Abstract Most patients who undergo surgical procedures experience acute postoperative pain, but evidence suggests that less than half report adequate postoperative pain relief. Many preoperative, intraoperative, and postoperative interventions and management strategies are available for reducing and managing postoperative pain. The American Pain Society, with input from the American Society of Anesthesiologists, commissioned an interdisciplinary expert panel to develop a clinical practice guideline to promote evidence-based, effective, and safer postoperative pain management in children and adults. The guideline was subsequently approved by the American Society for Regional Anesthesia. As part of the guideline development process, a systematic review was commissioned on various aspects related to various interventions and management strategies for postoperative pain. After a review of the evidence, the expert panel formulated recommendations that addressed various aspects of postoperative pain management, including preoperative education, perioperative pain management planning, use of different pharmacological and nonpharmacological modalities, organizational policies, and transition to outpatient care. The recommendations are based on the underlying premise that optimal management begins in the preoperative period with an assessment of the patient and development of a plan of care tailored to the individual and the surgical procedure involved. The panel found that evidence supports the use of multimodal regimens in many situations, although the exact components of effective multimodal care will vary depending on the patient, setting, and surgical procedure. Although these guidelines are based on a systematic review of the evidence on management of postoperative pain, the panel identified numerous research gaps. Of 32 recommendations, 4 were assessed as being supported by high-quality evidence, and 11 (in the areas of patient education and perioperative planning, patient assessment, organizational structures and policies, and transitioning to outpatient care) were made on the basis of low-quality evidence. Perspective This guideline, on the basis of a systematic review of the evidence on postoperative pain management, provides recommendations developed by a multidisciplinary expert panel. Safe and effective postoperative pain management should be on the basis of a plan of care tailored to the individual and the surgical procedure involved, and multimodal regimens are recommended in many situations.
Abstract Using a simple approach for coding pain severity, the present study describes self-reported pain in U.S. adults. Data are included for 8,781 adults who completed the Functioning and Disability Supplement of the 2012 National Health Interview Survey. An internationally piloted pain severity coding system was used to group participants into 5 discrete ordered pain categories based on their pain persistence (days with pain in the last 3 months) and bothersomeness (little, a lot, somewhere in between): pain free and categories 1 (low) to 4 (high). It is estimated that 126.1 million adults reported some pain in the previous 3 months, with 25.3 million adults (11.2%) suffering from daily (chronic) pain and 23.4 million (10.3%) reporting a lot of pain. Based on the persistence and bothersomeness of their pain, 14.4 million adults (6.4%) were classified as having the highest level of pain, category 4, with an additional 25.4 million adults (11.3%) experiencing category 3 pain. Individuals with category 3 or 4 pain were likely to have worse health status, to use more health care, and to suffer from more disability than those with less severe pain. Associations were seen between pain severity and selected demographic variables including race, ethnicity, preferred language, sex, and age. Perspective U.S. estimates of pain prevalence are presented using a simple approach for assigning pain severity developed by the Washington Group on Disability Statistics. Concurrent validity is assessed. Although this approach is promising, additional work is required to determine the usefulness of the Washington Group pain categories for pain research or clinical practice.
Abstract In 2008, according to the Medical Expenditure Panel Survey (MEPS), about 100 million adults in the United States were affected by chronic pain, including joint pain or arthritis. Pain is costly to the nation because it requires medical treatment and complicates treatment for other ailments. Also, pain lowers worker productivity. Using the 2008 MEPS, we estimated 1) the portion of total U.S. health care costs attributable to pain; and 2) the annual costs of pain associated with lower worker productivity. We found that the total costs ranged from $560 to $635 billion in 2010 dollars. The additional health care costs due to pain ranged from $261 to $300 billion. This represents an increase in annual per person health care costs ranging from $261 to $300 compared to a base of about $4,250 for persons without pain. The value of lost productivity due to pain ranged from $299 to $335 billion. We found that the annual cost of pain was greater than the annual costs of heart disease ($309 billion), cancer ($243 billion), and diabetes ($188 billion). Our estimates are conservative because they do not include costs associated with pain for nursing home residents, children, military personnel, and persons who are incarcerated. Perspective This study estimates that the national cost of pain ranges from $560 to $635 billion, larger than the cost of the nation's priority health conditions. Because of its economic toll on society, the nation should invest in research, education, and training to advocate the successful treatment, management, and prevention of pain.
