The CanPain SCI clinical practice guidelines for rehabilitation management of neuropathic pain after spinal cord injury: 2021 update.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: The objective was to update the 2016 version of the Canadian clinical practice guidelines for the management of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient, outpatient and community SCI rehabilitation settings in Canada. METHODS: The guidelines were updated in accordance with the Appraisal of Guidelines for Research and Evaluation II tool. A Steering Committee and Working Group reviewed the relevant evidence on neuropathic pain management (encompassing screening and diagnosis, treatment and models of care) after SCI. The quality of evidence was scored using Grading of Recommendations Assessment, Development and Evaluation (GRADE). A consensus process was followed to achieve agreement on recommendations and clinical considerations. RESULTS: The working group identified and reviewed 46 additional relevant articles published since the last version of the guidelines. The panel agreed on 3 new screening and diagnosis recommendations and 8 new treatment recommendations. Two key changes to these treatment recommendations included the introduction of general treatment principles and a new treatment recommendation classification system. No new recommendations to model of care were made. CONCLUSIONS: The CanPainSCI recommendations for the management of neuropathic pain after SCI should be used to inform practice.

Consensus-based recommendations for titrating cannabinoids and tapering opioids for chronic pain control.

AIMS: Opioid misuse and overuse have contributed to a widespread overdose crisis and many patients and physicians are considering medical cannabis to support opioid tapering and chronic pain control. Using a five-step modified Delphi process, we aimed to develop consensus-based recommendations on: 1) when and how to safely initiate and titrate cannabinoids in the presence of opioids, 2) when and how to safely taper opioids in the presence of cannabinoids and 3) how to monitor patients and evaluate outcomes when treating with opioids and cannabinoids. RESULTS: In patients with chronic pain taking opioids not reaching treatment goals, there was consensus that cannabinoids may be considered for patients experiencing or displaying opioid-related complications, despite psychological or physical interventions. There was consensus observed to initiate with a cannabidiol (CBD)-predominant oral extract in the daytime and consider adding tetrahydrocannabinol (THC). When adding THC, start with 0.5-3 mg, and increase by 1-2 mg once or twice weekly up to 30-40 mg/day. Initiate opioid tapering when the patient reports a minor/major improvement in function, seeks less as-needed medication to control pain and/or the cannabis dose has been optimised. The opioid tapering schedule may be 5%-10% of the morphine equivalent dose (MED) every 1 to 4 weeks. Clinical success could be defined by an improvement in function/quality of life, a ≥30% reduction in pain intensity, a ≥25% reduction in opioid dose, a reduction in opioid dose to <90 mg MED and/or reduction in opioid-related adverse events. CONCLUSIONS: This five-stage modified Delphi process led to the development of consensus-based recommendations surrounding the safe introduction and titration of cannabinoids in concert with tapering opioids.

Opioid therapy vs. multimodal analgesia in head and neck Cancer (OPTIMAL-HN): study protocol for a randomized clinical trial.

BACKGROUND: Radiation-induced mucositis (RIM) pain confers substantial morbidity for head and neck cancer (HNC) patients undergoing radiotherapy alone (RT) or chemoradiotherapy (CRT), often reducing treatment compliance. However, no standard currently exists for the treatment of RIM, and high dose opioid therapy, with its associated side effects and increased risk for chronic opioid use, remains the cornerstone of HNC pain management. The goal of this randomized clinical trial is to compare multimodal analgesia using analgesic medications with different mechanisms of action, to the institutional standard of opioid analgesia alone, in order to ascertain the optimal analgesic regimen for the management of RIM pain in HNC patients. METHODS: In this open-label, single-institution, non-inferiority, randomized clinical trial, sixty-two patients with mucosal head and neck malignancies treated with curative-intent radiation will be randomized in a 1:1 ratio, stratified by RT or CRT, between Arm 1: opioid analgesia alone as per the institutional standard, or Arm 2: multimodal analgesia using Pregabalin, Acetaminophen, and Naproxen, in addition to opioids, if required. The primary endpoint is the average 11-Numeric Rating Scale (11-NRS) score for pain during the last week of radiation treatment. Secondary endpoints include: average weekly opioid use, duration of opioid requirement, average daily 11-NRS score for pain, average weekly opioids dispensed, quality of life, hospitalizations for analgesic medication-induced complications, time to feeding tube insertion, weight loss, toxicity, treatment interruptions, and death within 3 months of completing RT treatment. Patients are eligible once analgesia is required for moderate 4/10 pain. DISCUSSION: This study will assess the efficacy and safety of multimodal analgesia and its impact on opioid requirements, clinical outcomes, and quality of life, as a potential new standard treatment for RIM pain in HNC patients undergoing definitive RT or CRT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04221165 . Date of registration: January 9, 2020. Appendix 2 reports the World Health Organization trial registration dataset.

