a feasibility study investigating patient-reported levels of pain

BACKGROUND

Postherpetic neuralgia (PHN) is a relatively common side effect after an outbreak of herpes zoster (HZ), characterized by chronic neuropathic dermal pain. No effective treatment exists today. Fat grafting has shown promise in alleviating neuropathic pain, yet the exact mechanism of action, at a biological level, is not yet known. We report on the first human study using autologous fat grafting for treating PHN. Our hypothesis was that fat grafting can alleviate pain and improve the quality of life (QoL) in patients suffering from PHN. If successful, this could be a safe, cost-effective alternative to analgesics. This safety and feasibility study aimed to investigate the possible pain-relieving effect of autologous fat grafting on PHN.

METHODS

Ten adult patients suffering from PHN underwent autologous fat grafting to a dermal area of neuralgia, with a 12-week follow up. The primary endpoint was patient-reported pain. Secondary endpoints were patient-reported changes in QoL, and the degree and quality of the neuropathic pain.

RESULTS

The pain was measured by using a visual analog scale (range: 0-10). We observed improvements in both the average and maximum level of pain with a reduction of (-4.0 ± 3.1) and (-5.1 ± 3.9), respectively, (Δ mean ± SD), P<0.05. All parameters investigating neuropathic pain were significantly reduced. No improvement was seen in the QoL. The average amount of fat grafted was 208 ml. We observed no serious adverse effects.

CONCLUSION

This study suggests that autologous fat grafting can relieve chronic pain resulting from HZ. The next step toward routine clinical translation is to perform a randomized, blinded, placebo-controlled trial with a more extended follow-up period.

Magnesium and Pain

In terms of antinociceptive action, the main mode of action of magnesium involves its antagonist action at the N-methyl-d-aspartate (NMDA) receptor, which prevents central sensitization and attenuates preexisting pain hypersensitivity. Given the pivotal function of NMDA receptors in pain transduction, magnesium has been investigated in a variety of pain conditions. The oral and parenteral administration of magnesium via the intravenous, intrathecal, or epidural route may alleviate pain and perioperative anesthetic and analgesic requirements. These beneficial effects of magnesium therapy have also been reported in patients with neuropathic pain, such as malignancy-related neurologic symptoms, diabetic neuropathy, postherpetic neuralgia, and chemotherapy-induced peripheral neuropathy. In addition, magnesium treatment is reportedly able to alleviate fibromyalgia, dysmenorrhea, headaches, and acute migraine attacks. Although magnesium plays an evolving role in pain management, better understanding of the mechanism underlying its antinociceptive action and additional clinical studies is required to clarify its role as an adjuvant analgesic.

Comparison of clinical characteristics of post-refractive surgery-related and post-herpetic neuropathic corneal pain

Purpose:

To compare the clinical characteristics and in vivo confocal microscopy (IVCM) findings of patients with neuropathic corneal pain (NCP) due to refractive surgery (RS-NCP) and herpetic eye disease (H-NCP) to controls.

Methods:

Sixteen patients with RS-NCP and 7 patients with H-NCP, and 37 healthy reference age- and sex-matched healthy controls were included to the study. The medical records were reviewed for demographic features, detailed disease history, ocular surface disease index (OSDI), ocular pain assessment survey (OPAS) scores. IVCM images of patients were analyzed and compared to reference controls by two masked observers.

Results:

The mean pain intensity score for the last 24 h (5.1 ± 2.4 vs. 3.9 ± 1.2; p = 0.27), last 2 weeks (6.1 ± 2.5 vs. 4.8 ± 2.3; p = 0.13) for RS-NCP vs. H-NCP respectively, and quality of life scores (p = 0.23) were similar in both groups. Quality of life, especially mood (p = 0.06) and enjoying life/relations to others (p = 0.10) were affected in both groups, but were not statistically significant between groups. The mean total nerve density was lower in RS-NCP (5,702.4 ± 4,599.0 μm/mm²) compared to their respective controls (26,422.8 ± 4,491.0; p < 0.001) and in the H-NCP group (2,149.5 ± 2,985.9) compared to their respective controls (22,948.8 ± 3,169.0; p < 0.001). Alterations in DC density were similar between all groups (38.3 ± 48.0 cells/mm² in RS-NCP, 61.0 ± 76.9 in H-NCP, p = 0.95).

Conclusion:

Neuropathic corneal pain patients due to refractive surgery show similar clinical characteristics, pain levels, quality of life impact, and IVCM findings as patients with NCP due to herpetic eye disease.

