Pregabalin for pain in fibromyalgia in adults

Insomnia and short sleep duration, but not chronotype, is associated with chronic widespread pain: Mendelian randomization study

OBJECTIVES

Sleep disturbance has been associated with chronic widespread pain (CWP), but their causal relationship remains unclear. We aimed to examine the causal relationship and direction between CWP and sleep traits, namely insomnia, sleep duration and chronotype, using Mendelian Randomization.

METHOD

We used genetic association data from ~0.5 million individuals and up to 1.8 million controls from the UK Biobank (UKB). All traits were defined predominantly by self-report. Short sleep duration was defined as average ≤6 hours per 24 hours. Chronotype refers to the inclination to sleep at certain times where some wake and go to bed early ('morning' person), and others wake and go to sleep later ('evening' person). To permit use of the largest available genetic association data, we used the Causal Analysis Using Summary Effect estimates (CAUSE) method, which allows for sample overlap.

RESULTS

Insomnia (OR 1.009, 95% credible interval 1.005, 1.014; p = 0.018 that the causal model is a better fit than non-causal model) and short sleep duration (OR 1.060, 95%CrI 1.038, 1.083; p = 0.040) were causally associated with increased risk of CWP, with limited evidence for reverse causation. There was no evidence in support of long sleep duration or chronotype being associated with CWP.

CONCLUSIONS

This study suggest that insomnia and short sleep duration (≤6 hours) are associated with an increased risk of CWP. Improving short sleep duration and insomnia, rather than chronotype, may be effective in reducing the risk of CWP, although these results should be replicated in epidemiological and interventional studies.

Direct-to-Consumer Educational Brochures to Promote Gabapentinoid Deprescribing in Older Adults

This study examines gabapentinoid deprescribing using a novel approach of direct-to-consumer educational brochures intended to empower older adults to initiate a discussion on gabapentinoid risks and tapering.

Comparison of Cannabis-Based Medicinal Product Formulations for Fibromyalgia: A Cohort Study

This cohort study aims to assess the outcomes of fibromyalgia patients enrolled in the UK Medical Cannabis Registry prescribed a homogenous selection of cannabis-based medicinal products (CBMPs). A cohort study of fibromyalgia patients treated with oils (Adven®, Curaleaf International, UK), dried flower (Adven®, Curaleaf International, UK) or both CBMPs was performed. Primary outcomes were changes from baseline at 1, 3, 6 and 12 months in validated patient-reported outcome measures. Secondary outcomes included descriptive analysis of adverse events. One hundred and forty-eight participants were treated with oils (n = 77; 52.03%), dried flower (n = 14; 9.46%) or both (n = 57; 38.51%). Improvements in the generalized anxiety disorder-7 questionnaire, single-item sleep quality scale, fibromyalgia symptom severity score and EQ-5D-5L Index values were observed at each follow up period compared to baseline (p < 0.050). Thirty-six (24.32%) patients experienced 648 adverse events. Improvements were observed across all primary outcomes with no differences observed across different formulations of CBMPs. Adverse events were reported by one-quarter of participants and were more likely to reported by cannabis naïve patients. This present work through focusing on a homogeneous group of CBMPs can help inform randomized controlled trials after observing signals of improvement associated with a specific cultivar of CBMPs.

Risk of adverse outcomes during gabapentinoid therapy and factors associated with increased risk in UK primary care using the clinical practice research datalink: a cohort study

ABSTRACT

Growing evidence from pharmacovigilance data and postmortem toxicology reports highlights the misuse potential of gabapentinoids. This study aimed to investigate the risk of serious adverse outcomes (drug misuse, overdose, major trauma), and their risk factors, in primary care patients who are prescribed gabapentinoids. Using the UK Clinical Practice Research Datalink, a matched cohort study calculated adverse event rates separately for gabapentinoid-exposed and unexposed cohorts. In the exposed cohort, event rates for exposure to a range of potential risk factors were calculated. Event rates were compared using Cox proportional hazards models, adjusted for age, sex, deprivation, previous mental health diagnosis, and coprescribing with potentially interacting medicines. Substance misuse (gabapentin adjusted hazard ratio [95% CI]: 2.40 [2.25-2.55]), overdose (2.99 [2.56-3.49]), and major trauma (0-2.5 years: 1.35 [1.28-1.42]; 2.5 to 10 years: 1.73 [1.56-1.95]) were more common among patients prescribed gabapentinoids than matched individuals who were not. The association with overdose was stronger for pregabalin than gabapentin. All adverse outcomes were significantly associated with smoking, history of substance misuse, overdose, or a mental health condition and prescription of opioids, benzodiazepines, antidepressants, and Z-drug hypnotics (eg, gabapentin hazard ratios for association of concurrent opioid use: misuse 1.49 [1.47-1.51]; overdose 1.87 [1.78-1.96]; major trauma 1.28 [1.26-1.30]). Our findings highlight the importance of careful patient selection when prescribing gabapentinoids and the need to educate prescribers about the risks of these drugs, particularly in combination with other central nervous system depressants.

Quality of Life Among Hospitalized Fibromyalgia Older Adults: a Case-Control Study

Background

Only few studies addressed the topic of Fibromyalgia Syndrome (FMS) effects on geriatric population quality of life and drug usage. The objective of this study was to demonstrate the significant impact of FMS in terms of quality of life (QOL) in geriatric aged patients.

Methods

80 patients were studied, 40 with FMS according to FMS 2016 classification criteria, and 40 non-FMS controls. The patients were all above the age of 65 years. The FMS and control group completed Widespread Pain Index (WPI) and Symptom Severity Score (SSS). Three questionnaires, Fibromyalgia Impact Questionnaire (FIQ), Short Form (SF-36) Questionnaire, and Health Assessment Questionnaire Disability Index (HAQ-DI) were completed. These with additional medical records were used to classify symptoms and severity in both groups.

Results

Fibromyalgia patients demonstrated significant higher disability scores, (FIQ of 79.5 vs. 33.9, p<.01, and HAQ-DI of 2.00 vs. 1.00, p<.01 for FMS vs. non-FMS, respectively), and lower social functioning in comparison to non-FMS controls (SF-36 of social functioning 0.31 vs. 0.92, p<.01 for FMS vs. non-FMS, respectively). The FMS group had a higher use of pain management medications (opioid use of 12 patients vs. 0, p<.01, use of non-steroidal anti-inflammatory drugs by 11 FMS patients vs. 4 non-FMS controls, p<.01).

Conclusions

Patients with FMS older than 65 years of age demonstrate poorer outcomes and worse symptoms in comparison to matched-aged non-FMS control group. An association was found between FMS and the effect on the quality of life in this population.

Diosmetin attenuates fibromyalgia-like symptoms in a reserpine-induced model in mice

Fibromyalgia is a potentially disabling idiopathic disease characterized by widespread chronic pain associated with comorbidities such as fatigue, anxiety, and depression. Current therapeutic approaches present adverse effects that limit adherence to therapy. Diosmetin, an aglycone of the flavonoid glycoside diosmin found in citrus fruits and the leaves of Olea europaea L., has antinociceptive, anti-inflammatory, and antioxidant properties. Here, we investigated the effect of diosmetin on nociceptive behaviors and comorbidities in an experimental fibromyalgia model induced by reserpine in mice. To induce the experimental fibromyalgia model, a protocol of subcutaneous injections of reserpine (1 mg/kg) was used once a day for three consecutive days in adult male Swiss mice. Mice received oral diosmetin on the fourth day after the first reserpine injection. Nociceptive (mechanical allodynia, muscle strength, and thermal hyperalgesia) and comorbid (depressive-like and anxiety behavior) parameters were evaluated. Potential adverse effects associated with diosmetin plus reserpine (locomotor alteration, cataleptic behavior, and body weight and temperature changes) were also evaluated. Oral diosmetin (0.015-1.5 mg/kg) reduced the mechanical allodynia, thermal hyperalgesia, and loss of muscle strength induced by reserpine. Diosmetin (0.15 mg/kg) also attenuated depressive-like and anxiety behaviors without causing locomotor alteration, cataleptic behavior, and alteration in weight and body temperature of mice. Overall, diosmetin can be an effective and safe therapeutic alternative to treat fibromyalgia symptoms, such as pain, depression and anxiety.

Beyond the Pain: A Systematic Narrative Review of the Latest Advancements in Fibromyalgia Treatment

Fibromyalgia is a complex chronic pain disorder that significantly impacts the quality of life of affected individuals. The etiology of fibromyalgia remains elusive, necessitating effective treatment options. This review aims to provide an overview of current treatment options for fibromyalgia and highlight recent updates in managing the condition. The methodology employed in this systematic review comprised the following key steps. We conducted a comprehensive search across various databases to identify pertinent studies published between 2000 and 2023. Inclusion criteria were defined to specifically target studies involving adult individuals diagnosed with fibromyalgia, with a focus on both pharmacological and non-pharmacological interventions for managing the condition. The review encompassed a range of study types, including randomized controlled trials, observational studies, and systematic reviews. To ensure the quality of the selected studies, we employed appropriate assessment tools, and data extraction and synthesis adhered to established guidelines. This rigorous approach allowed for a robust analysis of the literature on fibromyalgia management. In the course of our review, it became evident that a spectrum of treatment approaches holds significant promise in the management of fibromyalgia. Specifically, pharmacological interventions, including selective serotonin-norepinephrine reuptake inhibitors, anticonvulsants, cannabinoids, tropisetron, and sodium oxybate, have exhibited substantial potential in alleviating fibromyalgia symptoms. Concurrently, non-pharmacological strategies, such as cognitive-behavioral therapy, exercise regimens, and complementary and alternative therapies, have yielded positive outcomes in improving the condition's management. Recent developments in the field have introduced innovative pharmacological agents like milnacipran and pregabalin, in addition to non-pharmacological interventions like mindfulness-based stress reduction and aquatic exercise, expanding the array of options available to enhance fibromyalgia care and alleviating patient symptoms. Fibromyalgia necessitates a multidisciplinary approach to treatment, encompassing both pharmacological and non-pharmacological interventions. Recent updates in fibromyalgia management offer additional options to alleviate symptoms and improve the quality of life for individuals with fibromyalgia. Healthcare professionals should remain informed about these advancements to provide evidence-based care, addressing the complex symptoms associated with fibromyalgia and enhancing patient outcomes.

