Review of Lidocaine Patch 5% Studies in the Treatment of Postherpetic Neuralgia

The Randomised Evaluation of early topical Lidocaine patches In Elderly patients admitted to hospital with rib Fractures (RELIEF): feasibility trial protocol

Background

Topical lidocaine patches, applied over rib fractures, have been suggested as a non-invasive method of local anaesthetic delivery to improve respiratory function, reduce opioid consumption and consequently reduce pulmonary complications. Older patients may gain most benefit from improved analgesic regimens yet lidocaine patches are untested as an early intervention in the Emergency Department (ED). The aim of this trial is to investigate uncertainties around trial design and conduct, to establish whether a definitive randomised trial of topical lidocaine patches in older patients with rib fractures is feasible.

Methods

RELIEF is an open label, multicentre, parallel group, individually randomised, feasibility randomised controlled trial with economic scoping and nested qualitative study. Patients aged ≥ 65 years presenting to the ED with traumatic rib fracture(s) requiring admission will be randomised 1:1 to lidocaine patches (intervention), in addition to standard clinical management, or standard clinical management alone. Lidocaine patches will be applied immediately after diagnosis in ED and continued daily for 72 hours or until discharge. Feasibility outcomes will focus on recruitment, adherence and follow-up data with a total sample size of 100. Clinical outcomes, such as 30-day pulmonary complications, and resource use will be collected to understand feasibility of data collection. Qualitative interviews will explore details of the trial design, trial acceptability and recruitment processes. An evaluation of the feasibility of measuring health economics outcomes data will be completed.

Discussion

Interventions to improve outcomes in elderly patients with rib fractures are urgently required. This feasibility trial will test a novel early intervention which has the potential of fulfilling this unmet need. The Randomised Evaluation of early topical Lidocaine patches In Elderly patients admitted to hospital with rib Fractures (RELIEF) feasibility trial will determine whether a definitive trial is feasible.

ISRCTN Registration

ISRCTN14813929 (22/04/2021).

Lidocaine transdermal patches reduced pain intensity in neuropathic cancer patients already receiving opioid treatment

BACKGROUND

Limited efficacy has been observed when using opioids to treat neuropathic pain. Lidocaine patches reduce neuropathic pain in postherpetic neuralgia, but their benefits for cancer-related neuropathic pain remain unclear. This study aimed to investigate a treatment for cancer-related neuropathic pain.

METHODS

We conducted a prospective, open-label, single-arm study to assess the efficacy and safety of lidocaine transdermal patches in patients experiencing localized, superficial, neuropathic cancer pain. Terminal cancer patients already receiving opioid treatment participated in the 3-day study. The primary endpoint was pain intensity evaluated by the numerical rating scale (NRS). The secondary endpoints were the pain relief score and the quality of analgesic treatment.

RESULTS

The results showed a significant difference in the median NRS over 3 days (Kruskal-Wallis test, p < 0.0001). The median NRS pain intensity from Day 1 to Day 3 was 4.0 with 95% C.I. (3.3, 5.0), 3.0 (2.5, 3.5), and 2.6 (2.0, 3.0), respectively. The difference between the median NRS pain intensities of any 2 days was significant (Wilcoxon signed-rank test, p < 0.0001). The generalized estimating equation (GEE) estimation model showed significant differences between the NRS pain intensities on any 2 days. There was no significant difference in the pain relief score or the quality of analgesic treatment.

CONCLUSIONS

In this study, the 5% lidocaine transdermal patch reduced the NRS pain intensity in neuropathic cancer patients already receiving opioid treatment. Treatment of localized and superficial neuropathic pain caused by cancer was well tolerated and effective.

Intravenous Lidocaine for Treatment of Chronic Pain: A Retrospective Cohort Study

Introduction

Neuropathic pain is a widespread problem with a big impact on quality of life. The currently used drug regimens are often insufficiently effective or cause - sometimes unacceptable - side effects. Intravenous lidocaine could be an alternative treatment, by blocking spontaneous depolarization and hyperexcitability in upregulated sodium channels in nociceptors. Research so far has shown varying results but the treatment protocols differed a lot and follow-up was usually short. In our hospital, lidocaine infusions have been applied for many years in a unique treatment protocol consisting of a relatively high dose of lidocaine (1000 mg) administered over 25 hours. Our aim is to share information on both the efficacy and safety of this treatment schedule.

Methods

We conducted a retrospective cohort study in all patients who received a lidocaine infusion between January 2014 and January 2018. The standard infusion protocol consists of a total of 1000 mg lidocaine administered intravenously during 25 hours (40 mg/hour). Pain diagnoses were stratified into 15 groups, in agreement with diagnoses used in daily practice. Effectiveness of the treatment was classified as effect or no effect based on the description found in the chart.

Results

We included 282 patients, with a median age of 58 years and 64% of whom were female. Patients with myofascial pain syndrome, peripheral (mono)neuropathy, small fiber neuropathy and vascular disease benefited most. Patients with cancer pain, postherpetic neuralgia, chemotherapy-induced neuropathy and radicular pain showed the least pain improvement. There were no serious adverse events.

Conclusion

In selected patients, lidocaine infusions may be a safe and efficacious treatment for chronic neuropathic pain. More prospective research is needed to further determine the optimal dosing, duration and interval of lidocaine infusion therapy, and to better understand in which specific patient categories this treatment is most beneficial.

Effectiveness, Safety, and Predictors of Response to 5% Lidocaine-Medicated Plaster for the Treatment of Patients With Trigeminal Neuralgia: A Retrospective Study

BACKGROUND

Whether 5% lidocaine-medicated plaster (LMP) is a valuable therapeutic option for the treatment of trigeminal neuralgia (TN) is worth exploring. If LMP is proven effective for TN, positive predictors of the analgesic effects of LMP warrant further investigation.

