Intravenous Lidocaine for Neuropathic Pain: A Retrospective Analysis of Tolerability and Efficacy

Long-term pain outcomes after serial lidocaine infusion in participants with recent onset of peripheral neuropathic pain: A pilot double-blind, randomized, placebo-controlled trial

BACKGROUND

This study investigated the outcomes up to 12 weeks after serial lidocaine infusion for early-onset peripheral neuropathic pain.

METHODS

This pilot double-blind, randomized, 2-arm placebo-controlled trial recruited 50 participants with onset of peripheral neuropathic pain within the past 6 months and randomized them to either receive lidocaine (3 mg/kg) in normal saline (50 mL) intravenous infusion over 1 hour (lidocaine group) once a week for 4 weeks or 50 mL of normal saline infusion (placebo group) once a week for 4 weeks. Twenty-nine participants completed the protocol; 15 participants were assigned to the lidocaine group and 14 to the placebo group. The outcomes were pain intensity assessed using a numerical rating scale (NRS), quality of life assessed using EuroQol-Five Dimensions-Five Levels questionnaire (EQ-5D-5L), psychological function using the Thai version of the 21-item Depression Anxiety Stress Scales (DASS-21), pain medication use, and adverse effects, all assessed at baseline (BL) and again at 4, 8, and 12 weeks following randomization.

RESULTS

The reported tramadol use at 8 and 12 weeks following the first infusion was significantly lower in the lidocaine group (P = .023). No other significant between-group differences were observed at any time point or for any other outcome, and no serious adverse events were observed.

CONCLUSION

Multiple lidocaine infusions of 3 mg/kg once a week for 4 weeks in participants with recent onset of peripheral neuropathic pain demonstrated no significant benefits in pain intensity, quality of life, or psychological outcomes. At most, this treatment may result in less tramadol use.

The Pharmacological Treatment of Neuropathic Pain in Children

The International Association for the Study of Pain (IASP) defines neuropathic pain as pain caused by a lesion or disease of the somatosensory nervous system. It is characterized as a clinical condition in which diagnostic studies reveal an underlying cause of an abnormality in the peripheral or central nervous system. Many common causes of neuropathic pain in adults are rare in children. The purpose of this focused narrative review is, to 1) provide an overview of neuropathic pain in children, 2) highlight unique considerations related to the diagnosis and mechanisms of neuropathic pain in children, and 3) perform a comprehensive analysis of the pharmacological treatments available. We emphasize that data for routine use of pharmacological agents in children with neuropathic pain are largely inferred from adult literature with little research performed on pediatric populations, yet have clear evidence of harms to pediatric patients. Based on these findings, we propose risk mitigation strategies such as utilizing topical treatments whenever possible, assessing pain phenotyping to guide drug class choice, and considering pharmaceuticals in the broader context of the multidisciplinary treatment of pediatric pain. Furthermore, we highlight important directions for future research on pediatric neuropathic pain treatment.

Intravenous lidocaine bolus for reducing nefopam-induced venous pain: A randomized, intrasubject comparison trial

Background and Aims

Intravenous nefopam reduces postoperative pain and opioid consumption but can cause infusion-related pain. We aimed to investigate whether lidocaine can effectively reduce this pain.

Material and Methods

This prospective, randomized, double-blind, controlled, intrasubject comparison trial included 42 patients (20-60 years) undergoing elective surgery under regional or peripheral anesthesia. In the postanesthesia care unit, two 50 mL syringes containing nefopam (20 mg) diluted in saline (100 mL) were sequentially infused in 15 min into venous catheters in the left and right arms. Patients were randomly assigned to the "left side" or "right side" group based on the arm in which a bolus of 1% lidocaine (2 mL) (study group) was administered before nefopam infusion. Normal saline (2 mL) was administered on the control side. Numerical Rating Scale scores and the incidence of pain (scores > 3) and nausea or vomiting were recorded at 1, 5, 10, and 15 min.