Fibromyalgia interventions, obstacles and prospects: narrative review

This review aims to increase awareness and improve understanding, diagnosis, and management of fibromyalgia - a complex, distressing health challenge that significantly impacts people's lives due to its variable nature and lack of clear diagnostic markers. Healthcare professionals must assist those with this condition and improve their general quality of life. Further, they can do a lot to improve the lives of people with Fibromyalgia by resolving diagnostic hurdles, promoting collaboration, supporting patient advocacy, advancing medical technology, and adopting novel approaches.

Deprescribing interventions for gabapentinoids in adults: A scoping review

The emerging issue of rising gabapentinoid misuse is being recognized alongside the lack of current evidence supporting the safe and effective deprescribing of gabapentinoids. This scoping review aimed to assess the extent and nature of gabapentinoid deprescribing interventions in adults, either in reducing dosages, or prescribing of, gabapentinoids. Electronic databases were searched on 23 February 2022 without restrictions. Eligible studies included randomized, non-randomized and observational studies that assessed an intervention aimed at reducing/ceasing the prescription/use of a gabapentinoid in adults for any indication in a clinical setting. The research outcomes investigated the type of intervention, prescribing rates, cessations, patient outcomes and adverse events. Extracted outcome data were categorized as either short (≤3 months), intermediate (>3 but <12 months) or long (≥12 months) term. A narrative synthesis was conducted. The four included studies were conducted in primary and acute care settings. Interventions were of dose-reducing protocols, education and/or pharmacological-based approaches. In the randomized trials, gabapentinoid use could be ceased in at least one third of participants. In the two observational trials, gabapentinoid prescribing rates decreased by 9%. Serious adverse events and adverse events specifically related to gabapentinoids were reported in one trial. No study included patient-focused psychological interventions in the deprescribing process, nor provided any long-term follow-up. This review highlights the lack of existing evidence in this area. Due to limited available data, our review was unable to make any firm judgements on the most effective gabapentinoid deprescribing interventions in adults, highlighting the need for more research in this area.

Neural indices of multimodal sensory and autonomic hyperexcitability in fibromyalgia

Fibromyalgia (FM) is characterized by chronic widespread musculoskeletal pain and psychological distress. Research suggests people with FM experience increased somatosensory sensitization which generalizes to other sensory modalities and may indicate neural hyperexcitability. However, the available evidence is limited, and studies including measures of neural responsivity across sensory domains and both central and peripheral aspects of the neuraxis are lacking. Thirty-nine participants (51.5 ± 13.6 years of age) with no history of neurological disorders, psychosis, visual, auditory, or learning deficits, were recruited for this study. People with FM (N = 19) and control participants (CNT, N = 20) did not differ on demographic variables and cognitive capacity. Participants completed a task that combined innocuous auditory stimuli with electrocutaneous stimulation (ECS), delivered at individually-selected levels that were uncomfortable but not painful. Event-related potentials (ERPs) and electrodermal activity were analyzed to examine the central and sympathetic indices of neural responsivity. FM participants reported greater sensitivity to ECS and auditory stimulation, as well as higher levels of depression, anxiety, ADHD, and an array of pain-related experiences than CNT. In response to ECS, the P50 deflection was greater in FM than CNT participants, reflecting early somatosensory hyperexcitability. The P50 amplitude was positively correlated with the FM profile factor obtained with a principal component analysis. The N100 to innocuous tones and sympathetic reactivity to ECS were greater in FM participants, except in the subgroup treated with gabapentinoids, which aligns with previous evidence of symptomatic improvement with GABA-mimetic medications. These results support the principal tenet of generalized neural hyperexcitability in FM and provide preliminary mechanistic insight into the impact of GABA-mimetic pharmacological therapy on ameliorating the neural excitation dominance.

The Relative Value of Anti-Obesity Medications Compared to Similar Therapies

Purpose

To demonstrate a need for improved health insurance coverage for anti-obesity medications (AOMs) by comparing clinical and economic benefits of obesity treatments to covered medications for selected therapeutic areas.

Methods

Using a grey literature search, we identified and prioritized therapeutic areas and treatment analogues for comparison to obesity. A targeted literature review identified clinical and economic outcomes research across the therapeutic area analogues. Associated comorbidities, clinical evidence, indirect costs (ie, absenteeism and productivity loss), and direct medical costs were evaluated to determine the relative value of treating obesity.

Results

Four therapeutic areas/treatment analogues were selected for comparison to obesity: smoking cessation (varenicline), daytime sleepiness (modafinil), migraines (erenumab), and fibromyalgia (pregabalin). Obesity was associated with 17 comorbidities, more than migraine (9), smoking (8), daytime sleepiness (5), and fibromyalgia (2). Economic burden was greatest for obesity, followed by smoking, with yearly indirect and direct medical costs totaling $676 and $345 billion, respectively. AOMs resulted in cost savings of $2586 in direct medical costs per patient per year (PPPY), greater than that for varenicline at $930 PPPY, modafinil at $1045 PPPY, and erenumab at $468 PPPY; pregabalin utilization increased costs by $924 PPPY. AOMs were covered by 10-16% of United States health insurance plans, compared to 45-59% for the four comparators.

Conclusion

Compared to four therapeutic analogues, obesity represented the highest economic burden and was associated with more comorbidities. AOMs provide greater cost savings compared to selected analogues. However, AOMs have limited formulary coverage. Improved coverage of AOMs may increase access to these treatments and may help address the clinical and economic burden associated with obesity and its comorbidities.

Pregabalin attenuates long-lasting post-inflammatory nociplastic mechanical sensitization in mice

Nociplastic pain, the most recently proposed mechanistic descriptor of chronic pain, is the pain resulting from an altered nociceptive system and network without clear evidence of nociceptor activation, injury or disease in the somatosensory system. As the pain-associated symptoms in many patients suffering from undiagnosed pain would result from the nociplastic mechanisms, it is an urgent issue to develop pharmaceutical therapies that would mitigate the aberrant nociception in nociplastic pain. We have recently reported that a single injection of formalin to the upper lip shows sustained sensitization lasting for more than 12 days at the bilateral hindpaws, where there is no injury or neuropathy in rats. Using the equivalent model in mice, we show that pregabalin (PGB), a drug used for treating neuropathic pain, significantly attenuates this formalin-induced widespread sensitization at the bilateral hindpaws, even on the 6 day after the initial single orofacial injection of formalin. On the 10th day after formalin injection, the hindlimb sensitization before PGB injection was no more significant in mice receiving daily PGB injections, unlike those receiving daily vehicle injections. This result suggests that PGB would act on the central pain mechanisms that undergo nociplastic changes triggered by initial inflammation and mitigate widespread sensitization resulting from the established changes.

Comparative efficacy of amitriptyline, duloxetine and pregabalin for treating fibromyalgia in adults: an overview with network meta-analysis

Treatment recommendations for fibromyalgia (FM) include a range of predominantly pharmacological treatment options designed to ensure the maintenance of symptoms and improvement in the quality of life of these patients. Our aim is to identify and compare the efficacy of amitriptyline (AMT), duloxetine (DLX), and pregabalin (PGB) for reducing pain intensity by 30% (R30%) and 50% (R50%) in adult patients with fibromyalgia. The review was conducted in the Medline/PubMed, Cochrane Library, and Embase databases up to February 2022. This study included systematic reviews (SR) of randomized clinical trials (RCTs) targeting adult patients over 18 years of age diagnosed with fibromyalgia according to the criteria of scientific societies, which include the basic clinical diagnosis characterized by the presence of pressure sensitivity in at least 11 of the 18 tender points, in addition to the presence of widespread musculoskeletal pain for a period longer than 3 months and a general assessment of the patient's health status. Pregnant women and children or adolescents were excluded. The Rob 2.0 tool from the Cochrane Collaboration was used to assess the risk of bias in RCTs. The quality of evidence of the reviews included was assessed according to the Grading of Recommendations Assessment, Development and Evaluation-GRADE. A meta-analysis for the evidence network was performed using the Bayesian approach, which allows simultaneous comparison of all treatment options (medication and dose). The different treatments were ranked according to the response rate according to the surface under the curve (SUCRA), which was expressed as a percentage. The results were presented in tables and figures. The protocol with the detailed methods was registered in PROSPERO (CRD42021229264). Eight systematic reviews were identified, and, from these, 15 clinical trials comparing AMT (n = 273), DLX (n = 2595), and PGB (n = 3,506) against placebo were selected. For the outcome R30%, PGB 450 mg was superior to DLX 30 mg and PGB 150 mg, while DLX 20 mg and 30 mg were not superior to placebo. For the outcome R50%, AMT 25 mg was superior to all other alternatives evaluated. The calculation of the SUCRA indicated that PGB 450 mg was the best performance option for R30% and AMT 25 mg for R50%. PGB 150 mg was the drug with the worst performance in the two outcomes evaluated. The drugs evaluated showed benefits for pain reduction in patients with fibromyalgia. In the absence of direct comparison studies, indirect comparison meta-analyses are an important resource for assisting in clinical decision-making. Our data only provide an indicator of the effectiveness of the three drugs evaluated, but as with other health conditions, tolerability and safety are important for the decision-making process and clinical management. In this regard, we encourage caution in interpreting our data.