OBJECTIVE

To evaluate the efficacy and safety of LMP for the treatment of TN, and to explore the predictive factors for the treatment efficacy of LMP.

METHODS

This is a retrospective and observational study. We analyzed the efficacy of LMP for the treatment of TN between March 2019 and January 2022. The follow-up time was approximately 2 weeks, 1 month, 2 months, and 3 months after LMP treatment. The LMP response was considered the Barrow Neurological Institute (BNI) score of I to III and an improvement in BNI of at least I grade from pretreatment baseline. Univariable and multivariable logistic analyses were performed to identify the predictive factors for LMP response.

RESULTS

A total of 103 patients were included and analyzed in this study. LMP was effective in some TN patients, with an efficacy rate of 21.4%, 21.4%, 18.4%, and 16.5% after 2 weeks, 1 month, 2 months, and 3 months of LMP treatment, respectively. The overall adverse event rate associated with LMP was 5.8%, and the reported adverse events were all skin reactions. Facial trigger points (odds ratio [OR] = 0.25, 95% confidence interval [CI] = 0.07-0.86, P = 0.03) and a lower BNI score (OR = 0.37, 95% CI = 0.07-0.87, P = 0.01) were identified as potential predictors for initial efficacy (2-week follow-up) of LMP treatment.

CONCLUSIONS AND RELEVANCE

LMP has been shown to provide effective and sustained analgesia in some TN patients with minimal risk of systemic adverse reactions. Patients with facial trigger points and mild to moderate pain are more likely to benefit from LMP treatment. Our data suggest that LMP may be an effective treatment option for patients with the aforementioned characteristics of TN.

Open-Label Adhesion Performance Study of a Prescription Lidocaine Topical System 1.8% versus Three Lidocaine-Containing Over-the-Counter Patches in Healthy Subjects

Purpose

Patients and Methods

Results

Conclusion

Serial Thoracic Transforaminal Epidural Steroid Injections for Post-herpetic Neuralgia: A Case Report

The chronic neuropathic pain of post-herpetic neuralgia (PHN) often persists for months or years after the acute herpes zoster (shingles) episode, may be severe and intractable, and can severely impact the overall quality of life. Antivirals, analgesics, and nerve blocks can effectively shorten the course of shingles and may help to prevent PHN. Although vaccination effectively prevents shingles and PHN, current therapies may be ineffective, and pain management can be challenging when PHN occurs. A 78-year-old female with severe PHN pain in the right thoracolumbar spine, right flank, and right lower abdomen showed poor responses to treatment with amitriptyline, gabapentin, and oxycodone/acetaminophen. However, a series of three thoracic transforaminal epidural steroid injections (TFESIs) effectively treated the PHN and achieved near-complete pain resolution. TFESI can be considered an early and first-choice treatment for PHN, but several courses may be required to achieve adequate and prolonged symptom control.

Pharmacologic Management of Neuropathic Pain

This article aims to provide the practitioner with therapeutic options to treat a broad spectrum of acute and chronic orofacial pain syndromes. The focus will be nonsurgical that the oral health care physician can implement to treat this population of patients. The World Health Organization estimated that more than 1 in every 3 people suffers from acute or chronic pain. This article is primarily devoted to medication management once the diagnosis of neuropathic pain, a true trigeminal neuralgia, or a variant of trigeminal neuralgia often referred to as traumatic neuropathic pain or traumatic trigeminal neuralgia.

LP1 and LP2: Dual-Target MOPr/DOPr Ligands as Drug Candidates for Persistent Pain Relief

Although persistent pain is estimated to affect about 20% of the adult population, current treatments have poor results. Polypharmacology, which is the administration of more than one drug targeting on two or more different sites of action, represents a prominent therapeutic approach for the clinical management of persistent pain. Thus, in the drug discovery process the "one-molecule-multiple targets" strategy nowadays is highly recognized. Indeed, multitarget ligands displaying a better antinociceptive activity with fewer side effects, combined with favorable pharmacokinetic and pharmacodynamic characteristics, have already been shown. Multitarget ligands possessing non-opioid/opioid and opioid/opioid mechanisms of action are considered as potential drug candidates for the management of various pain conditions. In particular, dual-target MOPr (mu opioid peptide receptor)/DOPr (delta opioid peptide receptor) ligands exhibit an improved antinociceptive profile associated with a reduced tolerance-inducing capability. The benzomorphan-based compounds LP1 and LP2 belong to this class of dual-target MOPr/DOPr ligands. In the present manuscript, the structure-activity relationships and the pharmacological fingerprint of LP1 and LP2 compounds as suitable drug candidates for persistent pain relief is described.

Lidocaine Infusions for Pain Management in Pediatrics

Lidocaine is an amino amide with a well-established role as a local anesthetic agent. Systemic intravenous administration expands its clinical use to include acute and chronic pain circumstances, such as postoperative pain, neuropathic pain, postherpetic neuralgia, hyperalgesia, visceral pain, and centrally mediated pain. For refractory pain that has not responded to conventional therapy or if further escalation of treatment is prevented by contraindications or side effects to standard therapies, a continuous infusion of lidocaine may be considered as a single intervention or as a sequence of infusions. Here, we review and evaluate published data reflecting the use of lidocaine continuous infusions for pain management in the pediatric population.

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.

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.

