Therapeutic effects of lidocaine patch on myofascial pain syndrome of the upper trapezius: a randomized, double-blind, placebo-controlled study

Lidocaine patch for treatment of acute localized pain in the emergency department: a systematic review and meta-analysis

OBJECTIVE

Lidocaine patches are commonly prescribed for acute localized pain. Most of the existing evidence is, however, derived from postoperative or chronic pain. The objective of this study is to assess the efficacy and safety of lidocaine patch compared to placebo patch or nonsteroidal anti-inflammatory drugs (NSAIDs) for acute localized pain.

METHODS

Systematic review and meta-analysis of trials randomizing patients with acute localized pain to lidocaine patch versus placebo patch or NSAIDs.

OUTCOMES

Change in pain score (any validated scale) from baseline to a specific time endpoint (primary efficacy); adverse events (primary harm), and time to exit the study due to reaching a pain relief target (secondary). We used Cochrane revised tool to assess the risk of bias and GRADE to rate the quality of evidence. The meta-analysis was performed using a random-effects model and Cochrane Q test for heterogeneity. Data were summarized as risk ratios and weighted mean differences with 95% confidence interval (CI).

RESULTS

We conducted a comprehensive search of MEDLINE, EMBASE, and other major databases, identifying 10 randomized controlled trials with a total of 523 patients. These trials collectively found that lidocaine patches were more effective in controlling both musculoskeletal and neuropathic pain compared to placebo patches. Due to heterogeneity among the studies, we did not pool the efficacy data. The risk of adverse events was similar between the groups (risk ratio: 0.90; 95% CI: 0.48-1.67; moderate-quality evidence). In the two trials comparing lidocaine patches with NSAIDs, there was no statistically significant difference in pain relief between the treatments.

CONCLUSION

Low to moderate-quality evidence from small trials supports the efficacy and safety of lidocaine patch for the treatment of acute localized pain.

Multicenter, Randomized, Placebo-controlled Crossover Trial Evaluating Topical Lidocaine for Mechanical Cervical Pain

BACKGROUND

There are few efficacious treatments for mechanical neck pain, with controlled trials suggesting efficacy for muscle relaxants and topical nonsteroidal anti-inflammatory drugs. Although studies evaluating topical lidocaine for back pain have been disappointing, the more superficial location of the cervical musculature suggests a possible role for topical local anesthetics.

METHODS

This study was a randomized, double-blind, placebo-controlled crossover trial performed at four U.S. military, Veterans Administration, academic, and private practice sites, in which 76 patients were randomized to receive either placebo followed by lidocaine patch for 4-week intervals (group 1) or a lidocaine-then-placebo patch sequence. The primary outcome measure was mean reduction in average neck pain, with a positive categorical outcome designated as a reduction of at least 2 points in average neck pain coupled with at least a 5-point score of 7 points on the Patient Global Impression of Change scale at the 4-week endpoint.

RESULTS

For the primary outcome, the median reduction in average neck pain score was -1.0 (interquartile range, -2.0, 0.0) for the lidocaine phase versus -0.5 (interquartile range, -2.0, 0.0) for placebo treatment (P = 0.17). During lidocaine treatment, 27.7% of patients experienced a positive outcome versus 14.9% during the placebo phase (P = 0.073). There were no significant differences between treatments for secondary outcomes, although a carryover effect on pain pressure threshold was observed for the lidocaine phase (P = 0.015). A total of 27.5% of patients in the lidocaine group and 20.5% in the placebo group experienced minor reactions, the most common of which was pruritis (P = 0.36).

CONCLUSIONS

The differences favoring lidocaine were small and nonsignificant, but the trend toward superiority of lidocaine suggests more aggressive phenotyping and applying formulations with greater penetrance may provide clinically meaningful benefit.

EDITOR’S PERSPECTIVE

Comparative effectiveness of noninvasive therapeutic interventions for myofascial pain syndrome: a network meta-analysis of randomized controlled trials

BACKGROUND

Myofascial pain syndrome (MPS) has an impact on physical health and quality of life for patients, with various noninvasive methods used for relieving myofascial pain. The authors aimed to compare the effectiveness of different noninvasive therapeutic interventions for MPS.

MATERIALS AND METHODS

The authors searched PubMed, Embase, CINAHL Complete, Web of Science, Cochrane, and Scopus to identify randomized controlled trials describing the effects of any noninvasive treatments in patients with MPS. The primary outcome was pain intensity, while pressure pain threshold and pain-related disability were secondary outcomes.

