Multitarget ligands that comprise opioid/nonopioid pharmacophores for pain management: Current state of the science

Chronic pain, which affects more than one-third of the world's population, represents one of the greatest medical challenges of the 21st century, yet its effective management remains sub-optimal. The 'gold standard' for the treatment of moderate to severe pain consists of opioid ligands, such as morphine and fentanyl, that target the µ-opioid receptor (MOP). Paradoxically, these opioids also cause serious side effects, including constipation, respiratory depression, tolerance, and addiction. In addition, the development of opioid-use disorders, such as opioid diversion, misuse, and abuse, has led to the current opioid crisis, with dramatic increases in addiction, overdoses, and ultimately deaths. As pain is a complex, multidimensional experience involving a variety of pathways and mediators, dual or multitarget ligands that can bind to more than one receptor and exert complementary analgesic effects, represent a promising avenue for pain relief. Indeed, unlike monomodal therapeutic approaches, the modulation of several endogenous nociceptive systems can often result in an additive or even synergistic effect, thereby improving the analgesic-to-side-effect ratio. Here, we provide a comprehensive overview of research efforts towards the development of dual- or multi-targeting opioid/nonopioid hybrid ligands for effective and safer pain management. We reflect on the underpinning discovery rationale by discussing the design, medicinal chemistry, and in vivo pharmacological effects of multitarget antinociceptive compounds.

Multimodal analgesic strategies in polytraumatized patients

In recent years, the resuscitation of trauma patients has improved; however, pain related to trauma remains associated with systemic complications. In trauma patients, pain should be considered a vital sign, and its control is crucial for reducing complications, improving patient satisfaction, and enhancing the quality of life. The multimodal analgesia approach is the mainstay in pain control, and growing evidence in the literature supports a greater role of regional anesthesia in the management of trauma casualties. In this review, we offer the reader an updated general framework of the various approaches available for pain treatment in polytraumatized patients, with a focus on the opportunities presented by regional anesthesia. We will examine different types of locoregional anesthesia blocks and describe ultrasonographic execution techniques.

Biopolymeric 3D printed implantable scaffolds as a potential adjuvant treatment for acute post-operative pain management

BACKGROUND

Pain is characterized as a major symptom induced by tissue damage occurring from surgical procedures, whose potency is being experienced subjectively, while current pain relief strategies are not always efficient in providing individualized treatment. 3D printed implantable devices hold the potential to offer a precise and customized medicinal approach, targeting both tissue engineering and drug delivery.

RESEARCH DESIGN AND METHODS

Polycaprolactone (PCL) and PCL - chitosan (CS) composite scaffolds loaded with procaine (PRC) were fabricated by bioprinting. Geometrical features including dimensions, pattern, and infill of the scaffolds were mathematically optimized and digitally determined, aiming at developing structurally uniform 3D printed models. Printability studies based on thermal imaging of the bioprinting system were performed, and physicochemical, surface, and mechanical attributes of the extruded scaffolds were evaluated. The release rate of PRC was examined at different time intervals up to 1 week.

RESULTS

Physicochemical stability and mechanical integrity of the scaffolds were studied, while in vitro drug release studies revealed that CS contributes to the sustained release dynamic of PRC.

CONCLUSIONS

The printing extrusion process was capable of developing implantable devices for a local and sustained delivery of PRC as a 7-day adjuvant regimen in post-operative pain management.

Opioid-Sparing Nonsteroid Anti-inflammatory Drugs Protocol in Patients Undergoing Intramedullary Nailing of Tibial Shaft Fractures: A Randomized Control Trial

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective analgesics commonly used in fracture management. Although previously associated with delayed fracture healing, multiple studies have demonstrated their safety, with minimal risks of fracture healing. Given the current opioid crisis in the United States, alternate pain control modalities are essential to reduce opioid consumption. This study aims to determine whether the combination of oral acetaminophen and intravenous ketorolac is a viable alternative to opioid-based pain management in closed tibial shaft fractures treated with intramedullary nailing.