Post herpetic neuralgia: A retrospective study to evaluate response to modified Jaipur block with increased concentration of dexamethasone

Background:

Postherpetic neuralgia (PHN) is a complication of herpes zoster characterized by persistent dermatomal pain. It has a negative impact on the quality of life. There is no gold standard therapy for PHN, and various local and systemic treatments have been tried. There are studies reporting the use of combination of steroids and local anesthetics but there is no standardized method.

Aim:

To evaluate the response of modified Jaipur block with increased concentration of dexamethasone.

Methods:

We conducted a retrospective study in patients who were given Jaipur block. The patients age, sex, duration of PHN, type and severity of pain were observed. A combination of 2% lignocaine and 0.5% bupivacaine and dexamethasone was injected subcutaneously. The pain was scored using visual analogue scale at the baseline, and 1 month after 1^st, 2^nd, and 3^rd session of block and follow up after 6 months and 1 year.

Results:

The mean age of our patient was 63.33 ± 9.5 years. The males outnumbered females. Thoracic dermatomes were more commonly involved. The mean duration of PHN was 11.58 ± 12.76 months; stimulus evoked PHN was the commonest type of pain seen. The mean visual analogue score (VAS) decreased progressively after each session of the block. Maximum patients (50%) had excellent response, whereas 1.9% did not respond to the block. Relapse of pain was seen in 5.6% of the patients. There was no significant side effect noted.

Limitations:

There was no objective method used to assess pain.

Conclusion:

PHN is chronic neuropathic pain. Response to modified Jaipur block is good, but if the duration of PHN is more, the recurrence rate is higher. Modified Jaipur block is an effective and safe treatment for PHN

Pharmacological Management of Adults with Chronic Non-Cancer Pain in General Practice

Chronic pain is a public health priority that affects about 20% of the general population, causing disability and impacting productivity and quality of life. It is often managed in the primary care setting. Chronic pain management is most effective when the pain mechanism has been identified and addressed by appropriate therapy. This document provides an overview of pharmacological therapy for chronic non-cancer pain in the primary care setting, with the aim of improving treatment decisions based on the underlying pain mechanisms and pain neuroscience.

Topical Lidocaine Patch for Postthoracotomy and Poststernotomy Pain in Cardiothoracic Intensive Care Unit Adult Patients

BACKGROUND

Transdermal lidocaine patches have few systemic toxicities and may be useful analgesics in cardiac surgery patients. However, few studies have evaluated their efficacy in the perioperative setting. Objective To compare the efficacy of topical lidocaine 5% patch plus standard care (opioid and nonopioid analgesics) with standard care alone for postthoracotomy or poststernotomy pain in adult patients in a cardiothoracic intensive care unit.

METHODS

A single-center, retrospective cohort evaluation was conducted from January 2015 through December 2015 in the adult cardiothoracic intensive care unit at a tertiary academic medical center. Cardiac surgery patients with new sternotomies or thoracotomies were included. Patients in the lidocaine group received 1 to 3 topical lidocaine 5% patches near sternotomy and/or thoracotomy sites daily. Patches remained in place for 12 hours daily. Patients in the control group received standard care alone.

RESULTS

The primary outcome was numeric pain rating for sternotomy/thoracotomy sites. Secondary outcomes were cardiothoracic intensive care unit and hospital lengths of stay and total doses of analgesics received. Forty-seven patients were included in the lidocaine group; 44 were included in the control group. Mean visual analogue scores for pain did not differ between groups (lidocaine, 2; control, 1.9; P = .58). Lengths of stay were similar for both groups (cardiothoracic intensive care unit: lidocaine, 3.06 days; control, 3.11 days; P = .86; hospital: lidocaine, 8.26 days; control, 7.61 days; P = .47).

CONCLUSIONS

Adjunctive lidocaine 5% patches did not reduce acute pain in postthoracotomy and post-sternotomy patients in the cardiothoracic intensive care unit.

Neuromodulation in Postherpetic Neuralgia: Case Reports and Review of the Literature

Objective

Postherpetic neuralgia (PHN) is common in the United States. Current treatment options for PHN are fairly limited. Spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) are considered mostly experimental and still rarely performed in patients with PHN.

Design

Two case reports and a review of the literature.

Setting

Tertiary academic medical center.

Methods

1) Pubmed, Ovid, and EBMR databases were searched for all reports that had the following key words: postherpetic neuralgia, spinal cord stimulation, and peripheral nerve stimulation. 2) A retrospective chart review was performed for all the patients that underwent PNS for PHN at Mayo Clinic Florida (MCF).

Results

There were 20 original reports that described 309 patients with PHN who were treated with SCS. Sixteen reports had a permanent implantation of SCS, with a total of 255 patients, out of which 120 had long-term pain relief. There were six reports of subcutaneous PNS for PHN (in a thoracic area). Four reports provided data on success rates where all five patients received complete pain relief. In our practice, two patients underwent subcutaneous PNS for PHN (in the thoracic area) with good pain relief for 10 months and 2.5 years, respectively.

Conclusions

Based on our review of the literature and the two cases at MCF, subcutaneous PNS seems to be a promising intervention in the treatment of PHN.

