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Background: Integrated primary care programs for patients living with chronic pain which are accessible, interdisciplinary, and patient-centered are needed for preventing chronicity and improving outcomes. Evaluation of the implementation and impact of such programs supports further development of primary care chronic pain management. This study examined patient-reported outcomes among individuals with low back pain (LBP) receiving care in a novel interdisciplinary primary care program., Methods: Patients were referred by primary care physicians in four regions of Quebec, Canada, and eligible patients received an evidence-based interdisciplinary pain management program over a six-month period. Patients were screened for risk of chronicity. Patient-reported outcome measures of pain interference and intensity, physical function, depression, and anxiety were evaluated at regular intervals over the six-month follow-up. A multilevel regression analysis was performed to evaluate the association between patient characteristics at baseline, including risk of chronicity, and change in pain outcomes., Results: Four hundred and sixty-four individuals (mean age 55.4y, 63% female) completed the program. The majority (≥ 60%) experienced a clinically meaningful improvement in pain intensity and interference at six months. Patients with moderate (71%) or high risk (81%) of chronicity showed greater improvement in pain interference than those with low risk (51%). Significant predictors of improvement in pain interference included a higher risk of chronicity, younger age, female sex, and lower baseline disability., Conclusion: The outcomes of this novel LBP program will inform wider implementation considerations by identifying key components for further effectiveness, sustainability, and scale-up of the program., (© 2024. The Author(s).)

Objective: To evaluate the effectiveness of Δ9-tetrahydrocannabinol (dronabinol [DRO]) as an add-on treatment in patients with refractory chronic pain (CP)., Methods: An exploratory retrospective analysis of 12-week data provided by the German Pain e-Registry on adult patients with treatment refractory CP who received DRO., Results: Between March 10, 2017, and June 30, 2019, the German Pain e-Registry collected information on 89,095 patients with pain, of whom 1,145 patients (1.3%) received DRO (53.8% female, mean ± standard deviation age: 56.9 ± 10.6 years), and 70.0% documented use for the entire 12-week evaluation period. The average DRO daily dose was 15.8 ± 7.5 mg, typically in three divided doses (average DRO dose of 5.3 ± 2.1 mg). Average 24-hour pain intensity decreased from 46.3 ± 16.1 to 26.8 ± 18.7 mm on a visual analog scale (absolute visual analog scale difference: -19.5 ± 17.3; P < 0.001). Among patients who completed follow-up, an improvement from baseline of at least 50% was documented for pain (46.5%), activities of daily living (39%), quality of life (31.4%), and sleep (35.3%). A total of 536 patients (46.8%) reported at least one of 1,617 drug-related adverse events, none of which were serious, and 248 patients (21.7%) stopped treatment. Over the 12-week period, 59.0% of patients reported a reduction of other pain treatments, and 7.8% reported a complete cessation of any other pharmacological pain treatments., Conclusion: Add-on treatment with DRO in patients with refractory CP was well tolerated and associated with a significant improvement., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Academy of Pain Medicine.)

Objective: To determine the benefits and harms of medical cannabis and cannabinoids for chronic pain., Design: Systematic review and meta-analysis., Data Sources: MEDLINE, EMBASE, AMED, PsycInfo, CENTRAL, CINAHL, PubMed, Web of Science, Cannabis-Med, Epistemonikos, and trial registries up to January 2021., Study Selection: Randomised clinical trials of medical cannabis or cannabinoids versus any non-cannabis control for chronic pain at ≥1 month follow-up., Data Extraction and Synthesis: Paired reviewers independently assessed risk of bias and extracted data. We performed random-effects models meta-analyses and used GRADE to assess the certainty of evidence., Results: A total of 32 trials with 5174 adult patients were included, 29 of which compared medical cannabis or cannabinoids with placebo. Medical cannabis was administered orally (n=30) or topically (n=2). Clinical populations included chronic non-cancer pain (n=28) and cancer related pain (n=4). Length of follow-up ranged from 1 to 5.5 months. Compared with placebo, non-inhaled medical cannabis probably results in a small increase in the proportion of patients experiencing at least the minimally important difference (MID) of 1 cm (on a 10 cm visual analogue scale (VAS)) in pain relief (modelled risk difference (RD) of 10% (95% confidence interval 5% to 15%), based on a weighted mean difference (WMD) of -0.50 cm (95% CI -0.75 to -0.25 cm, moderate certainty)). Medical cannabis taken orally results in a very small improvement in physical functioning (4% modelled RD (0.1% to 8%) for achieving at least the MID of 10 points on the 100-point SF-36 physical functioning scale, WMD of 1.67 points (0.03 to 3.31, high certainty)), and a small improvement in sleep quality (6% modelled RD (2% to 9%) for achieving at least the MID of 1 cm on a 10 cm VAS, WMD of -0.35 cm (-0.55 to -0.14 cm, high certainty)). Medical