METHODS

We conducted a randomized controlled trial evaluating postoperative pain control and opioid consumption in patients with closed tibial shaft fractures who underwent intramedullary nailing. Patients were randomized into an NSAID-based pain control group (52 patients) and an opioid-based pain control group (44 patients). Visual analog scale (VAS) scores and morphine milligram equivalents (MMEs) were evaluated at 12-hour postoperative intervals during the first 48 hours after surgery. Nonunion and delayed healing rates were recorded for both groups.

RESULTS

A statistically significant decrease in MMEs was noted at every measured interval (12, 24, 36, and 48 hours) in the NSAID group compared with the opioid group ( P -value 0.001, 0.001, 0.040, 0.024, respectively). No significant change in visual analog scale scores was observed at 12, 36, and 48 hours between both groups ( P -value 0.215, 0.12, and 0.083, respectively). A significant decrease in VAS scores was observed at the 24-hour interval in the NSAID group compared with the opioid group ( P -value 0.041). No significant differences in union rates were observed between groups ( P -value 0.820).

DISCUSSION

Using an NSAID-based postoperative pain protocol led to a decrease in opioid consumption without affecting pain scores or union rates. Owing to the minimal risk of short-term NSAID use, their role in the perioperative management of tibia shaft fractures is justified, especially when they reduce opioid consumption markedly.

LEVEL OF EVIDENCE

Therapeutic Level I.

Transitional Pain Service: An Update

PURPOSE OF REVIEW

Chronic Postsurgical Pain (CPSP) and the risk for long-term opioid dependency are known complications following major surgery. The idea of Transitional Pain Service (TPS) has been introduced as an interdisciplinary setting to manage pain in the perioperative continuum. We expand on the basic framework and principles of TPS and summarize the current evidence of the TPS and possible interventions to adress postoperative pain. Areas of future work in TPS-related research are discussed.

RECENT FINDINGS

Several studies support the effectiveness of TPS in reducing opioid consumption in the perioperative period and following discharge. Some studies also show an improvement in functional outcome with TPS with patients reporting lower pain severity and pain interference. The TPS aims to halt the progress of acute postoperative pain to CPSP by providing longitudinal support with patient-centered care. While some studies suggest a positive impact of TPS implementation in terms of reduction in postoperative opioid consumption and improvement of some functional outcomes, direct evidence in terms of reduction in the incidence of CPSP is still missing. The cost-effectiveness of TPS and the expansion of TPS through e-health services and digital applications also need to be evaluated.

[Transitional pain service in surgery as an optimal strategy for the treatment and prevention of chronic postoperative pain]

The problem of chronic postoperative pain (CPP) has remained relevant over the past decades, despite the active development of anesthesiology and surgery. Existing approaches to the treatment of acute postoperative pain do not provide effective prevention of CPP. The analysis of the results of studies on this problem was carried out. It was shown that the introduction of an interdisciplinary transitional pain service in surgery allows to increase the effectiveness of prevention and treatment of CPP, accompanying patients with high risks of pain chronization at each stage of surgical treatment (surgery planning, perioperative and outpatient, after discharge up to full recovery after surgery). The interdisciplinary nature of the transitional pain service in surgery ensures the timeliness and multimodality of the pain treatment methods used. It can be concluded that the development of a transitional pain service is an optimal strategy for the prevention and treatment of CPP.

Bedside check of medication appropriateness (BED-CMA) as a risk-based tool for bedside clinical pharmacy services: A proof-of-concept study at the trauma surgery ward

Background

Bedside clinical pharmacy prevents drug-related problems, but is not feasible in many countries due to limited resources. Hence, clinical rules using structural information in the electronic health record can help identifying potentially inappropriate prescriptions (PIPs). We aimed to develop and implement a risk-based clinical pharmacy service and evaluate its impact on prescribing at the trauma surgery ward.

