Opioids combined with antidepressants or antiepileptic drugs for cancer pain: Systematic review and meta-analysis

The use of gabapentinoids and opioids and risk of developing opioid-induced respiratory depression among older breast cancer survivors with neuropathic pain

PURPOSE

To estimate the combined effect of gabapentinoid and opioid therapy compared to opioid monotherapy on the risk of developing opioid-induced respiratory depression among breast cancer survivors with neuropathic pain.

METHOD

A nested case-control study of Medicare female breast cancer survivors with neuropathic pain receiving both opioids and gabapentinoids, opioid monotherapy, gabapentinoid monotherapy, and none of these drugs was conducted using SEER-Medicare between 2007 and 2015. Cases were survivors with respiratory depression and were matched with controls on the event date (± 1 year), age at diagnosis (± 5 years), and stage at diagnosis. Exposure to opioids and gabapentinoids was assessed 120 days before the event date. Conditional logistic regression was used to assess the impact of exposure among cases and controls.

RESULTS

A total of 657 cases and 11,471 controls were identified. After matching, 656 cases and 5612 controls were retained, and cases were more likely to be diagnosed with mental health disorders (24.4% vs 10.5%, p < 0.0001) than controls. In the primary adjusted analysis, combined opioids and gabapentin use were associated with an increased risk of respiratory depression compared to opioid monotherapy (Adj. OR: 1.513; 95% CI: 1.473-2.350). Additionally, under secondary analysis, combined opioids and gabapentin use were associated with an increased risk of respiratory depression compared to receiving neither of these classes. (Adj. OR: 1.595; 95% CI: 1.050-2.421).

CONCLUSION

There is a need for dose titration strategies of gabapentinoids and caution when co-prescribing opioids and gabapentinoids in older cancer survivors.

Observational evidence linking psychotropic medicines to the dispensing of opioid agents in later life

BACKGROUND

The use of opioid medicines is common in developed countries, particularly among older adults and those with mental health disorders. It is unclear if the association between mental disorders and opioid medicines is causal, or is due to reverse causality or confounding.

METHODS

We used a 10% random sample of the Australian Pharmaceutical Benefits Scheme (years 2012-2022) to examine the cross-sectional, case-control and longitudinal association between the dispensing of antidepressants, anxiolytics, hypnotics, antipsychotics and lithium, and opioid medicines. We used logistic regression, structural equation models (SEM), and Cox regression to analyze the data. Analyses were adjusted for age (years), sex, and number of non-psychotropic medicines dispensed during the year.

RESULTS

The 2022 file contained 804 334 individuals aged 50 years or over (53.1% women), of whom 181 690 (22.6%) received an opioid medicine. The adjusted odds ratio of being dispensed opioid medicines was 1.44 (99% CI = 1.42-1.46) for antidepressants, 1.97 (99% CI = 1.92-2.03) for anxiolytics, 1.55 (99% CI = 1.51-1.60) for hypnotics, 1.32 (99% CI = 1.27-1.38) for antipsychotics, and 0.60 (99% CI = 0.53-0.69) for lithium. Similar associations were noticed when we compared participants who were or not dispensed opioid medicines in 2022 for exposure to psychotropic agents between 2012 and 2021. SEM confirmed that this association was not due to reverse causality. The dispensing of antidepressants was associated with increased adjusted hazard (HR) of subsequent dispensing of opioid medicines (HR = 1.29, 99% CI = 1.27-1.30). Similar associations were observed for anxiolytics, hypnotics and antipsychotics, but not lithium.

CONCLUSIONS

The dispensing of opioid medicines is higher among older individuals exposed to antidepressants, anxiolytics, hypnotics and antipsychotics than those who are not. These associations are not due to reverse causality or study design. Preventive strategies seeking to minimise the risk of inappropriate use of opioid medicines in later life should consider targeting this high-risk population.

From pain to tumor immunity: influence of peripheral sensory neurons in cancer

The nervous and immune systems are the primary sensory interfaces of the body, allowing it to recognize, process, and respond to various stimuli from both the external and internal environment. These systems work in concert through various mechanisms of neuro-immune crosstalk to detect threats, provide defense against pathogens, and maintain or restore homeostasis, but can also contribute to the development of diseases. Among peripheral sensory neurons (PSNs), nociceptive PSNs are of particular interest. They possess a remarkable capability to detect noxious stimuli in the periphery and transmit this information to the brain, resulting in the perception of pain and the activation of adaptive responses. Pain is an early symptom of cancer, often leading to its diagnosis, but it is also a major source of distress for patients as the disease progresses. In this review, we aim to provide an overview of the mechanisms within tumors that are likely to induce cancer pain, exploring a range of factors from etiological elements to cellular and molecular mediators. In addition to transmitting sensory information to the central nervous system, PSNs are also capable, when activated, to produce and release neuropeptides (e.g., CGRP and SP) from their peripheral terminals. These neuropeptides have been shown to modulate immunity in cases of inflammation, infection, and cancer. PSNs, often found within solid tumors, are likely to play a significant role in the tumor microenvironment, potentially influencing both tumor growth and anti-tumor immune responses. In this review, we discuss the current state of knowledge about the degree of sensory innervation in tumors. We also seek to understand whether and how PSNs may influence the tumor growth and associated anti-tumor immunity in different mouse models of cancer. Finally, we discuss the extent to which the tumor is able to influence the development and functions of the PSNs that innervate it.

An overview of the current drug treatment strategies for moderate to severe, chronic malignant tumor-related pain

INTRODUCTION

The pharmacological management of cancer pain is a complex issue that requires knowledge and experience in the use of analgesics. The aim of this expert review is to provide a panorama of the pharmacological strategies in cancer pain management.