Advances in the diagnosis and treatment of sickle cell disease

Sickle cell disease (SCD), which affects approximately 100,000 individuals in the USA and more than 3 million worldwide, is caused by mutations in the βb globin gene that result in sickle hemoglobin production. Sickle hemoglobin polymerization leads to red blood cell sickling, chronic hemolysis and vaso-occlusion. Acute and chronic pain as well as end-organ damage occur throughout the lifespan of individuals living with SCD resulting in significant disease morbidity and a median life expectancy of 43 years in the USA. In this review, we discuss advances in the diagnosis and management of four major complications: acute and chronic pain, cardiopulmonary disease, central nervous system disease and kidney disease. We also discuss advances in disease-modifying and curative therapeutic options for SCD. The recent availability of L-glutamine, crizanlizumab and voxelotor provides an alternative or supplement to hydroxyurea, which remains the mainstay for disease-modifying therapy. Five-year event-free and overall survival rates remain high for individuals with SCD undergoing allogeneic hematopoietic stem cell transplant using matched sibling donors. However, newer approaches to graft-versus-host (GVHD) prophylaxis and the incorporation of post-transplant cyclophosphamide have improved engraftment rates, reduced GVHD and have allowed for alternative donors for individuals without an HLA-matched sibling. Despite progress in the field, additional longitudinal studies, clinical trials as well as dissemination and implementation studies are needed to optimize outcomes in SCD.

Fibromyalgia syndrome: epidemiology, diagnosis and treatment

Fibromyalgia syndrome (FMS) profoundly impacts patients' quality of life with its symptoms and clinical signs. Fibromyalgia syndrome impairs daily living activities, reduces work efficiency and raises health-related costs. Although the prevalence rates vary depending on geographical location and diagnostic criteria, it is a common disorder worldwide. Females have a higher prevalence of fibromyalgia syndrome, with varied rates, and there is an increase in prevalence rates with age. Although its etiopathogenesis has not been fully elucidated, various hypotheses have been proposed that central sensitization is at the core of the process. Fibromyalgia syndrome diagnostic approaches have advanced significantly over time, moving away from pain assessments alone and emphasizing multiple clinical signs of FMS. This condition has raised physicians' and researchers' awareness of non-pain symptoms. Considering the complicated etiopathogenesis of fibromyalgia syndrome, diverse pathways connected with symptoms, and multiple clinical presentations, it becomes clear that drug and non-drug treatments should be chosen in combination.

Piperazinyl Bicyclic Derivatives as Selective Ligands of the α2δ-1 Subunit of Voltage-Gated Calcium Channels

The synthesis and pharmacological activities of a new series of piperazinyl quinazolin-4-(3H)-one derivatives acting toward the α2δ-1 subunit of voltage-gated calcium channels (Ca_vα2δ-1) are reported. Different positions of a micromolar HTS hit were explored, and best activities were obtained for compounds containing a small alkyl group in position 3 of the quinazolin-4-(3H)-one scaffold and a 3-methyl-piperazin-1-yl- or 3,5-dimethyl-piperazin-1-yl-butyl group in position 2. The activity was shown to reside in the R enantiomer of the chain in position 2, and several eutomers reached single digit nanomolar affinities. Final modification of the central scaffold to reduce lipophilicity provided the pyrido[4,3-d]pyrimidin-4(3H)-one 16RR, which showed high selectivity for Ca_vα2δ-1 versus Ca_vα2δ-2, probably linked to its improved analgesic efficacy-safety ratio in mice over pregabalin.

Therapeutic Effects of Ba-Duan-Jin versus Pregabalin for Fibromyalgia Treatment: Protocol for a Randomized Controlled Trial

INTRODUCTION

Fibromyalgia is characterized by multi-focal pain and is associated with fatigue, unrefreshing sleep and psychological impairment. Pregabalin is one of the most frequently used agents in fibromyalgia treatment. However, it has failed to demonstrate benefit over placebo for reducing fatigue and psychological impairment, and may cause adverse effects (e.g. somnolence, dizziness). "Ba-Duan-Jin" (BDJ) is a common form of "Qigong" exercise for health promotion in China. Growing evidence suggests that BDJ may achieve satisfactory control of fibromyalgia-related symptoms in Chinese patients. Therefore, we wish to ascertain if BDJ could overcome the disadvantages of pregabalin.

METHODS

A single-blind randomized controlled trial has been designed which will recruit 104 patients with fibromyalgia (age 18-70 years) with a visual analog scale (VAS) pain score of ≥ 40 mm These patients will be randomly assigned to one of two groups: (1) BDJ group (to undertake guided BDJ exercise and take a placebo capsule) or (2) pregabalin group (to take a pregabalin capsule and receive wellness education and guided muscle-relaxation exercises). The primary endpoint will be changes in the VAS score for pain. The secondary endpoints will be changes in the score for the Revised Fibromyalgia Impact Questionnaire, Multidimensional Fatigue Inventory-20, Pittsburgh Sleep Quality Index, Beck II Depression Inventory, Perceived Stress Scale and Short Form-36 Health Survey Questionnaire. These parameters will be assessed at 0, 4, 8, 12 and 24 weeks of follow-up.

PLANNED OUTCOMES

Our results are expected to provide more clinical evidence for the beneficial effects of BDJ in treating fibromyalgia.

TRIAL REGISTRATION

NCT03797560.

The Italian Society for Rheumatology clinical practice guidelines for the diagnosis and management of fibromyalgia Best practices based on current scientific evidence

Fibromyalgia or fibromyalgia syndrome (FMS) is defined as a central sensitization syndrome characterized by the dysfunction of neurocircuits detecting, transmitting and processing nociceptive stimuli; the prevalent manifestation is musculoskeletal pain. In addition to pain, there are multiple accompanying symptoms, in common with other algo-dysfunctional syndromes, which are reflected in a broad spectrum of somatic, neurocognitive and neuro-vegetative manifestations. An evidence-based approach is essential in FMS management, in order to improve patient health and to reduce its social burden. Since in the last ten years new international guidelines for clinical practice (Clinical Practice Guidelines or CPGs) concerning FMS diagnosis and pharmacological/ non-pharmacological management have been published, the Italian Society of Rheumatology (SIR) has decided to adapt them to the Italian national setting. The framework of the Guidelines International Network Adaptation Working Group was adopted to identify, appraise (AGREE II), synthesize, and customize the most recent CPGs on FMS to the needs of the Italian healthcare context. A working group of rheumatologists from SIR epidemiology unit and FMS experts identified relevant clinical questions to guide the systematic review of the literature. The target audience of these CPGs included physicians and healthcare professionals who manage FMS. The adapted recommendations were finally assessed by an external multidisciplinary panel. From the systematic search in databases (Pubmed/Medline, Embase) and grey literature, 6 CPGs were selected and appraised by two independent raters. The combination of the scientific evidence underlying the original CPGs with expert opinion lead to the development of 17 recommendations. The quality of evidence for each recommendation was reported and their potential impact on clinical practice was assessed. These SIR recommendations are expected to be a valuable aid in the diagnosis and treatment of FMS, as they will contribute to disseminate the best practice on the basis of the current scientific evidence.

Effects of Wearable Transcutaneous Electrical Nerve Stimulation on Fibromyalgia: A Randomized Controlled Trial

Purpose

Fibromyalgia is a chronic condition characterized by widespread pain and interference with daily activities. The aim of this study is to assess the benefit of transcutaneous electrical nerve stimulation (TENS) for persons diagnosed with fibromyalgia.

Patients and Methods

Adults meeting diagnostic criteria for fibromyalgia were randomized in a double-blind trial to receive either an active (n=62) or sham (n=57) wearable TENS device for 3-months. Subjects were classified as having lower or higher pain sensitivity by Quantitative Sensory Testing (QST). Patient Global Impression of Change (PGIC, primary outcome) and secondary efficacy measures including Fibromyalgia Impact Questionnaire (FIQR), Brief Pain Inventory (BPI) and painDETECT questionnaire (PDQ) were assessed at baseline, 6-weeks and 3-months. Treatment effects were determined by a mixed model for repeated measures (MMRM) analysis of the intention-to-treat (ITT) population (N=119). A pre-specified subgroup analysis of pain sensitivity was conducted using an interaction term in the model.