Efficacy and Safety of Mecobalamin on Peripheral Neuropathy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives: To assess the efficacy and safety of mecobalamin on peripheral neuropathy. Background: Mecobalamin is an active form of vitamin B12 that has been suggested to be beneficial in improving nerve conduction and neuropathic pain symptoms. Although it is already widely used in Asia for the treatment of peripheral neuropathies, its efficacy remains unclear. Methods: Relevant electronic databases were systematically searched for randomized controlled trials investigating the efficacy and safety of mecobalamin on peripheral neuropathy, from inception through December 2019. Study selection, data extraction, and quality assessment were performed independently by two reviewers. The clinical therapeutic efficacy, pain score, neuropathic symptom score, nerve conduction velocities (NCVs), and adverse events of mecobalamin were assessed and were pooled by using a random-effects model. Heterogeneity was assessed by I² and chi-squared tests. Results: Fifteen studies with 1707 peripheral neuropathy patients caused by diabetic peripheral neuropathy and herpetic neuropathy were included. Based on Cochrane's risk of bias criteria, most of the included studies (11/15, 73%) were rated high risk of bias, whereas 20% and 7% were rated some concerns and low risk of bias, respectively. In terms of the proportion of patients achieving clinical therapeutic efficacy, mecobalamin alone (risk ratio [RR] = 1.17; 95% confidence interval [CI] 1.03-1.33) and mecobalamin in combination (RR = 1.32; 95% CI 1.21-1.45) are more effective than active control. For NCV outcomes, only mecobalamin combination treatment was effective. Neither mecobalamin alone nor mecobalamin in combination is effective on the pain score and neuropathic symptom outcomes. No serious adverse events associated with mecobalamin were reported during the treatment periods. Conclusion: Our findings indicate that mecobalamin in combination may be effective in improving clinical therapeutic efficacy and NCV outcomes for peripheral neuropathy patients, but the evidence is not clear for mecobalamin alone. More high-quality studies are required to confirm this finding.

Kampo Medicine for Various Aging-Related Symptoms: A Review of Geriatric Syndrome

With the continued growth of the aging population in Japan, geriatric syndrome (GS), which is associated with aging-related symptoms, has become a social problem. GS is caused by physiological and pathological aging and may manifest various symptoms. Physicians use multidisciplinary approaches to provide treatment for individual GS symptoms. Kampo medicine, a Japanese traditional medicine that uses multiple pharmacologically active substances, is useful for many syndromes, conditions, disorders, and diseases associated with GS. Evidence of the effectiveness of Kampo medicine for GS has accumulated in recent years. The effects of Kampo treatment for symptoms related to functional decline of the cardiovascular, respiratory, and digestive systems, cognitive impairment and related disorders, pain and other sensory issues, among others, support the use of Kampo medicine for the management of GS. The role of Kampo medicine for GS is summarized in this review.

Postherpetic neuralgia and recalcitrant cystic lesions following herpes zoster: A case report and review of treatment options

Acute herpes zoster lesions in most cases are self-limited except in older and immunocompromised patients, wherein the pain can cause significant suffering. Postherpetic neuralgia is a painful situation for patients that can compromise the quality of life. Here, we report a 30-year-old healthy young man who developed treatment-resistant postherpetic neuralgia after herpes zoster (fourth/fifth thoracic segment) without any underlying immunocompromised state. He also developed some cystic lesions, which were removed by aspiration and surgery. The skin lesions improved 2 weeks after the surgery and postherpetic neuralgia was completely cured after 5 months, however cystic lesions recurred multiple times and were excised completely during each visit. Postherpetic neuralgia has a significant impact on the health-care cost borne by the society and affected individual, hence, it is essential to select appropriate treatment to manage the pain of postherpetic neuralgia.

Efficacy comparison of different acupuncture methods for herpes zoster: A Bayesian analysis protocol

BACKGROUND

Acupuncture methods (include moxibustion) are used frequently in the treatment of herpes zoster. However, the choice is usually made only based on personal experience among different acupuncture methods. This study aims to compare the efficacy of different acupuncture methods for herpes zoster.

METHODS

All randomized controlled trials of acupuncture methods for herpes zoster will be searched in 7 databases including Cochrane Library, Embase, PubMed, Web of Science, Wan-fang database, China National Knowledge Infrastructure database, and VIP Chinese Science and Technique Journals database database. After screening process, effectiveness rate will be extracted from all the included randomized controlled trials as primary outcomes. The Bayesian network meta-analysis will be conducted by generate mixed treatment comparisons 0.14.3, Stata13.0, and Review Man 5.3.

RESULTS

The results of this study will be submitted to a peer-reviewed journal for publication.

CONCLUSIONS

Our review will compare the efficacy of different acupuncture treatments for herpes zoster and find a better selection guideline for clinicians and patients.

PROSPERO REGISTRATION NUMBER

CRD42020175189.