AREAS COVERED

Opioid dose titration is a delicate process regarding the start of opioid treatment in different clinical conditions. How to improve the opioid response is a fundamental step, which includes different strategies when an initial treatment with opioids fails. The use of adjuvants is another relevant issue that should be considered in some specific circumstances to optimize the management of cancer pain management. Some clinical conditions, such as neuropathic pain and breakthrough pain, deserve a special attention. Relevant literature was selected to provide an overview of cancer pain management strategies.

EXPERT OPINION

Opioid therapy still remains the cornerstone of pharmacological management of cancer pain. Opioids should be used according to the level of tolerance, also personalizing the treatment (route, drug, and dosing). Adjuvant drugs may help in specific conditions, although their use should be balanced with the adverse effects. Breakthrough pain requires expertise in tailoring a treatment according to patient's profile and characteristics of episodes.

Developing non-opioid therapeutics to alleviate pain among persons with opioid use disorder: a review of the human evidence

The opioid crisis remains a major public health concern, causing significant morbidity and mortality worldwide. Pain is frequently observed among individuals with opioid use disorder (OUD), and the current opioid agonist therapies (OAT) have limited efficacy in addressing the pain needs of this population. We reviewed the most promising non-opioid analgesic therapies for opioid-dependent individuals synthesising data from randomised controlled trials in the Medline database from December 2022 to March 2023. Ketamine, gabapentin, serotoninergic antidepressants, and GABAergic drugs were found to be the most extensively studied non-opioid analgesics with positive results. Additionally, we explored the potential of cannabinoids, glial activation inhibitors, psychedelics, cholecystokinin antagonists, alpha-2 adrenergic agonists, and cholinergic drugs. Methodological improvements are required to advance the development of novel analgesic strategies and establish their safety profile for opioid-dependent populations. We highlight the need for greater integration of experimental pain methods and abuse liability assessments, more granular assessments of prior opioid exposure, greater uniformity of pain types within study samples, and a particular focus on individuals with OUD receiving OAT. Finally, future research should investigate pharmacokinetic interactions between OAT and various non-opioid analgesics and perform reverse translation basic experiments, particularly with methadone and buprenorphine, which remain the standard OUD treatment.

Enhanced acupuncture therapy for radiotherapy-related neuropathic pain in patients with gynecologic cancer: a report of two cases and brief review

As radiation therapy is increasingly utilized in the treatment of cancer, neuropathic pain (NP) is a common radiotherapy-related adverse effect and has a significant impact on clinical outcomes negatively. However, despite an improved understanding of neuropathic pain management, pain is often undertreated in patients with cancer. Herein, we reported two cases with radiotherapy-related neuropathic pain (RRNP) who presented a positive reaction to acupuncture. Patient 1 (a 73-year-old woman) with gynecologic cancer complained of burning and electric shock-like pain in the lower limb after radiotherapy. With the accepted combination of acupuncture and drugs, the pain was alleviated completely in 8 weeks. Patient 2 (a 64-year-old woman) accepted acupuncture in the absence of medication because of her inability to tolerate the adverse events of anticonvulsant drugs. She achieved remission of pain 4 weeks later. The results of this study showed that acupuncture might be promising for controlling the RRNP in patients with cancer, especially who were intolerant or unresponsive to medications.

Optimising psychological treatment for pain after breast cancer: a factorial design study protocol in Denmark

INTRODUCTION

One in five breast cancer (BC) survivors are affected by persistent pain years after completing primary treatment. While the efficacy of psychological interventions for BC-related pain has been documented in several meta-analyses, reported effect sizes are generally modest, pointing to a need for optimisation. Guided by the Multiphase Optimization Strategy, the present study aims to optimise psychological treatment for BC-related pain by identifying active treatment components in a full factorial design.

METHODS AND ANALYSIS

The study uses a 2×3 factorial design, randomising 192 women with BC-related pain (18-75 years) to eight experimental conditions. The eight conditions consist of three contemporary cognitive-behavioural therapy components, namely: (1) mindful attention, (2) decentring, and (3) values and committed action. Each component is delivered in two sessions, and each participant will receive either zero, two, four or six sessions. Participants receiving two or three treatment components will be randomised to receive them in varying order. Assessments will be conducted at baseline (T1), session by session, every day for 6 days following the first session in each treatment component, at post-intervention (T2) and at 12-week follow-up (T3). Primary outcomes are pain intensity (Numerical Rating Scale) and pain interference (Brief Pain Inventory interference subscale) from T1 to T2. Secondary outcomes are pain burden, pain quality, pain frequency, pain catastrophising, psychological distress, well-being and fear of cancer recurrence. Possible mediators include mindful attention, decentring, and pain acceptance and activity engagement. Possible moderators are treatment expectancy, treatment adherence, satisfaction with treatment and therapeutic alliance.

ETHICS AND DISSEMINATION

Ethical approval for the present study was received from the Central Denmark Region Committee on Health Research Ethics (no: 1-10-72-309-40). Findings will be made available to the study funders, care providers, patient organisations and other researchers at international conferences, and published in international, peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05444101).

Relationship between breakthrough cancer pain, background cancer pain and analgesic treatment - case series and review of the literature

The assessment and treatment of breakthrough cancer pain (BTcP) remain a major challenge in medicine due to its high impact on several aspects of health-related quality of life. BTcP should be carefully monitored in all cancer care settings by a multidisciplinary team to provide an appropriate and personalized clinical approach. The aim of this paper is to provide healthcare professionals involved in cancer pain management with a review of the relevant literature on the relationship between background cancer pain and BTcP which, by definition, occurs despite adequately controlled background cancer pain. The clinical cases presented contribute to a better understanding of this issue and underline its impact in daily clinical practice. This article is part of the Management of breakthrough cancer pain Special Issue: https://www.drugsincontext.com/special_issues/management-of-breakthrough-cancer-pain.