Results

No differences were found between active and sham treatment on PGIC scores at 3-months (0.34, 95% CI [−0.37, 1.04], p=0.351) in the ITT population. However, in subjects with higher pain sensitivity (n=60), PGIC was significantly greater for active treatment compared to sham (1.19, 95% CI [0.24, 2.13], p=0.014). FIQR total score (−7.47, 95% CI [−12.46, −2.48], p=0.003), FIQR pain item (−0.62, 95% CI [−1.17, −0.06], p=0.029), BPI Interference (−0.70, 95% CI [−1.30, −0.11], p=0.021) and PDQ (−1.69, 95% CI [−3.20, −0.18], p=0.028) exhibited significant improvements for active treatment compared to sham in the ITT population. Analgesics use was stable and comparable in both groups.

Conclusion

This study demonstrated modest treatment effects of reduced disease impact, pain and functional impairment from wearable TENS in individuals with fibromyalgia. Subjects with higher pain sensitivity exhibited larger treatment effects than those with lower pain sensitivity. Wearable TENS may be a safe treatment option for people with fibromyalgia.

Clinicaltrials.gov Registration

NCT03714425.

Fibromyalgia in Older Individuals

Fibromyalgia (FM) is a condition of chronic widespread pain (CWP) that can occur throughout the life cycle and is likely underrecognized in older patients. FM is associated with considerable suffering and reduction in quality of life and may occur as a unique condition, but in older patients is most likely to be associated with another medical illness. Understood mechanistically to be a sensitization of the nervous system, recently identified as nociplastic pain, FM is accepted as a valid medical illness that requires a positive diagnosis and directed treatments. The cornerstone of treatments for FM are nonpharmacologic interventions, with the understanding that medications provide only modest benefit for most patients, and with particular concern about adverse effects in older patients. If FM is not recognized, treatments may be misdirected to the other medical condition, with failure to address FM symptoms, leading to overall poor outcome. In contrast, new complaints in older patients should not immediately be attributed to FM, and physicians should be vigilant to ensure that onset of a new illness is not ignored. As FM is most often a lifelong condition, patients should be encouraged to identify their own personal strategies that can attenuate symptoms, especially when symptoms flare. Continued life participation should be the outcome goal.

American Society of Hematology 2020 guidelines for sickle cell disease: management of acute and chronic pain

BACKGROUND

The management of acute and chronic pain for individuals living with sickle cell disease (SCD) is a clinical challenge. This reflects the paucity of clinical SCD pain research and limited understanding of the complex biological differences between acute and chronic pain. These issues collectively create barriers to effective, targeted interventions. Optimal pain management requires interdisciplinary care.

OBJECTIVE

These evidence-based guidelines developed by the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in pain management decisions for children and adults with SCD.

METHODS

ASH formed a multidisciplinary panel, including 2 patient representatives, that was thoroughly vetted to minimize bias from conflicts of interest. The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic reviews. Clinical questions and outcomes were prioritized according to importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel reached consensus on 18 recommendations specific to acute and chronic pain. The recommendations reflect a broad pain management approach, encompassing pharmacological and nonpharmacological interventions and analgesic delivery.

CONCLUSIONS

Because of low-certainty evidence and closely balanced benefits and harms, most recommendations are conditional. Patient preferences should drive clinical decisions. Policymaking, including that by payers, will require substantial debate and input from stakeholders. Randomized controlled trials and comparative-effectiveness studies are needed for chronic opioid therapy, nonopioid therapies, and nonpharmacological interventions.

Genome-wide association study identifies RNF123 locus as associated with chronic widespread musculoskeletal pain

Background and objectives

Chronic widespread musculoskeletal pain (CWP) is a symptom of fibromyalgia and a complex trait with poorly understood pathogenesis. CWP is heritable (48%–54%), but its genetic architecture is unknown and candidate gene studies have produced inconsistent results. We conducted a genome-wide association study to get insight into the genetic background of CWP.

Methods

Northern Europeans from UK Biobank comprising 6914 cases reporting pain all over the body lasting >3 months and 242 929 controls were studied. Replication of three independent genome-wide significant single nucleotide polymorphisms was attempted in six independent European cohorts (n=43 080; cases=14 177). Genetic correlations with risk factors, tissue specificity and colocalisation were examined.

Results

Three genome-wide significant loci were identified (rs1491985, rs10490825, rs165599) residing within the genes Ring Finger Protein 123 (RNF123), ATPase secretory pathway Ca²⁺transporting 1 (ATP2C1) and catechol-O-methyltransferase (COMT). The RNF123 locus was replicated (meta-analysis p=0.0002), the ATP2C1 locus showed suggestive association (p=0.0227) and the COMT locus was not replicated. Partial genetic correlation between CWP and depressive symptoms, body mass index, age of first birth and years of schooling were identified. Tissue specificity and colocalisation analysis highlight the relevance of skeletal muscle in CWP.

Conclusions

We report a novel association of RNF123 locus and a suggestive association of ATP2C1 locus with CWP. Both loci are consistent with a role of calcium regulation in CWP. The association with COMT, one of the most studied genes in chronic pain field, was not confirmed in the replication analysis.

Bicyclic Diazepinones as Dual Ligands of the α2δ-1 Subunit of Voltage-Gated Calcium Channels and the Norepinephrine Transporter

The synthesis and pharmacological activity of a new series of bicyclic diazepinones with dual activity toward the α2δ-1 subunit of voltage-gated calcium channels (Ca_vα2δ-1) and the norepinephrine transporter (NET) are reported. Exploration of the positions amenable for substitution on a nonaminoacidic Ca_vα2δ-1 scaffold allowed the identification of favorable positions for the attachment of NET pharmacophores. Among the patterns explored, attachment of the 2-ethylamino-9-methyl-6-phenyl-6,7,8,9-tetrahydro-5H-pyrimido[4,5-e][1,4]diazepin-5-one framework to the meta-position of the phenyl ring of the 3-methylamino-1-phenylpropoxy and 3-methylamino-1-thiophenylpropoxy moieties provided dual compounds with excellent NET functionality. Alternative bicyclic frameworks were also explored, and some lead molecules were identified, which showed a balanced dual profile and exhibited good ADMET properties.

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.

Patterns of Psychoactive Medication Use in Community-Dwelling Older Adults in the US in 2016: A Descriptive Cross-Sectional Study

Objectives: We aim to quantify any use and long-term use patterns of psychoactive medications and explore differences in use by sociodemographic factors in older adults (60-85 years) using the 2016 Medical Expenditure Panel Survey. Methods: Prevalence estimates of any use and long-term use were calculated. Chi-square and crude odds ratios were calculated to estimate differences in any use and long-term use of psychoactive medication by sociodemographic characteristics of respondents. Results: Thirty percent of older adults in the US reported any use of psychoactive medications. Long-term use was significantly higher in women (28.3% [95% confidence interval: 26.5, 30.2]), white (27.8 [26.1, 29.7]), presently unmarried (27.5 [25.4, 29.7]), and low-income (30.3 [27.7, 32.9]) subgroups than in men (20.5 [18.4, 22.5]), Black (14.7 [12.3, 17.1]), presently married (22.8 [20.7, 24.9]), and high-income (21.1 [19.1, 23.1]) subgroups, respectively. Discussion: Despite continued risks associated with use, long-term use of psychoactive medications is prevalent in the older adult population in the US. Given the increased complexity of pharmacotherapy regimens in this population, enhanced efforts at improving use of psychoactive medications should be intensified.

Long-term safety and efficacy of mirogabalin in Asian patients with postherpetic neuralgia: Results from an open-label extension of a multicenter randomized, double-blind, placebo-controlled trial

OBJECTIVE

Postherpetic neuralgia (PHN) is a condition that results from nerve dysfunction following an episode of acute herpes zoster (shingles). Mirogabalin is a novel, selective oral α2δ ligand that demonstrated safety and efficacy in a multicenter, randomized, double-blind, placebo-controlled 14-week study in Asian patients with PHN. This 52-week, open-label extension study investigated the long-term safety and efficacy of flexible-dosage mirogabalin in Asian patients with PHN.

METHODS

This open-label extension study enrolled patients who completed the placebo-controlled study. Patients started with a dose of 5 mg mirogabalin twice daily (BID), which was followed by a flexible dose of 10 or 15 mg BID. During the study, patients assessed their pain using the Short-Form McGill Pain Questionnaire (SF-MPQ). Adverse events were monitored throughout the study.

RESULTS

Of 239 enrolled patients, 184 (77.0%) completed the study and 185 patients (77.4%) received the 15 mg BID dose most during the treatment duration. Most treatment-emergent adverse events (TEAEs) were mild or moderate. The most common TEAEs were nasopharyngitis, somnolence, dizziness, weight increased, and edema. All SF-MPQ scales decreased from baseline to week 52.

CONCLUSIONS

This study showed the safety and stable pain management of a long-term flexible dosing regimen of mirogabalin 10 or 15 mg twice daily for 52 weeks in patients with PHN. CLINICAL TRIAL REGISTERED AT CLINICALTRIALS.GOV:: NCT02318719.

SUMMARY FOR TABLE OF CONTENTS

Mirogabalin-a novel α2δ oral ligand-was shown to be effective and well tolerated for treating postherpetic neuralgia (PHN) in an Asian multicenter, randomized, double-blind, placebo-controlled, 14-week study. This open-label, 52-week study was conducted as an extension of the double-blind study to demonstrate long-term safety and efficacy of mirogabalin.