cannabis taken orally does not improve emotional, role, or social functioning (high certainty). Moderate certainty evidence shows that medical cannabis taken orally probably results in a small increased risk of transient cognitive impairment (RD 2% (0.1% to 6%)), vomiting (RD 3% (0.4% to 6%)), drowsiness (RD 5% (2% to 8%)), impaired attention (RD 3% (1% to 8%)), and nausea (RD 5% (2% to 8%)), but not diarrhoea; while high certainty evidence shows greater increased risk of dizziness (RD 9% (5% to 14%)) for trials with <3 months follow-up versus RD 28% (18% to 43%) for trials with ≥3 months follow-up; interaction test P=0.003; moderate credibility of subgroup effect)., Conclusions: Moderate to high certainty evidence shows that non-inhaled medical cannabis or cannabinoids results in a small to very small improvement in pain relief, physical functioning, and sleep quality among patients with chronic pain, along with several transient adverse side effects, compared with placebo. The accompanying BMJ Rapid Recommendation provides contextualised guidance based on this body of evidence. SYSTEMATIC REVIEW REGISTRATION: https://osf.io/3pwn2., Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form www.icmje.org/disclosure-of-interest/ and declare: no financial support from any industry for the submitted work; IP and SU have received research funds from Northern Green Canada; IP has been a paid consultant for Northern Green Science, Northern Green Canada, Monk-E psychedelics, and Evergreen Pacific Insurance Corporation; SU and IP received honoraria from Spectrum Therapeutics and Tilray Inc. for educational presentations; MAW is the chief medical officer for Canopy Growth Corporation., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objective: Despite evidence of the analgesic benefits of cannabis, there remains a relative scarcity of research on the short- and long-term effects of cannabis use in individuals with chronic pain., Design: The current study is a secondary analysis of clinical data from the Collaborative Health Outcomes Information Registry (CHOIR)., Setting: Data were drawn from a cohort of patients of a multidisciplinary tertiary care pain clinic., Subjects: The study sample consisted of data from 7,026 new patient visits from CHOIR; of these, 1,668 patients with a follow-up time point within 180 days were included in a longitudinal analysis., Methods: Clinical data were analyzed to characterize cross-sectional differences in pain and indicators of psychological and physical function according to self-reported, concurrent cannabis use. Additionally, a propensity score-weighted longitudinal analysis was conducted, examining cannabis use as a predictor of changes in clinical variables across time., Results: Cross-sectional analyses suggested significantly poorer sleep and significantly higher intensities of pain, emotional distress, and physical and social dysfunction in patients reporting ongoing cannabis use; however, these differences were relatively small in magnitude. However, no differences between cannabis users and nonusers in terms of longitudinal changes in clinical variables were noted., Discussion: Our results are among the first to examine concurrent cannabis use as a prognostic variable regarding trajectories of pain-related variables in tertiary care. Future studies may benefit from examining the effect of cannabis initiation, concurrent medication use, and specific aspects of cannabis use (dose, duration of use, or cannabis type) on clinical outcomes., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Ecological research suggests that increased access to cannabis may facilitate reductions in opioid use and harms, and medical cannabis patients describe the substitution of opioids with cannabis for pain management. However, there is a lack of research using individual-level data to explore this question. We aimed to investigate the longitudinal association between frequency of cannabis use and illicit opioid use among people who use drugs (PWUD) experiencing chronic pain., Methods and Findings: This study included data from people in 2 prospective cohorts of PWUD in Vancouver, Canada, who reported major or persistent pain from June 1, 2014, to December 1, 2017 (n = 1,152). We used descriptive statistics to examine reasons for cannabis use and a multivariable generalized linear mixed-effects model to estimate the relationship between daily (once or more per day) cannabis use and daily illicit opioid use. There were 424 (36.8%) women in the study, and the median age at baseline was 49.3 years (IQR 42.3-54.9). In total, 455 (40%) reported daily illicit opioid use, and 410 (36%) reported daily cannabis use during at least one 6-month follow-up period. The most commonly reported therapeutic reasons for cannabis use were pain (36%), sleep (35%), stress (31%), and nausea (30%). After adjusting for demographic characteristics, substance use, and health-related factors, daily cannabis use was associated with significantly lower odds of daily illicit opioid use (adjusted odds ratio 0.50, 95% CI 0.34-0.74, p < 0.001). Limitations of the study included self-reported measures of substance use and chronic pain, and a lack of data for cannabis preparations, dosages, and modes of administration., Conclusions: We observed an independent negative association between frequent cannabis use and frequent illicit opioid use among PWUD with chronic pain. These findings