Epidemiology, treatment and prevention of herpes zoster: A comprehensive review

Herpes zoster is a major health burden that can affect individuals of any age. It is seen more commonly among individuals aged ≥50 years, those with immunocompromised status, and those on immunosuppressant drugs. It is caused by a reactivation of varicella zoster virus infection. Cell-mediated immunity plays a role in this reactivation. Fever, pain, and itch are common symptoms before the onset of rash. Post-herpetic neuralgia is the most common complication associated with herpes zoster. Risk factors and complications associated with herpes zoster depend on the age, immune status, and the time of initializing treatment. Routine vaccination for individuals over 60 years has shown considerable effect in terms of reducing the incidence of herpes zoster and post-herpetic neuralgia. Treatment with antiviral drugs and analgesics within 72 hours of rash onset has been shown to reduce severity and complications associated with herpes zoster and post-herpetic neuralgia. This study mainly focuses on herpes zoster using articles and reviews from PubMed, Embase, Cochrane library, and a manual search from Google Scholar. We cover the incidence of herpes zoster, gender distribution, seasonal and regional distribution of herpes zoster, incidence of herpes zoster among immunocompromised individuals, incidence of post-herpetic neuralgia following a zoster infection, complications, management, and prevention of herpes zoster and post-herpetic neuralgia.

The Efficacy of Systemic Lidocaine in the Management of Chronic Pain: A Literature Review

Context

Despite recent advances in the understanding of the chronic pain concept, its diagnosis and management remains a daily challenge for clinicians and patients. Based on the published literature, this review discusses and tries to organize the current knowledge and the up-to-date clinical experience about the efficacy and safety of the use of intravenous lidocaine in treatment and prevention of chronic pain.

Evidence Acquisition

To prepare this narrative review, we performed an in depth literature review using the PubMed searching engine. We extracted all relevant articles published in English, up to April 2016.

Results

Lidocaine, administered as transdermal patch or intravenous lidocaine, is a safe and effective modality in the treatment of post-herpetic neuralgia (PHN), complex regional pain syndrome, as well and for prevention of chronic pain. It may be effective in the management of neuropathic pain syndromes, chronic pain, post-operative pain, and refractory cancer pain.

Conclusions

Intravenous lidocaine and lidocaine patch are effective and safe for the treatment of several chronic or neuropathic pain syndromes. The use of lidocaine during surgery could prevent the development of some chronic post-surgical pain syndromes.

Implantable polymeric microneedles with phototriggerable properties as a patient-controlled transdermal analgesia system

Adequate pain control can be achieved using a patient-controlled drug delivery system that can provide analgesia to patients as needed. To achieve this objective, we developed a phototriggered microneedle (MN) system that enables the on-demand delivery of pain medications to the skin under external near-infrared (NIR) light stimulation. In this system, polymeric MNs, containing NIR absorbers and analgesics, are combined with a poly(l-lactide-co-d,l-lactide) supporting array. A "removable design" of the supporting array enables the quick implantation of the MNs into the skin to act as a drug depot, thus shortening the patch application time. Upon irradiation with NIR light, the NIR absorbers in the implanted MNs can absorb light energy and induce a phase transition in the MNs to activate drug release. We demonstrated that lidocaine release can be modulated or repeatedly triggered by varying the duration of irradiation and controlling the on and off status of the laser. Lidocaine delivered by the implanted MNs can be rapidly absorbed into the blood circulation within 10 min and has a bioavailability of at least 95% relative to the subcutaneous injection, showing that the proposed system has the potential to provide a rapid onset of pain relief. Such an implantable device may allow pain sufferers receiving the painkiller without the need for multiple needle injections, and may enable controlling pain more conveniently and comfortably.

Orofacial Pain: Pharmacologic Paradigms for Therapeutic Intervention

Pain is a universal experience with profound effects on the physiology, psychology, and sociology of the population. Orofacial pain (OFP) conditions are especially prevalent and can be severely debilitating to a patient's health-related quality of life. Evidence-based clinical trials suggest that pharmacologic therapy may significantly improve patient outcomes either alone or when used as part of a comprehensive treatment plan for OFP. The aim of this article is to provide therapeutic options from a pharmacologic perspective to treat a broad spectrum of OFP. Clinical-based systemic and topical applied pharmaceutical approaches are presented to treat the most common OFP syndromes.

Neuropathic Pain due to Small Fiber Neuropathy in Aging: Current Management and Future Prospects

Over the last 10 years, the diagnosis small fiber neuropathy (SFN) has gained recognition worldwide. Patients often suffer from severe neuropathic pain that may be difficult to treat. A substantial subset of patients with SFN is aged 65 years or older, and these patients often exhibit comorbidities and usage of multiple drugs, making neuropathic pain treatment more challenging. In this review, we highlight relevant pathophysiological aspects and discuss currently used therapeutic strategies for neuropathic pain. Possible pitfalls in neuropathic pain treatment in the elderly will be underlined.

Case studies illustrating the management of trigeminal neuropathic pain using topical 5% lidocaine plasters

Chronic trigeminal pain, with its severe related functional problems, is difficult to treat. Treatment is often empirically based on medications used for other chronic pain conditions. Systemic sodium channel and calcium channel blocking agents may cause a multitude of complications that are often poorly tolerated by the patient.

AIM

The aim of this case report was to assess the efficacy of topical 5% lidocaine plasters in reducing pain and reducing adjuvant medication in patients with orofacial neuropathic pain.

METHOD

Fourteen patients with chronic orofacial pain conditions referred to the oral surgery department were instructed to wear 5% lidocaine plasters for 12 hours each day over the painful area. The conditions included post-surgical neuropathy (n = 10), multiple sclerosis-related pain (n = 1), persistent idiopathic facial pain (n = 1), Ramsay Hunt syndrome (post-herpetic neuralgia, n = 1) and trigeminal neuralgia (n = 1). Data were collected on patient demographics, pain levels and medication.

RESULTS

Pain levels improved in 12 out of 14 patients. Nine patients had a reduction in adjuvant medication, two of whom completely stopped adjuvant treatment.

CONCLUSION

This case series demonstrates that of the use of 5% lidocaine plasters may play a useful role in the management of chronic trigeminal pain. A suggested novel approach for the management of orofacial pain, for clinicians, is presented.