Pain-Related Activity Management Patterns as Predictors of Treatment Outcomes in Patients with Fibromyalgia Syndrome.

OBJECTIVES: This study sought to determine if pre- to post-treatment changes in pain-related activity patterns (i.e., overdoing, avoidance, and pacing) were associated with pre- to post-treatment changes in function (i.e., pain interference, psychological function, and physical function) in patients with fibromyalgia syndrome who participated in either an operant learning- or an energy conservation-based training in activity management. METHODS: Sixty-nine patients with fibromyalgia syndrome participated in an activity management treatment (32 in an operant learning group and 37 in an energy conservation group). Outcomes were assessed at pre- and post-treatment, and patients provided demographic information and completed measures assessing pain intensity, pain interference, psychological function, physical function, and pain management activity patterns. Three linear hierarchical regression analyses predicting changes in pain outcomes from changes in pacing, overdoing, and avoidant activity patterns were performed. RESULTS: Changes in pain-related activity patterns made significant contributions to the prediction of changes in patients' function. Specifically: (a) increases in overdoing predicted reductions in pain interference; (b) decreases in avoidance predicted improvements in psychological function; and (c) increases in pacing predicted improvements in physical function. CONCLUSIONS: This study provides support for a role of activity management treatments in improved adjustment to chronic pain. Research is needed to replicate and extend these findings in order to build an empirical basis for developing more effective chronic pain treatments for facilitating improved physical and psychological function in individuals with chronic pain.

An Evaluation of Sex Differences in Patients With Chronic Pain Undergoing an Interdisciplinary Pain Treatment Program.

OBJECTIVES: To determine if there are sex differences in a sample of patients participating in a 4-week interdisciplinary pain treatment program in (1) pretreatment pain intensity, physical function, psychological function, pain beliefs, kinesiophobia, pain catastrophizing, and activity management patterns; and (2) treatment response. METHODS: Seventy-two men and 130 women with chronic pain completed study measures. Analyses of covariance (ANCOVAs) were performed to compare men and women on pretreatment measures. Repeated-measures ANCOVAs were used to compare both sexes on 3 treatment outcomes (pain intensity, physical function, and depressive symptoms). RESULTS: Before treatment, compared to women, men reported higher levels of kinesiophobia, were more likely to view their pain as being harmful, and used more activity pacing when doing daily activities. Women were more likely to use an overdoing activity pattern than men. No sex differences emerged for pretreatment pain intensity, physical function, psychological function, catastrophizing, activity avoidance, or measures of other pain-related beliefs. At posttreatment, women reported more improvements in pain intensity and physical function compared to men, while both sexes reported similar reductions in depressive symptoms. All effect sizes for statistically significant findings were of small to moderate magnitude. DISCUSSION: The results of this study suggest that men and women have a comparable profile with respect to the overall burden of chronic pain. Nevertheless, sex differences were found for certain pain beliefs and coping styles. Women appear to reap more benefits from the interdisciplinary pain management program than men. These findings indicate that further research to develop sex-specific assessment procedures and tailored pain treatments may be warranted.

Intravenous lidocaine in the management of chronic peripheral neuropathic pain: a randomized-controlled trial.