Abstract A cross-sectional, Internet-based survey was conducted in a nationally representative sample of United States (US) adults to estimate the point prevalence of chronic pain and to describe sociodemographic correlates and characteristics of chronic pain. The survey was distributed to 35,718 members (aged 18 years and older) of a Web-enabled panel that is representative of the US population, and 27,035 individuals responded. Crude and weighted prevalence estimates were calculated and stratified by age, sex, and type of chronic pain. The weighted point-prevalence of chronic pain (defined as chronic, recurrent, or long-lasting pain lasting for at least 6 months) was 30.7% (95% CI, 29.8–31.7). Prevalence was higher for females (34.3%) than males (26.7%) and increased with age. The weighted prevalence of primary chronic lower back pain was 8.1% and primary osteoarthritis pain was 3.9%. Half of respondents with chronic pain experienced daily pain, and average (past 3 months) pain intensity was severe (≥7 on a scale ranging from 0 to 10) for 32%. Multiple logistic regression analysis identified low household income and unemployment as significant socioeconomic correlates of chronic pain. Chronic pain is prevalent among US adults and is related to indicators of poorer socioeconomic status. Perspective The results of this cross-sectional Internet-based survey suggest a considerable burden of chronic pain in US adults. Chronic pain, experienced by about a third of the population, was correlated with indicators of poorer socioeconomic status. Primary chronic pain was most commonly attributed to lower back pain, followed by osteoarthritis pain.
Abstract A consensus meeting was convened by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to provide recommendations for interpreting clinical importance of treatment outcomes in clinical trials of the efficacy and effectiveness of chronic pain treatments. A group of 40 participants from universities, governmental agencies, a patient self-help organization, and the pharmaceutical industry considered methodologic issues and research results relevant to determining the clinical importance of changes in the specific outcome measures previously recommended by IMMPACT for 4 core chronic pain outcome domains: (1) Pain intensity, assessed by a 0 to 10 numerical rating scale; (2) physical functioning, assessed by the Multidimensional Pain Inventory and Brief Pain Inventory interference scales; (3) emotional functioning, assessed by the Beck Depression Inventory and Profile of Mood States; and (4) participant ratings of overall improvement, assessed by the Patient Global Impression of Change scale. It is recommended that 2 or more different methods be used to evaluate the clinical importance of improvement or worsening for chronic pain clinical trial outcome measures. Provisional benchmarks for identifying clinically important changes in specific outcome measures that can be used for outcome studies of treatments for chronic pain are proposed. Perspective Systematically collecting and reporting the recommended information needed to evaluate the clinical importance of treatment outcomes of chronic pain clinical trials will allow additional validation of proposed benchmarks and provide more meaningful comparisons of chronic pain treatments.
Abstract Pain and depression are the most prevalent physical and psychological symptom-based disorders, respectively, and co-occur 30 to 50% of the time. However, their reciprocal relationship and potentially causative effects on one another have been inadequately studied. Longitudinal data analysis involving 500 primary care patients with persistent back, hip, or knee pain were enrolled in the Stepped Care for Affective Disorders and Musculoskeletal Pain (SCAMP) study. Half of the participants had comorbid depression and were randomized to a stepped care intervention (n = 123) or treatment as usual (n = 127). Another 250 nondepressed patients with similar pain were followed in a parallel cohort. Outcomes were assessed at baseline, 3, 6, and 12 months. Mixed effects model repeated measures (MMRM) multivariable analyses were conducted to determine if change in pain severity predicted subsequent depression severity, and vice versa. Change in pain was a strong predictor of subsequent depression severity (t-value = 6.63, P < .0001). Likewise, change in depression severity was an equally strong predictor of subsequent pain severity (t-value = 7.28, P < .0001). Results from the full cohort were similar in the clinical trial subgroup. In summary, pain and depression have strong and similar effects on one another when assessed longitudinally over 12 months. Perspective This study strengthens the evidence for a bidirectional and potentially causative influence of pain and depression on one another. A change in severity of either symptom predicts subsequent severity of the other symptom. Thus, recognition and management of both conditions may be warranted, particularly when treatment focused on 1 condition is not leading to an optimal response.