A simple mechanistic terminology of psychoactive drugs: a proposal

Antidepressants, antiepileptics, mood stabilizers, and antipsychotics are extremely broadly used psychoactive drugs. These drug terms are universally used in the literature. However, the indications of these drugs have broadened substantially and overlap. The mismatch between drug classification and clinical uses causes a lot of confusion in communication and renders literature searches increasingly difficult. Therefore, we propose to drop the above terms altogether and replace them by simple mechanistic terms. Antidepressants are re-named as norepinephrine/serotonin (NE/5-HT) enhancers, antiepileptics comprising drugs with different mechanisms become neuronal inhibitors with pleiotropic effects (NIPEs), and antipsychotics become antagonists at multiple G protein-coupled receptors (mGPCR antagonists). Alkali metal ions, comprising lithium, are integrated into NIPEs. The terms "typical/first-generation/conventional" and "atypical/second-generation/non-conventional" antipsychotics should be dropped, because the original criterion for distinction, i.e., the presence and absence of extrapyramidal motor effects, respectively, is not valid anymore. The suggested changes in drug nomenclature have already been implemented into a recent textbook (Seifert R, Basic Knowledge of Pharmacology). The revised nomenclature ensures consistency with other fields of pharmacology and assignment of drug classes to indications without causing confusion. The authors acknowledge that the change in drug nomenclature is a cultural process that will take time and openly discuss the problems associated with the proposal. Ultimately, international learned societies will have to agree on a new nomenclature.

A Randomized, Crossover, Pharmacokinetic and Adhesion Performance Study of a Lidocaine Topical System 1.8% During Physical Activity and Heat Treatment in Healthy Subjects

Purpose

This study compares the pharmacokinetic (PK) profile, adhesion, and safety of lidocaine topical system 1.8%, a novel lidocaine topical system approved to treat postherpetic neuralgia, under conditions of heat and exercise vs normal conditions.

Materials and Methods

This open-label, 3-period, 3-treatment crossover study randomized 12 healthy adults to receive three lidocaine topical systems 1.8% during each of three treatment periods, with 7-day washouts between treatments. The product was applied to the mid-lower back and was removed after 12 hours. During Treatment A, subjects exercised on a bicycle for 30 minutes at 0, 2.5, 5.5, and 8.5 hours. During Treatment B, heat (temperature set at 36.7-40.3°C) was applied at 0 and 8.5 hours. Treatment C was normal conditions. The PK profile of each subject under exercise and heat conditions was compared to normal conditions. Skin irritation, adhesion, and adverse events were assessed.

Results

Twelve subjects completed the study. Exposure to external heat resulted in increased peak plasma concentration of lidocaine with a mean C_max of 160.3±100.1 ng/mL vs 97.6±36.9 ng/mL under normal conditions, with no effect on the extent of exposure (AUC). Concentrations returned to normal within 4 hours after the heat was removed. No clinically relevant differences in absorption were observed under exercise conditions with a mean C_max of 90.5±25.4 ng/mL and no effect on the extent (AUC) of lidocaine exposure was observed relative to normal conditions. No systems detached during the study. Adverse events were mild, with none leading to discontinuation.

Conclusion

Transient heat exposure resulted in increased lidocaine plasma concentrations compared to normal conditions, whereas exercise had no effect. The effects of heat appear to be immediate, reversible, and below systemic therapeutic threshold in antiarrhythmic treatment (1000-1500 ng/mL), and well below the safe systemic threshold of 5000 ng/mL. Lidocaine topical system 1.8% remained adhered to the skin and was well tolerated under all conditions. ClinicalTrials.gov: NCT04150536.

Functional and Structural Changes in Postherpetic Neuralgia Brain Before and Six Months After Pain Relieving

Objective

Multimodal magnetic resonance imaging (MRI) was used to detect whether 6 months after pain relieving, the structural and functional abnormalities in the brain of postherpetic neuralgia (PHN) patients are changeable.

Methods

Fifteen successfully treated PHN patients were enrolled; the brain activity and structural abnormalities were detected and compared before and 6 months after treatment. The functional parameters were evaluated with resting-state functional MRI technique, i.e., the regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuation (fALFF). Structural changes were detected with voxel-based morphometry (VBM) and diffusion kurtosis imaging (DKI).

Results

Six months after pain relieving, PHN brain showed different ReHo and fALFF values in the frontal lobe, caudate, supramarginal gyrus, anterior cingulate cortex (ACC), cuneus, middle temporal gyrus, and cerebellum. In addition, VBM intensity in the cerebellum increased; DKI values decreased in the thalamus and increased in the temporal lobe after successful treatment.

Conclusion

Six months after pain relieving, functional and structural changes exist in PHN brain. Changes in some differential areas in PHN brain, such as ACC, frontal lobe, thalamus, and temporal lobe indicate that the central plasticity may be reversible after chronic pain relieving.

Pregabalin as a Pain Therapeutic: Beyond Calcium Channels

Initially developed to generate new treatments for epilepsy, gabapentin, and pregabalin (“gabapentinoids”) were engineered to mimic the action of GABA and to modulate GABA metabolism. Rather than their intended pharmacological action on GABA neurotransmission, instead, they exhibit a high affinity for the α2δ-1 and α2δ-2 subunits of voltage-activated calcium channels, wherein binding of gabapentinoids inhibits cellular calcium influx and attenuates neurotransmission. Despite a lack of activity on GABA levels, gabapentin and pregabalin are effective at suppressing seizures and subsequently approved as a new class of antiepileptic therapy for partial-onset epilepsy. Through the same hypothesized molecular mechanism and by controlling neuronal hyperexcitability, gabapentinoids demonstrate clear efficacy in pain management, which has arguably been their most extensively prescribed application to date. In this review, we focus on pregabalin as a second-generation gabapentinoid widely employed in the treatment of a variety of pain conditions. We also discuss the wider functional roles of α2δ subunits and the contributions that pregabalin might play in affecting physiological and pathophysiological processes.