SUMMARY POINTS

Management of chronic orofacial pain continues to be a major challenge to the clinician.Patients are often placed on a multitude of medications in an attempt to alleviate pain without success.Topical 5% lidocaine plasters, currently used for the management of post-herpetic neuralgia, offer the option of locally targeting trigeminal pain without the multiple side-effects of systemic medication.This case series demonstrates that lidocaine plasters decrease verbal pain scores in extraoral, trigeminal and neuropathic pain, and reduce the use of other neuromodulatory agents in some, but not all, patients.The plasters should be considered as a useful adjuvant in the management of pain in these patients.

Topical analgesics for neuropathic pain in the elderly: current and future prospects

Neuropathic pain (NeP) is a significant medical and socioeconomic burden with limited therapeutic options. Elderly patients exhibit a higher incidence of several NeP conditions and pose a particular challenge due to age-related pharmacokinetic and pharmacodynamic issues, comorbid conditions, and polypharmacy, as well as frailty and cognitive decline. Topical analgesics are of interest because of their comparable efficacy to oral agents, good tolerability and safety, and potential to be add-on therapies to oral treatments. In recent years, two topical formulations for NeP have been approved (5% lidocaine medicated plaster, 8% capsaicin patch) but are not available in all countries. There are controlled trials and a growing body of open-label reports on their use in clinical care. Some studies provide a post hoc analysis of data in relation to older age (≥65 years), which is useful. The body of evidence relating to topical investigational agents is growing and involves controlled trials as well as individual cases. The largest single body of information is for topical ketamine, administered either alone or combined with other agents (particularly amitriptyline), and some large randomized controlled trials report efficacy. Other large trials involve topical clonidine and further ketamine combinations. Compounding analgesics involves challenges, including uncertain composition (two to five ingredients are used) and concentrations (range 0.5-5%), as well as the heterogeneity of data that support choices. Nevertheless, case reports and acceptable response rates in larger cohorts are intriguing, and this area merits further investigation in controlled settings as well as continued documentation of clinical experiences.

Is lidocaine patch as effective as intravenous lidocaine in pain and illus reduction after laparoscopic colorectal surgery? A randomized clinical trial

Objective:

To evaluate the efficacy of lidocaine patch applied around wound in laparoscopic colorectal surgery in reduction of postoperative pain and illus compared to intravenous lidocaine infusion and placebo.

Background:

Postoperative illus and pain after colorectal surgery is a challenging problem associated with increased morbidity and cost. Inflammatory response to surgery plays crucial rule in inducing postoperative illus. Systemic local anesthetics proved to have anti-inflammatory properties that may be beneficial in preventing ileus added to its analgesic actions. The lidocaine patch evaluated in many types of pain with promising results. We try to evaluate the patch in perioperative field as a more simple and safe technique than the intravenous route.

Materials and Methods:

Prospective, randomized, controlled study was conducted, comparing three groups. Group 1 (placebo) received saline infusion, group 2 received i.v. lidocaine infusion after induction of anesthesia, 2 mg/min if body weight >70 kg or 1 mg/min if body weight <70 kg, group 3 received lidocaine patch 5%, three patches each one divided into two equal parts and applied around the three wounds just before induction. Data collected were, pain scores (VAS), morphine consumption, return of bowel function, pro-inflammatory cytokines plasma levels and plasma lidocaine level.

Results:

Pain intensity (VAS) scores at rest and during coughing were significantly lower during the first 72 h postoperative in i.v. lidocaine group and patch group compared to the placebo group. Mean morphine consumption were significantly lower in the i.v. lidocaine group and patch group compared to placebo group. Return of the bowel function was significantly earlier in i.v. lidocaine group in comparison to the other groups. Proinflammatory cytokines (IL6, IL8, and C3a) were significantly lower in i.v. lidocaine group compared to the other two groups.

Conclusion:

The lidocaine patch was equal to i.v. lidocaine infusion in decreasing pain scores and morphine consumption but not in acceleration of bowel function return.

Effect of lidocaine patches on upper trapezius EMG activity and pain intensity in patients with myofascial trigger points: A randomized clinical study

OBJECTIVE

To compare the effects of 5% lidocaine patches and placebo patches on pain intensity and electromyographic (EMG) activity of an active myofascial trigger point (MTrP) of the upper trapezius muscle.

MATERIALS AND METHODS

Thirty-six patients with a MTrP in the upper trapezius muscle were randomly divided into two groups: 20 patients received lidocaine patches (lidocaine group) and 16 patients received placebo patches (placebo group). They used the patches for 12 h each day, for 2 weeks. The patch was applied to the skin over the upper trapezius MTrP. Spontaneous pain, pressure pain thresholds, pain provoked by a 4-kg pressure applied to the MTrP and trapezius EMG activity were measured before and after treatment.

RESULTS

Baseline spontaneous pain values were similar in both groups and significantly lower in the lidocaine group than the placebo group after treatment. The baseline pressure pain threshold was significantly lower in the lidocaine group, but after treatment it was significantly higher in this group. Baseline and final values of the pain provoked by a 4-kg pressure showed no significant difference between the groups. Baseline EMG activity at rest and during swallowing of saliva was significantly higher in the lidocaine group, but no significant difference was observed after treatment. Baseline EMG activity during maximum voluntary clenching was similar in both groups, but significantly higher in the lidocaine group after treatment.

CONCLUSIONS

These clinical and EMG results support the use of 5% lidocaine patches for treating patients with MTrP of the upper trapezius muscle.