RESULTS

The analysis included 40 studies. Manual therapy [mean difference (MD) of pain: -1.60, 95% CI: -2.17 to -1.03; MD of pressure pain threshold: 0.52, 95% CI: 0.19 to 0.86; MD of pain-related disability: -5.34, 95% CI: -8.09 to -2.58], laser therapy (MD of pain: -1.15, 95% CI: -1.83 to -0.46; MD of pressure pain threshold: 1.00, 95% CI: 0.46 to 1.54; MD of pain-related disability: -4.58, 95% CI: -7.80 to -1.36), extracorporeal shock wave therapy (MD of pain: -1.61, 95% CI: -2.43 to -0.78; MD of pressure pain threshold: 0.84, 95% CI: 0.33 to 1.35; MD of pain-related disability: -5.78, 95% CI: -9.45 to -2.12), and ultrasound therapy (MD of pain: -1.54, 95% CI: -2.24 to -0.84; MD of pressure pain threshold: 0.77, 95% CI: 0.31 to 1.22) were more effective than no treatment.

CONCLUSION

Our findings support that manual therapy, laser therapy, and extracorporeal shock wave therapy could effectively reduce pain intensity, pressure pain threshold, and pain-related disability with statistical significance when compared with placebo. This finding may provide clinicians with appropriate therapeutic modalities for patients with MPS among different scenarios.

Advances in the management of fibromyalgia: what is the state of the art?

INTRODUCTION

Fibromyalgia (FM) is a chronic pain syndrome associated with fatigue, insomnia, dyscognition, and emotional distress. Critical illness mechanisms include central sensitization to nociceptive and non-nociceptive stimuli often resulting in hypersensitivity to all sensory input.

AREAS COVERED

The clinical presentation of FM can vary widely and therefore requires therapies tailored to each patient's set of symptoms. This manuscript examines currently prescribed therapeutic approaches supported by empirical evidence as well as promising novel treatments. Although pharmacological therapy until now has been only moderately effective for FM symptoms, it represents a critical component of every treatment plan.

EXPERT OPINION

Currently approved pharmacological therapies for FM symptoms have limited but proven effectiveness. Novel therapies with cannabinoids and naltrexone appear promising. Recent functional imaging studies of FM have discovered multiple brain network abnormalities that may provide novel targets for mechanism-based therapies. Future treatment approaches, however, need to improve more than clinical pain but also other FM domains like fatigue, insomnia, and distress.

Treatment and management of myofascial pain syndrome

Myofascial Pain Syndrome (MPS) is a regional pain disorder that affects every age-group and is characterized by the presence of trigger points (TrPs) within muscles or fascia. MPS is typically diagnosed via physical exam, and the general agreement for diagnostic criteria includes the presence of TrPs, pain upon palpation, a referred pain pattern, and a local twitch response. The prevalence of MPS among patients presenting to medical clinics due to pain ranges anywhere from 30 to 93%. This may be due to the lack of clear criteria and guidelines in diagnosing MPS. Despite the prevalence of MPS, its pathophysiology remains incompletely understood. There are many different ways to manage and treat MPS. Some include exercise, TrP injections, medications, and other alternative therapies. More research is needed to form uniformly-accepted diagnostic criteria and treatments.

Local Anesthetics: Pharmacology and Special Preparations

Local anesthetics are the only class of drugs that can block transduction and transmission of nociception. Physical properties, mechanism of action, and pharmacokinetics of this class of drugs are reviewed in this article. The clinical use, such intravenous administration of lidocaine, and local and systemic toxic effects are covered. A review of current studies published in the human and veterinary literature on lidocaine patches (Lidoderm) and liposomal bupivacaine (Experal and Nocita) are discussed.