Methods

The proportion of residual PIPs per day, i.e. the number of PIPs that persisted up to 24 h after pharmacist intervention divided by the number of PIPs at T0, was evaluated before and after implementation of the intervention in an interrupted time series analysis. The pre-intervention cohort received usual pharmacy services, i.e. a 0.3 FTE clinical pharmacist trainee. Fifteen clinical rules, targeting antimicrobial, anticoagulant and analgesic therapy were implemented in the post-intervention period. The pre-intervention period was compared to two post-intervention scenarios: A) clinical rule alerts reviewed by a 0.3 FTE clinical pharmacist trainee; and B) clinical rule alerts reviewed daily for approximately 1 h by a clinical pharmacist trainee.

Results

Pre-intervention, a median proportion of 67% (range 0%-100%) residual PIPs per day was observed. Scenario A showed an immediate relative reduction of 14% (p = 0.72) and scenario B a significant immediate relative reduction of 85% (p = 0.0015) in residual PIPs per day. In scenario A, recommendations were provided for 19% of clinical rule alerts, of which 67% was accepted by the surgeon within 24 h. In scenario B, recommendations were given for 56% of alerts, of which 84% was accepted.

Conclusions

Using clinical rules is an effective approach to organize bedside clinical pharmacy services and improves prescribing at the trauma surgery ward. Advanced training and daily follow-up of the clinical rules are two requirements to be considered.

Pain mitigation and management strategies for anti-GD2 infusions: An expert consensus

Monoclonal antibodies (mAbs) targeting disialoganglioside 2 (GD2) are an important treatment advance for high-risk neuroblastoma, including in patients with refractory or relapsed disease. Dinutuximab and dinutuximab beta are administered for ≥8 hours (and up to 10 days for dinutuximab beta), whereas naxitamab is administered over 0.5 to 2 hours as tolerated. As acute pain is a class effect of anti-GD2 mAbs, effective pain management is crucial to successful treatment. Here, we provide an overview of current pain-management strategies for anti-GD2 mAb infusions, with a focus on strategies suitable for naxitamab infusions, which cause a more rapid onset of often severe pain. We discuss opioid analgesics, ketamine, gabapentin, and other similar agents and nonpharmacologic approaches. Potential future pain-management options are also discussed, in addition to the use of sedatives to reduce the anxiety that may be associated with infusion-related pain. In this expert consensus paper, specific guidance for pain management during naxitamab infusions is provided, as these infusions are administered over 0.5 to 2 hours and may not need overnight hospitalization based on the physician's assessment, and require rapid-onset analgesia options suitable for potential outpatient administration.

Extended Release of Bupivacaine from Temperature-responsive Hydrogels Provides Multi-day Analgesia for Postoperative Pain

OBJECTIVE

A local anesthetic that provides analgesia lasting at least three days could significantly improve postoperative pain management. This study evaluated the analgesic efficacy and safety of an extended-release formulation of bupivacaine based on the injectable hydrogel carrier poly(N-isopropylacrylamide-co-dimethylbutyrolactone acrylamide-co-Jeffamine M-1000 acrylamide) (PNDJ).

METHODS

The efficacy of PNDJ containing 4% bupivacaine (SBG004) given by peri-incisional subcutaneous injection (SBG004 SC) or wound filling instillation (SBG004 WF) was evaluated compared to saline, liposomal bupivacaine, bupivacaine collagen sponge, bupivacaine-meloxicam polyorthoester, and bupivacaine HCl in a porcine skin and muscle incision model. Mechanical allodynia was assessed by withdrawal from application of von Frey filaments, and local tolerance was evaluated by histology. Bupivacaine pharmacokinetics for SBG004 SC were measured in rabbits (16.5 mg bupivacaine/kg).