provide longitudinal observational evidence that cannabis may serve as an adjunct to or substitute for illicit opioid use among PWUD with chronic pain., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: M-JM is the Canopy Growth professor of cannabis science at UBC, a position created using unstructured arms’ length gifts to the university from Canopy Growth Corporation and the Government of British Columbia’s Ministry of Mental Health and Addictions. The University of British Columbia has received unstructured funding from NG Biomed, Ltd., an applicant to the Canadian federal government for a license to produce cannabis, to support M-JM. ZW is Coordinating Principal Investigator on a clinical trial sponsored by Tilray, a licensed producer of medical cannabis. ZDC has received research funds and partial salary support from Insys Therapeutics. She has served as a consultant to GB Sciences and Beckley Canopy Therapeutics and is a scientific advisor to FSD Pharma. MAW has consulted for CHI, CannaRoyalty and Zynerba and has received a grant to his institution for clinical research from CanniMed. He was appointed to Chief Medical Officer at Canopy Growth Corp in July 2018 (after the study period ended). He supported the first author in conceptualization of the research, but did not contribute to the study’s methodological design or data analysis. All other authors report no competing interests in relation to the work described.

Over the past few decades, research has revealed high rates of substance-related disorders among patients with chronic pain. In addition to their potentially deleterious health consequences, substance-related disorders have consistently been associated with negative pain-related outcomes among patients with chronic pain. The goal of this narrative review was to provide an overview of studies that have examined the prevalence and correlates of substance-related disorders among patients with chronic pain. A particular focus was placed on opioids, sedatives/hypnotics, cannabis, tobacco, and alcohol given that these substances have received the bulk of research attention among patients with pain. Research conducted to date suggests that a host of biological and psychological factors are likely to contribute to the elevated rates of substance-related disorders among patients with chronic pain. In this review, in addition to reviewing the prevalence and correlates of substance-related disorders among patients with pain, we briefly discussed the changes that were recently made from the DSM-4 to the DSM-5 in the diagnostic criteria for substance-related disorders, and the implications of these changes for the assessment of patients with chronic pain. We also provided a brief overview of instruments that can be used for the assessment of these disorders in clinical and research settings., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Self-management can optimize health outcomes for individuals with chronic pain (CP), an increasing fiscal and social burden in Canada. However, self-management is rarely integrated into the regular care (team activities and medical treatment) patients receive. Health information technology offers an opportunity to provide regular monitoring and exchange of information between patient and care team., Objective: To identify information needs and gaps in chronic pain management as well as technology features to inform the development of an Internet-based self-management program., Methods: Two methods were used. First was a structured literature review: electronic databases were searched up to 2015 with combinations of MeSH terms and text-words such as chronic pain, self-management, self-efficacy, technology, Internet-based, patient portal, and e-health. A narrative synthesis of the characteristics and content of Internet-based pain management programs emerging from the literature review and how they relate to gaps in chronic pain management were completed. Second, four audiotaped focus group sessions were conducted with individuals with chronic pain and caregivers (n=9) and health professionals (n=7) recruited from three multidisciplinary tertiary and rehabilitation centres. A thematic analysis of the focus group transcripts was conducted., Results: Thirty-nine primary articles related to 20 patient-oriented Internet-based programs were selected. Gaps in CP management included lack of knowledge, limited access to health care, suboptimal care, and lack of self-management support. Overall, 14 themes related to information needs and gaps in care were identified by both health professionals and patients, three were exclusive to patients and five to health professionals. Common themes from the focus groups included patient education on chronic pain care, attitude-belief-culture, financial and legal issues, end-of-program crash, and motivational content., Conclusions: Internet-based programs contain automated, communication and decision support features that can address information and care gaps reported by patients and clinicians. However, focus groups identified functionalities not reported in the literature, non-medical and condition- and context-specific information, integration of personal health records, and the role of the different health professionals in chronic pain management were not identified. These gaps need to be considered in the future development of Internet-based programs. While the association between