Results

The analysis included 42 patients (84 infusions). Compared with the placebo, lidocaine lowered the mean infusion-related pain at 1 (0.07 vs. 2.21, P < 0.001), 5 (2 vs. 4.21, P < 0.001), 10 (2.02 vs. 3.95, P < 0.001), and 15 min (1.62 vs. 3.16, P = 0.003). At 5 min, significantly higher percentages of infusion sites with moderate and higher pain scores (> 3) were observed on the control side (30.95% vs. 14.29%, P = 0.000). Seven patients exhibited nausea or vomiting (16.7%).

Conclusion

For the nefopam infusion rate and concentration that we used, a 20 mg lidocaine pretreatment bolus significantly reduces infusion-related pain.

Systemic Lidocaine Infusions for Pediatric Patients with Cancer-Related Pain

Pediatric patients with cancer experience significant distress from both treatment and cancer-related pain. Careful selection of an analgesic regimen should be based upon individual patient factors, including the level of pain, response to therapy, and physiologic profile. Refractory pain is a therapeutic dilemma frequently encountered in the pediatric cancer setting. Systemic lidocaine infusions have been described as both safe and efficacious, as prior studies show patients reporting decreased pain scores and improved quality of life after lidocaine treatment. Given the favorable side effect profile of lidocaine, it has the potential to be considered for analgesia in the setting of refractory pain. This review discusses the use of systemic lidocaine infusions for analgesia in pediatric oncology patients with cancer-related pain.

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.

Computational design of peptides to target NaV1.7 channel with high potency and selectivity for the treatment of pain

The voltage-gated sodium Na_V1.7 channel plays a key role as a mediator of action potential propagation in C-fiber nociceptors and is an established molecular target for pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula venom that inhibits human Na_V1.7 activation. Here we used available structural and experimental data to guide Rosetta design of potent and selective ProTx-II-based peptide inhibitors of human Na_V1.7 channels. Functional testing of designed peptides using electrophysiology identified the PTx2-3127 and PTx2-3258 peptides with IC₅₀s of 7 nM and 4 nM for hNa_V1.7 and more than 1000-fold selectivity over human Na_V1.1, Na_V1.3, Na_V1.4, Na_V1.5, Na_V1.8, and Na_V1.9 channels. PTx2-3127 inhibits Na_V1.7 currents in mouse and human sensory neurons and shows efficacy in rat models of chronic and thermal pain when administered intrathecally. Rationally designed peptide inhibitors of human Na_V1.7 channels have transformative potential to define a new class of biologics to treat pain.

Nursing Care During Lidocaine Infusion Therapy for Chronic Pain

Pain is a universal event, and perianesthesia nurses provide a pivotal role in the assessment, treatment, and management of the physical and emotional responses to pain. Chronic neuropathic pain is particularly resistant to treatment, and patients often present after many failed therapies with multiple co-morbidities and complex medication histories. With more and more perianesthesia nurses involved with chronic pain management, it is imperative they understand the special nursing care needs of patients receiving intravenous lidocaine infusion therapy.

Lidocaine infusions and reduced opioid consumption-Retrospective experience in pediatric hematology and oncology patients with refractory pain

BACKGROUND

Despite a more robust experience with lidocaine infusions for pain management in adults and general pediatric population, there is limited evidence of efficacy of lidocaine infusions for pain management in patients with pediatric hematology and oncology diagnoses.

METHODS

Data pertaining to continuous intravenous lidocaine infusions prescribed between January 2009 and June 2019 were reviewed, including patients' demographic characteristics, hematology/oncology and pain diagnoses, concurrent pain medications, and lidocaine infusion dose regimens and duration. Pain scores and opioid consumption calculations based on morphine equivalent doses (mg/kg/day) of patient-controlled analgesia were collected 1 day before infusion (D1), during infusion (D2), and 1 day after infusion (D3).

RESULTS

The mean opioid consumption on D3 was significantly lower than that on D2 (p = .01). The pain scores on D3 were significantly lower than those on D1 when measured as average pain scores per 24 hours (p < .001) or as single pain scores immediately before and after infusions (p < .001). No significant associations were found between cumulative doses of lidocaine (loading dose plus total infusion dose) and either a decrease in the opioid consumption or a decrease in pain scores.