Abstract Although there is a growing body of research concerning the prevalence and correlates of chronic pain conditions and their association with mental disorders, cross-national research on age and gender differences is limited. The present study reports the prevalence by age and gender of common chronic pain conditions (headache, back or neck pain, arthritis or joint pain, and other chronic pain) in 10 developed and 7 developing countries and their association with the spectrum of both depressive and anxiety disorders. It draws on data from 18 general adult population surveys using a common survey questionnaire (N = 42,249). Results show that age-standardized prevalence of chronic pain conditions in the previous 12 months was 37.3% in developed countries and 41.1% in developing countries, with back pain and headache being somewhat more common in developing than developed countries. After controlling for comorbid chronic physical diseases, several findings were consistent across developing and developed countries. There was a higher prevalence of chronic pain conditions among females and older persons; and chronic pain was similarly associated with depression-anxiety spectrum disorders in developed and developing countries. However, the large majority of persons reporting chronic pain did not meet criteria for depression or anxiety disorder. We conclude that common pain conditions affect a large percentage of persons in both developed and developing countries. Perspective Chronic pain conditions are common in both developed and developing countries. Overall, the prevalence of pain is greater among females and among older persons. Although most persons reporting pain do not meet criteria for a depressive or anxiety disorder, depression/anxiety spectrum disorders are associated with pain in both developed and developing countries.
Abstract Despite rapidly increasing intervention, functional disability due to chronic low back pain (cLBP) has increased in recent decades. We often cannot identify mechanisms to explain the major negative impact cLBP has on patients' lives. Such cLBP is often termed non-specific and may be due to multiple biologic and behavioral etiologies. Researchers use varied inclusion criteria, definitions, baseline assessments, and outcome measures, which impede comparisons and consensus. Therefore, NIH Pain Consortium charged a Research Task Force (RTF) to draft standards for research on cLBP. The resulting multidisciplinary panel recommended using 2 questions to define cLBP; classifying cLBP by its impact (defined by pain intensity, pain interference, and physical function); use of a minimum dataset to describe research participants (drawing heavily on the PROMIS methodology); reporting “responder analyses” in addition to mean outcome scores; and suggestions for future research and dissemination. The Pain Consortium has approved the recommendations, which investigators should incorporate into NIH grant proposals. The RTF believes that these recommendations will advance the field, help to resolve controversies, and facilitate future research addressing the genomic, neurologic, and other mechanistic substrates of chronic low back pain. We expect that the RTF recommendations will become a dynamic document and undergo continual improvement. Perspective A task force was convened by the NIH Pain Consortium with the goal of developing research standards for chronic low back pain. The results included recommendations for definitions, a minimum dataset, reporting outcomes, and future research. Greater consistency in reporting should facilitate comparisons among studies and the development of phenotypes.