the mechanisms of Internet-based programs' features and outcomes is not clearly established, the results of this study indicate that interactivity, personalization and tailored messages, combined with therapist contact will maximize the effectiveness of an Internet-based chronic pain program in enhancing self-management., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objectives: The objectives of this study were to (1) determine the proportion of patients referred to a multidisciplinary pain treatment facility at risk of opioid abuse, (2) examine biopsychosocial factors associated with this risk, and (3) compare patient outcomes 6 months later across risk of opioid abuse and type of treatment (opioids vs. no opioids)., Methods: Participants were 3040 patients (mean age=53.3±14.7 y; female=56%) enrolled in the Quebec Pain Registry between July 2012 and May 2014. Patients answered self-report and nurse-administered questionnaires (pain and psychosocial constructs, Opioid Risk Tool, pain medication, etc.) before initiating treatment at the multidisciplinary pain treatment facility and 6 months later. Data were analyzed using the Pearson χ tests, multivariable binary logistic regression, and multivariate general linear model., Results: Results showed that 81%, 13%, and 6% of patients were at low, moderate, and severe risk of opioid abuse, respectively. Civil status, pain duration, mental health-related quality of life, and cigarette smoking were significantly associated with risk of opioid abuse (P<0.001). There was a significant interaction between risk of opioid abuse and type of treatment in predicting 6-month pain outcomes and quality of life., Discussion: Almost 20% of patients had a moderate/severe risk of opioid abuse; whether these patients were taking opioids or not for their pain, they had worse outcomes at follow-up. These results point to the importance of assessing risk of opioid abuse in chronic pain patients and to consider how this risk may impact on their clinical evolution.

Unlabelled: Cannabis is widely used as a self-management strategy by patients with a wide range of symptoms and diseases including chronic non-cancer pain. The safety of cannabis use for medical purposes has not been systematically evaluated. We conducted a prospective cohort study to describe safety issues among individuals with chronic non-cancer pain. A standardized herbal cannabis product (12.5% tetrahydrocannabinol) was dispensed to eligible individuals for a 1-year period; controls were individuals with chronic pain from the same clinics who were not cannabis users. The primary outcome consisted of serious adverse events and non-serious adverse events. Secondary safety outcomes included pulmonary and neurocognitive function and standard hematology, biochemistry, renal, liver, and endocrine function. Secondary efficacy parameters included pain and other symptoms, mood, and quality of life. Two hundred and fifteen individuals with chronic pain were recruited to the cannabis group (141 current users and 58 ex-users) and 216 controls (chronic pain but no current cannabis use) from 7 clinics across Canada. The median daily cannabis dose was 2.5 g/d. There was no difference in risk of serious adverse events (adjusted incidence rate ratio = 1.08, 95% confidence interval = .57-2.04) between groups. Medical cannabis users were at increased risk of non-serious adverse events (adjusted incidence rate ratio = 1.73, 95% confidence interval = 1.41-2.13); most were mild to moderate. There were no differences in secondary safety assessments. Quality-controlled herbal cannabis, when used by patients with experience of cannabis use as part of a monitored treatment program over 1 year, appears to have a reasonable safety profile. Longer-term monitoring for functional outcomes is needed., Study Registration: The study was registered with www.controlled-trials.com (ISRCTN19449752)., Perspective: This study evaluated the safety of cannabis use by patients with chronic pain over 1 year. The study found that there was a higher rate of adverse events among cannabis users compared with controls but not for serious adverse events at an average dose of 2.5 g herbal cannabis per day., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Unlabelled: Chronic neuropathic pain, the most frequent condition affecting the peripheral nervous system, remains underdiagnosed and difficult to treat. Inhaled cannabis may alleviate chronic neuropathic pain. Our objective was to synthesize the evidence on the use of inhaled cannabis for chronic neuropathic pain. We performed a systematic review and a meta-analysis of individual patient data. We registered our protocol with PROSPERO CRD42011001182. We searched in Cochrane Central, PubMed, EMBASE, and AMED. We considered all randomized controlled trials investigating chronic painful neuropathy and comparing inhaled cannabis with placebo. We pooled treatment effects following a hierarchical random-effects Bayesian responder model for the population-averaged subject-specific effect. Our evidence synthesis of individual patient data from 178 participants with 405 observed responses in 5 randomized controlled trials following patients for days to weeks provides evidence that inhaled cannabis results in short-term reductions in chronic neuropathic pain for 1 in every 5 to 6 patients treated (number needed to treat = 5.6 with a Bayesian 95% credible interval ranging