Pharmacological treatment of chronic non-cancer pain in pediatric patients

Chronic pain in children and young adults occurs frequently and contributes to early disability as well as personal and familial distress. A biopsychosocial approach to evaluation and treatment is recommended. Within this approach, there is a role for pharmacologic intervention. A variety of medications are used for chronic pain conditions in pediatric patients. Medication classes include anticonvulsants, muscle relaxants, antidepressants, opioids, local anesthetics, and anti-inflammatory drugs. Data is sparse, and most medications are used without condition-specific approval by national regulatory agencies such as the Food and Drug Administration in the US and the European Medicines Agency. In the absence of evidence on which to base practice, optimal drug therapy decisions rest on understanding proposed mechanisms of pain conditions, extrapolation from adult data-when such exists, and empirical and experiential knowledge. Drug delivery systems have evolved, and practitioners have to decide amongst not only medication classes, but also routes of delivery. Opioids are not recommended for use by non-pain specialists for the treatment of pediatric chronic pain, and even then the issues are more complex than can be addressed here. This article reviews the major medications used for pediatric chronic pain conditions.

Systematic review and recommendations for nonodontogenic toothache

Nonodontogenic toothache is a painful condition that occurs in the absence of a clinically evident cause in the teeth or periodontal tissues. The purpose of this review is to improve the accuracy of diagnosis and the quality of dental treatment regarding nonodontogenic toothache. Electronic databases were searched to gather scientific evidence regarding related primary disorders and the management of nonodontogenic toothache. We evaluated the level of available evidence in scientific literature. There are a number of possible causes of nonodontogenic toothache and they should be treated. Nonodontogenic toothache can be categorised into eight groups according to primary disorders as follows: 1) myofascial pain referred to tooth/teeth, 2) neuropathic toothache, 3) idiopathic toothache, 4) neurovascular toothache, 5) sinus pain referred to tooth/teeth, 6) cardiac pain referred to tooth/teeth, 7) psychogenic toothache or toothache of psychosocial origin and 8) toothache caused by various other disorders. We concluded that unnecessary dental treatment should be avoided.

Update on neuropathic pain treatment: ion channel blockers and gabapentinoids

Neuropathic pain is a debilitating chronic pain condition, which remains difficult to treat. The current mainstays of treatment include physical therapy, interventional procedures and medications. Among medications, ion channel blockers and gabapentinoids are the 2 classes of drugs commonly used to treat neuropathic pain. It has been suggested that these medications may be useful to treat a variety of neuropathic pain conditions. This article provides several updates on the utility of both ion channel blockers and gabapentinoids for the treatment of neuropathic pain.

Efficacy of EMLA cream phonophoresis comparison with ultrasound therapy on myofascial pain syndrome of the trapezius: a single-blind, randomized clinical study

The aim of this study is to investigate whether eutectic mixture of local anesthetics (EMLA) cream phonophoresis superior to conventional US over the trigger points (TPs) in terms of improvements of pain, range of motion and disability in myofascial pain syndrome (MPS). Fifty patients (42 female, 8 male) diagnosed with MPS were included in the study. Patients were randomly assigned into two treatment groups including phonophoresis (PH) group (n = 25) and ultrasound (US) group (n = 25). PH group received EMLA cream phonophoresis (2.5 % lidocaine, 2.5 % prilocaine); US group received conventional ultrasound therapy over the all active TPs on trapezius muscle for 10 min a day for 15 sessions. Outcome measures were performed before the treatment course and at the end of a 15-session course of treatment. Student T, Mann-Whitney U, chi-square and Wilcoxon tests were used for statistical analysis. At the end of the therapy, there was statistically significant decrease in both PH group and US group in terms of number of trigger point (NTP) (p = 0.001, p = 0.029), pain intensity on movement (p = 0.001 vs. 0.002) and right/left cervical lateral ROMs (p = 0.001/p = 0.001, p = 0.009/p = 0.020) relative to baseline. The NTP decrease in PH group was significantly higher than that in US group (1.84 ± 1.46 vs. 0.72 ± 1.45; p = 0.01). Pain intensity at rest (p = 0.001) and NPDI scores (p = 0.001) were statistically improvement in only PH group. EMLA cream phonophoresis is more effective than conventional ultrasound therapy in terms of pain and associated neck disability, and it seems the complementary treatment option for MPS.

The Glass Half Empty or Half Full-How Effective Are Long-Term Intrathecal Opioids in Post-herpetic Neuralgia? A Case Series and Review of the Literature

Objectives. Post-herpetic neuralgia (PHN) is a painful complication of herpes zoster infection and a common cause of chronic severe pain in elderly and/or debilitated patients. Although a wide range of treatments have been tried, a substantial number of patients continue to experience pain which remains refractory to all therapies. Increasingly, studies have demonstrated that oral opioids can have a beneficial effect on neuropathic pain. However, to date, few studies have examined the potential benefit(s) of chronic intrathecal opioids in the treatment of PHN. Methods. Long-term outcome results of four PHN patients who had a successful intrathecal opioid trial and underwent implantation of an intrathecal opioid pump were examined. Data were analyzed using univariate analysis of variance. Results. Duration of continuous intrathecal opioid therapy ranged from five to 50 months and mean pain reduction was 41% (range 27-50%) as measured by a verbal pain score (0-100), with the greatest benefit noticed earlier in therapy. Mean 24-hour intrathecal morphine dose was 2.29 mg (range 0.78-3.94 mg). Intrathecal therapy was discontinued in two patients because of opioid side-effects, depression, and loss of efficacy. Revision surgery was required in two cases. Patients most commonly reported improvement in the deep component of their pain, next allodynia, and less so superficial lancinating pain. Conclusions. In conclusion, while a complex therapy, long-term use of intrathecal opioids is well tolerated, doses are titratable, administration is safe, and may help relieve severe short- and long-term neuropathic pain in selected PHN patients. Whether the addition of newer investigational intrathecal agents could improve these results is yet to be determined.