CONCLUSIONS

In this retrospective series of pediatric hematology and oncology cases, we report positive outcomes in reducing opioid consumption and pain scores after lidocaine infusions. Prospective investigations designed in a collaborative, multi-institutional fashion, including a variety of pediatric populations are needed to further investigate the efficacy of lidocaine infusions.

Intravenous lidocaine in cancer-related neuropathic pain: case series

Introduction: Administering systemic lidocaine has been shown to deliver effective analgesia for both cancer-related and non-cancer pain. Adverse effects and toxicity are rare with controlled administration. Objective: To report the results obtained after the indication to manage with IV lidocaine infusion to control neuropathic pain flares in 9 cancer patients. Methodology: Observational, descriptive, case series-type study. A search was conducted in the files of the Pain and Palliative Care Service of the National Cancer Institute - Instituto Nacional de Cancerología - in Bogotá. Patients over 18 years old diagnosed with cancer, who experienced high intensity neuropathic pain and with the cognitive ability to rate their pain in a numerical analogue scale (NAS), without any absolute contraindications for the use of IV lidocaine were included; patients were assessed between September 27 and November 21, 2019. Results: 9 patients experiencing a pain flare-up which was characterized as neuropathic were registered, of which 89 % had some improvement following the administration of an initial lidocaine bolus. After one hour, 60 % reported over 40% improvement in the initial NAS. After 24 hours all patients had experienced some improvement, with a reduction of 46% in the pain scale as compared to the baseline. Conclusions: In this series of cases, the intravenous infusion of lidocaine as an option for the management of neuropathic pain flares seems to reduce pain intensity following the initial bolus administration.

Role of Intravenous Lidocaine Infusion in the Treatment of Peripheral Neuropathy

PURPOSE OF REVIEW

This is a comprehensive review of the literature regarding intravenous lidocaine infusion to treat peripheral neuropathy. The clinical symptoms of peripheral neuropathy occur on a broad spectrum and stem from many etiologies resulting in complex treatment approaches. This review presents the background, evidence, and indications for the use of intravenous lidocaine infusions as a treatment option for this condition.

RECENT FINDINGS

The clinical range of peripheral neuropathy symptoms includes pain, numbness, muscle weakness, paresthesia, balance difficulty, and autonomic dysfunction. However, severe neuropathic pain remains one of the most debilitating symptoms that significantly affects the quality of life. Current treatment options include antidepressants, anticonvulsants, and, in some cases, opiates, but these are often ineffective, creating the need for other therapeutic approaches.The pathophysiology of neuropathic pain involves sodium channels which create abnormal pain responses. Intravenous lidocaine primarily functions by inhibiting membrane sodium channels which desensitize peripheral nociceptors, thus creating an analgesic effect. The research in using intravenous lidocaine for neuropathic pain is not fully complete and requires further evaluation.

SUMMARY

Peripheral neuropathy is a manifestation commonly resulting from diabetes, alcohol abuse, vitamin deficiencies, and chemotherapy, among other causes. One of the most significant complications is neuropathic pain which is often resistant to multi-modal therapeutic regimens. Intravenous lidocaine infusions are a newer treatment option for neuropathic pain, which have additional anti-inflammatory effects with a minimal side effect profile. Studies have concluded it effectively treats neuropathic pain for weeks after administration, but results are variable depending on specific procedures. Further research, including additional direct comparison studies, should be conducted to fully evaluate this drug's usefulness.

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.

Subcutaneous Lidocaine Infusion for Complex Cancer Pain: A Retrospective Review

This retrospective review assesses the safety and efficacy of subcutaneous lidocaine infusions for complex cancer pain, in a specialist palliative care unit. A retrospective chart review was undertaken of 18 infusions over a 2-year period. Data collected included patient demographics, use of adjuvant analgesics, methadone use and opioid requirements (as oral morphine equivalent daily dose, oMEDD) at three time periods: 24 hours prior to starting infusion, 24 hours after starting infusion and 24 hours after stopping infusion. Data was collected on infusion characteristics, adverse events and the patient's perception of lidocaine efficacy. Eighteen infusions were analyzed; all patients had metastatic cancer with 83.3% having stage IV disease. The majority of patients were prescribed three or more adjuvant analgesics, in addition, methadone was prescribed in 16 oMEDD use both 24 hours after starting, and 24 hours after stopping the lidocaine infusions. Events were reported in three out of 18 infusions, only one minor adverse event was attributed to lidocaine. Thirteen out of 18 infusions were perceived, by patients, to be effective for pain. This retrospective review has shown that a subcutaneous lidocaine infusion is a safe and effective means of managing complex cancer pain in a specialist palliative care unit.