RESULTS

Animals demonstrated less mechanical allodynia at incisions receiving SBG004 SC for up to 96 hours postoperatively. Incisions treated with SBG004 SC tolerated more force without a withdrawal indicative of pain compared to saline for 96 hours, and compared to SBG004 WF and all active controls at 24, 48, and 72 hours except bupivacaine-meloxicam polyorthoester at 72 hours. By 49 days, SBG004 was histologically absent and was replaced with granulation tissue infiltrated with immune cells in some areas. In rabbits, Cmax was 41.6 ± 9.7 ng/mL with t1/2 82.0 ± 35.8 hours (mean ± SD).

CONCLUSIONS

Peri-incisional SBG004 SC provided extended release of bupivacaine sufficient to reduce sensation of incisional pain for 96 hours, in vivo bupivacaine delivery for at least 7 days, and a favorable local and systemic toxicity profile.

Multimodal analgesia is superior to opiates alone after tibial fracture in patients with substance abuse history

Objectives: To evaluate the effectiveness of multimodal analgesia in patients with a tibial shaft fracture. Design: Retrospective review. Setting: Large, urban, academic center. Patients: One hundred thirty-eight patients were evaluated before implementation of multimodal analgesia. Thirty-four patients were evaluated after implementation. All patients were treated operatively with internal fixation for their tibial shaft fracture. Patients with polytrauma were excluded. Intervention: Multimodal analgesia. Main Outcome Measures: Pain levels at rest and with movement were assessed. Morphine milligram equivalents (MMEs) dosed per patient were calculated each day. Length of stay was also documented. Results: After implementation of a multimodal analgesic program, there was a statistically significant decrease in pain score at rest (4.7-4.0, P = 0.034) and with movement (5.8-4.8, P = 0.007). MMEs dosed in the multimodal analgesic program correlated with pain score (R² = 0.5), whereas before implementation of the program, MMEs dosed were not dependent on pain score (R² = 0.007). Patients with a history of substance abuse had the most profound effect from this paradigm change. For those with a history of substance abuse, treatment of pain using a multimodal approach reduces MMEs dosed and length of stay (5.7-3.1 days, P = 0.016). Conclusions: Multimodal analgesia improves patient pain scores both at rest and during movement. In patients with a history of substance abuse, multimodal analgesia not only decreases pain but also decreases length of stay and MMEs dosed to levels consistent with someone who does not have a substance abuse history. Level of Evidence: Therapeutic Level III.

Efficacy of Methylprednisolone Compared to Other Drugs for Pain, Swelling, and Trismus Control after Third Molar Surgery: A Meta-Analysis

The purpose of this systematic review and meta-analysis was to assess the efficacy of methylprednisolone compared to other drugs to control postoperative complications following third molar surgery. PubMed and Google Scholar were used for article searching. Thereafter, the trials meeting the selection criteria and with high methodological quality, according to the Cochrane Collaboration’s risk of bias tool, were included in this study. The inverse variance test and mean difference using the Review Manager Software 5.3 for Windows were used to carry out data analysis. Qualitative analysis shows that methylprednisolone is more effective than NSAIDs, but inferior to dexamethasone, for controlling postoperative complications after third molar removal. The quantitative analysis showed no statistical difference for pain control, while trismus evaluation showed a statistical difference after 7 postoperative days in favor of methylprednisolone, when compared to other drugs. In conclusion, methylprednisolone was more effective for trismus control compared to other drugs after lower third molar surgery.

Treating trauma more effectively: A review of psychosocial programming

IMPORTANCE

Traumatic events are the leading cause of life-altering disability in adults of working age. The management of patients with traumatic injury has substantially improved due to development of sophisticated trauma centers increasing survival after injury. Unlike the adoption of the trauma system framework, the same has not occurred with specialized trauma recovery services to include mental and social health needs. This literature review will discuss unique issues facing trauma survivors, some current recovery programs available, outcomes and benefits of these programs, and barriers that impair widespread incorporation.