Comprehensive Targeted Treatment for Neuropathic and Nociceptive Pain in Palliative Care Patients

BACKGROUND

Pain is a common symptom in patients with advanced, metastatic, or terminal cancer. Neuropathic pain and psycho-emotional suffering are factors that increase the difficulty of pain management. Pain control in patients with cancer remains a challenge for medical professionals.

STUDY QUESTION

What is the evolution of neuropathic/mixed pain compared with nociceptive pain under standardized treatment in patients with cancer?

STUDY DESIGN

A prospective, longitudinal, open-label, nonrandomized study was conducted on patients with cancer pain.

MEASURES AND OUTCOMES

Pain type was assessed at admission using the modified Brief Pain Inventory, and pain intensity was assessed daily using the Numerical Rating Scale for 14 days and on days 21 and 28. Screening of depression was performed on days 1, 7, 14, 21, and 28 using the Hamilton Depression Rating Scale. Patients with pain and depression received analgesics with antidepressants, while patients without depression received analgesics or analgesics with an anticonvulsant depending on the pain subtype.

RESULTS

Of 72 patients, 23 had nociceptive pain and 49 had neuropathic/mixed pain. At admission, pain intensity was higher for patients with neuropathic/mixed pain compared with nociceptive pain (mean values: 7.06 vs. 5.82) with statistical significance (P = 0.001) and remained as such at the end of this study (mean values: 3.77 vs. 2.73). A decrease in the mean pain intensity was observed in all types of pain, but without statistical significance regardless of pain type and treatment protocol used (P = 0.77). If depression was present, antidepressants combined with analgesics decreased pain and depression scores significantly (P = 0.001).

CONCLUSIONS

Patients with neuropathic/mixed pain have higher levels of pain and lower response to treatment. Identifying psycho-emotional suffering can improve pain control by intervening in the physical and psycho-emotional components of pain.

Management of common clinical problems experienced by survivors of cancer

Improvements in early detection and treatment have led to a growing prevalence of survivors of cancer worldwide. Models of care fail to address adequately the breadth of physical, psychosocial, and supportive care needs of those who survive cancer. In this Series paper, we summarise the evidence around the management of common clinical problems experienced by survivors of adult cancers and how to cover these issues in a consultation. Reviewing the patient's history of cancer and treatments highlights potential long-term or late effects to consider, and recommended surveillance for recurrence. Physical consequences of specific treatments to identify include cardiac dysfunction, metabolic syndrome, lymphoedema, peripheral neuropathy, and osteoporosis. Immunotherapies can cause specific immune-related effects most commonly in the gastrointestinal tract, endocrine system, skin, and liver. Pain should be screened for and requires assessment of potential causes and non-pharmacological and pharmacological approaches to management. Common psychosocial issues, for which there are effective psychological therapies, include fear of recurrence, fatigue, altered sleep and cognition, and effects on sex and intimacy, finances, and employment. Review of lifestyle factors including smoking, obesity, and alcohol is necessary to reduce the risk of recurrence and second cancers. Exercise can improve quality of life and might improve cancer survival; it can also contribute to the management of fatigue, pain, metabolic syndrome, osteoporosis, and cognitive impairment. Using a supportive care screening tool, such as the Distress Thermometer, can identify specific areas of concern and help prioritise areas to cover in a consultation.

Treatment of Neuropathic Pain Directly Due to Cancer: An Update

Simple Summary

This review discusses treatment approaches for providing pain relief to oncological patients affected by pain caused by nerve damage due to the tumor, also known as neuropathic cancer pain. Although being encountered often and causing a relevant burden to these patients, neuropathic cancer pain remains still difficult to diagnose and treat. Strong evidence about the best drugs to be used remain limited, as do therapeutic choices.

Abstract

Neuropathic pain can be defined as pain related to abnormal somatosensory processing in either the peripheral or central nervous system. In this review article, with neuropathic cancer pain (NCP), we refer to pain due to nervous tissue lesions caused by the tumor or its metastases. Nervous tissue damage is the cause of cancer pain in approximately 40% of those experiencing cancer pain. Recognizing a neuropathic pathophysiology in these cases may be difficult and requires specific criteria that are not homogenously applied in clinical practice. The management of this type of pain can be challenging, requiring the use of specific non-opioid adjuvant drugs. The majority of the criteria for NCP diagnosis and management have been based mainly on results from the noncancer population, risking the failure of addressing the specific needs of this population of patients. In this review, we summarize current management options available for NCP and provide some insights on new promising treatments.

Nonopioid drug combinations for cancer pain: a systematic review

Supplemental Digital Content is Available in the Text.

This review is an evaluation of the efficacy and safety of nonopioid drug combinations for cancer pain. Little evidence exists to support the use of any given agent/combination.

Pain is highly prevalent in patients with cancer—nearly 40% report moderate-severe pain, which is commonly treated with opioids. Increasing cancer survivorship, opioid epidemics in some regions of the world, and limited opioid access in other regions have focused attention on nonopioid treatments. Given the limitations of monotherapy, combining nonopioids—such as antiepileptics and antidepressants—have shown promise in noncancer pain. This review seeks to evaluate efficacy of nonopioid combinations for cancer-related pain. Systematic searches of PubMed, EMBASE, and Cochrane CENTRAL were conducted for double-blind, randomized, controlled trials comparing a nonopioid combination with at least one of its components and/or placebo. This search yielded 4 randomized controlled trials, published between 1998 and 2019 involving studies of (1) imipramine + diclofenac; (2) mitoxantrone + prednisone + clodronate; (3) pentoxifylline + tocopherol + clodronate; and (4) duloxetine + pregabalin + opioid. In the first 3 of these trials, trends favouring combination efficacy failed to reach statistical significance. However, in the fourth trial, duloxetine + pregabalin + opioid was superior to pregabalin + opioid. This review illustrates recognition for the need to evaluate nonopioid drug combinations in cancer pain, although few trials have been published to date. Given the growing practice of prescribing more than 1 nonopioid for cancer pain and the need to expand the evidence base for rational combination therapy, more high-quality trials in this area are needed.