Whither pathogenetic treatments for diabetic polyneuropathy?

Diabetic distal symmetric polyneuropathy (DSPN) occurs in around one-third of patients with diabetes and is associated with significant morbidity and increased mortality. Diagnosis and clinical assessment of DSPN remain a challenge, not only for the physician in clinical practice but also for clinical trials. Optimal diabetes control is generally considered an essential first step in the prevention and management of DSPN. However, glycaemic control alone may be insufficient to prevent the development or progression of DSPN, especially in type 2 diabetes. Near-normoglycaemia is also difficult to achieve in a significant proportion of patients. Although considerable advances have been made in symptomatic pain management, these have not addressed the problem of sensory deficits and have no impact on the underlying pathogenesis of DSPN. There remains a lack of treatment options that effectively target the natural history of the disease. Several pathogenetic treatment approaches have been investigated, but evidence from clinical trials is limited with a number of treatments having shown disappointing results. However, some pathogenetic therapies have shown clinically relevant improvements in neuropathic endpoints in randomised controlled trials, in particular α-lipoic acid and Actovegin. These advances in DSPN disease modification need to be confirmed with further robust evidence from clinical trials together with a better understanding of the mechanisms of action of promising treatments.

Recent advances in the pharmaceutical management of pain

Pain is an unpleasant sensory and emotional experience for patients. Management of pain is the most frequent issue encountered by clinicians and treatment is usually with pharmacological therapy. This review discusses recent pharmaceutical advances in pain management with respect to new modes of analgesic delivery, as well as new analgesic agents and adjuvants that are currently being investigated for their analgesic properties. New modes of administration include transdermal delivery in the form of skin patches, transmucosal delivery, inhalational administration, various patient-controlled devices and extended-release analgesic formulations. Up-to-date research is presented on classical analgesics, such as opioids, anti-inflammatory agents, including cyclo-oxygenase-2 inhibitors and paracetamol (acetaminophen), local anesthetics and ketamine. In addition, newer agents such as antidepressants and antiepileptic drugs as well as medicinal cannabinoids are discussed. As our understanding of the multiple pain pathways involved in the pathogenesis of pain expands, further compounds with analgesic properties will be developed.

Topical pain management with the 5% lidocaine medicated plaster--a review

BACKGROUND

The topical 5% lidocaine medicated plaster is recommended as first-line treatment for localized peripheral neuropathic pain.

SCOPE

In order to provide an overview of the efficacy and safety of the lidocaine plaster in the treatment of different neuropathic pain conditions, all efficacy and safety studies (randomized, controlled, or open-label with well described methodology), case reports, and pharmacological studies on the lidocaine plaster retrieved from a PubMed literature research (1960-March 2012) plus additional references identified from retrieved articles were included.

FINDINGS

The lidocaine plaster is efficacious in the treatment of neuropathic pain symptoms associated with previous herpes zoster infection. Results from a large open-label controlled study suggest that the lidocaine plaster could be at least as effective as systemic pregabalin in the treatment of postherpetic neuralgia and painful diabetic polyneuropathy. Open-label studies indicate efficacy in the treatment of other localized neuropathic pain conditions, such as painful idiopathic sensory polyneuropathy, complex regional pain syndrome, carpal tunnel syndrome sequelae, postsurgical and posttraumatic pain. Quality of life markedly improved in a variety of neuropathic pain conditions and long-term treatment provided sustained relief in patients with neuropathic pain who are responsive to lidocaine plaster. The lidocaine plaster is usually well tolerated. The risk of systemic adverse events and pharmacokinetic interactions with concomitant medication is minimal owing to low systemic exposure.

CONCLUSIONS

Treatment of several, primarily neuropathic and mixed-pain conditions with the 5% lidocaine medicated plaster was found efficacious and safe. Further controlled studies, in particular where only small open-label studies or case reports are available, should be considered.

Pharmacological management of persistent pain in older persons

Drugs without a strong evidence base and outside of recommendations are too often prescribed for older adults. Established guidelines such as Beers criteria have identified both specific medications and certain drug classes as inappropriate for older adults, primarily due to adverse effects. Age-related physiological changes in distribution, metabolism, and elimination often alter the effects of pharmacotherapies in older adults. When designing a therapeutic program, all elements contributing to the pathophysiology of painful conditions should be considered, as well as the mechanisms of action of analgesic drug classes. Both appropriate and inappropriate medications for older adults are detailed herein, as well as their contraindications and potential drug-drug or drug-disease interactions. The number needed to treat (NNT) can be useful in considering efficacy, while the safety of a pharmacotherapy is indicated by the calculated number needed to harm (NNH). The NNT is a measure describing the number of patients who require treatment for every 1 who reaches the therapeutic goal, and the NNH describes the number of participants who manifest side effects; these can further be segregated into numbers who withdraw from studies due to intolerable side effects. These parameters, along with a patient's comorbidities and concomitant medications, should be considered when selecting an analgesic and dose regimen. In addition, practitioners should avoid prescribing multiple-drug therapies that have overlapping pharmacodynamics or that may have an adverse pharmacokinetic interaction.