PURPOSE: Neuropathic pain, resulting from injury to the peripheral or central nervous system, is due to upregulation of aberrant sodium channels with neuronal hyperexcitability. Lidocaine blocks these channels and several studies show that intravenous (IV) lidocaine infusion provides significant relief in patients with chronic peripheral neuropathic pain in the short term (for up to six hours). Our objective was to determine if IV lidocaine provides significant pain relief and overall improvement in quality of life in the longer term (for up to four weeks). METHODS: This single site randomized double-blind, crossover trial compared IV lidocaine infusion (5 mg·kg-1) with active placebo infusion containing diphenhydramine (50 mg) in patients with chronic neuropathic pain of peripheral nerve origin of at least six months duration. The primary outcome was average pain intensity reduction from IV lidocaine relative to placebo at four weeks post-infusion. Secondary outcome measures included parameters of physical function, mood, and overall quality of life. RESULTS: We enrolled 34 subjects in this trial-mostly with painful diabetic neuropathy and post-herpetic neuralgia. There were no significant differences between IV lidocaine and placebo infusions at any time point involving any of the outcome measures. Mean (standard deviation) pain intensity at week 4 for the placebo and lidocaine groups were not different [6.58 (1.97) vs 6.78 (1.56), respectively; between-group difference, 0.17; 95% confidence interval, - 0.50 to 0.84]. CONCLUSION: We found no significant long-term analgesic or quality of life benefit from IV lidocaine relative to control infusion for chronic peripheral neuropathic pain. TRIAL REGISTRATION: clinicaltrials.gov (NCT01669967); registered 22 June, 2012.

RéSUMé: OBJECTIF: La douleur neuropathique, résultat d'une lésion du système nerveux périphérique ou central, est due à l'augmentation de canaux sodiques aberrants accompagnée d'une hyperexcitabilité neuronale. La lidocaïne bloque ces canaux et plusieurs études ont démontré qu'une perfusion intraveineuse (IV) de lidocaïne offrait un important soulagement à court terme (pour une durée maximale de six heures) aux patients atteints de douleur neuropathique périphérique chronique. Notre objectif était de déterminer si la lidocaïne IV procurait un soulagement significatif de la douleur et une amélioration globale de la qualité de vie à plus long terme (pour une durée maximale de quatre semaines). MéTHODE: Cette étude randomisée croisée à double insu et mono-site a comparé une perfusion de lidocaïne IV (5 mg·kg−1) à une perfusion de placebo actif contenant de la diphenhydramine (50 mg) chez des patients atteints de douleur neuropathique chronique provenant du système nerveux périphérique et durant depuis au moins six mois. Le critère d'évaluation principal était la réduction moyenne de l'intensité de la douleur procurée par la lidocaïne IV par rapport au placebo à quatre semaines post-perfusion. Les critères d'évaluation secondaires comprenaient divers paramètres pour mesurer la capacité physique fonctionnelle, l'humeur et la qualité de vie globale. RéSULTATS: Nous avons recruté 34 patients pour cette étude, la plupart souffrant de neuropathie diabétique douloureuse et de névralgie post-herpétique. Aucune différence significative n'a été observée entre les perfusions de lidocaïne IV et de placebo, quel que soit le point de mesure dans le temps, pour aucun de nos critères d'évaluation. L'intensité de la douleur moyenne (écart type) à la semaine 4 était similaire dans les groupes placebo et lidocaïne [6,58 (1,97) vs 6,78 (1,56), respectivement; différence intergroupe, 0,17; intervalle de confiance 95 %, − 0,50 à 0,84]. CONCLUSION: Nous n'avons trouvé aucun bienfait significatif sur l'analgésie à long terme ou la qualité de vie d'une perfusion de lidocaïne IV par rapport à une perfusion témoin pour soulager la douleur neuropathique périphérique chronique. ENREGISTREMENT DE L'éTUDE: clinicaltrials.gov (NCT01669967); enregistrée le 22 juin 2012.

Long-Term Outcomes in the Management of Central Neuropathic Pain Syndromes: A Prospective Observational Cohort Study.