Phase III, international, multicentre, double-blind, dose increment, parallel-arm, randomised controlled trial of duloxetine versus pregabalin for opioid-unresponsive neuropathic cancer pain: a JORTC-PAL16 trial protocol

INTRODUCTION

Management of neuropathic cancer pain (NCP) refractory to regular opioids remains an important challenge. The efficacy of pregabalin for NCP except chemotherapy-induced peripheral neuropathy (CIPN) has already been confirmed in two randomised controlled trials (RCTs) compared with placebo. Duloxetine offers the potential of analgesia in opioid refractory NCP. However, there are no RCT of duloxetine for the management of opioid-refractory NCP as a first line treatment. Both classes of drugs have the potential to reduce NCP, but there has been no head-to-head comparison for the efficacy and safety, especially given differing side effect profiles.

METHODS AND ANALYSIS

An international, multicentre, double-blind, dose increment, parallel-arm, RCT is planned. Inclusion criteria include: adults with cancer experiencing NCP refractory to opioids; Brief Pain Inventory (BPI)-item 3 (worst pain) of ≥4; Neuropathic Pain on the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale of ≥12 despite of an adequate trial of regular opioid medication (≥60 mg/day oral morphine equivalent dose). Patients with CIPN are excluded.The study will recruit from palliative care teams (both inpatients and outpatients) in Japan and Australia. Participants will be randomised (1:1 allocation ratio) to duloxetine or pregabalin arm. Dose escalation is until day 14 and from day 14 to 21 is a dose de-escalation period to avoid withdrawal effects. The primary endpoint is defined as the mean difference in BPI item 3 for worst pain intensity over the previous 24 hours at day 14 between groups. A sample size of 160 patients will be enrolled between February 2020 and March 2023.

ETHICS AND DISSEMINATION

Ethics approval was obtained at Osaka City University Hospital Certified Review Board and South Western Sydney Local Health District Human Research Ethics Committee. The results of this study will be submitted for publication in international journals and the key findings presented at international conferences. TRIAL REGISTRATION NUMBERS: jRCTs051190097, ACTRN12620000656932.

Approaches to opioid prescribing in cancer survivors: Lessons learned from the general literature

LAY SUMMARY

Guidance on how to approach opioid decisions for people beyond active cancer treatment is lacking. This editorial discusses strategies from the general literature that can be thoughtfully tailored to cancer survivors to provide patient-centered pain and opioid care.

Multifarious Targets and Recent Developments in the Therapeutics for the Management of Bone Cancer Pain

Bone cancer pain (BCP) is a distinct pain state showing characteristics of both neuropathic and inflammatory pain. On average, almost 46% of cancer patients exhibit BCP with numbers flaring up to as high as 76% for terminally ill patients. Patients suffering from BCP experience a compromised quality of life, and the unavailability of effective therapeutics makes this a more devastating condition. In every individual cancer patient, the pain is driven by different mechanisms at different sites. The mechanisms behind the manifestation of BCP are very complex and poorly understood, which creates a substantial barrier to drug development. Nevertheless, some of the key mechanisms involved have been identified and are being explored further to develop targeted molecules. Developing a multitarget approach might be beneficial in this case as the underlying mechanism is not fixed and usually a number of these pathways are simultaneously dysregulated. In this review, we have discussed the role of recently identified novel modulators and mechanisms involved in the development of BCP. They include ion channels and receptors involved in sensing alteration of temperature and acidic microenvironment, immune system activation, sodium channels, endothelins, protease-activated receptors, neurotrophins, motor proteins mediated trafficking of glutamate receptor, and some bone-specific mechanisms. Apart from this, we have also discussed some of the novel approaches under preclinical and clinical development for the treatment of bone cancer pain.

Personalizing Cancer Pain Therapy: Insights from the Rational Use of Analgesics (RUA) Group

Introduction

A previous Delphi survey from the Rational Use of Analgesics (RUA) project involving Italian palliative care specialists revealed some discrepancies between current guidelines and clinical practice with a lack of consensus on items regarding the use of strong opioids in treating cancer pain. Those results represented the basis for a new Delphi study addressing a better approach to pain treatment in patients with cancer.

Methods

The study consisted of a two-round multidisciplinary Delphi study. Specialists rated their agreement with a set of 17 statements using a 5-point Likert scale (0 = totally disagree and 4 = totally agree). Consensus on a statement was achieved if the median consensus score (MCS) (expressed as value at which at least 50% of participants agreed) was at least 4 and the interquartile range (IQR) was 3–4.

Results

This survey included input from 186 palliative care specialists representing all Italian territory. Consensus was reached on seven statements. More than 70% of participants agreed with the use of low dose of strong opioids in moderate pain treatment and valued transdermal route as an effective option when the oral route is not available. There was strong consensus on the importance of knowing opioid pharmacokinetics for therapy personalization and on identifying immediate-release opioids as key for tailoring therapy to patients’ needs. Limited agreement was reached on items regarding breakthrough pain and the management of opioid-induced bowel dysfunction.

Conclusion

These findings may assist clinicians in applying clinical evidence to routine care settings and call for a reappraisal of current pain treatment recommendations with the final aim of optimizing the clinical use of strong opioids in patients with cancer.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-021-00248-x.

