Preliminary experience using milnacipran in patients with juvenile fibromyalgia: lessons from a clinical trial program

Assessing Ethnic Minority Representation in Fibromyalgia Clinical Trials: A Systematic Review of Recruitment Demographics

The under-representation of non-White participants in Western countries in clinical research has received increased attention, due to recognized physiological differences between ethnic groups, which may affect the efficacy and optimal dosage of some treatments. This review assessed ethnic diversity in pharmaceutical trials for fibromyalgia, a poorly understood chronic pain disorder. We also investigated longitudinal change to non-White participant proportions in trials and non-White participants' likelihood to discontinue with fibromyalgia research between trial stages (retention). First, we identified relevant trials conducted in the United States and Canada between 2000 and 2022, by searching PubMed, Web of Science, Scopus, and the Cochrane Library databases. In trials conducted both across the United States and Canada, and exclusively within the United States, approximately 90% of participants were White. A longitudinal analysis also found no change in the proportion of non-White participants in trials conducted across the United States and Canada between 2000 and 2022. Finally, we found no significant differences in trial retention between White and non-White participants. This review highlights the low numbers of ethnic minorities in fibromyalgia trials conducted in the United States and Canada, with no change to these proportions over the past 22 years. Furthermore, non-White participants were not more likely to discontinue with the fibromyalgia research once they were recruited.

Juvenile Fibromyalgia

Juvenile fibromyalgia is a common referral in pediatric rheumatology settings. Providing a clear diagnosis and explanation of altered pain processing offers reassurance that pain has a biologic basis and the symptoms are part of a recognized pain syndrome. Physicians should acknowledge the impact of chronic pain and associated symptoms on patient's lives and take time to understand contributing factors including stress, mood, inactivity, and lifestyle factors. The optimal treatment for juvenile fibromyalgia is multidisciplinary, focusing on education about juvenile fibromyalgia, along with physical therapy, cognitive behavioral therapy, sleep hygiene, healthy lifestyle habits, and medications for symptom management as appropriate.

Juvenile primary fibromyalgia syndrome: A Review- Treatment and Prognosis

Juvenile primary fibromyalgia syndrome (JPFS) is a chronic musculoskeletal pain syndrome affecting children and adolescents. In part one of this review, we discussed the epidemiology, etiology, pathogenesis, clinical manifestations and diagnosis of JPFS. Part two focuses on the treatment and prognosis of JPFS. Early intervention is important. The standard of care is multidisciplinary, combining various modalities-most importantly, exercise and cognitive behavioral therapy. Prognosis varies and symptoms may persist into adulthood.

Randomized clinical trial of Fibromyalgia Integrative Training (FIT teens) for adolescents with juvenile fibromyalgia - Study design and protocol

OBJECTIVE

Juvenile-onset fibromyalgia (JFM) is a chronic debilitating pain condition that negatively impacts physical, social and academic functioning. Cognitive-behavioral therapy (CBT) is beneficial in reducing functional disability among adolescents with JFM but has only a modest impact on pain reduction and does not improve physical exercise participation. This randomized controlled trial (RCT) aims to test whether a novel intervention that combines CBT with specialized neuromuscular exercise training (the Fibromyalgia Integrative Training program for Teens "FIT Teens") is superior to CBT alone or a graded aerobic exercise (GAE) program.

DESIGN/METHODS

This 3-arm multi-site RCT will examine the efficacy of the FIT Teens intervention in reducing functional disability (primary outcome) and pain intensity (secondary outcome), relative to CBT or GAE. All interventions are 8-weeks (16 sessions) in duration and are delivered in small groups of 4-6 adolescents with JFM. A total of 420 participants are anticipated to be enrolled across seven sites with approximately equal allocation to each treatment arm. Functional disability and average pain intensity in the past week will be assessed at baseline, post-treatment and at 3-, 6-, 9- and 12-month follow-up. The 3-month follow-up is the primary endpoint to evaluate treatment efficacy; longitudinal assessments will determine maintenance of treatment gains. Changes in coping, fear of movement, biomechanical changes and physical fitness will also be evaluated.

CONCLUSIONS

This multi-site RCT is designed to evaluate whether the combined FIT Teens intervention will have significantly greater effects on disability and pain reduction than CBT or GAE alone for youth with JFM. Clinical trials.gov registration: NCT03268421.