BACKGROUND: Central neuropathic pain syndromes are a result of central nervous system injury, most commonly related to stroke, traumatic spinal cord injury, or multiple sclerosis. These syndromes are distinctly less common than peripheral neuropathic pain, and less is known regarding the underlying pathophysiology, appropriate pharmacotherapy, and long-term outcomes. The objective of this study was to determine the long-term clinical effectiveness of the management of central neuropathic pain relative to peripheral neuropathic pain at tertiary pain centers. METHODS: Patients diagnosed with central (n=79) and peripheral (n=710) neuropathic pain were identified for analysis from a prospective observational cohort study of patients with chronic neuropathic pain recruited from seven Canadian tertiary pain centers. Data regarding patient characteristics, analgesic use, and patient-reported outcomes were collected at baseline and 12-month follow-up. The primary outcome measure was the composite of a reduction in average pain intensity and pain interference. Secondary outcome measures included assessments of function, mood, quality of life, catastrophizing, and patient satisfaction. RESULTS: At 12-month follow-up, 13.5% (95% confidence interval [CI], 5.6-25.8) of patients with central neuropathic pain and complete data sets (n=52) achieved a ≥30% reduction in pain, whereas 38.5% (95% CI, 25.3-53.0) achieved a reduction of at least 1 point on the Pain Interference Scale. The proportion of patients with central neuropathic pain achieving both these measures, and thus the primary outcome, was 9.6% (95% CI, 3.2-21.0). Patients with peripheral neuropathic pain and complete data sets (n=463) were more likely to achieve this primary outcome at 12 months (25.3% of patients; 95% CI, 21.4-29.5) (p=0.012). CONCLUSION: Patients with central neuropathic pain syndromes managed in tertiary care centers were less likely to achieve a meaningful improvement in pain and function compared with patients with peripheral neuropathic pain at 12-month follow-up.

Long-Term Outcomes in the Management of Painful Diabetic Neuropathy.

BACKGROUND: Painful diabetic neuropathy (PDN) is a frequent complication of diabetes mellitus. Current treatment recommendations are based on short-term trials, generally of ≤3 months' duration. Limited data are available on the long-term outcomes of this chronic disease. The objective of this study was to determine the long-term clinical effectiveness of the management of chronic PDN at tertiary pain centres. METHODS: From a prospective observational cohort study of patients with chronic neuropathic non-cancer pain recruited from seven Canadian tertiary pain centres, 60 patients diagnosed with PDN were identified for analysis. Data were collected according to Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials guidelines including the Brief Pain Inventory. RESULTS: At 12-month follow-up, 37.2% (95% confidence interval [CI], 23.0-53.3) of 43 patients with complete data achieved pain reduction of ≥30%, 51.2% (95% CI, 35.5-66.7) achieved functional improvement with a reduction of ≥1 on the Pain Interference Scale (0-10, Brief Pain Inventory) and 30.2% (95% CI, 17.2-46.1) had achieved both these measures. Symptom management included at least two medication classes in 55.3% and three medication classes in 25.5% (opioids, antidepressants, anticonvulsants). CONCLUSIONS: Almost one-third of patients being managed for PDN in a tertiary care setting achieve meaningful improvements in pain and function in the long term. Polypharmacy including analgesic antidepressants and anticonvulsants were the mainstays of effective symptom management.

Selective Cannabinoids for Chronic Neuropathic Pain: A Systematic Review and Meta-analysis.

BACKGROUND: There is a lack of consensus on the role of selective cannabinoids for the treatment of neuropathic pain (NP). Guidelines from national and international pain societies have provided contradictory recommendations. The primary objective of this systematic review and meta-analysis (SR-MA) was to determine the analgesic efficacy and safety of selective cannabinoids compared to conventional management or placebo for chronic NP. METHODS: We reviewed randomized controlled trials that compared selective cannabinoids (dronabinol, nabilone, nabiximols) with conventional treatments (eg, pharmacotherapy, physical therapy, or a combination of these) or placebo in patients with chronic NP because patients with NP may be on any of these therapies or none if all standard treatments have failed to provide analgesia and or if these treatments have been associated with adverse effects. MEDLINE, EMBASE, and other major databases up to March 11, 2016, were searched. Data on scores of numerical rating scale for NP and its subtypes, central and peripheral, were meta-analyzed. The certainty of evidence was classified using the Grade of Recommendations Assessment, Development, and Evaluation approach. RESULTS: Eleven randomized controlled trials including 1219 patients (614 in selective cannabinoid and 605 in comparator groups) were included in this SR-MA. There was variability in the studies in quality of reporting, etiology of NP, type and dose of selective cannabinoids. Patients who received selective cannabinoids reported a significant, but clinically small, reduction in mean numerical rating scale pain scores (0-10 scale) compared with comparator groups (-0.65 points; 95% confidence interval, -1.06 to -0.23 points; P = .002, I = 60%; Grade of Recommendations Assessment, Development, and Evaluation: weak recommendation and moderate-quality evidence). Use of selective cannabinoids was also associated with improvements in quality of life and sleep with no major adverse effects. CONCLUSIONS: Selective cannabinoids provide a small analgesic benefit in patients with chronic NP. There was a high degree of heterogeneity among publications included in this SR-MA. Well-designed, large, randomized studies are required to better evaluate specific dosage, duration of intervention, and the effect of this intervention on physical and psychologic function.