between 3.4 and 14). Our inferences were insensitive to model assumptions, priors, and parameter choices. We caution that the small number of studies and participants, the short follow-up, shortcomings in allocation concealment, and considerable attrition limit the conclusions that can be drawn from the review. The Bayes factor is 332, corresponding to a posterior probability of effect of 99.7%., Perspective: This novel Bayesian meta-analysis of individual patient data from 5 randomized trials suggests that inhaled cannabis may provide short-term relief for 1 in 5 to 6 patients with neuropathic pain. Pragmatic trials are needed to evaluate the long-term benefits and risks of this treatment., (Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Purpose: The objective of this study was to evaluate the validity of diagnostic codes recorded in the Régie de l'assurance maladie du Québec (RAMQ) administrative database for identifying patients suffering from various types of chronic non-cancer pain., Methods: The validity of published International Classification of Diseases, Ninth Revision, coding algorithms for identifying patients with particular chronic pain syndromes in the RAMQ database was tested using pain specialist-established diagnostic data of 561 patients enrolled in the Quebec Pain Registry, which was used as the reference standard. Modified versions of these algorithms (i.e., adaptation of the number of healthcare encounters) were also tested. For each algorithm, sensitivity, specificity, positive/negative predictive values, and their respective 95% confidence intervals (95%CI) were calculated., Results: In the RAMQ database, some previously published algorithms and modified versions of these algorithms were found to be valid for identifying patients suffering from chronic lumbar pain (sensitivity: 0.65, 95%CI: 0.59-0.71; specificity: 0.83, 95%CI: 0.79-0.87), chronic back pain (sensitivity: 0.70, 95%CI: 0.64-0.76; specificity: 0.73, 95%CI: 0.68-0.78), and chronic neck/back pain (sensitivity: 0.71, 95%CI: 0.65-0.76; specificity: 0.78, 95%CI: 0.72-0.82). Algorithms to identify patients with other types of chronic pain showed low sensitivity: complex regional pain syndrome (≤0.07), fibromyalgia (≤0.42), and neuropathic pain (≤0.39)., Conclusions: Our study provides evidence supporting the value of the RAMQ administrative database for conducting research on certain types of chronic pain disorders including back and neck pain. Users should, however, be cautious about the limitations of this database for studying other types of chronic pain syndromes such as complex regional pain syndrome, fibromyalgia, and neuropathic pain., (Copyright © 2015 John Wiley & Sons, Ltd.)

An updated systematic review of randomized controlled trials examining cannabinoids in the treatment of chronic non-cancer pain was conducted according to PRISMA guidelines for systematic reviews reporting on health care outcomes. Eleven trials published since our last review met inclusion criteria. The quality of the trials was excellent. Seven of the trials demonstrated a significant analgesic effect. Several trials also demonstrated improvement in secondary outcomes (e.g., sleep, muscle stiffness and spasticity). Adverse effects most frequently reported such as fatigue and dizziness were mild to moderate in severity and generally well tolerated. This review adds further support that currently available cannabinoids are safe, modestly effective analgesics that provide a reasonable therapeutic option in the management of chronic non-cancer pain.

We previously reported that effective treatment of chronic low back pain (CLBP) reversed abnormal brain structure and functional MRI (fMRI) activity during cognitive task performance, particularly in the left dorsolateral prefrontal cortex (DLPFC). Here, we used resting-state fMRI to examine how chronic pain affects connectivity of brain networks supporting cognitive functioning and the effect of treatment in 14 CLBP patients and 16 healthy, pain-free controls (scans were acquired at baseline for all subjects and at 6-months post-treatment for patients and a matched time-point for 10 controls). The main networks activated during cognitive task performance, task-positive network (TPN) and task-negative network (TNN) (aka default mode) network, were identified in subjects' task fMRI data and used to define matching networks in resting-state data. The connectivity of these cognitive resting-state networks was compared between groups, and before and after treatment. Our findings converged on the bilateral insula (INS) as the region of aberrant cognitive resting-state connectivity in patients pretreatment versus controls. These findings were complemented by an independent, data-driven approach showing altered global connectivity of the INS. Detailed investigation of the INS confirmed reduced connectivity to widespread TPN and TNN areas, which was partially restored post-treatment. Furthermore, analysis of diffusion-tensor imaging (DTI) data revealed structural changes in white matter supporting these findings. The left DLPFC also showed aberrant connectivity that was restored post-treatment. Altogether, our findings implicate the bilateral INS and left DLPFC as key nodes of disrupted cognition-related intrinsic connectivity in CLBP, and the resulting imbalance between TPN and TNN function is partially restored with treatment., (© 2015 Wiley Periodicals, Inc.)