Beyond Amitriptyline: A Pediatric and Adolescent Oriented Narrative Review of the Analgesic Properties of Psychotropic Medications for the Treatment of Complex Pain and Headache Disorders

Children and adolescents with recurrent or chronic pain and headache are a complex and heterogenous population. Patients are best served by multi-specialty, multidisciplinary teams to assess and create tailored, individualized pain treatment and rehabilitation plans. Due to the complex nature of pain, generalizing pharmacologic treatment recommendations in children with recurrent or chronic pains is challenging. This is particularly true of complicated patients with co-existing painful and psychiatric conditions. There is an unfortunate dearth of evidence to support many pharmacologic therapies to treat children with chronic pain and headache. This narrative review hopes to supplement the available treatment options for this complex population by reviewing the pediatric and adult literature for analgesic properties of medications that also have psychiatric indication. The medications reviewed belong to medication classes typically described as antidepressants, alpha 2 delta ligands, mood stabilizers, anti-psychotics, anti-sympathetic agents, and stimulants.

Prevalence of Juvenile Fibromyalgia Syndrome Among Children and Adolescents and its Relationship With Academic Success, Depression and Quality of Life, Çorum Province, Turkey

Objectives

This study aims to determine the frequency of juvenile fibromyalgia syndrome (JFMS) among children and adolescents in Çorum Province, Turkey, and its impact by comparing the levels of academic success, depression and quality of life (QoL) in individuals with and without JFMS.

Patients and methods

This was a cross-sectional study on 476 children and adolescents (245 boys, 231 girls; mean age 13.81±2.3 years; range, 9 to 17 years). The control group (non-JFMS group) consisted of 105 age- and sex-matched healthy participants (75 girls, 30 boys; mean age 14.1±1.8 years; range; 9 to 17 years). Participants' sociodemographic data, parental information, and school achievement in addition to data on chronic illness and drug use were collected via questionnaires (depression and QoL). A tender point (TP) examination was performed on each participant.

Results

Thirty-five (7.35%) of the participants (girls, n=25; boys, n=10) were diagnosed with JFMS. The number of minor JFMS diagnostic criteria, number of TPs, depression level and number of days the participants were absent from school were significantly higher in the JFMS group compared with the non-JFMS group (p<0.05). The mean grade point scores of the JFMS group were significantly lower than those of the non-JFMS group (p<0.05). The QoL subgroup scores as assessed by physical functioning, emotional functioning, social functioning and school-related problems of the JFMS group were significantly lower than the non-JFMS group (p<0.05). Age had a statistically significant negative correlation with QoL and school-related problems (r= -0.421, r= -0.494; p<0.05, respectively). Depression was negatively correlated with QoL and school-related problems (r= -0.672, r= -0.731; p<0.05, respectively).

Conclusion

Juvenile fibromyalgia syndrome affects QoL and can lead to school absenteeism, poor academic performance, depression and anxiety among the school-age population. Early identification of JFMS and early intervention may be the most effective strategy for preventing problems in later life.

Efficacy and safety of duloxetine versus placebo in adolescents with juvenile fibromyalgia: results from a randomized controlled trial

BACKGROUND

Currently, there are no medications approved for the treatment of juvenile fibromyalgia (JFM). We evaluated the safety and efficacy of duloxetine 30/60 mg once daily (QD) versus placebo in adolescents with JFM.

METHODS

In this Phase 3b, multisite (US, Argentina, Puerto Rico, and India) trial, patients aged 13-17 years with JFM and a score of ≥4 on the Brief Pain Inventory-Modified Short Form: Adolescent Version (BPI) 24-h average pain severity score were randomized to duloxetine or placebo for the 13-week double-blind period. The starting duloxetine dose was 30 mg, with a target dose of 60 mg QD, as tolerated. The primary endpoint was the mean change in 24-h average pain severity of the Brief Pain Inventory (BPI) from baseline to Week 13, analyzed using mixed-model repeated measures (MMRM) technique. Secondary measures were BPI severity and interference scores; treatment response (≥30%, ≥50% reductions on BPI average pain severity); Pediatric Pain Questionnaire; Clinical Global Impression of Severity: Overall and Mental Illness scales; Functional Disability Inventory: child and parent versions; Children's Depression Inventory; Multidimensional Anxiety Scale for Children; and safety and tolerability. Continuous secondary efficacy measures were analyzed using analysis of covariance or MMRM, and categorical data using Cochran-Mantel-Haenszel test and Fisher's exact test, where appropriate.