Factors Associated with Suicidal Ideation in Patients with Chronic Non-Cancer Pain.

Objectives: This study's aim was to identify the most important general and pain-related risk factors of suicidal ideation in a large sample of patients with chronic non-cancer pain. Methods: A total of 728 patients with chronic non-cancer pain were recruited from the waitlists of eight multidisciplinary pain clinics across Canada. Patients were assessed using self-administered questionnaires to measure demographic, pain-related (intensity, duration, interference, sleep problems), psychological (anxiety, anger, depressive symptoms including suicidal ideation), cognitive (catastrophizing, attitudes/beliefs), and health-related quality of life variables. A hierarchical logistic regression analysis was used to identify the factors that were associated with presence/absence of suicidal ideation while controlling for depressive symptoms. Results: The results showed that being a male, longer pain duration, higher anger levels, feelings of helplessness, greater pain magnification, and being more depressed were significant independent predictor factors of suicidal ideation, while better perceived mental health was related with a lesser likelihood of suicidal ideation. Moreover, being in a relationship and believing in a medical cure for pain might be protective of suicidal ideation while being anxious may be more associated with suicidal ideation. Conclusions: These results indicate that development of suicidal ideation is more closely related to pain chronicity and certain psychosocial factors than how severe or physically incapacitating the pain is. Many of these factors could potentially be modified by early identification of suicidal ideation and developing targeted cognitive interventions for suicidal at-risk patients. Research to examine the efficacy of these interventions for reducing suicidal ideation is warranted.

Pharmacologic management of chronic neuropathic pain: Review of the Canadian Pain Society consensus statement.

OBJECTIVE: To provide family physicians with a practical clinical summary of the Canadian Pain Society (CPS) revised consensus statement on the pharmacologic management of neuropathic pain. QUALITY OF EVIDENCE: A multidisciplinary interest group within the CPS conducted a systematic review of the literature on the current treatments of neuropathic pain in drafting the revised consensus statement. MAIN MESSAGE: Gabapentinoids, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors are the first-line agents for treating neuropathic pain. Tramadol and other opioids are recommended as second-line agents, while cannabinoids are newly recommended as third-line agents. Other anticonvulsants, methadone, tapentadol, topical lidocaine, and botulinum toxin are recommended as fourth-line agents. CONCLUSION: Many pharmacologic analgesics exist for the treatment of neuropathic pain. Through evidence-based recommendations, the CPS revised consensus statement helps guide family physicians in the management of patients with neuropathic pain.

Severe myositis of the hip flexors after pre-operative chemoradiation therapy for locally advanced rectal cancer: case report.

BACKGROUND: The use of neoadjuvant radiation therapy and chemotherapy in the treatment of locally advanced rectal adenocarcinoma has been shown to reduce disease recurrence when combined with surgery and adjuvant chemotherapy. We report a case of a patient who developed a debilitating bilateral myopathy of the hip flexors after successful treatment for rectal cancer. To the best of our knowledge, this is the first such complication from radiation therapy reported in a patient with colorectal cancer. The disproportionate severity of our patient's myopathy relative to the dose of radiation used also makes this case unique among reports of neuromuscular complications from radiation therapy. CASE PRESENTATION: The patient is a 65-year-old male with node negative, high-grade adenocarcinoma of the rectum penetrating through the distal rectal wall. He underwent neoadjuvant concurrent pelvic radiation therapy and capecitabine-based chemotherapy, followed by abdominoperineal resection and post-operative FOLFOX chemotherapy. Five months post-completion of pelvic radiotherapy and 2 months after the completion of adjuvant chemotherapy, he presented with bilateral weakness of the iliopsoas muscles and severe pain radiating to the groin. The patient improved with 40 mg/d of prednisone, which was gradually tapered to 2 mg/d over 6 months, with substantial recovery of muscle strength and elimination of pain. CONCLUSIONS: The timing, presentation and response of our patient's symptoms to corticosteroids are most consistent with a radiation recall reaction. Radiation recall is a phenomenon whereby previously irradiated tissue becomes vulnerable to toxicity by subsequent systemic therapy and is rarely associated with myopathies. Radiation recall should be considered a potential complication of neoadjuvant radiation therapy for rectal cancer, and for ongoing research into the optimization of treatment for these patients. Severe myopathies caused by radiation recall may be fully reversible with corticosteroid treatment.