Background: Pregabalin is frequently prescribed for chronic non-cancer pain. No previous study has examined its off-label use., Objectives: Our primary aim was to assess the proportion of patients taking pregabalin for conditions approved by Health Canada ('on-label') and compare their perspectives on its use to those who use pregabalin for other conditions ('off-label')., Methods: Patients who have used pregabalin within the past year were recruited from two registries of chronic non-cancer pain patients treated in tertiary care clinics: the Quebec Pain Registry and the Fibromyalgia Patients Registry. Data on the use of pregabalin and its perceived benefits were collected from the registries and from completed questionnaires., Results: Out of 4339 screened chronic non-cancer pain patients, 355 (8.18%) met the study selection criteria. Three-quarters of them (268/355) used pregabalin for pain conditions not approved by Health Canada and were therefore regarded as off-label users. The most prevalent condition for pregabalin use was lumbar back pain (103/357; 28.85%). There were no significant differences between on- and off-label users in their perceived satisfaction from pregabalin therapy and its effect on function and quality of life. Among former users, the most prevalent reason for discontinuation was adverse effects, mainly dry mouth and weight gain., Conclusions: We conclude that despite specific indications for pregabalin prescription, it is mainly used off-label, notably for low back pain. Nevertheless, off-label users were equally satisfied with its clinical effects. Although formal exploration of the broader analgesic properties of pregabalin is warranted, treating heterogeneous chronic pain conditions with pregabalin may be legitimate., Limitations: The main limitations of the study are patients' low response rate, the recruitment of participants solely from a tertiary pain center and not from the general patient population and a possible recall bias that may have arisen from the retrospective nature of the study.

Background: Neuropathic pain (NeP), redefined as pain caused by a lesion or a disease of the somatosensory system, is a disabling condition that affects approximately two million Canadians., Objective: To review the randomized controlled trials (RCTs) and systematic reviews related to the pharmacological management of NeP to develop a revised evidence-based consensus statement on its management., Methods: RCTs, systematic reviews and existing guidelines on the pharmacological management of NeP were evaluated at a consensus meeting in May 2012 and updated until September 2013. Medications were recommended in the consensus statement if their analgesic efficacy was supported by at least one methodologically sound RCT (class I or class II) showing significant benefit relative to placebo or another relevant control group. Recommendations for treatment were based on the degree of evidence of analgesic efficacy, safety and ease of use., Results: Analgesic agents recommended for first-line treatments are gabapentinoids (gabapentin and pregabalin), tricyclic antidepressants and serotonin noradrenaline reuptake inhibitors. Tramadol and controlled-release opioid analgesics are recommended as second-line treatments for moderate to severe pain. Cannabinoids are now recommended as third-line treatments. Recommended fourth-line treatments include methadone, anticonvulsants with lesser evidence of efficacy (eg, lamotrigine, lacosamide), tapentadol and botulinum toxin. There is support for some analgesic combinations in selected NeP conditions., Conclusions: These guidelines provide an updated, stepwise approach to the pharmacological management of NeP. Treatment should be individualized for each patient based on efficacy, side-effect profile and drug accessibility, including cost. Additional studies are required to examine head-to-head comparisons among analgesics, combinations of analgesics, long-term outcomes and treatment of pediatric, geriatric and central NeP.