RESULTS

A total of 184 patients with JFM received duloxetine (N = 91) or placebo (N = 93), of which 149 patients (81.0%) completed the 13-week double-blind treatment period. Baseline characteristics were comparable between groups; majority of the patients were Caucasian (77.17%) and females (75.0%), with a mean age of 15.53 years. For the primary measure, BPI average pain severity, the mean change was not statistically different between duloxetine and placebo (- 1.62 vs. -0.97, respectively; p = .052). For secondary efficacy outcomes, statistically significantly more duloxetine- versus placebo-treated patients had a treatment response (≥30% and ≥50% reductions on BPI average pain severity) and improvement of the general activity and relationships items on the BPI interference subscale. The percentage of patients reporting at least 1 treatment-emergent adverse event was higher in the duloxetine versus placebo groups (82.42% vs. 62.37%, respectively; p = .003). The overall safety profile of duloxetine in this study was similar to that reported previously in duloxetine pediatric trials of other indications.

CONCLUSIONS

The primary study outcome, mean change in 24-h BPI average pain severity rating from baseline to Week 13, did not significantly improve with duloxetine compared to placebo in patients with JFM. However, significantly more patients on duloxetine compared to placebo had a ≥30% and ≥50% reduction in pain severity. There were no new safety concerns related to duloxetine in the study population.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01237587 . Registered 08 November, /2010.

Design and Reporting Characteristics of Clinical Trials of Select Chronic and Recurrent Pediatric Pain Conditions: An Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks Systematic Review

Fewer randomized clinical trials (RCTs) are conducted for chronic or recurrent pain in pediatric populations compared with adult populations; thus, data to support treatment efficacy in children are limited. This article evaluates the design features and reporting practices of RCTs for chronic and recurrent pain that are likely unique to, or particularly important in, a pediatric population to promote improvements in the evidence base for pediatric pain treatments. Areas covered include outcome measure selection and reporting and reporting of adverse events and challenges to recruitment and retention. A search of PubMed and EMBASE identified primary publications describing RCTs of treatments for select chronic and recurrent pain conditions in children or adolescents published between 2000 and 2017. Only 49% of articles identified a primary outcome measure. The primary outcome measure assessed pain intensity in 38% of the trials, specifically measure by verbal rating scale (13%), faces pain scale (11%), visual analogue scale (9%), or numeric rating scale (5%). All of the CONSORT harms reporting recommendations were fulfilled by <50% of the articles. Discussions of recruitment challenges occurred in 64% of articles that enrolled <90% of their target sample. However, discussions regarding retention challenges only occurred in 14% of trials in which withdrawal rates were >10%. The goal of this article is to promote comprehensive reporting of pediatric pain RCTs to improve the design of future trials, facilitate conduction of systematic reviews and meta-analyses, and better inform clinical practice. PERSPECTIVE: This review of chronic and recurrent pediatric pain trials demonstrates inadequacies in the reporting quality of key features specifically important to pediatric populations. It provides recommendations that address these shortcomings to promote continued efforts toward improving the quality of the design and publication of future pediatric clinical pain trials.

Milnacipran poorly modulates pain in patients suffering from fibromyalgia: a randomized double-blind controlled study

Introduction

Fibromyalgia is characterized by widespread and chronic pain, and its prevalence is increasing worldwide. Milnacipran, an antidepressant, is often prescribed for fibromyalgia with a possible beneficial effect on central pain modulation. The aim of this study was to evaluate if milnacipran could modify the status of conditioned pain modulation (CPM) in patients suffering from fibromyalgia.

Design and setting

Randomized, double-blind controlled trial.

Subjects and methods

Women with fibromyalgia received milnacipran 100 mg or placebo. The primary end point was the evolution of CPM with treatments after a 30-second painful stimulus. Secondary outcomes included the predictability of milnacipran efficacy from CPM performance, evolution of global pain, mechanical sensitivity, thermal pain threshold, mechanical allodynia, cognitive function, and tolerance.