Repeated Intravenous Lidocaine Infusions for Patients with Fibromyalgia: Higher Doses of Lidocaine Have a Stronger and Longer-Lasting Effect on Pain Reduction

OBJECTIVES

To determine the effect of escalating doses of lidocaine infusion with or without added magnesium on pain levels and the duration of pain relief in patients with fibromyalgia (FM).

METHODS

A retrospective chart review of 74 patients diagnosed with FM who underwent at least three escalating doses of intravenous (IV) lidocaine infusions (5 mg/kg of body weight, 7.5 mg/kg, and 7.5 mg/kg of lidocaine + 2.5 g of magnesium sulfate) was conducted. Each patient's subjective impression of change in pain intensity and duration of pain relief after each treatment was recorded, along with an 11-point numeric rating scale (NRS) for pain intensity, immediately before and after each infusion.

RESULTS

Short-term lidocaine analgesia was evaluated by the reduction in NRS pain score according to the patients reported pre- (immediately before treatment) and post-treatment (immediately after treatment) values. There was a statistical difference in the NRS score reduction between doses 5 mg/kg and 7.5 mg/kg of lidocaine (P = 0.009). Long-term analgesia was evaluated at follow-up visits by the patient's subjective impression of change in pain intensity and duration of pain relief. There was a statistical difference in the percentage of pain relief and the mean duration of pain relief between the treatments with 5 mg/kg and 7.5 mg/kg of lidocaine (P = 0.007 and P = 0.003). Although there was a trend of greater response to magnesium sulfate as a beneficial adjunct to the lidocaine infusion, we were unable to find a statistically significant difference for any of the variables studied.

CONCLUSIONS

This study demonstrated that escalating doses of IV lidocaine to 7.5 mg/kg safely and effectively reduced the pain with prolonged effect in a significant number of patients diagnosed with fibromyalgia. Larger, prospective clinical studies are required to confirm this finding.

Small Fiber Polyneuropathy in Hunner Lesion and Non-Hunner Lesion Interstitial Cystitis/Bladder Pain Syndrome

OBJECTIVE

This study aimed to determine whether small fiber polyneuropathy (SFPN) diagnosis differs between Hunner lesion interstitial cystitis/bladder pain syndrome (HL IC/BPS) and non-Hunner lesion IC/BPS (NHL IC/BPS).

METHODS

This was a pilot study of 20 women with IC/BPS. Results from baseline questionnaires, such as Genitourinary Pain Index, Interstitial Cystitis Symptom Index/Interstitial Cystitis Problem Index (ICSI/ICPI), Patient Health Questionnaire-2, were collected.Two punch biopsies were performed on each patient: distal leg and thigh. The samples were evaluated for intraepidermal nerve fiber density. One intraepidermal nerve fiber density less than the fifth percentile, regardless of site, indicated a positive SPFN diagnosis.

RESULTS

Twenty patients were enrolled; 10 HL IC/BPS and 10 NHL IC/BPS. The HL IC/BPS group was found to be significantly older than the NHL IC/BPS group (63 vs 48 years, P = 0.007). No significant differences were found in employment or relationship statuses, or in levels of education or comorbidities between the 2 groups.Sixty percent (6/10) of patients had SFPN in the NHL IC/BPS group compared with 40% (4/10) in the HL IC/BPS group. No significant differences were seen in SFPN positivity (P = 0.3) or Genitourinary Pain Index, Patient Health Questionnaire-2, or Interstitial Cystitis Symptom Index/Interstitial Cystitis Problem Index scores between the NHL and HL IC/BPS groups.