Abstract Oxycodone hydrochloride controlled-release, also known as extended-release oxycodone (ER oxycodone), was reformulated with physicochemical barriers to crushing and dissolving intended to reduce abuse through nonoral routes of administration (ROAs) that require tampering (eg, injecting and snorting). Manufacturer shipments of original ER oxycodone (OC) stopped on August 5, 2010, and reformulated ER oxycodone (ORF) shipments started August 9, 2010. A sentinel surveillance sample of 140,496 individuals assessed for substance abuse treatment at 357 U.S. centers between June 1, 2009, and March 31, 2012, was examined for prevalence and prescription-adjusted prevalence rates of past-30-day abuse via any route, as well as abuse through oral, nonoral, and specific ROAs for ER oxycodone and comparators (ER morphine and ER oxymorphone) before and after ORF introduction. Significant reductions occurred for 8 outcome measures of ORF versus OC historically. Abuse of ORF was 41% lower (95% CI: −44 to −37) than historical abuse for OC, with oral abuse 17% lower (95% CI: −23 to −10) and nonoral abuse 66% lower (95% CI: −69 to −63). Significant reductions were not observed for comparators. Observations were consistent with the goals of a tamper resistant formulation for an opioid. Further research is needed to determine the persistence and generalizability of these findings. Perspective This article presents preliminary findings indicating that 8 outcome measures of abuse of a reformulated ER oxycodone were lower than that for original ER oxycodone historically, particularly through nonoral ROAs that require tampering (ie, injection, snorting, smoking), in a sentinel sample of individuals assessed for substance use problems for treatment planning.
Abstract Under the auspices of the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT), 26 professionals from academia, governmental agencies, and the pharmaceutical industry participated in a 2-stage Delphi poll and a consensus meeting that identified core outcome domains and measures that should be considered in clinical trials of treatments for acute and chronic pain in children and adolescents. Consensus was refined by consultation with the international pediatric pain community through announcement of our recommendations on the Pediatric Pain List and inviting and incorporating comments from external sources. There was consensus that investigators conducting pediatric acute pain clinical trials should consider assessing outcomes in pain intensity; global judgment of satisfaction with treatment; symptoms and adverse events; physical recovery; emotional response; and economic factors. There was also agreement that investigators conducting pediatric clinical trials in chronic and recurrent pain should consider assessing outcomes in pain intensity; physical functioning; emotional functioning; role functioning; symptoms and adverse events; global judgment of satisfaction with treatment; sleep; and economic factors. Specific measures or measurement strategies were recommended for different age groups for each domain. Perspective Based on systematic review and consensus of experts, core domains and measures for clinical trials to treat pain in children and adolescents were defined. This will assist in comparison and pooling of data and promote evidence-based treatment, encourage complete reporting of outcomes, simplify the review of proposals and manuscripts, and facilitate clinicians making informed decisions regarding treatment.
Abstract We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling medium-dose (3.53%), low-dose (1.29%), or placebo cannabis with the primary outcome being visual analog scale pain intensity. Psychoactive side effects and neuropsychological performance were also evaluated. Mixed-effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the 2 active dose groups' results ( P > .7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo versus low-dose, 2.9 for placebo versus medium-dose, and 25 for medium- versus low-dose. As these NNTs are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well tolerated, and neuropsychological effects were of limited duration and readily reversible within 1 to 2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. Perspective The analgesia obtained from a low dose of delta-9-tetrahydrocannabinol (1.29%) in patients, most of whom were experiencing neuropathic pain despite conventional treatments, is a clinically significant outcome. In general, the effect sizes on cognitive testing were consistent with this minimal dose. As a result, one might not anticipate a significant impact on daily functioning.
Abstract Central sensitization (CS) is a proposed physiological phenomenon in which central nervous system neurons become hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli. The term central sensitivity syndrome (CSS) describes a group of medically indistinct (or nonspecific) disorders, such as fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome, for which CS may be a common etiology. In a previous study, the Central Sensitization Inventory (CSI) was introduced as a screening instrument for clinicians to help identify patients with a CSS. It was found to have high reliability and validity (test-retest reliability = .82; Cronbach's alpha = .88). The present study investigated a cohort of 121 patients who were referred to a multidisciplinary pain center, which specializes in the assessment and treatment of complex pain and psychophysiological disorders, including CSSs. A large percentage of patients (n = 89, 74%) met clinical criteria for one or more CSSs, and CSI scores were positively correlated with the number of diagnosed CSSs. A receiver operating characteristic analysis determined that a CSI score of 40 out of 100 best distinguished between the CSS patient group and a nonpatient comparison sample (N = 129) (area under the curve = .86, sensitivity = 81%, specificity = 75%). Perspective The CSI is a new self-report screening instrument to help identify patients with CSSs, including fibromyalgia. The present study investigated CSI scores in a heterogeneous pain population with a large percentage of CSSs, and a normative nonclinical sample to determine a clinically relevant cutoff value.