Results

Fifty-four women with fibromyalgia (46.7±10.6 years) were included and randomized, and 24 patients were analyzed in each group. At inclusion, CPM was dysfunctional (CPM₃₀=-0.5±1.9), and global pain was 6.5±1.8. After treatment, there was a nonsignificant CPM difference between milnacipran and placebo (CPM₃₀=-0.46±1.22 vs -0.69±1.43, respectively, p=0.55) and 18.8% vs 6.3% (p=0.085) patients did reactivate CPM after milnacipran vs placebo. Initial CPM was not a predictor of milnacipran efficacy. Global pain, mechanical and thermal thresholds, allodynia, cognition, and tolerance were not significantly different between both groups.

Conclusion

Milnacipran did not display a significant analgesic effect after 1-month treatment, but the tendency of milnacipran to reactivate CPM in a number of patients must be explored with longer treatment duration in future studies and pleads for possible subtypes of fibromyalgia patients.

[Definition, diagnostics and therapy of chronic widespread pain and the (so-called) fibromyalgia syndrome in children and adolescents : Updated guidelines 2017]

BACKGROUND

The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017.

METHODS

The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n = 8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A search of the literature for case series (cross-sectional- and longitudinal studies) for the topics diagnosis, etiology and pathophysiology and for randomised controlled trials (RCT) for treatment modalities from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was achieved by multiple step formalized procedures to reach a consensus. Efficacy, risks, patient preferences and applicability of available therapies were weighed up against each other. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines.

RESULTS AND CONCLUSION

No consensus was achieved in the guideline group on whether the diagnostic label "juvenile fibromyalgia" should be used in the management of children and adolescents with chronic widespread pain. There was consensus in the guideline group that antidepressants and anticonvulsants should not be used to treat pain in the so-called juvenile fibromyalgia syndrome.

Serotonin and noradrenaline reuptake inhibitors (SNRIs) for fibromyalgia

BACKGROUND

Fibromyalgia is a clinically defined chronic condition of unknown etiology characterized by chronic widespread pain that often co-exists with sleep disturbances, cognitive dysfunction and fatigue. People with fibromyalgia often report high disability levels and poor quality of life. Drug therapy, for example, with serotonin and noradrenaline reuptake inhibitors (SNRIs), focuses on reducing key symptoms and improving quality of life. This review updates and extends the 2013 version of this systematic review.

OBJECTIVES

To assess the efficacy, tolerability and safety of serotonin and noradrenaline reuptake inhibitors (SNRIs) compared with placebo or other active drug(s) in the treatment of fibromyalgia in adults.

SEARCH METHODS

For this update we searched CENTRAL, MEDLINE, Embase, the US National Institutes of Health and the World Health Organization (WHO) International Clinical Trials Registry Platform for published and ongoing trials and examined the reference lists of reviewed articles, to 8 August 2017.