Introduction: The presence of multiple coexisting chronic pain (CP) conditions (eg, low-back pain and migraines) within patients has received little attention in literature. The goals of this observational longitudinal study were to determine the prevalence of coexisting CP conditions, identify the most frequent ones and patterns of coexistence, investigate the relationships among patients' biopsychosocial characteristics and number of CP conditions, and determine the impact of coexisting CP conditions on treatment response. Patients and methods: A total of 3,966 patients attending multidisciplinary pain-treatment centers who were enrolled in the Quebec Pain Registry were included. Patients completed selfreport and nurse-administered questionnaires before their first visit and 6 months later. Results were analyzed using descriptive statistics, factor and cluster analyses, negative binomials with log-link generalized linear models, and linear mixed-effect models. Results: A third of patients reported coexisting CP conditions. No specific patterns of comorbidities emerged. The presence of coexisting CP conditions was associated with longer pain duration, older age, being female, and poorer quality of life. The presence of more than one CP condition did not have a clinically significant impact on treatment responses. Discussion: The novelty of the study results relate to the heterogeneity that was found in the patterns of coexistence of CP conditions and the fact that having multiple CP conditions did not clinically impact treatment response. These results highlight the need for future research that examines causes of coexistence among CP conditions across the spectrum of CP, as opposed to focusing on specific conditions, and to examine whether multiple CP conditions impact on additional domains, such as treatment satisfaction. These results highlight the importance of studying the pathophysiological mechanisms underlying the development of coexisting CP conditions, in order eventually to prevent/minimize their occurrence and/or develop optimal treatment and management approaches. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Pain is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Pain is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Few studies have been conducted to explore physicians' prescription practices and attitudes toward the use of cannabinoids in Canada. We measured the prevalence and identified determinants of cannabinoid prescription for the management of chronic noncancer pain among physicians in southwestern Quebec. Methods: In February 2013, we conducted a postal survey using a modified Dillman method that involved physicians practising in the Abitibi-Témiscamingue region of Quebec. We used multivariate logistic regression models to identify determinants of cannabinoid prescription. Results: A total of 166 physicians of 318 practising in the region participated in the survey (response rate 52.2%). The prevalence of cannabinoid prescription was 27.3% (45/165) for any indication and 23.0% (38/165) for the management of chronic noncancer pain; 91.1% (41/45) of the physicians prescribed cannabinoids to 5 or fewer patients. Of the 38 physicians who prescribed cannabinoids for chronic noncancer pain, 35 (92.1%) prescribed nabilone, 7 (18.4%) medical marijuana and 2 (5.3%) nabiximols. The principal determinant of cannabinoid prescription was the physician's level of comfort with prescribing cannabinoids (adjusted odds ratio 1.25, 95% confidence interval 1.01-1.55, per 1-point increase in comfort level measured on 10-point scale). Respondents reported that continuing medical education (CME) activities could increase their comfort level. They also indicated a need for guidelines or algorithms that included cannabinoid use as well as more studies about the efficacy and safety of cannabinoids for the management of chronic noncancer pain. Interpretation: We found that cannabinoids were not often prescribed for the management of chronic noncancer pain and that survey respondents were not comfortable with prescribing this drug class. This degree of discomfort could be addressed by CME activities, more effective dissemination of guidelines and more evidence regarding cannabinoid use for the management of chronic noncancer pain. [ABSTRACT FROM AUTHOR]

Chronic pain is associated with reduced brain gray matter and impaired cognitive ability. In this longitudinal study, we assessed whether neuroanatomical and functional abnormalities were reversible and dependent on treatment outcomes. We acquired MRI scans from chronic low back pain (CLBP) patients before (n=18) and 6 months after (spine surgery or facet joint injections; n=14) treatment. In addition, we scanned 16 healthy controls, 10 of which returned 6 months after the first visit. We performed cortical thickness analysis on structural MRI scans, and subjects performed a cognitive task during the functional MRI. We compared patients and controls, as well as patients before versus after treatment. After treatment, patients had increased cortical thickness in the left dorsolateral prefrontal cortex (DLPFC), which was thinner before treatment compared with controls. Increased DLPFC thickness correlated with the reduction of both pain and physical disability. Additionally, increased thickness in primary motor cortex was associated specifically with reduced physical disability, and right anterior insula was associated specifically with reduced pain. Left DLPFC activity during an attention-demanding cognitive task was abnormal before treatment, but normalized following treatment. These data indicate that functional and structural brain abnormalities-specifically in the left DLPFC-are reversible, suggesting that treating chronic pain can restore normal brain function in humans. [ABSTRACT FROM AUTHOR]