CONCLUSIONS

Similar to previously published studies, 60% of NHL IC/BPS patients in this cohort were positive for SFPN compared with only 40% of the HL IC/BPS patients. Larger studies may be needed to realize the full impact of SFPN in IC/BPS.

Intravenous lidocaine affects oxaliplatin pharmacokinetics in simultaneous infusion

BACKGROUND

Oxaliplatin is a chemotherapeutic agent used to treat malignancies of the gastrointestinal tract. Neuropathy is a frequent dose-limiting side-effect of oxaliplatin therapy, without preventive or curative strategies. Concomitant administration of intravenous lidocaine could be a promising treatment. However, the effect of intravenous lidocaine on oxaliplatin pharmacokinetics was never studied before. We evaluated the effect of lidocaine on the area under the curve and C_max of oxaliplatin as a part of a larger study addressing the prevention and treatment of oxaliplatin induced peripheral neuropathy with lidocaine.

METHODS

In this prospective cross-over trial, patients received an oxaliplatin cycle with and without lidocaine (bolus 1.5 mg kg^-1 followed by 1.5 mg kg^-1 h^-1 in 3 h). Levels of oxaliplatin, measured as ultrafiltrable platinum were determined at 10 min after cessation of oxaliplatin infusion and hourly thereafter. Outcomes are the difference in area under the curve of oxaliplatin (primary) and the difference in the C_max of oxaliplatin (secondary).

RESULTS

No difference in the %Δ area under the curve of oxaliplatin (-2.40 ± 7.66, 90% CI +10.50 to -15.31) was found. However, %Δ C_max of oxaliplatin (-28.72 ± 6.01, 90% CI -18.59 to -38.85) was lower to a statistically significant extent in the chemotherapy cycle with lidocaine. No (serious) adverse events were reported.

CONCLUSIONS

Lidocaine does not affect the area under the curve of oxaliplatin, which is the most important parameter in drug interaction studies and for oxaliplatin treatment effect. The lower C_max in the chemotherapeutic cycle with lidocaine is significant and remarkable, but with an unknown exact mechanism or clinical significance, making further research desirable.

The Analgesic and Emotional Response to Intravenous Lidocaine Infusion in the Treatment of Postherpetic Neuralgia: A Randomized, Double-Blinded, Placebo-controlled Study

OBJECTIVES

This study evaluated the analgesic efficacy and emotional response to intravenous lidocaine infusion compared with placebo in patients with postherpetic neuralgia (PHN).

METHODS

In this randomized, double-blinded study, patients with PHN received 5 mg/kg intravenous lidocaine infusion or placebo. The primary outcome was pain measured by Visual Analogue Scale, Von Frey, and area of allodynia. Moreover, emotional status of anxiety and depression were evaluated by Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS). Quality of life was assessed by Short Form Health Survey 36.

RESULTS

In total, 197 patients were enrolled and eligible data were collected from 183 of those patients. The Visual Analogue Scale scores were reduced to a minimum at 2 weeks (2.74, 2.99) after infusion, but no significant difference was found between the lidocaine and placebo groups. Similar changes were also found in mechanical pain threshold and area of allodynia. However, the lidocaine group was associated with a statistically significant reduction in consumption of analgesics with a relative risk of 6.2 (95% confidence interval [CI], 2.24-17.16). Lidocaine infusion also significantly improved the anxiety and depression status; the values of mean change in anxiety and depression were 3.89 (95% CI, 1.43-6.35) and 4.3 (95% CI, 0.63-7.98), respectively, at 2 weeks. Moreover, improvement was exhibited in Short Form Health Survey 36 health status, with the mean change of 49.81 (95% CI, 28.17-71.46) at 1 week, in particular scores on vitality, physical and emotional role functioning, and mental health.

CONCLUSIONS

The analgesic response of 5 mg/kg lidocaine intravenous infusion is comparable to placebo in patients with PHN, but intravenous lidocaine infusion significantly reduced total analgesic consumption, and improved the overall emotional and health status.

Small Fiber Polyneuropathy Is Prevalent in Patients Experiencing Complex Chronic Pelvic Pain

OBJECTIVE

To demonstrate the prevalence of small fiber polyneuropathy (SFPN) in patients with refractory chronic pelvic pain (CPP).