Management of functional neurological disorder

Functional neurological disorder (FND) is a common cause of persistent and disabling neurological symptoms. These symptoms are varied and include abnormal control of movement, episodes of altered awareness resembling epileptic seizures and abnormal sensation and are often comorbid with chronic pain, fatigue and cognitive symptoms. There is increasing evidence for the role of neurologists in both the assessment and management of FND. The aim of this review is to discuss strategies for the management of FND by focusing on the diagnostic discussion and general principles, as well as specific treatment strategies for various FND symptoms, highlighting the role of the neurologist and proposing a structure for an interdisciplinary FND service.

Long-term safety and efficacy of mirogabalin in Asian patients with diabetic peripheral neuropathic pain

AIMS/INTRODUCTION

Diabetic peripheral neuropathic pain (DPNP) affects the functionality, mood and sleep patterns of patients with diabetes. Mirogabalin, an α2 δ ligand with a slower dissociation for α2 δ-1 versus α2 δ-2 subunits, showed efficacy and safety in a randomized, double-blind, placebo-controlled, 14-week study in Asian patients with DPNP. This open-label extension study evaluated the long-term safety and efficacy of mirogabalin in Asian patients with DPNP.

MATERIAL AND METHODS

This 52-week open-label extension study was carried out in Japan, Korea and Taiwan in patients with DPNP. Patients received mirogabalin, initiated at 5 mg twice daily and increased to a flexible maintenance dosage of 10 or 15 mg twice daily. Adverse events were monitored throughout the study. Patients provided a self-assessment of pain using the Short-Form McGill Pain Questionnaire.

RESULTS

Of the 214 patients who entered the study, 172 (80.4%) completed the extension study. Of 172 patients who completed the study, 149 received the highest dosage of mirogabalin (15 mg twice daily). The most common treatment-emergent adverse events were nasopharyngitis, diabetic retinopathy, peripheral edema, somnolence, diarrhea, increased weight and dizziness. Most treatment-emergent adverse events were mild or moderate in severity. The incidence of treatment-emergent adverse events leading to treatment discontinuation was 13.1%. The visual analog scale and all other Short-Form McGill Pain Questionnaire subscales (sensory score, affective score, total score and present pain intensity) generally decreased over time from baseline until week 52.

CONCLUSIONS

This extension study showed the safety and efficacy of a long-term flexible dosing regimen of mirogabalin 10 or 15 mg twice daily in patients with DPNP.

Pregabalin as a Pain Therapeutic: Beyond Calcium Channels

Initially developed to generate new treatments for epilepsy, gabapentin, and pregabalin (“gabapentinoids”) were engineered to mimic the action of GABA and to modulate GABA metabolism. Rather than their intended pharmacological action on GABA neurotransmission, instead, they exhibit a high affinity for the α2δ-1 and α2δ-2 subunits of voltage-activated calcium channels, wherein binding of gabapentinoids inhibits cellular calcium influx and attenuates neurotransmission. Despite a lack of activity on GABA levels, gabapentin and pregabalin are effective at suppressing seizures and subsequently approved as a new class of antiepileptic therapy for partial-onset epilepsy. Through the same hypothesized molecular mechanism and by controlling neuronal hyperexcitability, gabapentinoids demonstrate clear efficacy in pain management, which has arguably been their most extensively prescribed application to date. In this review, we focus on pregabalin as a second-generation gabapentinoid widely employed in the treatment of a variety of pain conditions. We also discuss the wider functional roles of α2δ subunits and the contributions that pregabalin might play in affecting physiological and pathophysiological processes.

Gabapentinoids: pharmacokinetics, pharmacodynamics and considerations for clinical practice

The gabapentinoids are often recommended as first-line treatments for the management of neuropathic pain. The differing pharmacodynamic and pharmacokinetic profiles can have implications for clinical practice. This article has summarised these key differences. In addition to their use in managing neuropathic pain, gabapentinoids are increasingly being used for off-label conditions despite the lack of evidence. Prescription rates for off-label conditions have overtaken that for on-label use. Similarly, the use of gabapentinoids in the perioperative period is now embedded in clinical practice despite conflicting evidence. This article summarises the risks associated with this increasing use. There is increasing evidence of the potential to cause harm in vulnerable populations such as the elderly and increasing prevalence of abuse. The risk of respiratory depression in combination with opioids is of particular concern in the context of the current opioid crisis. This article describes the practical considerations involved that might help guide appropriate prescribing practices.

A Multicenter, Prospective, Randomized, Placebo-Controlled, Double-Blind Study of a Novel Pain Management Device, AT-02, in Patients with Fibromyalgia

Objectives

Existing treatments for fibromyalgia have limited efficacy, and only a minority of individuals clinically respond to any single intervention. This study was a prospective, multicenter, randomized, double-blind, controlled clinical trial to evaluate the feasibility of alternating magnetic field therapy in fibromyalgia patients by comparing the Angel Touch device (AT-02) with a sham control (S-01).

Methods

Two sites enrolled 44 subjects with diagnosed fibromyalgia. After informed consent, subjects taking prohibited concomitant drugs underwent a washout period of two or more weeks. All subjects then began a one-week run-in period. Numerical rating scale (NRS) pain scores were collected without device intervention for one day, followed by S-01 application to four or more painful sites for 10 minutes at each site, twice daily for six days. Subjects were then randomized to AT-02 or S-01, applied to four or more painful sites for 10 minutes at each site, twice daily for eight weeks. NRS scores were obtained twice daily during the entire treatment period.

Results

The primary end point (change in NRS ± SD at week 8 vs baseline) was –0.94 ± 1.33 in the AT-02 group and –0.22 ± 1.38 in the S-01 group. A trend toward a between-group difference in eight-week NRS scores favored the AT-02 group (–0.73, 95% confidence interval = –1.56 to 0.11, P = 0.086). An adjusted repeated measure analysis detected a significant difference in NRS scores (P = 0.039).

Conclusions

The reduction in NRS scores for AT-02 relative to sham was comparable to reductions observed in meta-analyses of fibromyalgia drug therapy. The unadjusted results and the persistence of the pain score reductions remain encouraging.

Involvement of TRPV1 and the efficacy of α-spinasterol on experimental fibromyalgia symptoms in mice

Fibromyalgia is characterised mainly by symptoms of chronic widespread pain and comorbidities like depression. Although these symptoms cause a notable impact on the patient's quality of life, the underlying aetiology and pathophysiology of this disease remain incompletely elucidated. The transient receptor potential vanilloid type 1 (TRPV1) is a polymodal receptor that is involved in the development of nociceptive and depressive behaviours, while α-spinasterol, a multitarget TRPV1 antagonist and cyclooxygenase inhibitor, presents antinociceptive and antidepressant effects. The present study investigated the involvement of the TRPV1 channel and the possible effects of α-spinasterol on nociceptive and depressive-like behaviours in an experimental fibromyalgia model. The fibromyalgia model was induced with a subcutaneous (s.c.) injection of reserpine (1 mg/kg) once daily for 3 consecutive days in male Swiss mice. Reserpine administration depleted monoamines and caused mechanical allodynia. This dysfunction was inhibited by SB-366791 (1 mg/kg, oral route [p.o.]), a selective TRPV1 antagonist, with a maximum inhibition (I_max) of 73.4 ± 15.5%, or by the single or 3-day-repeated administration of α-spinasterol (0.3 mg/kg, p.o.), with an I_max of 72.8 ± 17.8% and 78.9 ± 32.9%, respectively. SB-366791 also inhibited the increase of the reserpine-induced immobility time, with an I_max of 100%, while α-spinasterol inhibited this parameter with an I_max of 98.2 ± 21.5% and 100%, by single or repeated administration, respectively. The reserpine-induced mechanical allodynia and the thermal hyperalgesia were abolished by TRPV1-positive fibers desensitization induced by previous resiniferatoxin (RTX) administration. In summary, the TRPV1 channel is involved in the development and maintenance of nociception and depressive-like behaviours in a fibromyalgia model, while the α-spinasterol has therapeutic potential to treat the pain and depression symptoms in fibromyalgia patients.

CSF levels of apolipoprotein C1 and autotaxin found to associate with neuropathic pain and fibromyalgia

Objective

Neuropathic pain and fibromyalgia are two common and poorly understood chronic pain conditions that lack satisfactory treatments, cause substantial suffering and societal costs. Today, there are no biological markers on which to base chronic pain diagnoses, treatment choices or to understand the pathophysiology of pain for the individual patient. This study aimed to investigate cerebrospinal fluid (CSF) protein profiles potentially associated with fibromyalgia and neuropathic pain.

Methods

CSF samples were collected from 25 patients with neuropathic pain (two independent sets, n=14 patients for discovery, and n=11 for verification), 40 patients with fibromyalgia and 134 controls without neurological disease from two different populations. CSF protein profiling of 55 proteins was performed using antibody suspension bead array technology.

Results

We found increased levels of apolipoprotein C1 (APOC1) in CSF of neuropathic pain patients compared to controls and there was a trend for increased levels also in fibromyalgia patients. In addition, levels of ectonucleotide pyrophosphatase family member 2 (ENPP2, also referred to as autotaxin) were increased in the CSF of fibromyalgia patients compared to all other groups including patients with neuropathic pain.

Conclusion

The increased levels of APOC1 and ENPP2 found in neuropathic pain and fibromyalgia patients may shed light on the underlying mechanisms of these conditions. Further investigation is required to elucidate their role in maintaining pain and other main symptoms of these disorders.