Abstract The aim of this study was to assess the economic cost of chronic pain among adolescents receiving interdisciplinary pain treatment. Information was gathered from 149 adolescents (ages 10–17) presenting for evaluation and treatment at interdisciplinary pain clinics in the United States. Parents completed a validated measure of family economic attributes, the Client Service Receipt Inventory, to report on health service use and productivity losses due to their child's chronic pain retrospectively over 12 months. Health care costs were calculated by multiplying reported utilization estimates by unit visit costs from the 2010 Medical Expenditure Panel Survey. The estimated mean and median costs per participant were $11,787 and $6,770, respectively. Costs were concentrated in a small group of participants; the top 5% of those patients incurring the highest costs accounted for 30% of total costs, whereas the lower 75% of participants accounted for only 34% of costs. Total costs to society for adolescents with moderate to severe chronic pain were extrapolated to $19.5 billion annually in the United States. The cost of adolescent chronic pain presents a substantial economic burden to families and society. Future research should focus on predictors of increased health services use and costs in adolescents with chronic pain. Perspective This cost of illness study comprehensively estimates the economic costs of chronic pain in a cohort of treatment-seeking adolescents. The primary driver of costs was direct medical costs followed by productivity losses. Because of its economic impact, policy makers should invest resources in the prevention, diagnosis, and treatment of chronic pediatric pain.
Abstract Case-control studies have consistently associated psychological factors with chronic pain in general and with temporomandibular disorder (TMD) specifically. However, only a handful of prospective studies have explored whether preexisting psychological characteristics represent risk factors for first-onset TMD. The current findings derive from the prospective cohort study of the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) cooperative agreement. For this study, 3,263 TMD-free participants completed a battery of psychological instruments assessing general psychological adjustment and personality, affective distress, psychosocial stress, somatic symptoms, and pain coping and catastrophizing. Study participants were then followed prospectively for an average of 2.8 years to ascertain cases of first-onset of TMD, and 2,737 provided follow-up data and were considered in the analyses of TMD onset. In bivariate and demographically adjusted analyses, several psychological variables predicted increased risk of first-onset TMD, including reported somatic symptoms, psychosocial stress, and affective distress. Principal component analysis of 26 psychological scores was used to identify latent constructs, revealing 4 components: stress and negative affectivity, global psychological and somatic symptoms, passive pain coping, and active pain coping. In multivariable analyses, global psychological and somatic symptoms emerged as the most robust risk factor for incident TMD. These findings provide evidence that measures of psychological functioning can predict first onset of TMD. Future analyses in the OPPERA cohort will determine whether these psychological factors interact with other variables to increase risk for TMD onset and persistence. Perspective This article reports that several premorbid psychological variables predict first-onset TMD in the OPPERA study, a large prospective cohort study designed to discover causal determinants of TMD pain. Measures of somatic symptoms were most strongly associated with TMD onset, but perceived stress, previous life events, and negative affect also predicted TMD incidence.