DESIGN

Retrospective study of prospective database.

SUBJECTS

Participants were complex CPP patients recruited from subspecity referral clinics defined as those who were refractory to initial treatment and/or exhibited comorbid pain syndromes at initial presentation.

METHODS

Comprehensive treatment history for CPP was obtained, and participants referred as above; 3-mm punch biopsies were obtained of the lower extremity and sent to diagnostic reference labs to evaluate for SFPN. The reported lab sensitivity and specificity for SFPN are 78-92% and 65-90%, respectively.

RESULTS

Twenty-five of 39 patients (64%) were positive for SFPN. Comorbid conditions noted in our population included gastroesophageal reflux disease (46%), migraine (38%), irritable bowel syndrome (33%), lower back pain (33%), fibromyalgia (38%), endometriosis (15%), interstitial cystitis (18%), vulvodynia (5%), and other chronic pain syndromes (36%).

CONCLUSIONS

The prevalence of SFPN in our specialty referral patients with complex CPP is remarkably high vs published general population prevalence data (53/100,000). Identification of SFPN in this complex population shifts the focus from undefined syndromes to symptom complexes with linked potentially treatable mechanisms (e.g., SFPN, central sensitization). Most CPP patients with SFPN are undiagnosed. Considering the diagnosis may expand treatment options beyond conventional or so-called adjuvant analgesics. Treatment may expand to therapies such as IV lidocaine, IVIG, or other immunomodulatory options. In addition, the value to the patient of receiving a diagnosis for a multisystem or refractory pain syndrome, often attributed to negative psychologic factors, cannot be underestimated. Identifying SFPN should be contemplated in CPP patients who present with multisystem pain or who have not responded to initial evaluation and management.

Intravenous Lidocaine for Chronic Neuropathic Pain A Systematic Review Addressing Nursing Care

BACKGROUND

The intravenous administration of lidocaine for patients with chronic neuropathic pain is well documented in the literature. However, little is known about the role of the nurse caring for patients receiving the infusion.

AIM

The purpose of this systematic review was to examine and describe common side effects associated with the intravenous administration of lidocaine to patients with chronic neuropathic pain and outline nursing care described in an effort to develop evidence-based protocols for care.

METHOD

A comprehensive search of databases was completed and yielded eleven (n = 11) articles and one care protocol for analysis.

RESULTS

Evidence was appraised and findings suggest intravenous lidocaine has a low risk of causing adverse events, however patients should be monitored closely.

CONCLUSIONS

Nursing care focuses on pain assessment, close observation and intervention if neurological changes occur.

Tertiary Care Clinical Experience with Intravenous Lidocaine Infusions for the Treatment of Chronic Pain

Objective

To evaluate the safety of and long-term pain relief due to intravenous lidocaine infusion for the treatment of chronic pain in a tertiary pain management clinic.

Design

Retrospective chart review.

Methods

Medical records were reviewed from 233 adult chronic pain patients who underwent one to three lidocaine infusions. The initial lidocaine challenge consisted of 1,000 mg/h administered intravenously for up to 30 minutes until infusion was complete, full pain resolution, the patient requested to stop, side effects (SEs) became intolerable, and/or if there were any safety concerns. Subsequent infusions were tailored to patient response. Data reviewed included pain diagnosis, lidocaine dose, SEs, and duration of pain relief documented at a follow-up visit.

Results

Patients primarily had neuropathic pain (80%), were 94% white, 58% were female, and there was an average pain duration of 7.9 years. SEs were usually mild and transient, including perioral tingling, dizziness, tinnitus, and nausea/vomiting, and they were uncommon after the initial infusion. Overall, 41% of patients showed long-lasting pain relief, with positive response to the initial infusion associated with receiving and benefitting from subsequent infusions. Benefit by pain diagnoses varied from 32% to 58%.

Conclusions

Our retrospective study in a heterogeneous population with chronic pain suggests that intravenous lidocaine is a safe treatment. Data also suggest long-term pain relief in a significant proportion of patients. Additional study is important in order to delineate patient selection, determine optimal dosing and treatment frequency, assess pain reduction and duration, and treatment cost-effectiveness.