Management of Central Poststroke Pain: Systematic Review of Randomized Controlled Trials.

BACKGROUND AND PURPOSE: Central poststroke pain is a chronic neuropathic disorder that follows a stroke. Current research on its management is limited, and no review has evaluated all therapies for central poststroke pain. METHODS: We conducted a systematic review of randomized controlled trials to evaluate therapies for central poststroke pain. We identified eligible trials, in any language, by systematic searches of AMED, CENTRAL, CINAHL, DARE, EMBASE, HealthSTAR, MEDLINE, and PsychINFO. Eligible trials (1) enrolled ≥10 patients with central poststroke pain; (2) randomly assigned them to an active therapy or a control arm; and (3) collected outcome data≥14 days after treatment. Pairs of reviewers, independently and in duplicate, screened titles and abstracts of identified citations, reviewed full texts of potentially eligible trials, and extracted information from eligible studies. We used a modified Cochrane tool to evaluate risk of bias of eligible studies, and collected patient-important outcomes according to recommendations by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials. We conducted, when possible, random effects meta-analyses, and evaluated our certainty in treatment effects using the Grading of Recommendations Assessment, Development, and Evaluation System. RESULTS: Eight eligible English language randomized controlled trials (459 patients) tested anticonvulsants, an antidepressant, an opioid antagonist, repetitive transcranial magnetic stimulation, and acupuncture. Results suggested that all therapies had little to no effect on pain and other patient-important outcomes. Our certainty in the treatment estimates ranged from very low to low. CONCLUSIONS: Our findings are inconsistent with major clinical practice guidelines; the available evidence suggests no beneficial effects of any therapies that researchers have evaluated in randomized controlled trials.

Physical Functioning and Opioid use in Patients with Neuropathic Pain.

OBJECTIVE: To evaluate the association between opioid dosage and ongoing therapy with physical function and disability in patients with neuropathic pain (NeP). DESIGN: Secondary analysis of a prospective cohort. SETTING: Multicenter clinical NeP registry. SUBJECTS: Seven hundred eighty-nine patients treated for various NeP diagnoses. METHODS: The following measures were included: dependent variables. 12-month self-reported physical function (pain disability index [PDI] and medical outcomes study short form-12 physical function [PCSS-12]); independent variables: baseline opioid dose (none, ≤200 mg and >200 mg of morphine equivalent), ongoing opioid use; potential confounding variables: age, sex, baseline pain intensity, and psychological distress (profile of mood states). Analysis of covariance models was created to examine the relationship between opioid therapy and both physical functioning outcomes with adjustment for confounding. RESULTS: Complete data was available for 535 patients (68%). Compared with the lower and high dose opioid groups, NeP patients not taking opioids had statistically lower disability and higher physical functioning scores, after adjusting for disease severity. Compared with patients prescribed opioid therapy on an ongoing basis, NeP patients who were not prescribed had statistically lower disability and higher physical functioning scores, after adjusting for disease severity. Improvements in disability and physical functioning scores from baseline and 12-months in all groups were modest and may not be clinically significant. CONCLUSIONS: Physical functioning and disability did not improve in patients with NeP who were prescribed opioids compared with those who are not prescribed, even after adjusting for disease severity.

The Activity Management Inventory for Pain (AMI-P): Initial Development and Validation of a Questionnaire Based on Operant Learning and Energy Conservation Models of Activity Management.

OBJECTIVES: Activity management is an important treatment component in chronic pain programs. However, there are shortcomings in measures of this construct, leading to inconsistencies in research findings. Here, we describe the development of the Activity Management Inventory for Pain (AMI-P). MATERIALS AND METHODS: The AMI-P was developed by a group of international researchers with extensive expertise in both chronic pain and activity management. The initial evaluation of the AMI-P items included 2 studies that were both conducted in Canadian tertiary pain care centers. RESULTS: The resulting 20-item measure has 3 behavior scales (Rest, Alternating Activity, and Planned Activity), and 4 goal scales (Feel Less Pain, Get More Done, Complete the Task, and Save Energy). The behavior scales evidenced marginal to good internal consistency and test-retest reliability, and a moderate positive association with an existing pacing measure. The Rest and Alternating Activity scales were associated with greater pain interference, the Alternating Activity and Planned Activity scales were associated with less satisfaction with social roles, and the Planned Activity scale was associated with fewer depressive symptoms. The Alternating Activity scale increased significantly from pretreatment to posttreatment. All goal scales were positively associated with all behavior scales. The Feel Less Pain goal scale was positively associated with measures of avoidance and pain interference, while the Get More Done goal scale was negatively associated with measures of depressive symptoms and overdoing. DISCUSSION: The findings support the reliability and validity of the AMI-P scales, while also highlighting the complexity and multidimensional aspects of activity management.