Modified Jaipur block for the treatment of post-herpetic neuralgia

Post-herpetic neuralgia means pain which occurs for longer than one to three months after the resolution of the rash of herpes zoster. We conducted a study of 30 patients having post herpetic neuralgia. All the patients were treated with modified Jaipur block consisting of local subcutaneous infiltration of 2% Xylocaine, 0.5% bupivacaine and methylprednisolone. In our study, it was seen that 20% patients had complete relief of pain after first injection, 60% patients had complete relief of pain after second injection, 10% patients had complete relief of pain after third injection, and only 10% patients did not respond to treatment. The non-responders were either old (over 60 years) or had pain lasting for more than two years.

Preventing Chronic Pain following Acute Pain: Risk Factors, Preventive Strategies, and their Efficacy

Chronic pain is the leading cause of disability in the United States. The transition from acute to persistent pain is thought to arise from maladaptive neuroplastic mechanisms involving three intertwined processes, peripheral sensitization, central sensitization, and descending modulation. Strategies aimed at preventing persistent pain may target such processes. Models for studying preventive strategies include persistent post-surgical pain (PPP), persistent post-trauma pain (PTP) and post-herpetic neuralgia (PHN). Such entities allow a more defined acute onset of tissue injury after which study of the long-term effects is more easily examined. In this review, we examine the pathophysiology, epidemiology, risk factors, and treatment strategies for the prevention of chronic pain using these models. Both pharmacological and interventional approaches are described, as well as a discussion of preventive strategies on the horizon.

Post herpetic neuralgia

BACKGROUND

During the past decade, important advances have been made in understanding the epidemiology, pathogenesis, prevention and treatment of post herpetic neuralgia pain as well as treatment of other neuropathic pain conditions. PHN is accepted as a model for management and clinical trials of neuropathic pain of less clear etiologies. In palliative medicine, where the etiology of pain may be nociceptive, neuropathic, or mixed, it is frequently to the research on PHN that we turn in order to extrapolate the data to the patients at hand.

OBJECTIVE

To review and summarize what is known about epidemiology, pathogenesis, clinical features and prevention strategies for post herpetic neuralgia. Discuss the available including the most recent therapeutic options as regards to their mechanism of action, efficacy, safety and tolerability in an attempt to explain the rationale for their use.

CONCLUSION

A multidisciplinary and integrative approach has the best chance of success in the management of patients with PHN pain, a problem that can be often frustrating to the patient and challenging to the clinician. Prevention strategies for PHN include administration of zoster vaccine, treatment with antiviral therapy within 72 hours of rash onset and aggressive pain control. First and second line pharmacotherapy include anticonvulsants, antidepressants, topical lidocaine, high dose capsaicin, and opioids either used individually or in combination. Interventional techniques play a limited role in the management of PHN although some data indicate that Intrathecal methylprednisolone and spinal cord stimulation may be effective.

Chronic pain after trauma

Chronic pain is more common following trauma than often realised. It may be due to nociceptive pain or often include a neuropathic component which can be difficult to treat. There are several pain syndromes, such as complex regional pain syndrome and post-amputation pains, which are specifically associated with trauma. These are described, as are the differences in features of nociceptive and neuropathic pain. This article aims to describe the features of chronic pain following trauma using a bio-psycho-social model. An approach to taking a comprehensive pain history and management options are also considered. A multi-disciplinary team using physiotherapists and psychologists is generally required and the importance of good rehabilitation following major trauma cannot be over-emphasised. For the physician, there are a range of pharmaceutical options available and a multimodal approach is recommended. There are also a number of non-invasive therapies on offer such as transcutaneous electrical nerve stimulation and massage. The limited role of invasive procedures is also discussed.

Herpes zoster ophthalmicus

OPINION STATEMENT

The management of herpes zoster (HZ) usually involves a multidisciplinary approach aiming to reduce complications and morbidity. Patients with herpes zoster ophthalmicus (HZO) are referred to ophthalmologists for prevention or treatment of its potential complications. Without prompt detection and treatment, HZO can lead to substantial visual disability. In our practice, we usually evaluate patients with HZO for corneal complications such as epithelial, stromal, and disciform keratitis; anterior uveitis; necrotizing retinitis; and cranial nerve palsies in relation to the eye. These are acute and usually sight-threatening. We recommend oral acyclovir in conjunction with topical 3% acyclovir ointment, lubricants, and steroids for conjunctival, corneal, and uveal inflammation associated with HZO. Persistent vasculitis and neuritis may result in chronic ocular complications, the most important of which are neurotrophic keratitis, mucus plaque keratitis, and lipid degeneration of corneal scars. Postherpetic complications, especially postherpetic neuralgia (PHN), are observed in well over half of patients with HZO. The severe, debilitating, chronic pain of PHN is treated locally with cold compresses and lidocaine cream (5%). These patients also receive systemic treatment with NSAIDs, and our medical colleagues cooperate in managing their depression and excruciating pain. Pain is the predominant symptom in all phases of HZ disease, being reported by up to 90% of patients. Ocular surgery for HZO-related complications is performed only after adequately stabilizing pre-existing ocular inflammation, raised intraocular pressure, dry eye, neurotrophic keratitis, and lagophthalmos. Cranial nerve palsies are common and most often involve the facial nerve, although palsy of the oculomotor, trochlear, and abducens nerves may occur in isolation or (rarely) simultaneously. In our setting, complete ophthalmoplegia is seen more often than isolated palsies, but recovery is usually complete. Vasculitis within the orbital apex (orbital apex syndrome) or brainstem dysfunction is postulated to be the cause of cranial nerve palsies. A vaccine of a lyophilized preparation of the oka strain of live, attenuated varicella-zoster virus is suggested for patients who are at risk of developing HZ and has been shown to boost immunity against HZ virus in older patients.