SELECTION CRITERIA

We selected randomized, controlled trials of any formulation of SNRIs against placebo or any other active treatment of fibromyalgia in adults.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, examined study quality, and assessed risk of bias. For efficacy, we calculated the number needed to treat for an additional beneficial outcome (NNTB) for pain relief of 50% or greater and of 30% or greater, patient's global impression to be much or very much improved, dropout rates due to lack of efficacy, and the standardized mean differences (SMD) for fatigue, sleep problems, health-related quality of life, mean pain intensity, depression, anxiety, disability, sexual function, cognitive disturbances and tenderness. For tolerability we calculated number needed to treat for an additional harmful outcome (NNTH) for withdrawals due to adverse events and for nausea, insomnia and somnolence as specific adverse events. For safety we calculated NNTH for serious adverse events. We undertook meta-analysis using a random-effects model. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We added eight new studies with 1979 participants for a total of 18 included studies with 7903 participants. Seven studies investigated duloxetine and nine studies investigated milnacipran against placebo. One study compared desvenlafaxine with placebo and pregabalin. One study compared duloxetine with L-carnitine. The majority of studies were at unclear or high risk of bias in three to five domains.The quality of evidence of all comparisons of desvenlafaxine, duloxetine and milnacipran versus placebo in studies with a parallel design was low due to concerns about publication bias and indirectness, and very low for serious adverse events due to concerns about publication bias, imprecision and indirectness. The quality of evidence of all comparisons of duloxetine and desvenlafaxine with other active drugs was very low due to concerns about publication bias, imprecision and indirectness.Duloxetine and milnacipran had no clinically relevant benefit over placebo for pain relief of 50% or greater: 1274 of 4104 (31%) on duloxetine and milnacipran reported pain relief of 50% or greater compared to 591 of 2814 (21%) participants on placebo (risk difference (RD) 0.09, 95% confidence interval (CI) 0.07 to 0.11; NNTB 11, 95% CI 9 to 14). Duloxetine and milnacipran had a clinically relevant benefit over placebo in patient's global impression to be much or very much improved: 888 of 1710 (52%) on duloxetine and milnacipran (RD 0.19, 95% CI 0.12 to 0.26; NNTB 5, 95% CI 4 to 8) reported to be much or very much improved compared to 354 of 1208 (29%) of participants on placebo. Duloxetine and milnacipran had a clinically relevant benefit compared to placebo for pain relief of 30% or greater. RD was 0.10; 95% CI 0.08 to 0.12; NNTB 10, 95% CI 8 to 12. Duloxetine and milnacipran had no clinically relevant benefit for fatigue (SMD -0.13, 95% CI -0.18 to -0.08; NNTB 18, 95% CI 12 to 29), compared to placebo. There were no differences between either duloxetine or milnacipran and placebo in reducing sleep problems (SMD -0.07; 95 % CI -0.15 to 0.01). Duloxetine and milnacipran had no clinically relevant benefit compared to placebo in improving health-related quality of life (SMD -0.20, 95% CI -0.25 to -0.15; NNTB 11, 95% CI 8 to 14).There were 794 of 4166 (19%) participants on SNRIs who dropped out due to adverse events compared to 292 of 2863 (10%) of participants on placebo (RD 0.07, 95% CI 0.04 to 0.10; NNTH 14, 95% CI 10 to 25). There was no difference in serious adverse events between either duloxetine, milnacipran or desvenlafaxine and placebo (RD -0.00, 95% CI -0.01 to 0.00).There was no difference between desvenlafaxine and placebo in efficacy, tolerability and safety in one small trial.There was no difference between duloxetine and desvenlafaxine in efficacy, tolerability and safety in two trials with active comparators (L-carnitine, pregabalin).

AUTHORS' CONCLUSIONS

The update did not change the major findings of the previous review. Based on low- to very low-quality evidence, the SNRIs duloxetine and milnacipran provided no clinically relevant benefit over placebo in the frequency of pain relief of 50% or greater, but for patient's global impression to be much or very much improved and in the frequency of pain relief of 30% or greater there was a clinically relevant benefit. The SNRIs duloxetine and milnacipran provided no clinically relevant benefit over placebo in improving health-related quality of life and in reducing fatigue. Duloxetine and milnacipran did not significantly differ from placebo in reducing sleep problems. The dropout rates due to adverse events were higher for duloxetine and milnacipran than for placebo. On average, the potential benefits of duloxetine and milnacipran in fibromyalgia were outweighed by their potential harms. However, a minority of people with fibromyalgia might experience substantial symptom relief without clinically relevant adverse events with duloxetine or milnacipran.We did not find placebo-controlled studies with other SNRIs than desvenlafaxine, duloxetine and milnacipran.

Antidepressants for chronic non-cancer pain in children and adolescents

BACKGROUND

Pain is a common feature of childhood and adolescence around the world, and for many young people, that pain is chronic. The World Health Organization guidelines for pharmacological treatments for children's persisting pain acknowledge that pain in children is a major public health concern of high significance in most parts of the world. While in the past pain was largely dismissed and was frequently left untreated, views on children's pain have changed over time and relief of pain is now seen as important.We designed a suite of seven reviews on chronic non-cancer pain and cancer pain (looking at antidepressants, antiepileptic drugs, non-steroidal anti-inflammatory drugs, opioids, and paracetamol) in order to review the evidence for children's pain utilising pharmacological interventions.As the leading cause of morbidity in the world today, chronic disease (and its associated pain) is a major health concern. Chronic pain (that is pain lasting three months or longer) can arise in the paediatric population in a variety of pathophysiological classifications (nociceptive, neuropathic, or idiopathic) from genetic conditions, nerve damage pain, chronic musculoskeletal pain, and chronic abdominal pain, as well as for other unknown reasons.Antidepressants have been used in adults for pain relief and pain management since the 1970s. The clinical impression from extended use over many years is that antidepressants are useful for some neuropathic pain symptoms, and that effects on pain relief are divorced and different from effects on depression; for example, the effects of tricyclic antidepressants on pain may occur at different, and often lower, doses than those on depression. Amitriptyline is one of the most commonly used drugs for treating neuropathic pain in the UK.