PRECISE trial (Pain RElief Combination Intervention StratEgies): protocol for the clinical trial of a pregabalin-melatonin combination for fibromyalgia.

INTRODUCTION: Fibromyalgia is associated with chronic widespread pain and disturbed sleep. Multidisciplinary, multimodal management often includes pharmacotherapy; however, current drugs used to treat fibromyalgia provide meaningful benefit to only 30-60% of treated individuals. Combining two or more different drugs is common in clinical practice with the expectation of better efficacy, tolerability or both; however, further research is needed to identify which combinations actually provide added benefit. Thus, we are planning a clinical trial to evaluate melatonin (MLT)-pregabalin (PGB) combination in participants with fibromyalgia. METHODS AND ANALYSIS: This will be a single-centre, double-blind, randomised, double-dummy, three-period, crossover trial comparing a MLT-PGB combination to each monotherapy in 54 adult participants satisfying the 2016 American College of Rheumatology criteria for fibromyalgia. Participants will receive maximally tolerated doses of MLT, PGB and MLT-PGB combination for 6 weeks. The primary outcome will be daily pain intensity (0-10); secondary outcomes will include the Fibromyalgia Impact Questionnaire, SF-36 survey, Medical Outcomes Study Sleep Scale, Beck Depression Inventory (BDI-II), adverse events and other measures. Analysis of the primary and secondary outcomes will involve a linear mixed model with sequence, period, treatment, the first-order carryover and baseline pain score as fixed effects and participant as a random effect to test whether there are any treatment differences among three treatments and to estimate the least square mean of the mean daily pain intensity for each treatment, adjusting for carryover as well as period effects (ie, stability of pain levels). ETHICS AND DISSEMINATION: This trial has been registered with the International Standard Randomised Controlled Trial Number Registry, ISRCTN #18278231, has been granted ethical approval by the Queen's University Health Sciences Research Ethics Board (Queen's HSREB Protocol #6040998) and is currently under review for a Clinical Trial Application to Health Canada Natural and Non-prescription Health Products Directorate. All participants will provide written informed consent prior to trial participation. Following trial completion, results will be disseminated in one or more biomedical journal publications and presented at one or more scientific meetings. TRIAL REGISTRATION NUMBER: This trial has been registered with the International Standard Randomised Controlled Trial Number Registry, ISRCTN18278231.

Nonopioid drug combinations for cancer pain: a systematic review.

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.

Melatonin for Neuropathic Pain: Protocol for a Double-blind, Randomized Controlled Trial.

BACKGROUND: Neuropathic pain (NP), a complication of several conditions (eg, diabetic neuropathy and varicella zoster), is a common challenging problem, and there is a growing need to develop safe and effective nonopioid treatments. Sleep disturbance is commonly associated with NP because pain intensity in NP conditions is often worse at night. The pineal hormone melatonin has been shown to reduce pain in both preclinical and clinical settings, in addition to multiple trials demonstrating efficacy for primary insomnia and delayed sleep phase syndrome. OBJECTIVE: We propose to conduct a clinical trial to evaluate the efficacy and safety of melatonin for NP. METHODS: Using a double-blind, placebo-controlled, crossover design, 30 adults with NP will be randomly allocated to one of two sequences of treatment with melatonin and placebo. During each of the two treatment periods, participants will take capsules containing melatonin or placebo for 4 weeks, followed by a 7-day washout period. The primary outcome will be mean daily pain intensity (scored 0-10) at maximally tolerated doses (MTDs) during each period. Secondary outcomes, assessed at MTDs, will include global improvement, adverse events, mood, and quality of life. RESULTS: This trial was registered in the International Standard Randomized Controlled Trial registry May 4, 2022 (ISRCTN #16215617), attained conditional ethics approval May 9, 2022 (Queen's University Health Sciences & Affiliated Teaching Hospitals Research Ethics Board protocol number ANAE-387-22), and recruitment is set to start August 2022. CONCLUSIONS: This trial will provide rigorous evidence comparing the efficacy of melatonin to that of placebo in the treatment of NP. TRIAL REGISTRATION: ISRCTN Registry 16215617; https://www.isrctn.com/ISRCTN16215617. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/40025.