Non-opioid Analgesics and Emerging Therapies

Pain is a common and debilitating symptom of cancer. Cancer-related pain can occur at any point along the continuum from diagnosis to treatment to survivorship¹. A systematic review published in 2016 estimated the prevalence of cancer pain to be 55% in those undergoing antineoplastic treatment, 66.4% in advanced cancer, and 39.3% in the post-treatment population. Thirty-eight percent of cancer patients in this pooled analysis experienced moderate to severe pain².

Nonopioid drug combinations for cancer pain: protocol for a systematic review

This protocol will guide a review of clinical trials that evaluate the efficacy and safety of nonopioid analgesic drug combinations for the management of cancer-related pain.

Introduction:

Pain related to cancer, and its treatment, is common, may severely impair quality of life, and imposes a burden on patients, their families and caregivers, and society. Cancer-related pain is often challenging to manage, with limitations of analgesic drugs including incomplete efficacy and dose-related adverse effects.

Objectives:

Given problems with, and limitations of, opioid use for cancer-related pain, the identification of nonopioid treatment strategies that could improve cancer pain care is an attractive concept. The hypothesis that combinations of mechanistically distinct analgesic drugs could provide superior analgesia and/or fewer adverse effects has been tested in several pain conditions, including in cancer-related pain. Here, we propose to review trials of nonopioid analgesic combinations for cancer-related pain.

Methods:

Using a predefined literature search strategy, trials—comparing the combination of 2 or more nonopioid analgesics with at least one of the combination's individual components—will be searched on the PubMed and EMBASE databases from their inception until the date the searches are run. Outcomes will include pain intensity or relief, adverse effects, and concomitant opioid consumption.

Results/Conclusions:

This review is expected to synthesize available evidence describing the efficacy and safety of nonopioid analgesic combinations for cancer-related pain. Furthermore, a review of this literature will serve to identify future research goals that would advance our knowledge in this area.

Frequency of Concomitant Use of Gabapentinoids and Opioids among Patients with Cancer-Related Pain at an Outpatient Palliative Care Clinic

Background: Patients with cancer-related pain use opioids for nociceptive pain, while gabapentinoids are common to treat neuropathic pain. The simultaneous use of opioids with gabapentinoids has been associated with an increased risk of opioid-related death. Objectives: Determine the frequency of combined use of gabapentinoids among patients receiving opioids for cancer-related pain. We also examined if concomitant use of opioids and gabapentinoids together was associated with increased scores of fatigue and drowsiness on the Edmonton Symptom Assessment Scale (ESAS) compared to patients on opioids. Design: Retrospective study of patients on opioids and opioids plus gabapentinoids at their third visit to the outpatient Supportive Care Center. Results: We found that 48% (508/1059) of patients were on opioids. Of these patients, 51% (257/508) were on opioids only, and 49% (251/508) were on opioids plus gabapentinoids. The median (interquartile range [IQR]) morphine equivalent daily dose for patients on opioids was 75 (45, 138) mg, and opioids plus gabapentinoids was 68 (38, 150) mg (p = 0.94). The median (IQR) gabapentinoid equivalent daily dose was 900 (300, 1200) mg. The median (IQR) for ESAS-fatigue in patients on opioids was 5 (3, 7), and opioids plus gabapentinoids was 5 (3, 7) (p = 0.27). The median (IQR) for ESAS-drowsiness in patients on opioids was 3 (0, 5), and opioids plus gabapentinoids was 3 (0, 6) (p = 0.11). Conclusion: Almost 50% of advanced cancer patients receiving opioids for pain were exposed to gabapentinoids. Maximal efforts should be made to minimize potential complications from the concomitant use of opioids with gabapentinoids.

Practice review: Evidence-based and effective management of pain in patients with advanced cancer

BACKGROUND

Pain of a moderate or severe intensity affects over half of patients with advanced cancer and remains undertreated in at least one-third of these patients.

AIM

The aim of this study was to provide a pragmatic overview of the evidence supporting the use of interventions in pain management in advanced cancer and to identify where encouraging preliminary results are demonstrated but further research is required.

DESIGN

A scoping review approach was used to examine the evidence supporting the use of guideline-recommended interventions in pain management practice.

DATA SOURCES

National or international guidelines were selected if they described pain management in adult cancer patients and were written within the last 5 years in English. The Cochrane Database of Systematic Reviews (January 2014 to January 2019) was searched for 'cancer' AND 'pain' in the title, abstract or keywords. A MEDLINE search was also made.

RESULTS

A strong opioid remains the drug of choice for treating moderate or severe pain. Bisphosphonates and radiotherapy are also effective for cancer-related bone pain. Optimal management requires a tailored approach, support for self-management and review of treatment outcomes. There is likely a role for non-pharmacological approaches. Paracetamol should not be used in patients taking a strong opioid to treat pain. Cannabis-based medicines are not recommended. Weak opioids, ketamine and lidocaine are indicated in specific situations only.

CONCLUSION

Interventions commonly recommended by guidelines are not always supported by a robust evidence base. Research is required to evaluate the efficacy of non-steroidal anti-inflammatory drugs, anti-convulsants, anti-depressants, corticosteroids, some invasive anaesthetic techniques, complementary therapies and transcutaneous electrical nerve stimulation.