Challenges of neuropathic pain: focus on diabetic neuropathy

Neuropathic pain is a frequent condition caused by a lesion or disease of the central or peripheral somatosensory nervous system. A frequent cause of peripheral neuropathic pain is diabetic neuropathy. Its complex pathophysiology is not yet fully elucidated, which contributes to underassessment and undertreatment. A mechanism-based treatment of painful diabetic neuropathy is challenging but phenotype-based stratification might be a way to develop individualized therapeutic concepts. Our goal is to review current knowledge of the pathophysiology of peripheral neuropathic pain, particularly painful diabetic neuropathy. We discuss state-of-the-art clinical assessment, validity of diagnostic and screening tools, and recommendations for the management of diabetic neuropathic pain including approaches towards personalized pain management. We also propose a research agenda for translational research including patient stratification for clinical trials and improved preclinical models in relation to current knowledge of underlying mechanisms.

Role of Pregabalin in Treatment of Polyneuropathy in Multiple Myeloma Patients: A Retrospective Study

OBJECTIVES

Polyneuropathy (PN) is a frequent and significant clinical manifestation of multiple myeloma that may be observed at onset of disease or induced during treatment as a therapy-related complication. Polyneuropathy may be a relevant issue in myeloma patients owing to its significant impact on the quality of life, considering that it may lead to dose reduction or treatment discontinuation. The present retrospective study intended to evaluate efficacy of pregabalin (PGB) in treatment of PN in multiple myeloma patients.

MATERIALS AND METHODS

Medical charts of 108 consecutive PN myeloma patients were reviewed. Data regarding the tumor history and therapy as well as the clinical and neurophysiological examinations 6 months before and after initiation of PGB therapy were collected.

RESULTS

Thirty-eight medical charts had all the requested information. All patients (n = 38) underwent bortezomib-based treatment; 19 were previously treated and 19 were treatment naive. At first neurologic visit, all patients had PN symptoms (grade 2 of National Cancer Institute-Common Toxicity Criteria) without relevant pain. Neurophysiological evaluation showed a significant decrease in sensory nerve action potential amplitude (P = 0.006), conduction velocity (P = 0.006), and distal latency (P = 0.03) of sensory nerves between the first and the last neurological examination, in all patient population. Similar results were observed in treatment-naive patients, when the study cohort was stratified according to previous treatment. On the contrary, no significant differences were found between the first and the last neurophysiological follow-up evaluation in previously treated patients. Six months after PGB treatment, all patients reported disappearance of neurological symptoms (grade 0 National Cancer Institute-Common Toxicity Criteria).

CONCLUSIONS

In this retrospective study, improvement in neurological symptoms during PGB therapy was observed in the total population, despite the presence of a distal, sensory axonal neuropathy, as evidenced by neurophysiological examination.

Manipulation of the Innate Immune Response by Varicella Zoster Virus

Varicella zoster virus (VZV) is the causative agent of chickenpox (varicella) and shingles (herpes zoster). VZV and other members of the herpesvirus family are distinguished by their ability to establish a latent infection, with the potential to reactivate and spread virus to other susceptible individuals. This lifelong relationship continually subjects VZV to the host immune system and as such VZV has evolved a plethora of strategies to evade and manipulate the immune response. This review will focus on our current understanding of the innate anti-viral control mechanisms faced by VZV. We will also discuss the diverse array of strategies employed by VZV to regulate these innate immune responses and highlight new knowledge on the interactions between VZV and human innate immune cells.

γ-Aminobutyric Acid and Derivatives Reduce the Incidence of Acute Pain after Herpes Zoster - A Systematic Review and Meta-analysis

Herpes zoster (HZ) causes considerable pain and distress, and γ-Aminobutyric acid (GABA) and its derivatives are assumed to control this, but the available data are inconsistent. This meta-analysis and systematic review aimed to assess the effectiveness of GABA derivatives in the prevention of acute herpetic pain. The metaanalysis was conducted following the PRISMA guidelines using PICO format, registered in PROSPERO number CRD42018095758. PubMed, Web of Science, Ovid, Scopus, and EMBASE databases were searched. Records were included if they were randomized controlled trials of patients undergoing HZ infection, investigating the effect of GABA derivatives versus placebo in the treatment of HZ pain. Eligible trials were evaluated for the risk of bias. Then data were extracted and analysed. The number of patients with observed presence of pain after treatment was used to calculate odds ratio in a random effect model with the DerSimonian-Laird estimator. The I2 statistic was analysed for heterogeneity. The potential risk of bias was measured using Egger's regression test. The meta-analysis included three randomized controlled trials with a total of 297 patients. The incidence of acute HZ pain events for GABA group was significantly lower compared to placebo group,18/148 vs 44/149, respectively (OR = 0.36; 95% CI = 0.14 to 0.93; Z = 2.11; P = 0.035), Egger's test yielded P = 0.308. In conclusion, the present meta-analysis demonstrates that GABA derivatives reduce the incidence of acute herpetic pain. However, additional, well-designed randomized clinical trials are needed to determine their dose- and time-dependency regarding this symptom.