Abstract This paper tests the contribution of the toll-like receptors, TLR4 in particular, in the initiation and maintenance of paclitaxel-related chemotherapy-induced peripheral neuropathy. TLR4 and its immediate downstream signaling molecules—myeloid differentiation primary response gene 88 (MyD88) and toll/interleukin 1 receptor domain–containing adapter-inducing interferon-β (TRIF)—were found to be increased in the dorsal root ganglion (DRG) using Western blot by day 7 of paclitaxel treatment. The behavioral phenotype, the increase of both TLR4 and MyD88, was blocked by cotreatment with the TLR4 antagonist lipopolysaccharide– Rhodobacter sphaeroides during chemotherapy. A similar, but less robust, behavioral effect was observed using intrathecal treatment of MyD88 homodimerization inhibitory peptide. DRG levels of TLR4 and MyD88 reduced over the next 2 weeks, whereas these levels remained increased in spinal cord through day 21 following chemotherapy. Immunohistochemical analysis revealed TLR4 expression in both calcitonin gene-related peptide–positive and isolectin B4–positive small DRG neurons. MyD88 was only found in calcitonin gene-related peptide–positive neurons, and TRIF was found in both calcitonin gene-related peptide–positive and isolectin B4–positive small DRG neurons as well as in medium- and large-size DRG neurons. In the spinal cord, TLR4 was only found colocalized to astrocytes but not with either microglia or neurons. Intrathecal treatment with the TLR4 antagonist lipopolysaccharide– R. sphaeroides transiently reversed preestablished chemotherapy-induced peripheral neuropathy mechanical hypersensitivity. These results strongly implicate TLR4 signaling in the DRG and the spinal cord in the induction and maintenance of paclitaxel-related chemotherapy-induced peripheral neuropathy. Perspective The toll-like receptor TLR4 and MyD88 signaling pathway could be a new potential therapeutic target in paclitaxel-induced painful neuropathy.
Abstract Published adult prevalence estimates of chronic pain in the United States vary significantly. A more consistent pain measure is needed to assess unmet need for pain management in the general population. In this study, secondary analyses of the 2010 Quality of Life Supplement of the National Health Interview Survey are used to calculate the point prevalence of “persistent pain,” which we defined as constant or frequent pain persisting for at least 3 months. Rates of persistent pain are also calculated by risk group, chronic condition, and disability status. Findings show that about 19.0% of adults in the United States report persistent pain. Rates of persistent pain are higher among women, adults aged 60 to 69, adults who rate their health as fair or poor, adults who are overweight or obese, and those who were hospitalized 1 or more times in the preceding year. Most adults who report conditions such as arthritis, carpal tunnel syndrome, or back or joint pain do not describe their pain as “persistent.” Of the estimated 39.4 million adults who report persistent pain, 67.2% say their pain is “constantly present,” and 50.5% say their pain is sometimes “unbearable and excruciating.” Perspective Persistent pain, defined as self-reported pain “every day” or “most days” in the preceding 3 months, is a useful way to characterize health-related quality of life in the general population, and policy makers should consider including this core measure in ongoing health surveys like the National Health Interview Survey and the Medical Expenditure Panel Survey, the authors conclude.
Abstract Knowledgeable and compassionate care regarding pain is a core responsibility of health professionals associated with better medical outcomes, improved quality of life, and lower healthcare costs. Education is an essential part of training healthcare providers to deliver conscientious pain care but little is known about whether medical school curricula meet educational needs. Using a novel systematic approach to assess educational content, we examined the curricula of Liaison Committee on Medical Education-accredited medical schools between August 2009 and February 2010. Our intent was to establish important benchmark values regarding pain education of future physicians during primary professional training. External validation was performed. Inclusion criteria required evidence of substantive participation in the curriculum management database of the Association of American Medical Colleges. A total of 117 U.S. and Canadian medical schools were included in the study. Approximately 80% of U.S. medical schools require 1 or more pain sessions. Among Canadian medical schools, 92% require pain sessions. Pain sessions are typically presented as part of general required courses. Median hours of instruction on pain topics for Canadian schools was twice the U.S. median. Many topics included in the International Association for the Study of Pain core curriculum received little or no coverage. There were no correlations between the types of pain education offered and school characteristics (eg, private versus public). We conclude that pain education for North American medical students is limited, variable, and often fragmentary. There is a need for innovative approaches and better integration of pain topics into medical school curricula. Perspective This study assessed the scope and scale of pain education programs in U.S. and Canadian medical schools. Significant gaps between recommended pain curricula and documented educational content were identified. In short, pain education was limited and fragmentary. Innovative and integrated pain education in primary medical education is needed.