OBSERVATIONS

Studies have shown that patients with traumatic injury experience reduction in quality of life and concurrent threats to mental health, including post-traumatic stress disorder (PTSD), alcohol use disorder, and recreational substance abuse. Patients with traumatic injury also have high recidivism rates, low pain management satisfaction, and poor engagement in care following injury. Screening efforts for PTSD, mental illness, and alcohol and substance abuse are more widely available interventions. Early coordinated efforts included dedicated multidisciplinary recovery teams. Recently, more methodical and organized programs, such as the Trauma Survivors Network, trauma collaborative care, Trauma Recovery Services, and Center of Trauma Survivorship, have been implemented.

CONCLUSIONS AND RELEVANCE

The enrollment of patients with traumatic injury in novel programs to enhance recovery has led to heightened self-efficacy, better coping mechanisms, and increased use of mental health services. Additionally, trauma recovery services have been shown to reduce recidivism and have generated cost savings for hospital systems. While positive outcomes have been demonstrated, they are not consistently predictable. Barriers for widespread implementation include limitations of time, funding, and institutional support. This article describes models of successful programs initiated within some trauma centers, which may be duplicated to serve future trauma survivors.

Outpatient administration of naxitamab in combination with granulocyte-macrophage colony-stimulating factor in patients with refractory and/or relapsed high-risk neuroblastoma: Management of adverse events

BACKGROUND

Naxitamab is a humanized GD2-binding monoclonal antibody that received accelerated approval from the U.S. Food and Drug Administration for refractory or relapsed high-risk neuroblastoma limited to bone or bone marrow. Trial 201 (NCT03363373) is an ongoing global clinical trial to evaluate the efficacy and safety of naxitamab in combination with granulocyte-macrophage colony-stimulating factor in this population.

AIMS

Here, we review the safety profile and adverse event (AE) management associated with naxitamab administration in a pediatric population, based on Trial 201 protocol guidelines and clinical trial experience.

METHODS AND RESULTS

At least 50% of patients experienced pain, hypotension, bronchospasm, cough, vomiting, diarrhea, nausea, and tachycardia, with the following reported at grade ≥3 AEs for at least 10% of patients: pain, hypotension, urticaria, and bronchospasm. These AEs were generally manageable in the outpatient setting using premedications, supportive therapies, and appropriate monitoring post-infusion. Algorithms were established for infusion-related AEs, including hypotension and bronchospasm, to provide guidance to investigators for early recognition and timely intervention, including medication and infusion rate modification or interruption, or treatment discontinuation, based on AE severity. Educating patients and caregivers on what to expect regarding premedication at home, experience during the infusion cycle, and post-infusion monitoring helps optimize naxitamab treatment and supportive therapies and may reduce treatment burden.

CONCLUSION

This article highlights the protocol-based recommendations for the management of acute AEs associated with outpatient naxitamab treatment in Trial 201. The authors recommend close monitoring and timely implementation of measures to ensure that patients can remain on treatment and obtain maximum clinical benefit from naxitamab therapy.

Paracetamol for multimodal analgesia

Pain and related disability remain a major social and therapeutic problem. Comorbidities and therapies increase drug interactions and side effects making pain management more compounded especially in the elderly who are the fastest-growing pain population. Multimodal analgesia consists of using two or more drugs and/or techniques that target different sites of pain, increasing the level of analgesia and decreasing adverse events from treatment. Paracetamol enhances multimodal analgesia in experimental and clinical pain states. Strong preclinical evidence supports that paracetamol has additive and synergistic interactions with anti-inflammatory, opioid and anti-neuropathic drugs in rodent models of nociceptive and neuropathic pain. Clinical studies in young and adult elderly patients confirm the utility of paracetamol in multimodal, non-opioid or opioid-sparing, therapies for the treatment of acute and chronic pain.