Reduced Glutamate in the Medial Prefrontal Cortex Is Associated With Emotional and Cognitive Dysregulation in People With Chronic Pain

A decrease in glutamate in the medial prefrontal cortex (mPFC) has been extensively found in animal models of chronic pain. Given that the mPFC is implicated in emotional appraisal, cognition and extinction of fear, could a potential decrease in glutamate be associated with increased pessimistic thinking, fear and worry symptoms commonly found in people with chronic pain? To clarify this question, 19 chronic pain subjects and 19 age- and gender-matched control subjects without pain underwent magnetic resonance spectroscopy. Both groups also completed the Temperament and Character, the Beck Depression and the State Anxiety Inventories to measure levels of harm avoidance, depression, and anxiety, respectively. People with chronic pain had significantly higher scores in harm avoidance, depression and anxiety compared to control subjects without pain. High levels of harm avoidance are characterized by excessive worry, pessimism, fear, doubt and fatigue. Individuals with chronic pain showed a significant decrease in mPFC glutamate levels compared to control subjects without pain. In people with chronic pain mPFC glutamate levels were significantly negatively correlated with harm avoidance scores. This means that the lower the concentration of glutamate in the mPFC, the greater the total scores of harm avoidance. High scores are associated with fearfulness, pessimism, and fatigue-proneness. We suggest that chronic pain, particularly the stress-induced release of glucocorticoids, induces changes in glutamate transmission in the mPFC, thereby influencing cognitive, and emotional processing. Thus, in people with chronic pain, regulation of fear, worry, negative thinking and fatigue is impaired.

The Study of Pain in Rats and Mice

Pain is a clinical syndrome arising from a variety of etiologies in a heterogeneous population, which makes successfully treating the individual patient difficult. Organizations and governments recognize the need for tailored and specific therapies, which drives pain research. This review summarizes the different types of pain assessments currently being used and the various rodent models that have been developed to recapitulate the human pain condition.

Intravenous infusion of lidocaine enhances the efficacy of conventional treatment of postherpetic neuralgia

BACKGROUND

Postherpetic neuralgia (PHN) is one kind of severe neuropathic pain which currently cannot be effectively cured. Recent researches suggest that intravenous infusion of lidocaine has a therapeutic effect on neuropathic pain such as PHN; however, the optimal dose and frequency of lidocaine infusion and the effectiveness and safety of this treatment in PHN patients still needs more clinical research. The aim of this study was to evaluate the therapeutic effects of daily intravenous lidocaine infusion on the outcome of the routine treatment of PHN.

METHODS

Sixty PHN patients were randomly divided into two groups: 1) control group (Control), treated with conventional therapies, such as antiepileptic pills, analgesics, neurotrophic medicines, paravertebral spinal nerve block and physiotherapy; 2) lidocaine group (Lido) received daily infusion of lidocaine (4 mg/kg) besides the conventional treatments. If the pain is not controlled sufficiently, additional tramadol is given and the average consumption of tramadol is calculated. Pain intensity was assessed before and after each infusion, and the number of breakthrough pain in the last 24 hrs were recorded. The incidence of adverse reactions related to intravenous lidocaine infusion was recorded.

RESULTS

For five consecutive days, numeric rating scale (NRS) scores were significantly decreased after 1 hr of intravenous infusion of lidocaine. Compared with Control, the NRS scores and the frequency of breakthrough pain in the Lido were significantly reduced. In addition, the extra tramadol consumption in the Lido was significantly lower than that in the Control, and the average hospital stay of patients in Lido was decreased. However, anxiety and depression scores showed no difference between Lido and Control.

CONCLUSION

Daily intravenous lidocaine (4 mg/kg for 5 days) enhanced the outcome of PHN treatment, reduced the amount of analgesic medicine and shortened the length of hospital stay with no obvious adverse side effects.

Pain management and stroke prevention in HHV-3-associated infection

The modern information on the epidemiology, pathogenesis, clinical manifestations, diagnosis and pain management in HHV-3-associated neuro-infection is presented. The criteria for the phased diagnostics and approaches to the rational therapy for shingles and postherpetic neuralgia are presented. The conditions aimed at the prevention of pain due to the damage to peripheral nervous system and stroke due to HHV-3-associated vasculopathy are discussed.