Aim Nabilone is a synthetic cannabinoid prescription drug approved in Canada since 1981 to treat chemotherapy-induced nausea and vomiting. In recent years, off-label use of nabilone for chronic pain management has increased, and physicians have begun to express concerns about nabilone becoming a drug of abuse. This study evaluates the evidence for abuse of nabilone, which is currently ill-defined. Study design Scientific literature, popular press and internet databases were searched extensively for evidence of nabilone abuse. Focused interviews with medical professionals and law enforcement agencies across Canada were also conducted. Findings The scientific literature and popular press reviews found very little reference to nabilone abuse. Nabilone is perceived to produce more undesirable side effects, to have a longer onset of action and to be more expensive than smoked cannabis. The internet review revealed rare and isolated instances of recreational use of nabilone. The database review yielded little evidence of nabilone abuse, although nabilone seizures and thefts have occurred in Canada in the past few years, especially in Ontario. Most law enforcement officers reported no instances of nabilone abuse or diversion, and the drug has no known street value. Medical professionals reported that nabilone is not perceived to be a matter of concern with respect to its abuse potential. Conclusions Reports of nabilone abuse are extremely rare. However, follow-up of patients using nabilone for therapeutic purposes is prudent and should include assessment of tolerance and dependence. Prospective studies are also needed to definitively address the issue of nabilone abuse. [ABSTRACT FROM AUTHOR]

Chronic noncancer pain includes a heterogenous group of disorders and is often refractory to treatment. Cannabis products have historically been used for chronic pain and are attracting renewed pharmaceutical interest. Nabilone is a synthetic cannabinoid licensed in Canada for the treatment of severe nausea and vomiting associated with cancer chemotherapy. We have used nabilone off-label for the treatment of chronic noncancer pain since 1999. In this article, we review our clinical experience of 20 adult patients with chronic noncancer pain who had been treated with nabilone and followed up for an average of 1.5 years. Prior to nabilone therapy, patients had used a wide range of therapies, including 11 who had used cannabis. Fifteen patients reported subjective overall improvement with nabilone, and nine reported reduced pain intensity. Beneficial effects on sleep and nausea were the main reasons for continuing use. Intolerable side effects were experienced in three patients (palpitations, urinary retention, dry mouth). Nabilone may be a useful addition to pain management and should be further evaluated in randomized controlled trials. [ABSTRACT FROM AUTHOR]

There has been a surge in interest in medicinal cannabis in Canada. We conducted a questionnaire survey to determine the current prevalence of medicinal cannabis use among patients with chronic non-cancer pain, to estimate the dose size and frequency of cannabis use, and to describe the main symptoms for which relief was being sought. Over a 6-week period in mid-2001, 209 chronic non-cancer pain patients were recruited in an anonymous cross-sectional survey. Seventy-two (35%) subjects reported ever having used cannabis. Thirty-two (15%) subjects reported having used cannabis for pain relief (pain users), and 20 (10%) subjects were currently using cannabis for pain relief. Thirty-eight subjects denied using cannabis for pain relief (recreational users). Compared to never users, pain users were significantly younger (P=0.001) and were more likely to be tobacco users (P=0.0001). The largest group of patients using cannabis had pain caused by trauma and/or surgery (51%), and the site of pain was predominantly neck/upper body and myofascial (68% and 65%, respectively). The median duration of pain was similar in both pain users and recreational users (8 vs. 7 years; P=0.7). There was a wide range of amounts and frequency of cannabis use. Of the 32 subjects who used cannabis for pain, 17 (53%) used four puffs or less at each dosing interval, eight (25%) smoked a whole cannabis cigarette (joint) and four (12%) smoked more than one joint. Seven (22%) of these subjects used cannabis more than once daily, five (16%) used it daily, eight (25%) used it weekly and nine (28%) used it rarely. Pain, sleep and mood were most frequently reported as improving with cannabis use, and ‘high’ and dry mouth were the most commonly reported side effects. We conclude that cannabis use is prevalent among the chronic non-cancer pain population, for a wide range of symptoms, with considerable variability in the amounts used. Discussions between patients and health care providers concerning cannabis use may facilitate education and follow up, and would allow side effects and potential interactions with other medications to be monitored. Clinical trials of cannabis for chronic non-cancer pain are warranted. [Copyright &y& Elsevier]

Opioids are commonly prescribed to patients with chronic pain associated with end-stage renal disease requiring hemodialysis. The stability of opioid analgesia during dialysis may vary among different opioids. No studies to date have corroborated this clinical observation by directly comparing plasma concentrations of different opioids during dialysis. We compared changes in peridialysis plasma concentrations of 2 pharmacokinetically distinct opioids, methadone and hydromorphone (HM). Fourteen dialysis patients with chronic pain received either methadone or HM for at least 2weeks before beginning the study. Blood samples were obtained immediately before, during, and after hemodialysis in 2 separate dialysis sessions, 1week apart, and were analyzed for opioid concentrations. Methadone plasma concentrations were more stable during hemodialysis compared to HM: the mean percent change of methadone plasma levels was 14.9%±8.2% (±SD) compared with 55.1%±8.1% in the HM treatment group, a difference of 40.2% (95% confidence interval 17.14 to 63.14). The mean plasma clearance of methadone was 19.9±8.5mL/min (±SD) compared with 105.7±8.3mL/min for HM, a difference of 85.7mL/min (95% confidence interval 61.9 to 109.1). There were no differences between the 2 opioid groups in pain scores, side effect profile, and quality of life. Methadone therapy was not associated with an increased rate of adverse events. If confirmed by larger clinical studies, methadone could be considered as one of the opioids of choice in dialysis patients. [ABSTRACT FROM AUTHOR]