How we approach the treatment of patients with high-risk neuroblastoma with naxitamab: experience from the Hospital Sant Joan de Déu in Barcelona, Spain

Naxitamab [humanized 3f8 (hu3F8)] is a humanized monoclonal antibody (mAb) targeting the disialoganglioside GD2. It was approved in 2020 by the United States Food and Drug Administration (FDA) in combination with granulocyte–macrophage colony-stimulating factor (GM-CSF) for treatment of pediatric and adult patients with relapsed/refractory high-risk neuroblastoma, limited to the bone or bone marrow (BM). The team at Sant Joan de Déu Children’s Hospital in Barcelona, Spain, have been using naxitamab to treat neuroblastoma under clinical trial protocols [e.g. Trial 201, and hu3F8, irinotecan, temozolomide, and sargramostim (GM-CSF) (HITS) study] and compassionate use since 2017. The team has experience with two primary regimens: naxitamab with GM-CSF only, or naxitamab in combination with irinotecan, temozolomide, and GM-CSF (chemoimmunotherapy). This article aims to provide a practical overview of the team’s experience with naxitamab to date, including preparing the treatment room and selecting the team. Adverse event management, including the use of ketamine to manage pain during anti-GD2 mAb infusions, is also discussed. We hope this will provide practical information for other health care providers considering offering this treatment.

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Immunotherapy with anti-GD2 antibodies has revolutionized the treatment of patients with high-risk neuroblastoma.

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In 2020, FDA approved naxitamab + GM-CSF for treatment of patients with R/R neuroblastoma in the bone and/or BM.

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Outpatient treatment with naxitamab-based immunotherapy may improve health-related quality of life.

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Naxitamab infusions require specific training and teamwork to prevent and efficiently manage most frequent adverse events.

Impact of the 2018 Society of Critical Care Medicine Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Guidelines on Nonopioid Analgesic Use and Related Outcomes in Critically Ill Adults After Major Surgery

We compared ICU nonopioid analgesic use, opioid use, and pain before and after Pain, Agitation/Sedation, Delirium, Immobility, and Sleep guideline publication at one academic center among critically ill adults receiving an opioid infusion and greater than or equal to 24 hours of mechanical ventilation after major surgery. The 2017 (n = 77) and 2019 (n = 57) groups were similar at baseline. The 2019 (vs 2017) patients were more likely to receive scheduled IV/oral acetaminophen (84% vs 69%; p = 0.05), less likely to receive a lidocaine patch (33% vs 50%; p = 0.05), and just as likely to receive ketamine (4% vs 3%; p = 1.0), an nonsteroidal anti-inflammatory drug (7% vs 3%; p = 0.26), or gabapentin/pregabalin (16% vs 9%; p = 0.23). Daily average opioid exposure (in IV morphine milligram equivalent) was not different (70 [42–99] [2017] vs 78 mg [49–109 mg]; p = 0.94). The 2019 (vs 2017) group spent more ICU days with severe pain (p = 0.04). At our center, Pain, Agitation/Sedation, Delirium, Immobility, and Sleep guideline publication had little effect on nonopioid analgesic or opioid prescribing practices in critically ill surgical adults.

Perioperative Pain Management and Opioid Stewardship: A Practical Guide

Surgical procedures are key drivers of pain development and opioid utilization globally. Various organizations have generated guidance on postoperative pain management, enhanced recovery strategies, multimodal analgesic and anesthetic techniques, and postoperative opioid prescribing. Still, comprehensive integration of these recommendations into standard practice at the institutional level remains elusive, and persistent postoperative pain and opioid use pose significant societal burdens. The multitude of guidance publications, many different healthcare providers involved in executing them, evolution of surgical technique, and complexities of perioperative care transitions all represent challenges to process improvement. This review seeks to summarize and integrate key recommendations into a "roadmap" for institutional adoption of perioperative analgesic and opioid optimization strategies. We present a brief review of applicable statistics and definitions as impetus for prioritizing both analgesia and opioid exposure in surgical quality improvement. We then review recommended modalities at each phase of perioperative care. We showcase the value of interprofessional collaboration in implementing and sustaining perioperative performance measures related to pain management and analgesic exposure, including those from the patient perspective. Surgery centers across the globe should adopt an integrated, collaborative approach to the twin goals of optimal pain management and opioid stewardship across the care continuum.