Targeting Serotonin1A Receptors for Treating Chronic Pain and Depression

The association of chronic pain with depression is becoming increasingly recognized. Treating both the conditions together is essential for an effective treatment outcome. In this regard, it is important to identify a shared mechanism involved in the association of chronic pain with depression. Central serotonin (5-hydroxytryptamine; 5-HT) neurotransmission has long been known to participate in the processing of signals related to pain. It also plays a key role in the pathogenesis and treatment of depression. Although functional responses to serotonin are mediated via the activation of multiple receptor types and subtypes, the 5-HT1A subtype is involved in the processing of nociception as well as the pathogenesis and treatment of depression. This receptor is located presynaptically, as an autoreceptor, on the perikaryon and dendritic spines of serotonin-containing neurons. It is also expressed as a heteroreceptor on neurons receiving input from serotonergic neurons. This arti-cle targets the 5-HT1A receptors to show that indiscriminate activation of pre and postsynaptic 5-HT1A receptors is likely to produce no therapeutic benefits; biased activation of the 5-HT heteroreceptors may be a useful strategy for treating chronic pain and depression individually as well as in a comorbid condition.

Factors Influencing the Initiation of Strong Opioids in Cancer Patients on Palliative Care: An Audit from a Tertiary Cancer Center in India

Aim

This audit was done to analyze the factors influencing the use of strong opioids in cancer patients receiving comprehensive palliative care from a tertiary institute.

Materials and Methods

Case records of patients registered for palliative care at our center in 3 months were retrospectively reviewed and followed up throughout the course of their illness. Demographic factors, prior treatments, social support system, analgesic use at registration, and use of radiation and adjuvant analgesics were recorded. Strong opioid use and their time of initiation were evaluated, and multivariate analysis was used to identify the factors correlating with the above.

Results

After registration, strong opioids were initiated in 16% of the patients. It was observed that patients younger than 55 years and those with visceral metastases and history of use of weak opioids at the time of registration had a higher probability of being started on strong opioids. Factors associated with a significantly longer strong opioid-free interval were having spouse as primary caregiver, presence of skeletal metastases, use of palliative radiotherapy, and low socioeconomic status.

Conclusion

It is certain that the use of strong opioids for adequate analgesia is a necessity for palliative-care patients. However, optimal utilization of adjunctive analgesic modalities, coupled with good supportive care, can minimize the requirement and duration of strong opioid use, especially in developing countries with limited access to specialist palliative care.

Palliative Care and the Management of Common Distressing Symptoms in Advanced Cancer: Pain, Breathlessness, Nausea and Vomiting, and Fatigue

Good symptom management in oncology is associated with improved patient and family quality of life, greater treatment compliance, and may even offer survival advantages. With population growth and aging, the proportion of patients with multiple symptoms—both related and unrelated to their cancer—is anticipated to increase, supporting calls for a more routine and integrated approach to symptom management. This article presents a summary of the literature for the use of symptom assessment tools and reviews the management of four common and distressing symptoms commonly experienced by people with advanced cancer: pain, breathlessness, nausea and vomiting, and fatigue. We also discuss the role of palliative care in supporting a holistic approach to symptom management throughout the cancer trajectory.

Pain And The Use Of Gabapentinoids In German Nursing Home Residents - Results From An Analysis Based On Statutory Health Insurance Data

Background

Gabapentinoids (gabapentin and pregabalin) are psychoactive medications that are increasingly used for different conditions. Since there is evidence that psychotropic drugs, in general, are often inappropriately prescribed in elderly patients, we aimed to determine frequency and indications of gabapentinoid prescribing for nursing home residents.

Methods

We analyzed data from a large German statutory health insurance database. Included were records from people ≥65 years-of-age, who were admitted to a nursing home between January 2010 and December 2014. We determined the number and proportion of common indications for on- and off-label prescriptions, the most frequent co-medications, and the characteristics of patients and prescribers.

Results

Of 127,277 residents, 9539 (7.5%) received gabapentinoids and 4852 initiated treatment (4.0%; with 66.3% pregabalin). Median age of gabapentinoid initiators was 84 years (78.5% females). In these users, on-label prescribing was found in 57.4%, predominantly for neuropathic pain. Other painful conditions were also chief causes (84.7%) for off-label prescribing. Gabapentinoids were mainly started by general practitioners (64.5%) while pain specialists contributed <2%. Forty-six percent of users received additional opioids and in 27.5% gabapentinoids were prescribed only once.

Conclusion

Gabapentinoids were frequently used in nursing home residents. Regular co-prescribing with opioids and psychotropic drugs might indicate employment to improve pain or assist treatment of conditions that are frequently associated with disruptive behavior such as dementia. However, more research is needed to better understand decision-making regarding gabapentinoid prescribing, especially in view of aggressive marketing, uncertain analgesic effects, problematic side effects, and uncritical use in the elderly.

Additive Duloxetine for Cancer-Related Neuropathic Pain Nonresponsive or Intolerant to Opioid-Pregabalin Therapy: A Randomized Controlled Trial (JORTC-PAL08)

CONTEXT

Although opioids and pregabalin are widely used for cancer-related neuropathic pain (CNP), no clinical trials exist to determine which medications are effective when an opioid-pregabalin combination therapy fails.

OBJECTIVES

We investigated the efficacy of duloxetine for CNP nonresponsive or intolerant to opioid-pregabalin combination therapy.

METHODS

A multicenter, randomized, double-blind, placebo-controlled trial was performed at 12 specialized palliative care services in Japan. Patients with CNP average pain scores (Brief Pain Inventory [BPI]-Item 5) ≥ 4 in the previous 24 hours and nonresponsive or intolerant to opioid-pregabalin combination therapy were eligible. Patients with chemotherapy-induced peripheral neuropathies were excluded. Patients were administered duloxetine 20 mg/day titrated to 40 mg/day or placebo for 10 days. The primary endpoint was BPI-Item 5 on Day 10. Responder analysis measured proportions of patients with 30% and 50% pain decreases.