Efficacy and tolerability of a fixed dose combination of cortex phospholipid liposomes and cyanocobalamin for intramuscular use in peripheral neuropathies

Peripheral neuropathies are frequently encountered in clinical practice and are associated with a major impairment in quality of life. However, their management remains poor, and current therapies are often burdened with major side effects and can present poor efficacy on pain and functionality. Therefore, it has been suggested that the combination of two or more different drugs may improve analgesic efficacy and reduce side effects. Tricortin® 1000 is formulated with 12 mg of Brain cortex phospholipid liposomes + 1000 µg of Cyanocobalamin injectable solution (PL+CNCbl) for intramuscular use and is indicated in the treatment of poly-algo-neuropathic syndromes. This combination exerts a marked neurotrophic action by promoting the synthesis of endogenous phospholipids; moreover, the peculiar formulation optimizes the delivery of CNCbl which has analgesic and neurotrophic action. This paper discusses the pharmacotherapy of peripheral neuropathies, including low-back pain, neck pain, postherpetic neuropathy (PHN) and focuses on the fixed dose combination PL+CNCbl clinical efficacy in association with other treatments or in monotherapy.

Immunosenescence: A systems-level overview of immune cell biology and strategies for improving vaccine responses

Immunosenescence contributes to a decreased capacity of the immune system to respond effectively to infections or vaccines in the elderly. The full extent of the biological changes that lead to immunosenescence are unknown, but numerous cell types involved in innate and adaptive immunity exhibit altered phenotypes and function as a result of aging. These manifestations of immunosenescence at the cellular level are mediated by dysregulation at the genetic level, and changes throughout the immune system are, in turn, propagated by numerous cellular interactions. Environmental factors, such as nutrition, also exert significant influence on the immune system during aging. While the mechanisms that govern the onset of immunosenescence are complex, systems biology approaches allow for the identification of individual contributions from each component within the system as a whole. Although there is still much to learn regarding immunosenescence, systems-level studies of vaccine responses have been highly informative and will guide the development of new vaccine candidates, novel adjuvant formulations, and immunotherapeutic drugs to improve vaccine responses among the aging population.

Descriptive, observational study of pharmaceutical and non-pharmaceutical arrests, use, and overdoses in Maine

OBJECTIVES

The Maine Diversion Alert Program grants healthcare providers access to law enforcement data on drug charges. The objectives of this report were to analyse variations in drug charges by demographics and examine recent trends in arrests, prescriptions of controlled substances and overdoses.

DESIGN

Observational.

SETTING

Arrests, controlled prescription medication distribution and overdoses in Maine.

PARTICIPANTS

Drug arrestees (n=1272) and decedents (n=2432).

PRIMARY OUTCOME MEASURES

Arrestees were analysed by sex and age. Substances involved in arrests were reported by schedule (I-V or non-controlled prescription) and into opioids, stimulants or other classes. Controlled substances reported to the Drug Enforcement Administration (2007-2017) were evaluated. Drug-induced deaths (2007-2017) reported to the medical examiner were examined by the substance(s) identified.

RESULTS

Males were more commonly arrested for stimulants and schedule II substances. More than two-thirds of arrests involved individuals under the age of 40. Individuals age >60 were elevated for oxycodone arrests. Over three-fifths (63.38%) of arrests involved schedule II-IV substances. Opioids accounted for almost half (44.6%) of arrests followed by stimulants (32.5%) and sedatives (9.1%). Arrests involving buprenorphine exceeded those for oxycodone, hydrocodone, methadone, tramadol and morphine, combined. Prescriptions for hydrocodone (-56.0%) and oxycodone (-46.9%) declined while buprenorphine increased (+58.1%) between 2012 and 2017. Deaths from 2007 to 2017 tripled. Acetylfentanyl and furanylfentanyl were the most common fentanyl analogues identified.

CONCLUSIONS

Although the overall profile of those arrested for drug crimes in 2017 involve males, age <40 and heroin, exceptions (oxycodone for older adults) were observed. Most prescription opioids are decreasing while deaths involving opioids continue to increase in Maine.

Efficacy and Safety of Computed Tomography-Guided Pulsed Radiofrequency Modulation of Thoracic Dorsal Root Ganglion on Herpes Zoster Neuralgia

OBJECTIVE

Pulsed radiofrequency (PRF) can relieve postherpetic neuralgia (PHN) caused by herpes zoster (HZ) infection. Nevertheless, its curative effect can vary and may be related to the duration of treatment period. The following study investigates the efficacy and safety of CT-guided PRF modulation on HZ neuralgia over different periods and different time points.

MATERIALS AND METHODS

A total of 150 patients with HZ/PHN were enrolled at the Pain Department, Shengjing Hospital of China Medical University between January 2013 and December 2016. According to the course of disease, the patients were randomly divided into group A, which included patients with acute stage (n = 50; course <1 m); group B, which included patients with subacute stage (n = 50; 1 m <course <3 m); and group C, which included patients with chronic stage (n = 50; course >3 m). The PRF therapy was performed in all patients by targeting thoracic dorsal root ganglion (DRG). The visual analogue scale (VAS), SF-36, total effective rate of treatment, and dosage of antiepileptic analgesic drugs were observed at different time points, before and after the surgery.

