Parenteral lidocaine for severe intractable pain in six hospice patients continued at home

Lidocaine for Neuropathic Cancer Pain (LiCPain): study protocol for a mixed-methods pilot study

INTRODUCTION

Many patients experience unrelieved neuropathic cancer-related pain. Most current analgesic therapies have psychoactive side effects, lack efficacy data for this indication and have potential medication-related harms. The local anaesthetic lidocaine (lignocaine) has the potential to help manage neuropathic cancer-related pain when administered as an extended, continuous subcutaneous infusion. Data support lidocaine as a promising, safe agent in this setting, warranting further evaluation in robust, randomised controlled trials. This protocol describes the design of a pilot study to evaluate this intervention and explains the pharmacokinetic, efficacy and adverse effects evidence informing the design.

METHODS AND ANALYSIS

A mixed-methods pilot study will determine the feasibility of an international first, definitive phase III trial to evaluate the efficacy and safety of an extended continuous subcutaneous infusion of lidocaine for neuropathic cancer-related pain. This study will comprise: a phase II double-blind randomised controlled parallel-group pilot of subcutaneous infusion of lidocaine hydrochloride 10% w/v (3000 mg/30 mL) or placebo (sodium chloride 0.9%) over 72 hours for neuropathic cancer-related pain, a pharmacokinetic substudy and a qualitative substudy of patients' and carers' experiences. The pilot study will provide important safety data and help inform the methodology of a definitive trial, including testing proposed recruitment strategy, randomisation, outcome measures and patients' acceptability of the methodology, as well as providing a signal of whether this area should be further investigated.

ETHICS AND DISSEMINATION

Participant safety is paramount and standardised assessments for adverse effects are built into the trial protocol. Findings will be published in a peer-reviewed journal and presented at conferences. This study will be considered suitable to progress to a phase III study if there is a completion rate where the CI includes 80% and excludes 60%. The protocol and Patient Information and Consent Form have been approved by Sydney Local Health District (Concord) Human Research Ethics Committee 2019/ETH07984 and University of Technology Sydney ETH17-1820.

TRIAL REGISTRATION NUMBER

ANZCTR ACTRN12617000747325.

Parenteral Lidocaine for Complex Cancer Pain in the Home or Inpatient Hospice Setting: A Review and Synthesis of the Evidence

Background: Cancer pain can remain refractory despite escalating opioids and adjuvants. Systemic Lidocaine is an option, but current approaches are hospital centered. While advantageous in advanced cancer, evidence is lacking for parenteral Lidocaine use in community-based care. Objectives: Review evidence for parenteral lidocaine in complex cancer pain outside the hospital setting. Design: Systematic review of peer-reviewed articles of any study design, including reviews. Search in four databases used keyword variations of "cancer," "pain," "Lidocaine," and "parenteral." Search was extended through reference lists of full texts assessed. Abstracted data from articles screened and selected were synthesized narratively by a palliative care clinician in Singapore. Results: Eight hundred eighty-three articles identified were screened by title and abstract. Twenty-eight full texts were assessed. Seven articles fulfilled criteria for synthesis of findings. A total of 73 patients received parenteral Lidocaine for mixed pains, reported collectively in 1 retrospective chart review, 3 practice guidelines, 2 case series, and 1 case study. Intravenous or subcutaneous Lidocaine was commenced in hospital or hospice and continued at home. Dosages and administration schedules varied, involving slow bolus with continuous infusion or the latter alone, for up to 240 days. All produced positive outcomes, with no severe adverse events. Monitoring included routine vital signs and conscious levels; electrocardiogram, liver, and renal function tests were uncommon. Lidocaine levels were not consistently assessed. Conclusion: Parenteral Lidocaine can be effective and safe in the community setting. More empirical studies are needed to inform patient selection and treatment protocol, and to validate expected outcomes.

Lidocaine Continuous Subcutaneous Infusion for Neuropathic Pain in Hospice Patients: Safety and Efficacy

Lidocaine continuous subcutaneous infusion (L-CSCI) for neuropathic pain in hospice patients has limited evidence for its safety and efficacy, and guidelines are lacking. This study assesses a series of patients admitted to a hospice over a six-month period that had neuropathic pain and received L-CSCI. The primary outcome was improvement in patient-rated distress from pain following L-CSCI titration. Also assessed were changes in oral morphine equivalent dose (OME), frequency of breakthrough medication, functional status, adverse effects and perception of response. Fifteen patients received L-CSCI for an average of 6.7 days (range 1-92). Average pain distress score decreased by 2 or more in six patients. Positive responses to L-CSCI were documented in the clinical notes of 10 patients. Opioid down-titration occurred in four patients. Lidocaine levels were performed in 3 patients but did not change management. Five patients experienced adverse effects attributable to lidocaine and all responded to simple measures. In conclusion, L-CSCI can help manage neuropathic pain in hospice patients, particularly in those who cannot swallow oral medications. Further systematic research is warranted to establish efficacy and tolerability, and to inform guideline development.