RESULTS

Seventy patients were enrolled. Complete case analysis revealed mean BPI-Item 5 on Day 10 of 4.03 for Group D vs. 4.88 for Group P (P = 0.053). Baseline observation carried forward analysis revealed mean BPI-Item 5 on Day 10 of 4.06 and 4.91 for Groups D and P, respectively (P = 0.048). Clinically meaningful pain improvement (≥30%) was reported by 44.1% (n = 15) of patients in Group D vs. 18.2% (n = 6) in Group P (P = 0.02); 32.4% (n = 11) vs. 3.0% (n = 1) of patients in Groups D and P, respectively, reported pain reduction ≥ 50% (P = 0.002).

CONCLUSION

Adding duloxetine to opioid-pregabalin therapy might have clinical benefit in alleviating refractory CNP. Further studies are needed to conclude the efficacy of adding duloxetine.

Retrospective Cohort Study of the Prevalence of Off-label Gabapentinoid Prescriptions in Hospitalized Medical Patients

Gabapentinoid prescriptions are increasing in North America, with frequent off-label use despite limited proven efficacy. This retrospective cohort study describes prescribing trends among hospitalized patients with a focus on dosing and deprescribing. We examined consecutive inpatients between December 2013 and July 2017 on a 52-bed medical unit in Montréal, Canada. Prevalence of off-label use, median doses prescribed, and deprescribing trends were analyzed over time. Of 4,103 hospitalized patients, 550 (13.4%) were prescribed gabapentinoids preadmission, with two patients being coprescribed gabapentin and pregabalin (total 552 prescriptions). A minority (94/552, or 17%) were for approved indications. Although it was uncommon for gabapentinoids to be newly prescribed in hospital, preadmission gabapentinoids were also seldom deprescribed (65/495 patients discharged alive, or 13%). Given a high prevalence of use, limited efficacy, and potential harms, gabapentinoids may represent an ideal target for re-evaluation of indication and effectiveness in hospitalized adults, with consideration given to deprescribing.

Adult Cancer Pain, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology

In recent years, the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Adult Cancer Pain have undergone substantial revisions focusing on the appropriate and safe prescription of opioid analgesics, optimization of nonopioid analgesics and adjuvant medications, and integration of nonpharmacologic methods of cancer pain management. This selection highlights some of these changes, covering topics on management of adult cancer pain including pharmacologic interventions, nonpharmacologic interventions, and treatment of specific cancer pain syndromes. The complete version of the NCCN Guidelines for Adult Cancer Pain addresses additional aspects of this topic, including pathophysiologic classification of cancer pain syndromes, comprehensive pain assessment, management of pain crisis, ongoing care for cancer pain, pain in cancer survivors, and specialty consultations.

Reviewing without a Clinical Background Is Detrimental for Cancer Pain Management

Reviews are a fundamental space for summarizing and spreading knowledge on a particular topic. Methodologic skills may improve the clarity and the meaning of data presentation. A recent editorial choice provided an advanced update on a topic such as cancer pain, providing meaningful and appropriate information on hot topics of cancer pain management. Recent reviews have reported strange and misleading data, suggesting to some adjuvant drugs or opioids for mild-moderate pain instead of opioids on the basis of an incomprehensible analysis performed without any clinical sense. This is a serious problem because such information, published in an authoritative journal, could dis-educate oncologists in their daily practice.

Assessment and Management of Chronic Pain in the Seriously Ill

The intent of this article is to help clinicians to have practical knowledge and skills related to both assessment and pharmacotherapy of chronic pain in the seriously ill patients. Treating patients with chronic pain and progressive disease should include assessment of "total pain" (physical, psychological, and spiritual suffering) and the care givers as part of treatment team. Effective management of chronic pain starts with thorough assessment and diagnosis of the pain syndrome. A worldwide consensus endorses use of multimodal approach and opioid pharmacotherapy as the mainstay approach to moderate to severe pain in cancer and pain associated with serious illness.

A critical appraisal of gabapentinoids for pain in cancer patients

PURPOSE OF REVIEW

Gabapentinoids are frequently used in the management of cancer pain. In recent Cochrane systematic reviews, although there was an abundance of evidence relating to non-cancer pain, only a few studies related to cancer pain. This review summarizes recent randomised controlled trials (RCTs) evaluating the use of gabapentinoids for tumour-related (as monotherapy or part of combination therapy) and treatment-related pain.

RECENT FINDINGS

For tumour-related pain, ten out of thirteen studies showed statistically significant benefits in favour of gabapentinoids. When used, as part of monotherapy or combination therapy, benefits were observed in five out of six studies evaluating gabapentin, and in six out of eight studies evaluating pregabalin. For treatment-related pain, none of the four studies (two gabapentin, two pregabalin) showed statistically significant benefits in favour of gabapentinoids. Unfortunately, many of the studies included were limited by small sample size, lack of blinding, and inadequate follow-up.

SUMMARY

More and better quality studies are required, although it may be challenging to accomplish in this patient population. Gabapentinoids may offer benefits to cancer patients with pain, but careful titration and monitoring of adverse effects is necessary.

Attitude of Japanese palliative care specialists towards adjuvant analgesics cancer-related neuropathic pain refractory to opioid therapy: a nationwide cross-sectional survey

Cancer-related neuropathic pain (CNP) requires therapy involving multiple pharmaceuticals, including anticonvulsants and antidepressants; however, strong evidence to support this practice is limited. This study is a cross-sectional questionnaire-based survey. As the standard dose of adjuvant analgesics for CNP refractory to opioid therapy is not clear, the purpose of this study is to clarify the opinions of specialists about the usage of duloxetine and pregabalin for patients with CNP refractory to opioid therapy. Two hundred and eight certified palliative care specialists were surveyed and a total of 87 (42%) responses were analyzed. Twenty-five percent of specialists had considered increasing duloxetine doses up to 60 mg/day and 58% had considered increasing pregabalin doses up to 300 mg/day for CNP refractory to opioid therapy. However, 23% of the specialists succeeded in increasing duloxetine doses up to 60 mg/day and 17% in increasing pregabalin doses up to 300 mg/day, respectively.