RESULTS

Compared to preoperative time, decreased VAS, improved SF-36, and the decreased dosage of antiepileptic analgesic drugs were observed at all time points, and in all groups after surgery (p < 0.05). In group A, pain relief lasted longer, and it further decreased over time. In addition, significantly lower VAS, higher SF-36, and lower dosage of antiepileptic analgesic drugs were found in group A compared to group B, and in group B compared to group C (all p < 0.05). Furthermore, the total effective rates in groups A, B, and C were 88, 72, and 52%, respectively.

CONCLUSIONS

CT-guided PRF targeting thoracic DRG for modulation of HZ neuralgia in different periods is safe and effective. It is recommended to perform early intervention therapy at the acute phase of HZ.

Coadministration of probenecid and cimetidine with mirogabalin in healthy subjects: A phase 1, randomized, open-label, drug-drug interaction study

AIMS

The primary aim of this study was to assess the individual effects of probenecid and cimetidine on mirogabalin exposure.

METHODS

This phase 1, open-label, crossover study randomized healthy adults to receive three treatment regimens, each separated by ≥5-day washout: a single oral dose of mirogabalin 15 mg on day 2, mirogabalin 15 mg on day 2 plus probenecid 500 mg every 6 h from days 1 to 4, and mirogabalin 15 mg on day 2 plus cimetidine 400 mg every 6 h from days 1 to 4.

RESULTS

Coadministration of mirogabalin with probenecid or cimetidine increased the maximum and total mirogabalin exposure. The geometric mean ratios of Cmax and AUC(0-t) (90% CI) with and without coadministration of probenecid were 128.7% (121.9-135.7%) and 176.1% (171.9-180.3%), respectively. The geometric mean ratios of Cmax and AUC(0-t) (90% CI) with and without coadministration of cimetidine were 117.1% (111.0-123.6%) and 143.7% (140.3-147.2%), respectively. Mean (standard deviation) renal clearance of mirogabalin (l h-1 ) was substantially slower after probenecid [6.67 (1.53)] or cimetidine [7.17 (1.68)] coadministration, compared with mirogabalin alone [11.3 (2.39)]. Coadministration of probenecid or cimetidine decreased mirogabalin mean (standard deviation) apparent total body clearance [10.5 (2.33) and 12.8 (2.67) l h-1 , respectively, vs. 18.4 (3.93) for mirogabalin alone].

CONCLUSIONS

A greater magnitude of change in mirogabalin exposure was observed when coadministered with a drug that inhibits both renal and metabolic clearance (probenecid) vs. a drug that only affects renal clearance (cimetidine). However, as the increase in exposure is not clinically significant (>2-fold), no a priori dose adjustment is recommended.

Modalities in managing postherpetic neuralgia

Postherpetic neuralgia (PHN) is the most troublesome side effect of Herpes Zoster (HZ), which mainly affects the elderly and immunocompromised populations. Despite the current advancement of treatments, PHN persists in many individuals influencing their daily activities and reducing their quality of life. Anticonvulsants, antidepressants, topical therapies including lidocaine and capsaicin, and opioids, are the most widely used therapies for the treatment of PHN. These medications come with their adverse effects, so they should be used carefully with the elderly or with patients with significant comorbidities. Other measures like botulinum toxin, nerve blocks, spinal cord stimulation, and radiofrequency have also contributed significantly to the management of PHN. However, the efficacy, safety, and tolerability of these invasive methods need to be carefully monitored when administering them. Early diagnosis and early initiation of treatment can reduce the burden associated with PHN. The zoster vaccine has effectively reduced the incidence of HZ and PHN. In this article, we discuss the treatment options available for the management of PHN, mainly focusing on the efficacy and safety of different therapeutic modalities.

The effect and safety of ozone autohemotherapy combined with pharmacological therapy in postherpetic neuralgia

Introduction

We investigated the effect and safety of ozone autohemotherapy combined with pharmacological therapy in postherpetic neuralgia (PHN).

Methods

Ninety-eight patients with PHN were enrolled in this study and randomly divided into a pharmacological therapy group and ozone autohemotherapy group (49 patients in each group). The PHN patients in the pharmacological therapy group were administered pharmacological therapy for 2 weeks, whereas PHN patients in the ozone autohemotherapy group were given ozone autohemotherapy (200 mL blood from patients, the concentration of medical ozone was set as 30 μg/mL using an ozone medical apparatus, 40 mL medical ozone was incubated in 200 mL autologous blood for 3–5 minutes) combined with pharmacological therapy for 2 weeks. The Visual Analog Scale (VAS), the 50% VAS reduction in the initial value, McGill Pain Questionnaire (MPQ), the Patients’ Global Impression of Change (PGIC) scale, and the World Health Organization Quality of Life (WHOQOL-BREF) instrument were used to evaluate the outcomes of all PHN patients before therapy and at 1 week, 1 month, and 3 months after therapy.