OBJECTIVES

To assess the analgesic efficacy and adverse events of antidepressants used to treat chronic non-cancer pain in children and adolescents aged between birth and 17 years, in any setting.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online, MEDLINE via Ovid, and Embase via Ovid from inception to 6 September 2016. We also searched the reference lists of retrieved studies and reviews, and searched online clinical trial registries.

SELECTION CRITERIA

Randomised controlled trials, with or without blinding, of any dose and any route, treating chronic non-cancer pain in children and adolescents, comparing any antidepressant with placebo or an active comparator.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility. We planned to use dichotomous data to calculate risk ratio and number needed to treat for one additional event, using standard methods. We assessed the evidence using GRADE and created three 'Summary of findings' tables.

MAIN RESULTS

We included four studies with a total of 272 participants (6 to 18 years of age) who had either chronic neuropathic pain, complex regional pain syndrome type 1, irritable bowel syndrome, functional abdominal pain, or functional dyspepsia. All of the studies were small. One study investigated amitriptyline versus gabapentin (34 participants), two studies investigated amitriptyline versus placebo (123 participants), and one study investigated citalopram versus placebo (115 participants). Due to a lack of available data we were unable to complete any quantitative analysis.Risk of bias for the four included studies varied, due to issues with randomisation and allocation concealment (low to unclear risk); blinding of participants, personnel, and outcome assessors (low to unclear risk); reporting of results (low to unclear risk); and size of the study populations (high risk). We judged the remaining domains, attrition and other potential sources of bias, as low risk of bias. Primary outcomesNo studies reported our primary outcomes of participant-reported pain relief of 30% or greater or 50% or greater (very low-quality evidence).No studies reported on Patient Global Impression of Change (very low-quality evidence).We rated the overall quality of the evidence (GRADE rating) as very low. We downgraded the quality of the evidence by three levels to very low because there was no evidence to support or refute. Secondary outcomesAll studies measured adverse events, with very few reported (11 out of 272 participants). All but one adverse event occurred in the active treatment groups (amitriptyline, citalopram, and gabapentin). Adverse events in all studies, across active treatment and comparator groups, were considered to be a mild reaction, such as nausea, dizziness, drowsiness, tiredness, and abdominal discomfort (very low-quality evidence).There were also very few withdrawals due to adverse events, again all but one from the active treatment groups (very low-quality evidence).No serious adverse events were reported across any of the studies (very low-quality evidence).There were few or no data for our remaining secondary outcomes (very low-quality evidence).We rated the overall quality of the evidence (GRADE rating) for these secondary outcomes as very low. We downgraded the quality of the evidence by three levels to very low due to too few data and the fact that the number of events was too small to be meaningful.

AUTHORS' CONCLUSIONS

We identified only a small number of studies with small numbers of participants and insufficient data for analysis.As we could undertake no meta-analysis, we are unable to comment about efficacy or harm from the use of antidepressants to treat chronic non-cancer pain in children and adolescents. Similarly, we cannot comment on our remaining secondary outcomes: Carer Global Impression of Change; requirement for rescue analgesia; sleep duration and quality; acceptability of treatment; physical functioning; and quality of life.There is evidence from adult randomised controlled trials that some antidepressants, such as amitriptyline, can provide some pain relief in certain chronic non-cancer pain conditions.There is no evidence from randomised controlled trials to support or refute the use of antidepressants to treat chronic non-cancer pain in children or adolescents.

Fibromyalgia: Treating Pain in the Juvenile Patient

Presently, evidence for the efficacy of medications for the treatment of juvenile fibromyalgia syndrome (JFMS) is limited. While there are medications approved by the US Food and Drug Administration (duloxetine, milnacipran and pregabalin) for adults with fibromyalgia syndrome, there are none for the treatment of JFMS. A variety of medications have been prescribed for the treatment of JFMS, including (but not limited to) non-opioid analgesics, opioids, anticonvulsants, antidepressants, and muscle relaxants. Psychological therapies, most prominently cognitive behavioral therapy, are the most evidenced-based treatment modalities for JFMS. A multidisciplinary approach, combining pharmacological, behavioral and exercise-based modalities is currently the standard of care for JFMS. In the future, more stringent randomized, controlled trials with longer follow-up periods are needed in order to determine the long-term efficacy and safety of medications in the treatment of JFMS. Additionally, improved recognition of JFMS will allow for better patient recruitment to permit for adequately powered study designs.