Alternatives to Opioids in the Pharmacologic Management of Chronic Pain Syndromes: A Narrative Review of Randomized, Controlled, and Blinded Clinical Trials

Chronic pain exerts a tremendous burden on individuals and societies. If one views chronic pain as a single disease entity, then it is the most common and costly medical condition. At present, medical professionals who treat patients in chronic pain are recommended to provide comprehensive and multidisciplinary treatments, which may include pharmacotherapy. Many providers use nonopioid medications to treat chronic pain; however, for some patients, opioid analgesics are the exclusive treatment of chronic pain. However, there is currently an epidemic of opioid use in the United States, and recent guidelines from the Centers for Disease Control (CDC) have recommended that the use of opioids for nonmalignant chronic pain be used only in certain circumstances. The goal of this review was to report the current body of evidence-based medicine gained from prospective, randomized-controlled, blinded studies on the use of nonopioid analgesics for the most common noncancer chronic pain conditions. A total of 9566 studies were obtained during literature searches, and 271 of these met inclusion for this review. Overall, while many nonopioid analgesics have been found to be effective in reducing pain for many chronic pain conditions, it is evident that the number of high-quality studies is lacking, and the effect sizes noted in many studies are not considered to be clinically significant despite statistical significance. More research is needed to determine effective and mechanism-based treatments for the chronic pain syndromes discussed in this review. Utilization of rigorous and homogeneous research methodology would likely allow for better consistency and reproducibility, which is of utmost importance in guiding evidence-based care.

Anatomical versus functional motor points of selected upper body muscles

INTRODUCTION

In this study we aimed to identify nerve entry points (NEPs) of superficial skeletal muscles obtained by dissection of 20 human cadavers and compared them with motor points (MP) obtained previously by electrical stimulation.

METHODS

The biceps brachii (BB), trapezius (TZ), latissimus dorsi (LD), pectoralis major (Pmaj), and pectoralis minor (Pmin) muscles were dissected from human cadavers. NEP data (mean ± standard deviation) from each muscle were calculated. F-tests with Bonferroni corrections were used to compare NEPs and MPs.

RESULTS

The number of NEPs was 2 in BB, 1 in Pmin, 4 in TZ, and 3 in LD, whereas the total number in Pmaj varied from 3 to 5. NEPs and MPs were statistically equal only in Pmin and in the descending part of TZ.

DISCUSSION

The findings show crucial differences between NEPs and MPs, possibly impacting the effectiveness of several medical treatment strategies. Muscle Nerve 57: 460-465, 2018.

Advances in topical analgesics

PURPOSE OF REVIEW

The recent increase in opioid consumption in the modern world prompted pain physicians to find new and improved solutions to tackle chronic, refractory pain syndromes. Topical analgesics are emerging as a valued multimodal analgesic arm in the fight against chronic pain.

RECENT FINDINGS

New and improved topical formulations have emerged as effective tools to treat chronic refractory pain. In addition to formulations manufactured by the pharmaceutical industry, there has been a recent interest in mixed topical products by local, regional and national compounding pharmacies. This review will focus on advances in topical analgesics, especially their role as an effective analgesic in nociceptive and neuropathic refractory pain states. We will explore topical analgesics' mechanisms of action and their efficacy as opioid-sparing formulations.

SUMMARY

This review will allow physicians to understand the role of topical agents in the treatment of intractable pain syndromes. Increasing medical providers' familiarity with these agents will allow their incorporation as part of a complex analgesic regimen for an improved pain management plan benefiting the patient population at large.

Treatment of myofascial pain syndrome with lidocaine injection and physical therapy, alone or in combination: a single blind, randomized, controlled clinical trial

BACKGROUND

Myofascial pain syndrome (MPS) of the shoulder girdle and cervical region is a common musculoskeletal problem that is often chronic or recurrent. Physical therapy (PT) and lidocaine injections (LI) are two treatments with demonstrated effectiveness compared to a control group, however little is known about their combined value. The objective of this study was to determine whether LI into trigger points combined with a PT program would be more effective than each separate treatment alone in improving pain, function, and quality of life in a group of patients with MPS of the shoulder girdle and cervical region.

METHODS

A single-blind, randomized, controlled clinical trial (RCT) was conducted with three parallel groups in the Departments of Physical Medicine and Rehabilitation of two urban hospitals in Medellin, Colombia. One hundred and twenty seven patients with shoulder girdle MPS for more than 6 weeks and pain greater than 40 mm on the visual analog scale (VAS) were assigned to 1 of 3 intervention groups: PT, LI, or the combination of both (PT + LI). The primary outcome was VAS pain rating at 1-month post-treatment. The secondary outcomes included VAS pain rating at 3 months, and, at both 1 and 3 months post-treatment: (a) function, evaluated by hand-back maneuver and the hand-mouth maneuver, (b) quality of life, as measured by sub-scales of the Short Form - 36 (SF-36), and (c) depressive symptoms, as measured by the Patient Health Questionnaire - 9 (PHQ-9). Independent t-tests were used to compare outcomes between groups at 1 month and 3 months post-treatment.