Intravenous Lidocaine Alleviates the Pain of Propofol Injection by Local Anesthetic and Central Analgesic Effects

Objective

Lidocaine alleviates propofol injection pain. However, whether lidocaine works through a local anesthetic effect at the site of intravenous injection or through a systemic effect on the central nervous system remains unknown. This study aimed to determine the pain-alleviating mechanism of lidocaine.

Design

A randomized controlled study.

Setting

A gastroscopy facility.

Methods

The study was divided into two parts. Part 1 involved 717 patients who were randomly assigned into five groups. Groups PR, RL20, and RL40 received normal saline or saline containing 20 or 40 mg of lidocaine, injected via the vein on the right hand. Groups LL20 and LL40 received 20 or 40 mg of lidocaine, injected via the vein on the left hand. Part 2 involved 378 patients who were randomly assigned into five groups. Groups RL40, RL1.2, and RL1.5 received 40 mg, 1.2 mg/kg, and 1.5 mg/kg of lidocaine, injected via the vein on the right hand. Groups LL1.2 and LL1.5 received 1.2 or 1.5 mg/kg of lidocaine, injected via the vein on the left hand. All received 2 mg/kg of propofol via the vein on the right hand two minutes later. Injection pain and patient satisfaction were recorded.

Results

The incidence of pain of group RL40 was lower than that of group PR. The incidence of pain of group LL1.2 was higher than that of other groups.

Conclusions

A dosage of 40 mg lidocaine is an appropriate dosage to alleviate propofol injection pain within the same vein. Lidocaine reduces propofol injection pain through both a local anesthetic effect and a central analgesic effect when the dosage reaches 1.5 mg/kg.

Recommendations for Evaluation and Management of Pain in Patients With Mucopolysaccharidosis in Latin America

The mucopolysaccharidosis (MPS) constitutes a heterogeneous group of rare genetic disorders caused by enzymatic deficiencies that lead to the accumulation of glycosaminoglycans. Several types of MPS are described, historically numbered from I to IX. Clinical observations strongly suggest the presence of chronic pain in patients with all types of MPS. There are few data in the literature on the evaluation and management of pain in these patients, a fact that can compromise the quality of life even more. Professionals with extensive experience in the care for patients with MPS held a meeting in April 2017 to discuss and propose recommendations for the evaluation and management of pain in patients with MPS in Latin America. This article summarizes the content of the discussions and presents the recommendations produced at the meeting. Patients with MPS present joint, bone, and muscle pain, as well as entrapment syndromes (spinal, optic nerve, carpal tunnel). The panel suggests the use of the following instruments for pain assessment: Face, Legs, Activity, Cry and Consolability Scale for children of up to four years of age and patients unable to communicate their pain; Child Health Assessment Questionnaire Scale; Facial Pain Scale and Numerical Pain Scale for patients of five to <18 years of age; Brief Pain Inventory and Short Form Health Survey 36 scales for patients aged 18 years or older. Based on the scores verified in these scales, the panel proposes pharmacological interventions for pain relief in this population of patients.

WITHDRAWN: Recommendations for evaluation and management of pain in patients with mucopolysaccharidosis in Latin America

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.jpainsymman.2018.03.023. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Interventional treatment for neuropathic pain due to combined cervical radiculopathy and carpal tunnel syndrome: a case report

The coexistence of median and cervical nerve root damage might hide a complex pathophysiology. Here, we describe and discuss the case of a patient suffering from numbness and painful tingling of the hand, whose symptoms were effectively treated with pulsed radiofrequency and epidural administration of bupivacaine and morphine.

Subcutaneous Lidocaine Infusion for Pain in Patients with Cancer

BACKGROUND

Intravenous lidocaine is effective in treating pain. Limited studies have assessed the effectiveness and safety of subcutaneous lidocaine infusions.