Juvenile Fibromyalgia: Different from the Adult Chronic Pain Syndrome?

While a majority of research has focused on adult fibromyalgia (FM), recent evidence has provided insights into the presence and impact of FM in children and adolescents. Commonly referred as juvenile fibromyalgia (JFM), youths, particularly adolescent girls, present with persistent widespread pain and cardinal symptoms observed in adult FM. A majority of youth with JFM continue to experience symptoms into adulthood, which highlights the importance of early recognition and intervention. Some differences are observed between adult and juvenile-onset FM syndrome with regard to comorbidities (e.g., joint hypermobility is common in JFM). Psychological comorbidities are common but less severe in JFM. Compared to adult FM, approved pharmacological treatments for JFM are lacking, but non-pharmacologic approaches (e.g., cognitive-behavioral therapy and exercise) show promise. A number of conceptual issues still remain including (1) directly comparing similarities and differences in symptoms and (2) identifying shared and unique mechanisms underlying FM in adults and youths.

Juvenile Fibromyalgia: A Primary Pain, or Pain Processing, Disorder

Juvenile fibromyalgia (JFM), a chronic disorder of widespread musculoskeletal pain in combination with autonomic, sensory, and cognitive dysfunction, is responsible for considerable morbidity and impaired quality of life in affected patients and their families. Historically, fibromyalgia has been incorrectly characterized as a psychosomatic or psychogenic disorder, but new understanding of the science of pain has demonstrated unambiguously that it is an organic disorder of the pain processing system itself. This new science provides a framework for understanding the pathophysiology of fibromyalgia and for developing rational therapeutic interventions. Advances in JFM include the verification of adult criteria for diagnosis in pediatric patients and the publication of effective therapies based on cognitive and physical neuromuscular intervention. Although primarily nonpharmacologic therapy can include adjunctive medications as well. Finally, the recognition that JFM is a disorder of the central and peripheral nervous systems suggests that neurologists can be important in the care of these patients.

Safety and efficacy of pregabalin in adolescents with fibromyalgia: a randomized, double-blind, placebo-controlled trial and a 6-month open-label extension study

BACKGROUND

Fibromyalgia (FM) is a common pain condition characterized by widespread musculoskeletal pain and tenderness. Pregabalin is an approved treatment for adults in the United States, but there are no approved treatments for adolescents with FM.

METHODS

This was a 15-week, randomized, double-blind, placebo-controlled study and 6-month open-label safety trial of flexible-dose pregabalin (75-450 mg/day) for the treatment of adolescents (12-17 years) with FM. Primary outcome was change in mean pain score at endpoint (scored from 0-10, with 24-h recall). Secondary outcomes included global assessments and measures of pain, sleep, and FM impact.

RESULTS

A total of 107 subjects were randomized to treatment (54 pregabalin, 53 placebo) and 80 completed the study (44 pregabalin, 36 placebo). Improvement in mean pain score at endpoint with pregabalin versus placebo was not statistically significant, treatment difference (95 % CI), -0.66 (-1.51, 0.18), P = 0.121. There were significant improvements with pregabalin versus placebo in secondary outcomes of change in pain score by week (P < 0.05 for 10 of 15 weeks); change in pain score at week 15 (1-week recall), treatment difference (95 % CI), -0.87 (-1.68, -0.05), P = 0.037; and patient global impression of change, 53.1 % versus 29.5 % very much or much improved (P = 0.013). Trends toward improvement with pregabalin in other secondary outcomes measuring pain, sleep, and FM impact were not significant. Safety was consistent with the known profile of pregabalin in adults with FM.

CONCLUSION

Pregabalin did not significantly improve the mean pain score in adolescents with FM. There were significant improvements in secondary outcomes measuring pain and impression of change.

TRIAL REGISTRATIONS

NCT01020474 ; NCT01020526 .