RESULTS

In the per protocol analysis, there were no significant intergroup differences in VAS at 1 month PT + LI, 40.8 [25.3] vs. PT, 37.8 [21.9], p = 0.560 and vs. LI, 44.2 [24.9], p = 0.545. There were also no differences between groups on secondary outcomes except that the PT and PT + LI groups had higher right upper limb hand-back maneuver scores compared to the LI alone group at both 1 and 3 months (p = 0.013 and p = 0.016 respectively).

CONCLUSIONS

The results of this RCT showed that no differences in pain ratings were observed between the individual treatments (PT or LI) compared to the combined treatment of PT and LI. In general, no difference in primary or secondary outcomes was observed between treatments.

TRIAL REGISTRATION

NTC01250184 November 27, 2010.

The topical 5% lidocaine medicated plaster in localized neuropathic pain: a reappraisal of the clinical evidence

Topical 5% lidocaine medicated plasters represent a well-established first-line option for the treatment of peripheral localized neuropathic pain (LNP). This review provides an updated overview of the clinical evidence (randomized, controlled, and open-label clinical studies, real-life daily clinical practice, and case series). The 5% lidocaine medicated plaster effectively provides pain relief in postherpetic neuralgia, and data from a large open-label controlled study indicate that the 5% lidocaine medicated plaster is as effective as systemic pregabalin in postherpetic neuralgia and painful diabetic polyneuropathy but with an improved tolerability profile. Additionally, improved analgesia and fewer side effects were experienced by patients treated synchronously with the 5% lidocaine medicated plaster, further demonstrating the value of multimodal analgesia in LNP. The 5% lidocaine medicated plaster provides continued benefit after long-term (≤7 years) use and is also effective in various other LNP conditions. Minor application-site reactions are the most common adverse events associated with the 5% lidocaine medicated plaster; there is minimal risk of systemic adverse events and drug–drug interactions. Although further well-controlled studies are warranted, the 5% lidocaine medicated plaster is efficacious and safe in LNP and may have particular clinical benefit in elderly and/or medically compromised patients because of the low incidence of adverse events.

Cancer Pain Management

Safe, effective, and evidence-based management of cancer-related pain is a cornerstone of comprehensive cancer care. Despite increasing interest in and efforts to improve its management, pain remains poorly controlled in nearly half of all patients with cancer, with little change in the past 20 years. Limited training in pain assessment and management, overestimation of providers' own skills to treat pain, and failure to refer patients to pain specialists can result in suboptimal pain management with devastating effects on quality of life, physical functioning, and increased psychological distress. From a thorough assessment of cancer-related pain to appropriate treatments that may include opiates, adjuvant medications, nerve blocks, and nondrug interventions, this article is intended as a brief overview of the mechanisms and types of pain as well as a review of current, new, and promising approaches to its management.

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.

Symptom management in the older adult: 2015 update

This article updates the 2002 Jamie von Roenn article about "the palliation of commonly observed symptoms in older patients, including pain, neuropsychiatric, gastrointestinal, and respiratory symptoms." When palliative care was last covered in Clinics in Geriatric Medicine, President George W. Bush had just signed the No Child Left Behind Act, Homeland Security was being established, Michael Jackson won the Artist of the Century Award at the American Music Awards, and gas cost $1.61 a gallon. What has changed in the last decade and a half?

Mechanisms of Myofascial Pain

Myofascial pain syndrome is an important health problem. It affects a majority of the general population, impairs mobility, causes pain, and reduces the overall sense of well-being. Underlying this syndrome is the existence of painful taut bands of muscle that contain discrete, hypersensitive foci called myofascial trigger points. In spite of the significant impact on public health, a clear mechanistic understanding of the disorder does not exist. This is likely due to the complex nature of the disorder which involves the integration of cellular signaling, excitation-contraction coupling, neuromuscular inputs, local circulation, and energy metabolism. The difficulties are further exacerbated by the lack of an animal model for myofascial pain to test mechanistic hypothesis. In this review, current theories for myofascial pain are presented and their relative strengths and weaknesses are discussed. Based on new findings linking mechanoactivation of reactive oxygen species signaling to destabilized calcium signaling, we put forth a novel mechanistic hypothesis for the initiation and maintenance of myofascial trigger points. It is hoped that this lays a new foundation for understanding myofascial pain syndrome and how current therapies work, and gives key insights that will lead to the improvement of therapies for its treatment.