The Use of Intravenous Lidocaine for the Management of Acute Pain Secondary to Traumatic Ankle Injury: A Case Report

Sports-related injuries are a frequent cause of visits to the emergency department (ED) across the United States. A majority of these injuries affect the lower extremities with the ankle as the most frequently reported site. Most sports-related injuries are not severe enough to require inpatient hospitalization; however, they often lead to acute distress and pain which require prompt treatment with analgesics. Approximately 22% of patients who presented to the ED required pharmacotherapy for acute pain management. Opioids have been traditionally used for the management of severe acute pain in the ED; however, there are growing concerns for opioid overuse and misuse. As a result, there is growing controversy regarding the appropriate selection of analgesic agents, optimal dosing, and need for outpatient therapy which has contributed to changes in prescribing patterns of opioids in the ED. Lidocaine, a class 1b antiarrhythmic, has been utilized as an analgesic agent. Its use has been documented for the management of intractable chronic pain caused by cancer, stroke, neuropathies, or nephrolithiasis. However, literature describing the use of intravenous lidocaine for the management of acute pain secondary to trauma is limited to a single case series. This case report describes the use of intravenous lidocaine in a 17-year-old male who presented to the ED in acute distress secondary to ankle dislocation and fracture. This report serves to describe additional clinical experience with intravenous lidocaine for the management of acute pain secondary to ankle fracture in the emergency department.

Lidocaine Infusion: A Promising Therapeutic Approach for Chronic Pain

Opioid abuse is a national epidemic in the United States, where it is estimated that a prescription drug overdose death occurs every 19 minutes. While opioids are highly effective in acute and subacute pain control, their use for treatment of chronic pain is controversial. Chronic opioids use is associated with tolerance, dependency, hyperalgesia. Although there are new strategies and practice guidelines to reduce opioid dependence and opioid prescription drug overdose, there has been little focus on development of opioid-sparing therapeutic approaches. Lidocaine infusion has been shown to be successful in controlling pain where other agents have failed. The opioid sparing properties of lidocaine infusion added to its analgesic and antihyperalgesic properties make lidocaine infusion a viable option for pain control in opioid dependent patients. In this review, we provide an overview of the opioid abuse epidemic, and we outline current evidence supporting the potential use of lidocaine infusion as an adjuvant therapeutic approach for management of chronic pain.

Lidocaine and pain management in the emergency department: a review article

Context:

In the present review, the analgesic effects of lidocaine in acute or chronic painful conditions in the emergency department are discussed. Lidocaine, as a medium-acting local anesthetic with short onset time, is well-recognized, not only as a valuable medication for numerous neuropathic pain conditions, but also for the management of both acute and chronic pain.

Evidence Acquisition:

Research studies related to the different applications of lidocaine in the emergency department were collected from different databases including Cochrane library, Medline (Ovid) and PubMed. The pooled data were categorized, summarized and finally compared.

Results:

Our study revealed that lidocaine is broadly used in various therapeutic approaches for different types of pain, such as visceral/central pain, renal colic etc., in the emergency department.

Conclusions:

The antinociceptive properties of lidocaine are derived from multifaceted mechanisms, turning it into a medication that is safe to administer via different routes which makes it available for use in a variety of medical conditions.

Pharmacological treatment of neuropathic cancer pain: a comprehensive review of the current literature

Neuropathic cancer pain (NCP), commonly encountered in clinical practice, may be cancer-related, namely resulting from nervous system tumor invasion, surgical nerve damage during tumor removal, radiation-induced nerve damage and chemotherapy-related neuropathy, or may be of benign origin, unrelated to cancer. A neuropathic component is evident in about 1/3 of cancer pain cases. Although from a pathophysiological perspective NCP may differ from chronic neuropathic pain (NP), such as noncancer-related pain, clinical practice, and limited publications have shown that these two pain entities may share some treatment modalities. For example, co-analgesics have been well integrated into cancer pain-management strategies and are often used as First-Line options for the treatment of NCP. These drugs, including antidepressants and anticonvulsants, are recommended by evidence-based guidelines, whereas, others such as lidocaine patch 5%, are supported by randomized, controlled, clinical data and are included in guidelines for restricted conditions treatment. The vast majority of these drugs have already been proven useful in the management of benign NP syndromes. Treatment decisions for patients with NP can be difficult. The intrinsic difficulties in performing randomized controlled trials in cancer pain have traditionally justified the acceptance of drugs already known to be effective in benign NP for the management of malignant NP, despite the lack of relevant high quality data. Interest in NCP mechanisms and pharmacotherapy has increased, resulting in significant mechanism-based treatment advances for the future. In this comprehensive review, we present the latest knowledge regarding NCP pharmacological management.