METHODS

We conducted a retrospective review of patients with cancer who received subcutaneous lidocaine infusions for pain. Patient characteristics, pain scores and opioid doses before and after lidocaine, and details of infusions were recorded. We identified three time periods of interest. T0 is defined as the 24-hour period immediately before commencing lidocaine treatment. T1 is defined as the 24-hour period before lidocaine was ceased. T2 is defined as the first 24-hour period after lidocaine was ceased. In addition, the overall impression of the effectiveness of lidocaine was subjectively evaluated by the authors.

RESULTS

Twenty patients (13M;7F) received lidocaine. Two patients received it twice, totaling 22 episodes. The median lidocaine dose was 0.67 mg/kg/h with the median duration being 5.5 days. The median worst pain score at T0 and T1 was 8.5 and 5.5, respectively. The difference in the mean pain scores was 3.2 95% CI (2.1, 4.4; p < 0.001). In 15/22 episodes (68%), patients experienced a decrease in pain scores of more than 2. The median morphine oral equivalent (MOE) daily doses at T0, T1, and T2 were 425, 362.5, and 275 mg, respectively. The difference in the mean MOE between T0 and T1 was -126 (95% CI [-281, 28]; p = 0.13). The difference in the mean MOE between T0 and T2 was -207 (95% CI [-370, -44]; p = 0.025). Lidocaine was subjectively deemed effective in 10/22 episodes (45%). There were no documented adverse events attributed to lidocaine. Univariate analyses did not identify any subgroups likely to benefit from lidocaine.

CONCLUSION

Subcutaneous lidocaine infusions may be used safely in cancer pain management and is effective in some patients.

Combined epidural morphine and bupivacaine in the treatment of lumbosacral radicular neuropathic pain: a noncontrolled prospective study

Objective

The aim of this study was to investigate the therapeutic effectiveness of epidural morphine and bupivacaine in patients with chronic lumbosacral radicular neuropathic pain after the cessation of treatment.

Methods

Twenty-two patients with chronic lumbosacral pain with neuropathic features were enrolled. An indwelling catheter was placed into the epidural space, and each patient received an epidural injection of morphine chlorhydrate and bupivacaine up to three times a day. The medication was administered for 4 weeks. The pain intensity score on a 0–10 numeric rating scale (NRS), the total pain rating index rank (PRIr-T), and its coefficients were evaluated before treatment and 1 month after catheter removal. P-value <0.05 was considered statistically significant.

Results

NRS and PRIr-T were significantly reduced at follow-up (P=0.001 and P=0.03, respectively), whereas the parallel evolution of the two scores (r=0.75 and P<0.001, respectively) confirmed significant pain relief lasting up to 1 month after treatment cessation. None of the four pain rating coefficients was significantly modified compared to the others in either responders or nonresponders. Successful clinical outcome (pain reduction >30% in NRS) was reached and maintained in half of the patients at follow-up.

Conclusion

Combined epidural morphine and bupivacaine seems to be effective in the treatment of neuropathic pain.

Novel sodium channel antagonists in the treatment of neuropathic pain

INTRODUCTION

Effective and safe drugs for the treatment of neuropathic pain are still an unmet clinical need. Neuropathic pain, caused by a lesion or disease that affects the somatosensory system, is a debilitating and hampering condition that has a great economic cost and, above all, a tremendous impact on the quality of life. Sodium channels are one of the major players in generating and propagating action potentials. They represent an appealing target for researchers involved in the development of new and safer drugs useful in the treatment of neuropathic pain. The actual goal for researchers is to target sodium channels selectively to stop the abnormal signaling that characterizes neuropathic pain while leaving normal somatosensory functions intact.

AREAS COVERED

This review covers the most recent publications regarding sodium channel blockers and their development as new treatments for neuropathic pain. The main areas discussed are the natural sources of new blockers, such as venom extracts and the recent efforts from many pharmaceutical companies in the field.

EXPERT OPINION

There have been serious efforts by both the pharmaceutical industry and academia to develop new and safer therapeutic options for neuropathic pain. A number of different strategies have been undertaken; the main efforts directed towards the identification of selective blockers starting from both natural products or screening chemical libraries. At this time, researchers have identified and characterized selective compounds against NaV1.7 or NaV1.8 voltage-gated sodium channels but only time will tell if they reach the market.