Combining opioids and non-opioids for pain management: Current status

Pain remains a global health challenge. For decades, clinicians have been primarily relying on μ-opioid receptor (MOR) agonists and nonsteroidal anti-inflammatory drugs (NSAIDs) for pain management. MOR agonists remain the most efficacious analgesics available; however, adverse effects related to MOR agonists use are severe which often lead to forced drug discontinuation and inadequate pain relief. The recent opioid overdose epidemic urges the development of safer analgesics. Combination therapy is a well-established clinical pharmacotherapeutic strategy for the treatment of various clinical disorders. The combination of MOR agonists with non-MOR agonists may increase the analgesic potency of MOR agonists, reduce the development of tolerance and dependence, reduce the diversion and abuse, overdose, and reduce other clinically significant side effects associated with prolonged opioid use such as constipation. Overall, the combination therapy approach could substantially improve the therapeutic profile of MOR agonists. This review summarizes some recent developments in this field. This article is part of the Special Issue entitled 'New Vistas in Opioid Pharmacology'.

Cancer-Related Neuropathic Pain

Neuropathic pain in cancer is common and debilitating. It is important to differentiate neuropathic pain from other cancer-related pains as it is associated with worse pain outcomes and requires different treatment strategies. This review summarises recent updates to pain classification, aetiology, pain assessment and current recommendations for treatment in patients with cancer-related neuropathic pain.

Nonopioid versus opioid agents for chronic neuropathic pain, rheumatoid arthritis pain, cancer pain and low back pain

Chronic pain continues to be a major health issue throughout the world and a huge economic burden for nations around the world. While the use of opioids does have risks, they are still widely used by clinicians as a treatment option for various chronic pain conditions. This review explores and compares the efficacy and safety of opioid and nonopioid agents for the following commonly encountered chronic pain conditions: neuropathic pain, rheumatoid arthritis joint pain, cancer pain and low back pain. Our findings demonstrate that while there are several nonopioid pharmacologic options that are clinically effective, opioids maintain a role in the treatment of certain chronic pain conditions and should continue to have an important place in the armamentarium of clinicians.

Pain: Persistent postsurgery and bone cancer-related pain

The generation of neuropathic pain is a complex dynamic process. Factors involved include one or more dysregulated sensory neural pathways; dysregulated activity of specific neurotransmitters, synapses, receptors and cognitive and emotional neural circuits; and the balance between degenerative and regenerative neural events. Risk factors include age, sex, cognition, emotions, genetic polymorphism, previous or ongoing chronic pain conditions and the use of certain drugs. Intense pain experienced before, during and after surgery is a risk factor for the development of central sensitization with consequent persistent postsurgery neuropathic pain. Blockade of N-methyl-D-aspartate receptors with appropriate drugs during and immediately after surgery may prevent persistent postsurgical pain. Most cancers, but particularly malignant metastases in bone, can induce persistent pain. Local factors including direct damage to sensory nerve fibres, infiltration of nerve roots by cancer cells and algogenic biological agents within the microenvironment of the tumour bring about central sensitization of dorsal horn neurons, characterized by neurochemical reorganization with persistent cancer pain. In this article, the clinical features, pathogenesis and principles of management of persistent postsurgery pain and cancer pain are briefly discussed.

Thematic Trends in Complementary and Alternative Medicine Applied in Cancer-Related Symptoms

Purpose

The main goal of this study is to discover the scientific evolution of Cancer-Related Symptoms in Complementary and Alternative Medicine research area, analyzing the articles indexed in the Web of Science database from 1980 to 2013.

Design/Methodology/Approach

A co-word science mapping analysis is performed under a longitudinal framework (1980 to 2013). The documental corpus is divided into two subperiods, 1980–2008 and 2009–2013. Thus, the performance and impact rates, and conceptual evolution of the research field are shown.

Findings

According to the results, the co-word analysis allows us to identify 12 main thematic areas in this emerging research field: anxiety, survivors and palliative care, meditation, treatment, symptoms and cancer types, postmenopause, cancer pain, low back pain, herbal medicine, children, depression and insomnia, inflammation mediators, and lymphedema. The different research lines are identified according to the main thematic areas, centered fundamentally on anxiety and suffering prevention. The scientific community can use this information to identify where the interest is focused and make decisions in different ways.

Research limitation

Several limitations can be addressed: 1) some of the Complementary and Alternative Medicine therapies may not have been included; 2) only the documents indexed in Web of Science are analyzed; and 3) the thematic areas detected could change if another dataset was considered.

Practical implications

The results obtained in the present study could be considered as an evidence-based framework in which future studies could be built.

Originality/value

Currently, there are no studies that show the thematic evolution of this research area.

Updates in palliative care - overview and recent advancements in the pharmacological management of cancer pain

Pain is a common symptom in many types of cancer. Interdisciplinary team management, including pain assessment, explanation to the patient/family, treating the reversible, non-pharmacological treatments and reassessment are essential. This article focuses on the pharmacological management of cancer pain, and overviews and updates on the recent advances in this field. Both non-opioid and opioid analgesia as well as coanalgesics (adjuvants) are reviewed. Within non-opioid analgesia the risks of non-steroidal anti-inflammatory drugs (NSAIDs) are considered and recommendations for NSAIDs in patients at risk of gastrointestinal and cardiovascular toxicity are made. For opioid analgesics, side effects of opioids are discussed alongside practical guidance on opioid prescribing and converting between opioids. Newer drugs such as tapentadol are considered in this update. Amitriptyline, duloxetine, gabapentin and pregabalin, and the guidance for their use are reviewed in the coanalgesics (adjuvants) section.