Glial-modulating agents for the treatment of pain: protocol for a systematic review.

INTRODUCTION: Evidence suggests a role for Central nervous system glia in pain transmission and in augmenting maladaptive opioid effects. Identification of drugs that modulate glia has guided the evaluation of glial suppression as a pain management strategy. This planned systematic review will describe evidence of the efficacy and adverse effects of glial-modulating drugs in pain management. METHODS AND ANALYSIS: A detailed search will be conducted on the Cochrane Central Register of Controlled Trials, Medline, and Embase from their inception until the date the final searches are run to identify relevant randomised controlled trials. The reference lists of retrieved studies, as well as online trial registries, will also be searched. English language, randomised, double-blind trials comparing various glial-modulating drugs with placebo and/or other comparators, with participant-reported pain assessment, will be included. Two reviewers will independently evaluate studies for eligibility, extract data and assess trial quality and potential bias. Risk of bias will be assessed using criteria outlined in the Cochrane Handbook for Systematic Review of Interventions. Primary outcomes for this review will include any validated measure of pain intensity and/or pain relief. Dichotomous data will be used to calculate risk ratio and number needed to treat or harm. The quality of evidence will be assessed using Grading of Recommendations Assessment, Development and Evaluation. ETHICS AND DISSEMINATION: This systematic review does not require formal ethics approval. The findings will be disseminated through peer-reviewed publications and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42021262074.

Risk of Chronic Opioid Use After Radiation for Head and Neck Cancer: A Systematic Review and Meta-Analysis.

PURPOSE: Opioid addiction is a major public health concern. Chronic opioid use (COU) patterns after radiation for head and neck cancer (HNC) remain poorly understood. The aim of this study was to estimate the prevalence of COU and to identify its risk factors in patients with HNC undergoing curative-intent radiation therapy (RT) or chemoradiotherapy (CRT). METHODS AND MATERIALS: We performed a systematic review and meta-analysis using the PubMed (Medline), EMBASE, and Cochrane Library databases, queried from dates of inception until January 2020. COU was defined as persistent use of opioids ≥ 3 months after treatment completion. Meta-analyses were performed using random effects models. Heterogeneity was assessed using the I2 value. RESULTS: Seven retrospective studies, reporting on 1841 patients, met the inclusion criteria. Median age was 59.4 (range: 56.0-62.0) years with 1343 (72.9%) men and 498 (27.1%) women. Primary tumor locations included oropharynx (n = 891, 48.4%), oral cavity (n = 533, 29.0%), larynx (n = 93, 5.1%), hypopharynx (n = 32, 1.7%), and nasopharynx (n = 29, 1.6%). Eight hundred fifty-four (46.0%) patients had stage I/II and 952 (50.3%) had stage III-IV disease. Three hundred one (16.3%) patients had RT alone, 738 (40.1%) received CRT, and 594 (32.3%) underwent surgery followed by adjuvant RT/CRT. The proportion of patients with HNC who developed COU post-RT/CRT was 40.7% at 3 months (95% confidence interval [CI]: 22.6%-61.7%; I2 = 97.1%) and 15.5% at 6 months (95% CI: 7.3%-29.7%; I2 = 94.3%). Oropharyngeal malignancies had the highest rate of COU based on primary tumor location (46.6%; 95% CI: 30.8%-63.1%; P < .0001). High proportions of COU were found in patients with a history of psychiatric disorder(s) (61.7%), former/current alcohol abuse (53.9%), and opioid requirements before radiation treatment (51.6%; P = .035). CONCLUSIONS: A significant proportion of patients who undergo RT for HNC suffer from COU. High-risk factors for COU include an oropharyngeal primary, history of psychiatric disorder, former/current alcohol abuse, and pre-treatment opioid use. New strategies to mitigate COU are needed.