Flexibility exercise training for adults with fibromyalgia

BACKGROUND

Exercise training is commonly recommended for adults with fibromyalgia. We defined flexibility exercise training programs as those involving movements of a joint or a series of joints, through complete range of motion, thus targeting major muscle-tendon units. This review is one of a series of reviews updating the first review published in 2002.

OBJECTIVES

To evaluate the benefits and harms of flexibility exercise training in adults with fibromyalgia.

SEARCH METHODS

We searched the Cochrane Library, MEDLINE, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), PEDro (Physiotherapy Evidence Database), Thesis and Dissertation Abstracts, AMED (Allied and Complementary Medicine Database), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), and ClinicalTrials.gov up to December 2017, unrestricted by language, and we reviewed the reference lists of retrieved trials to identify potentially relevant trials.

SELECTION CRITERIA

We included randomized trials (RCTs) including adults diagnosed with fibromyalgia based on published criteria. Major outcomes were health-related quality of life (HRQoL), pain intensity, stiffness, fatigue, physical function, trial withdrawals, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected articles for inclusion, extracted data, performed 'Risk of bias' assessments, and assessed the certainty of the body of evidence for major outcomes using the GRADE approach. All discrepancies were rechecked, and consensus was achieved by discussion.

MAIN RESULTS

We included 12 RCTs (743 people). Among these RCTs, flexibility exercise training was compared to an untreated control group, land-based aerobic training, resistance training, or other interventions (i.e. Tai Chi, Pilates, aquatic biodanza, friction massage, medications). Studies were at risk of selection, performance, and detection bias (due to lack of adequate randomization and allocation concealment, lack of participant or personnel blinding, and lack of blinding for self-reported outcomes). With the exception of withdrawals and adverse events, major outcomes were self-reported and were expressed on a 0-to-100 scale (lower values are best, negative mean differences (MDs) indicate improvement). We prioritized the findings of flexibility exercise training compared to land-based aerobic training and present them fully here.Very low-certainty evidence showed that compared with land-based aerobic training, flexibility exercise training (five trials with 266 participants) provides no clinically important benefits with regard to HRQoL, pain intensity, fatigue, stiffness, and physical function. Low-certainty evidence showed no difference between these groups for withdrawals at completion of the intervention (8 to 20 weeks).Mean HRQoL assessed on the Fibromyalgia Impact Questionnaire (FIQ) Total scale (0 to 100, higher scores indicating worse HRQoL) was 46 mm and 42 mm in the flexibility and aerobic groups, respectively (2 studies, 193 participants); absolute change was 4% worse (6% better to 14% worse), and relative change was 7.5% worse (10.5% better to 25.5% worse) in the flexibility group. Mean pain was 57 mm and 52 mm in the flexibility and aerobic groups, respectively (5 studies, 266 participants); absolute change was 5% worse (1% better to 11% worse), and relative change was 6.7% worse (2% better to 15.4% worse). Mean fatigue was 67 mm and 71 mm in the aerobic and flexibility groups, respectively (2 studies, 75 participants); absolute change was 4% better (13% better to 5% worse), and relative change was 6% better (19.4% better to 7.4% worse). Mean physical function was 23 points and 17 points in the flexibility and aerobic groups, respectively (1 study, 60 participants); absolute change was 6% worse (4% better to 16% worse), and relative change was 14% worse (9.1% better to 37.1% worse). We found very low-certainty evidence of an effect for stiffness. Mean stiffness was 49 mm to 79 mm in the flexibility and aerobic groups, respectively (1 study, 15 participants); absolute change was 30% better (8% better to 51% better), and relative change was 39% better (10% better to 68% better). We found no evidence of an effect in all-cause withdrawal between the flexibility and aerobic groups (5 studies, 301 participants). Absolute change was 1% fewer withdrawals in the flexibility group (8% fewer to 21% more), and relative change in the flexibility group compared to the aerobic training intervention group was 3% fewer (39% fewer to 55% more). It is uncertain whether flexibility leads to long-term effects (36 weeks after a 12-week intervention), as the evidence was of low certainty and was derived from a single trial.Very low-certainty evidence indicates uncertainty in the risk of adverse events for flexibility exercise training. One adverse effect was described among the 132 participants allocated to flexibility training. One participant had tendinitis of the Achilles tendon (McCain 1988), but it is unclear if the tendinitis was a pre-existing condition.

AUTHORS' CONCLUSIONS

When compared with aerobic training, it is uncertain whether flexibility improves outcomes such as HRQoL, pain intensity, fatigue, stiffness, and physical function, as the certainty of the evidence is very low. Flexibility exercise training may lead to little or no difference for all-cause withdrawals. It is also uncertain whether flexibility exercise training has long-term effects due to the very low certainty of the evidence. We downgraded the evidence owing to the small number of trials and participants across trials, as well as due to issues related to unclear and high risk of bias (selection, performance, and detection biases). While flexibility exercise training appears to be well tolerated (similar withdrawal rates across groups), evidence on adverse events was scarce, therefore its safety is uncertain.

Functional Somatic Symptoms

BACKGROUND

Approximately 10% of the general population and around one third of adult patients in clinical populations suffer from functional somatic symptoms. These take many forms, are often chronic, impair everyday functioning as well as quality of life, and are cost intensive.

METHODS

The guideline group (32 medical and psychological professional societies, two patients' associations) carried out a systematic survey of the literature and ana- lyzed 3795 original articles and 3345 reviews. The aim was to formulate empirically based recommendations that were practical and user friendly.

RESULTS

Because of the variation in course and symptom severity, three stages of treatment are distinguished. In early contacts, the focus is on basic investigations, reassurance, and advice. For persistent burdensome symptoms, an extended, simultaneous and equitable diagnostic work-up of physical and psychosocial factors is recommended, together with a focus on information and self-help. In the pres- ence of severe and disabling symptoms, multimodal treatment includes further elements such as (body) psychotherapeutic and social medicine measures. Whatever the medical specialty, level of care, or clinical picture, an empathetic professional attitude, reflective communication, information, a cautious, restrained approach to diagnosis, good interdisciplinary cooperation, and above all active interventions for self-efficacy are usually more effective than passive, organ- focused treatments.

CONCLUSION

The cornerstones of diagnosis and treatment are biopsychosocial ex- planatory models, communication, self-efficacy, and interdisciplinary mangagement. This enables safe and efficient patient care from the initial presentation onwards, even in cases where the symptoms cannot yet be traced back to specific causes.

Characterization of Cancer-Induced Nociception in a Murine Model of Breast Carcinoma

Severe and poorly treated pain often accompanies breast cancer. Thus, novel mechanisms involved in breast cancer-induced pain should be investigated. Then, it is necessary to characterize animal models that are reliable with the symptoms and progression of the disease as observed in humans. Explaining cancer-induced nociception in a murine model of breast carcinoma was the aim of this study. 4T1 (104) lineage cells were inoculated in the right fourth mammary fat pad of female BALB/c mice; after this, mechanical and cold allodynia, or mouse grimace scale (MGS) were observed for 30 days. To determine the presence of bone metastasis, we performed the metastatic clonogenic test and measure calcium serum levels. At 20 days after tumor induction, the antinociceptive effect of analgesics used to relieve pain in cancer patients (acetaminophen, naproxen, codeine or morphine) or a cannabinoid agonist (WIN 55,212-2) was tested. Mice inoculated with 4T1 cells developed mechanical and cold allodynia and increased MGS. Bone metastasis was confirmed using the clonogenic assay, and hypercalcemia was observed 20 days after cells inoculation. All analgesic drugs reduced the mechanical and cold allodynia, while the MGS was decreased only by the administration of naproxen, codeine, or morphine. Also, WIN 55,212-2 improved all nociceptive measures. This pain model could be a reliable form to observe the mechanisms of breast cancer-induced pain or to observe the efficacy of novel analgesic compounds.

Comparative Efficacy of Therapeutics for Chronic Cancer Pain: A Bayesian Network Meta-Analysis

PURPOSE

Opioids are the primary choice for managing chronic cancer pain. However, many nonopioid therapies are currently prescribed for chronic cancer pain with little published evidence comparing their efficacy.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) comparing any systemic pharmaceutical intervention and/or combination thereof in treating chronic cancer pain. The primary outcome was global efficacy reported as an odds ratio (OR). The secondary outcome was change in pain intensity reported as a standardized mean difference (SMD).

RESULTS

We included 81 RCTs consisting of 10,003 patients investigating 11 medication classes. Most RCTs (80%) displayed low risk of bias. The top-ranking classes for global efficacy were nonopioid analgesics (network OR, 0.30; 95% credibility interval [CrI], 0.13 to 0.67), nonsteroidal anti-inflammatory drugs (network OR, 0.44; 95% CrI, 0.22 to 0.90), and opioids (network OR, 0.49; 95% CrI, 0.27 to 0.86), whereas the top-ranked interventions were lidocaine (network OR, 0.04; 95% CrI, 0.01 to 0.18; surface under the cumulative ranking curve analysis [SUCRA] score, 98.1), codeine plus aspirin (network OR, 0.22; 95% CrI, 0.08 to 0.63; SUCRA score, 81.1), and pregabalin (network OR, 0.29; 95% CrI, 0.08 to 0.92; SUCRA score, 73.8). In terms of reducing pain intensity, we found that no class was superior to placebo, whereas the following top-ranked interventions were superior to placebo: ziconotide (network SMD, −24.98; 95% CrI, −32.62 to −17.35; SUCRA score, 99.8), dezocine (network SMD, −13.56; 95% CrI, −23.37 to −3.69; SUCRA score, 93.5), and diclofenac (network SMD, −11.22; 95% CrI, −15.91 to −5.80; SUCRA score, 92.9).