Results

Forty-five patients in the pharmacological therapy group and 47 patients in the ozone autohemotherapy group completed the study. Compared with before therapy, the two groups showed significant improvements in VAS, MPQ, PGIC, and WHOQOL-BREF scores after therapy (P<0.05). Moreover, compared with the scores of the pharmacological therapy group, the ozone autohemotherapy group’s scores were significantly improved in the VAS, MPQ, PGIC, and WHOQOL-BREF as well as the 50% VAS reduction of the initial value after therapy (P<0.05). Finally, there were no statistically significant differences in adverse effects between groups after therapy (P>0.05).

Conclusion

The results of this study demonstrated that ozone autohemotherapy combined with pharmacological therapy was superior to isolated pharmacological therapy in patients with PHN and was an effective and safe way to relieve PHN.

Development of adjuvanted recombinant zoster vaccine and its implications for shingles prevention

INTRODUCTION

GSK has developed a two-dose adjuvanted recombinant zoster vaccine (Shingrix, RZV) to protect people aged ≥50 years (50+) against herpes zoster (HZ) and its complications. RZV showed >90% efficacy against HZ, sustained over 4 years of follow-up, in all studied age groups.

AREAS COVERED

This article reviews the scientific rationale underlying the design of RZV; the clinical evidence demonstrating immunogenicity, safety, and efficacy in persons 50+; and the public health implications and cost-effectiveness.

EXPERT COMMENTARY

A decline in varicella zoster virus (VZV) immunity is associated with increased risk of HZ in adults 50+ and immunocompromised individuals. RZV was designed to restore levels of anti-VZV cellular and humoral immunity to prevent VZV reactivation. RZV includes the recombinant gE glycoprotein antigen, and Adjuvant System AS01_B which promotes cellular and antibody responses. In two Phase III studies in subjects aged 50+ and 70+ years, RZV efficacy against HZ compared to placebo was >90% and ≥89% against post-herpetic neuralgia (PHN). RZV is expected to dramatically impact HZ morbidity including its complications, and associated health-care costs. In the US population aged 50+ years, vaccination with RZV can be cost-effective compared to no vaccination and cost-saving compared to the currently available live-attenuated HZ vaccine (Zostavax, Merck).

Effects of gabapentin, pregabalin and gastroretentive gabapentin on simulated driving, daytime sedation and cognition

Aim: Randomized Phase I study examining the effects of gabapentinoids gabapentin, pregabalin and gastroretentive gabapentin on simulated driving performance, sedation and cognitive function in healthy volunteers (n = 32). Methods: Driving attentiveness, sleepiness and cognition were evaluated prior to subjects receiving study doses. Blood samples were collected during each treatment. Results: Subjects receiving gastroretentive gabapentin showed less change in variation in lateral lane position (p = 0.0275), less tremor (p = 0.0304) and fewer vision disturbances compared with gabapentin (p = 0.0177). Statistically significant decrease in One Card Learning Test performance was observed after treatment with gastroretentive gabapentin. Conclusion: Gastroretentive gabapentin demonstrated reduced driving impairment and lower scores on key neurotoxicity measures. Further studies in patients with postherpetic neuralgia are needed.

Clinical trial number: NCT03179345

Combined therapy of pulsed radiofrequency and nerve block in postherpetic neuralgia patients: a randomized clinical trial

Caused by viral infection, postherpetic neuralgia (PHN) is the most common chronic neuropathic pain. Various treatment modalities such as early use of nerve block therapy (NBT) and pulsed radiofrequency (PRF) have been studied in reducing pain, however, no consistent success was achieved in all the patients treated with single regimen. The combined therapy of PRF and NBT with different targeting mechanism are of interest and remains to be determined. Here we investigated the combined effects of pulsed radiofrequency (PRF) with nerve block therapy (NBT) in PHN patients in a prospective randomized clinical trial. Sixty PHN patients were divided into four groups (n = 15 each): the conventional puncture group (group CP), the nerve block therapy group (group NB), the PRF group (group PRF), and the combined treatment group (PRF combined with nerve block therapy (group CT). To evaluate the extent of remission of hyperalgesia, we recorded the visual analogue scale (VAS) scores during cotton swab reaction before and after treatment and in the resting and active pain states. In addition, blood samples were collected and plasma cytokine and neuropeptides such as interleukin-6 (IL-6), substance P (SP), and β-endorphin (β-EP) were measured by enzyme-linked immunosorbent assay (ELISA) at the admission (basic state), before the operation, and at 12 h postoperatively. The number of adverse events (nausea, vomiting, constipation, puncture point hemorrhage, swelling and redness) within 12 h of the treatment were also documented. Our results showed that VAS scores during cotton swab reaction decreased after treatment in all patients (p < 0.05). Compared to group CP, plasma IL-6 and SP levels decreased (p < 0.05) and β-EP levels increased (p < 0.05) in groups NB, PRF, and CT. There were no significant differences in adverse events among groups (p > 0.05). We found that PRF in combination with NBT increased β-EP levels and decreased plasma IL-6 and SP, thereby alleviating pain and hyperalgesia in PHN patients. Taken together, our data suggest combined therapy of PRF and NBT is effective and safe for PHN patients.