A phase II pilot study to evaluate use of intravenous lidocaine for opioid-refractory pain in cancer patients

Opioid-refractory pain is distressing because it is notoriously difficult to treat. Relief from adjuvant therapies often occurs after a lag time. Retrospective evidence points to a role for intravenous (IV) lidocaine in this setting for pain relief. This study was planned as a randomized, double-blind, placebo-controlled, crossover study in which eligible patients received both lidocaine and placebo infusions separated by two weeks. Primary endpoints were magnitude and duration of pain relief. Fifty patients were included in the study. Pain relief was significantly better (P<0.001) and more patients reported a decrease in analgesic requirements (P=0.0012) after lidocaine infusion than after placebo. Onset of analgesia was noted at a mean of 40+/-16.28 minutes after initiation of infusion of IV lidocaine. Mean duration of this analgesia, 9.34+/-2.58 days after the single infusion, was significantly longer than that for placebo (P<0.01). Side effects observed were tinnitus, perioral numbness, sedation, light-headedness, and headache. All side effects were self-limited and did not require any intervention except termination of lidocaine infusion in one case. These data demonstrate that a single IV infusion of lidocaine provided a significantly greater magnitude and duration of pain relief than placebo infusion in opioid-refractory patients with cancer pain. Side effects were tolerable. It is thus a promising modality worth investigating further to establish guidelines for its use in cancer patients with opioid-refractory pain.

Flecainide for the treatment of chronic neuropathic pain: a Phase II trial

BACKGROUND

Management of neuropathic pain is challenging. Medications that interfere with sodium channel transport, such as lidocaine, mexilitene and flecainide, are promising as analgesics.

OBJECTIVE

In a general population of patients with a working diagnosis of neuropathic pain, whether if flecainide produces enough of an improvement in pain to warrant further clinical study is determined.

DESIGN

Phase I/II prospective exploratory clinical trial. Eligible patients were observed for week 1, then 50 mg flecainide was administered twice daily for week 2 and then administered 100 mg twice daily for week 3. SETTING/ SUBJECTS: Multi-institutional members of the Eastern Co-operative Oncology Group. Patients had neuropathic pain diagnosed by their oncologists as defined by the International Association for the Study of Pain and a diagnosis of cancer or AIDS.

MEASUREMENTS

The Wisconsin Brief Pain Inventory was used. The primary endpoint was a decrease of 3 points (0-10 numerical scale) or a decrease of 50% in the worst pain rating at either day 15 or day 22 relative to the average of days 1 and 8 ratings.

RESULTS

Nineteen patients were registered for the study. Four patients were ineligible. Of the remaining 15, one was unevaluable due to incomplete pain rating. Four out of 14 patients had an average drop of 5 points or 53% in their worst pain ratings on a 0-10 numerical scale of pain. No patients withdrew from study because of toxicity. There were no life-threatening or lethal toxicities. All patients were alive at the time of the analysis.

CONCLUSIONS

Flecainide produced a 30% response rate. Response in this study was defined to be highly relevant and clinically significant reduction in pain. The drug merits study in a randomized placebo-controlled trial.

Initial Experiences with Subcutaneous Recombinant Human Hyaluronidase

We report here our retrospective observations on the use of recombinant human hyaluronidase (rHuPH20) for the facilitation of subcutaneous hydration and drug infusion. Thirty-two patients were treated with rHuPH20 in a hospice setting over a 6-month period. Of these, 26 received this agent to enhance hypodermoclysis with standard hydration fluids for symptom control of delirium, myoclonus and mild to moderate dehydration. Flow rates up to 500 mL/hr were attained without difficulty. Electrolyte replacement in hydration fluid was achieved without incident in 5 patients receiving potassium and in 1 patient receiving both potassium and magnesium. In addition to use for hydration, 6 patients received recombinant human hyaluronidase to enhance subcutaneous infusion of 9 medications, primarily because the medication dosage required subcutaneous flow rates greater than the standard 3 mL/hr. There were no significant adverse events. Induration at the infusion site occurred in 1 patient receiving hydration and higher than expected serum lidocaine concentration was observed in another patient. Based on our positive initial experience with recombinant human hyaluronidase, there is interest in expanding its use in our facility in both the inpatient and outpatient settings.

Intravenous lidocaine relieves severe pain: results of an inpatient hospice chart review

BACKGROUND

Parenteral lidocaine has been reported to relieve neuropathic pain and/or pain refractory to opioid therapy.

METHOD

A retrospective chart review of 768 consecutive patients acutely admitted to a hospice inpatient unit was performed to assess the efficacy and tolerability of parenteral lidocaine for pain relief.

RESULTS

Eighty-two patients (approximately 11%) received parenteral lidocaine. Typically, a patient received a parenteral bolus and pain relief was evaluated 30 minutes later. If there was an effect, a continuous infusion was started. Sixty-one patients receiving lidocaine were evaluable for pain relief response. Fifty patients (82% of evaluable patients) reported a major response of their pain to lidocaine. Five patients (8% of evaluable patients) reported a partial response. Six (10% of evaluable patients) reported no benefit.

DISCUSSION

Evaluable patients in an opioid refractory class had a 91% major response rate to lidocaine. Overall, lidocaine was well tolerated. Approximately 30% of evaluable patients reported some adverse event; the most common being lethargy. However, the effect was not clearly related to lidocaine.

CONCLUSION

Parenteral lidocaine appears to be rapidly effective for opioid refractory pain and is well tolerated. A randomized controlled trial is needed to confirm these impressive but preliminary uncontrolled results.