CONCLUSION

There are significant differences in efficacy among current regimens for chronic cancer pain. Our evidence suggests that certain nonopioid analgesics and nonsteroidal anti-inflammatory drugs can serve as effectively as opioids in managing chronic cancer pain.

Impact of Polypharmacy on Candidate Biomarker miRNomes for the Diagnosis of Fibromyalgia and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Striking Back on Treatments

Fibromyalgia (FM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are diseases of unknown etiology presenting complex and often overlapping symptomatology. Despite promising advances on the study of miRNomes of these diseases, no validated molecular diagnostic biomarker yet exists. Since FM and ME/CFS patient treatments commonly include polypharmacy, it is of concern that biomarker miRNAs are masked by drug interactions. Aiming at discriminating between drug-effects and true disease-associated differential miRNA expression, we evaluated the potential impact of commonly prescribed drugs on disease miRNomes, as reported by the literature. By using the web search tools SM2miR, Pharmaco-miR, and repoDB, we found a list of commonly prescribed drugs that impact FM and ME/CFS miRNomes and therefore could be interfering in the process of biomarker discovery. On another end, disease-associated miRNomes may incline a patient’s response to treatment and toxicity. Here, we explored treatments for diseases in general that could be affected by FM and ME/CFS miRNomes, finding a long list of them, including treatments for lymphoma, a type of cancer affecting ME/CFS patients at a higher rate than healthy population. We conclude that FM and ME/CFS miRNomes could help refine pharmacogenomic/pharmacoepigenomic analysis to elevate future personalized medicine and precision medicine programs in the clinic.

Pregabalin for neuropathic pain in adults

BACKGROUND

This review updates part of an earlier Cochrane Review titled "Pregabalin for acute and chronic pain in adults", and considers only neuropathic pain (pain from damage to nervous tissue). Antiepileptic drugs have long been used in pain management. Pregabalin is an antiepileptic drug used in management of chronic pain conditions.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of pregabalin for chronic neuropathic pain in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase for randomised controlled trials from January 2009 to April 2018, online clinical trials registries, and reference lists.

SELECTION CRITERIA

We included randomised, double-blind trials of two weeks' duration or longer, comparing pregabalin (any route of administration) with placebo or another active treatment for neuropathic pain, with participant-reported pain assessment.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality and biases. Primary outcomes were: at least 30% pain intensity reduction over baseline; much or very much improved on the Patient Global Impression of Change (PGIC) Scale (moderate benefit); at least 50% pain intensity reduction; or very much improved on PGIC (substantial benefit). We calculated risk ratio (RR) and number needed to treat for an additional beneficial (NNTB) or harmful outcome (NNTH). We assessed the quality of the evidence using GRADE.

MAIN RESULTS

We included 45 studies lasting 2 to 16 weeks, with 11,906 participants - 68% from 31 new studies. Oral pregabalin doses of 150 mg, 300 mg, and 600 mg daily were compared with placebo. Postherpetic neuralgia, painful diabetic neuropathy, and mixed neuropathic pain predominated (85% of participants). High risk of bias was due mainly to small study size (nine studies), but many studies had unclear risk of bias, mainly due to incomplete outcome data, size, and allocation concealment.Postherpetic neuralgia: More participants had at least 30% pain intensity reduction with pregabalin 300 mg than with placebo (50% vs 25%; RR 2.1 (95% confidence interval (CI) 1.6 to 2.6); NNTB 3.9 (3.0 to 5.6); 3 studies, 589 participants, moderate-quality evidence), and more had at least 50% pain intensity reduction (32% vs 13%; RR 2.5 (95% CI 1.9 to 3.4); NNTB 5.3 (3.9 to 8.1); 4 studies, 713 participants, moderate-quality evidence). More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (62% vs 24%; RR 2.5 (95% CI 2.0 to 3.2); NNTB 2.7 (2.2 to 3.7); 3 studies, 537 participants, moderate-quality evidence), and more had at least 50% pain intensity reduction (41% vs 15%; RR 2.7 (95% CI 2.0 to 3.5); NNTB 3.9 (3.1 to 5.5); 4 studies, 732 participants, moderate-quality evidence). Somnolence and dizziness were more common with pregabalin than with placebo (moderate-quality evidence): somnolence 300 mg 16% versus 5.5%, 600 mg 25% versus 5.8%; dizziness 300 mg 29% versus 8.1%, 600 mg 35% versus 8.8%.Painful diabetic neuropathy: More participants had at least 30% pain intensity reduction with pregabalin 300 mg than with placebo (47% vs 42%; RR 1.1 (95% CI 1.01 to 1.2); NNTB 22 (12 to 200); 8 studies, 2320 participants, moderate-quality evidence), more had at least 50% pain intensity reduction (31% vs 24%; RR 1.3 (95% CI 1.2 to 1.5); NNTB 22 (12 to 200); 11 studies, 2931 participants, moderate-quality evidence), and more had PGIC much or very much improved (51% vs 30%; RR 1.8 (95% CI 1.5 to 2.0); NNTB 4.9 (3.8 to 6.9); 5 studies, 1050 participants, moderate-quality evidence). More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (63% vs 52%; RR 1.2 (95% CI 1.04 to 1.4); NNTB 9.6 (5.5 to 41); 2 studies, 611 participants, low-quality evidence), and more had at least 50% pain intensity reduction (41% vs 28%; RR 1.4 (95% CI 1.2 to 1.7); NNTB 7.8 (5.4 to 14); 5 studies, 1015 participants, low-quality evidence). Somnolence and dizziness were more common with pregabalin than with placebo (moderate-quality evidence): somnolence 300 mg 11% versus 3.1%, 600 mg 15% versus 4.5%; dizziness 300 mg 13% versus 3.8%, 600 mg 22% versus 4.4%.Mixed or unclassified post-traumatic neuropathic pain: More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (48% vs 36%; RR 1.2 (1.1 to 1.4); NNTB 8.2 (5.7 to 15); 4 studies, 1367 participants, low-quality evidence), and more had at least 50% pain intensity reduction (34% vs 20%; RR 1.5 (1.2 to 1.9); NNTB 7.2 (5.4 to 11); 4 studies, 1367 participants, moderate-quality evidence). Somnolence (12% vs 3.9%) and dizziness (23% vs 6.2%) were more common with pregabalin.Central neuropathic pain: More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (44% vs 28%; RR 1.6 (1.3 to 2.0); NNTB 5.9 (4.1 to 11); 3 studies, 562 participants, low-quality evidence) and at least 50% pain intensity reduction (26% vs 15%; RR 1.7 (1.2 to 2.3); NNTB 9.8 (6.0 to 28); 3 studies, 562 participants, low-quality evidence). Somnolence (32% vs 11%) and dizziness (23% vs 8.6%) were more common with pregabalin.Other neuropathic pain conditions: Studies show no evidence of benefit for 600 mg pregabalin in HIV neuropathy (2 studies, 674 participants, moderate-quality evidence) and limited evidence of benefit in neuropathic back pain or sciatica, neuropathic cancer pain, or polyneuropathy.Serious adverse events, all conditions: Serious adverse events were no more common with placebo than with pregabalin 300 mg (3.1% vs 2.6%; RR 1.2 (95% CI 0.8 to 1.7); 17 studies, 4112 participants, high-quality evidence) or pregabalin 600 mg (3.4% vs 3.4%; RR 1.1 (95% CI 0.8 to 1.5); 16 studies, 3995 participants, high-quality evidence).

AUTHORS' CONCLUSIONS

Evidence shows efficacy of pregabalin in postherpetic neuralgia, painful diabetic neuralgia, and mixed or unclassified post-traumatic neuropathic pain, and absence of efficacy in HIV neuropathy; evidence of efficacy in central neuropathic pain is inadequate. Some people will derive substantial benefit with pregabalin; more will have moderate benefit, but many will have no benefit or will discontinue treatment. There were no substantial changes since the 2009 review.

Facts and myths pertaining to fibromyalgia

Fibromyalgia (FM) is characterized by chronic widespread pain, unrefreshing sleep, physical exhaustion, and cognitive difficulties. It occurs in all populations throughout the world, with prevalence between 2% and 4% in general populations. Definition, pathogenesis, diagnosis, and treatment of FM remain points of contention, with some even contesting its existence. The various classification systems according to pain medicine, psychiatry, and neurology (pain disease; persistent somatoform pain disorder; masked depression; somatic symptom disorder; small fiber neuropathy; brain disease) mostly capture only some components of this complex and heterogeneous disorder. The diagnosis can be established in most cases by a general practitioner when the symptoms meet recognized criteria and a somatic disease sufficiently explaining the symptoms is excluded. Evidence-based interdisciplinary guidelines give a strong recommendation for aerobic exercise and cognitive behavioral therapies. Drug therapy is not mandatory. Only a minority of patients experience substantial symptom relief with duloxetine, milnacipran, and pregabalin.