Opioids are commonly used to treat patients with chronic pain (CP), though there is little evidence that they are effective for long term CP treatment. Previous studies reported strong associations between passage of medical cannabis laws and decrease in opioid overdose statewide. Our aim was to examine whether using medical cannabis for CP changed individual patterns of opioid use. Using an online questionnaire, we conducted a cross-sectional retrospective survey of 244 medical cannabis patients with CP who patronized a medical cannabis dispensary in Michigan between November 2013 and February 2015. Data collected included demographic information, changes in opioid use, quality of life, medication classes used, and medication side effects before and after initiation of cannabis usage. Among study participants, medical cannabis use was associated with a 64% decrease in opioid use (n = 118), decreased number and side effects of medications, and an improved quality of life (45%). This study suggests that many CP patients are essentially substituting medical cannabis for opioids and other medications for CP treatment, and finding the benefit and side effect profile of cannabis to be greater than these other classes of medications. More research is needed to validate this finding. This article suggests that using medical cannabis for CP treatment may benefit some CP patients. The reported improvement in quality of life, better side effect profile, and decreased opioid use should be confirmed by rigorous, longitudinal studies that also assess how CP patients use medical cannabis for pain management.
Abstract Methadone is used for the treatment of opioid addiction and for treatment of chronic pain. The safety of methadone has been called into question by data indicating a large increase in the number of methadone-associated overdose deaths in recent years that has occurred in parallel with a dramatic rise in the use of methadone for chronic pain. The American Pain Society and the College on Problems of Drug Dependence, in collaboration with the Heart Rhythm Society, commissioned an interdisciplinary expert panel to develop a clinical practice guideline on safer prescribing of methadone for treatment of opioid addiction and chronic pain. As part of the guideline development process, the American Pain Society commissioned a systematic review of various aspects related to safety of methadone. After a review of the available evidence, the expert panel concluded that measures can be taken to promote safer use of methadone. Specific recommendations include the need to educate and counsel patients on methadone safety, use of electrocardiography to identify persons at greater risk for methadone-associated arrhythmia, use of alternative opioids in patients at high risk of complications related to corrected electrocardiographic QTc interval prolongation, careful dose initiation and titration of methadone, and diligent monitoring and follow-up. Although these guidelines are based on a systematic review, the panel identified numerous research gaps, most recommendations were based on low-quality evidence, and no recommendations were based on high-quality evidence. Perspective This guideline, based on a systematic review of the evidence on methadone safety, provides recommendations developed by a multidisciplinary expert panel. Safe use of methadone requires clinical skills and knowledge in use of methadone to mitigate potential risks, including serious risks related to risk of overdose and cardiac arrhythmias.
Abstract Several studies have reported reduced cerebral gray matter (GM) volume or density in chronic pain conditions, but there is limited research on the plasticity of the human cortex in response to psychological interventions. We investigated GM changes after cognitive-behavioral therapy (CBT) in patients with chronic pain. We used voxel-based morphometry to compare anatomic magnetic resonance imaging scans of 13 patients with mixed chronic pain types before and after an 11-week CBT treatment and to 13 healthy control participants. CBT led to significant improvements in clinical measures. Patients did not differ from healthy controls in GM anywhere in the brain. After treatment, patients had increased GM in the bilateral dorsolateral prefrontal, posterior parietal, subgenual anterior cingulate/orbitofrontal, and sensorimotor cortices, as well as hippocampus, and reduced GM in supplementary motor area. In most of these areas showing GM increases, GM became significantly higher than in controls. Decreased pain catastrophizing was associated with increased GM in the left dorsolateral prefrontal and ventrolateral prefrontal cortices, right posterior parietal cortex, somatosensory cortex, and pregenual anterior cingulate cortex. Although future studies with additional control groups will be needed to determine the specific roles of CBT on GM and brain function, we propose that increased GM in the prefrontal and posterior parietal cortices reflects greater top-down control over pain and cognitive reappraisal of pain, and that changes in somatosensory cortices reflect alterations in the perception of noxious signals. Perspective An 11-week CBT intervention for coping with chronic pain resulted in increased GM volume in prefrontal and somatosensory brain regions, as well as increased dorsolateral prefrontal volume associated with reduced pain catastrophizing. These results add to mounting evidence that CBT can be a valuable treatment option for chronic pain.