Management of Functional Somatic Syndromes and Bodily Distress

Functional somatic syndromes (FSS), like irritable bowel syndrome or fibromyalgia and other symptoms reflecting bodily distress, are common in practically all areas of medicine worldwide. Diagnostic and therapeutic approaches to these symptoms and syndromes vary substantially across and within medical specialties from biomedicine to psychiatry. Patients may become frustrated with the lack of effective treatment, doctors may experience these disorders as difficult to treat, and this type of health problem forms an important component of the global burden of disease. This review intends to develop a unifying perspective on the understanding and management of FSS and bodily distress. Firstly, we present the clinical problem and review current concepts for classification. Secondly, we propose an integrated etiological model which encompasses a wide range of biopsychosocial vulnerability and triggering factors and considers consecutive aggravating and maintaining factors. Thirdly, we systematically scrutinize the current evidence base in terms of an umbrella review of systematic reviews from 2007 to 2017 and give recommendations for treatment for all levels of care, concentrating on developments over the last 10 years. We conclude that activating, patient-involving, and centrally acting therapies appear to be more effective than passive ones that primarily act on peripheral physiology, and we recommend stepped care approaches that translate a truly biopsychosocial approach into actual management of the patient.

Mirtazapine for fibromyalgia in adults

BACKGROUND

Fibromyalgia is a clinically defined chronic condition of unknown etiology characterised by chronic widespread pain, sleep disturbance, cognitive dysfunction, and fatigue. Many patients report high disability levels and poor quality of life. Drug therapy aims to reduce key symptoms, especially pain, and improve quality of life. The tetracyclic antidepressant, mirtazapine, may help by increasing serotonin and noradrenaline in the central nervous system (CNS).

OBJECTIVES

To assess the efficacy, tolerability and safety of the tetracyclic antidepressant, mirtazapine, compared with placebo or other active drug(s) in the treatment of fibromyalgia in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, SCOPUS, the US National Institutes of Health, and the World Health Organization (WHO) International Clinical Trials Registry Platform for published and ongoing trials, and examined reference lists of reviewed articles, to 9 July 2018.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of any formulation of mirtazapine against placebo, or any other active treatment of fibromyalgia, in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted study characteristics, outcomes of efficacy, tolerability and safety, examined issues of study quality, and assessed risk of bias, resolving discrepancies by discussion. Primary outcomes were participant-reported pain relief (at least 50% or 30% pain reduction), Patient Global Impression of Change (PGIC; much or very much improved), safety (serious adverse events), and tolerability (adverse event withdrawal). Other outcomes were health-related quality of life (HRQoL) improved by 20% or more, fatigue, sleep problems, mean pain intensity, negative mood and particular adverse events. We used a random-effects model to calculate risk difference (RD), standardised mean difference (SMD), and numbers needed to treat. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Three studies with 606 participants compared mirtazapine with placebo (but not other drugs) over seven to 13 weeks. Two studies were at unclear or high risk of bias in six or seven of eight domains. We judged the evidence for all outcomes to be low- or very low-quality because of poor study quality, indirectness, imprecision, risk of publication bias, and sometimes low numbers of events.There was no difference between mirtazapine and placebo for any primary outcome: participant-reported pain relief of 50% or greater (22% versus 16%; RD 0.05, 95% confidence interval (CI) -0.01 to 0.12; three studies with 591 participants; low-quality evidence); no data available for PGIC; only a single serious adverse event for evaluation of safety (RD -0.00, 95% CI -0.01 to 0.02; three studies with 606 participants; very low-quality evidence); and tolerability as frequency of dropouts due to adverse events (3% versus 2%; RD 0.00, 95% CI -0.02 to 0.03; three studies with 606 participants; low-quality evidence).Mirtazapine showed a clinically-relevant benefit compared to placebo for some secondary outcomes: participant-reported pain relief of 30% or greater (47% versus 34%; RD 0.13, 95% CI 0.05 to 0.21; number needed to treat for an additional beneficial outcome (NNTB) 8, 95% CI 5 to 20; three studies with 591 participants; low-quality evidence); participant-reported mean pain intensity (SMD -0.29, 95% CI -0.46 to -0.13; three studies with 591 participants; low-quality evidence); and participant-reported sleep problems (SMD -0.23, 95% CI -0.39 to -0.06; three studies with 573 participants; low-quality evidence). There was no benefit for improvement of participant-reported improvement of HRQoL of 20% or greater (58% versus 50%; RD 0.08, 95% CI -0.01 to 0.16; three studies with 586 participants; low-quality evidence); participant-reported fatigue (SMD -0.02, 95% CI -0.19 to 0.16; two studies with 533 participants; low-quality evidence); participant-reported negative mood (SMD -0.67, 95% CI -1.44 to 0.10; three studies with 588 participants; low-quality evidence); or withdrawals due to lack of efficacy (1.5% versus 0.1%; RD 0.01, 95% CI -0.01 to 0.02; three studies with 605 participants; very low-quality evidence).There was no difference between mirtazapine and placebo for participants reporting any adverse event (76% versus 59%; RD 0.12, 95 CI -0.01 to 0.26; three studies with 606 participants; low-quality evidence). There was a clinically-relevant harm with mirtazapine compared to placebo: in the number of participants with somnolence (42% versus 14%; RD 0.24, 95% CI 0.18 to 0.30; number needed to treat for an additional harmful outcome (NNTH) 5, 95% CI 3 to 6; three studies with 606 participants; low-quality evidence); weight gain (19% versus 1%; RD 0.17, 95% CI 0.11 to 0.23; NNTH 6, 95% CI 5 to 10; three studies with 606 participants; low-quality evidence); and elevated alanine aminotransferase (13% versus 2%; RD 0.13, 95% CI 0.04 to 0.22; NNTH 8, 95% CI 5 to 25; two studies with 566 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

Studies demonstrated no benefit of mirtazapine over placebo for pain relief of 50% or greater, PGIC, improvement of HRQoL of 20% or greater, or reduction of fatigue or negative mood. Clinically-relevant benefits were shown for pain relief of 30% or greater, reduction of mean pain intensity, and sleep problems. Somnolence, weight gain, and elevated alanine aminotransferase were more frequent with mirtazapine than placebo. The quality of evidence was low or very low, with two of three studies of questionable quality and issues over indirectness and risk of publication bias. On balance, any potential benefits of mirtazapine in fibromyalgia were outweighed by its potential harms, though, a small minority of people with fibromyalgia might experience substantial symptom relief without clinically-relevant adverse events.

A pilot study investigating whether quantitative sensory testing alters after treatment in patients with fibromyalgia

Background

Fibromyalgia is a chronic musculoskeletal pain condition that is often associated with sleep disturbances and fatigue. The pathophysiology of fibromyalgia is not understood, but indirect evidence suggests a central dysfunction of the nociceptive modulating system. The aim of this study was to evaluate whether quantitative sensory testing detects a change in pain thresholds in fibromyalgia patient receiving pregabalin treatment.

Methods

A total of 25 patients were recruited for the study and received routine pregabalin, but only 14 patients completed the treatment. Assessment of pressure pain thresholds and changes in conditioned pain modulation using ischaemic pain as a conditioning stimulus were measured at baseline and every 4 weeks for 12 weeks. Fibromyalgia impact questionnaire, PainDETECT and SF-12 were also completed.

Results

Patients with fibromyalgia demonstrated a less-efficient conditioned pain modulation at baseline. An efficient conditioned pain modulation was observed at 1 month and this was maintained until the final visit. Pressure pain thresholds (PPTs) showed a significant improvement from baseline. Patients also reported a similar magnitude of improvements in PainDETECT, fibromyalgia impact questionnaire (FIQ) and its impact on daily life and change in outcome for SF-12.

Conclusion

This pilot study reports an increase in PPTs and improved conditioned pain modulation response after commencing pregabalin, which was maintained at 12 weeks, and this was supported by positive pain scores. Pregabalin is a licenced treatment for fibromyalgia in Europe, and its response to central sensitisation, particularly 'dynamic responses', has not been reported. We conclude that pregabalin has the potential to reduce peripheral and central sensitisation in patients with fibromyalgia, as measured using quantitative sensory testing.

Facts and myths pertaining to fibromyalgia

Fibromyalgia (FM) is characterized by chronic widespread pain, unrefreshing sleep, physical exhaustion, and cognitive difficulties. It occurs in all populations throughout the world, with prevalence between 2% and 4% in general populations. Definition, pathogenesis, diagnosis, and treatment of FM remain points of contention, with some even contesting its existence. The various classification systems according to pain medicine, psychiatry, and neurology (pain disease; persistent somatoform pain disorder; masked depression; somatic symptom disorder; small fiber neuropathy; brain disease) mostly capture only some components of this complex and heterogeneous disorder. The diagnosis can be established in most cases by a general practitioner when the symptoms meet recognized criteria and a somatic disease sufficiently explaining the symptoms is excluded. Evidence-based interdisciplinary guidelines give a strong recommendation for aerobic exercise and cognitive behavioral therapies. Drug therapy is not mandatory. Only a minority of patients experience substantial symptom relief with duloxetine, milnacipran, and pregabalin.

Combination pharmacotherapy for the treatment of fibromyalgia in adults

BACKGROUND

Fibromyalgia is a chronic widespread pain condition affecting millions of people worldwide. Current pharmacotherapies are often ineffective and poorly tolerated. Combining different agents could provide superior pain relief and possibly also fewer side effects.

OBJECTIVES

To assess the efficacy, safety, and tolerability of combination pharmacotherapy compared to monotherapy or placebo, or both, for the treatment of fibromyalgia pain in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase to September 2017. We also searched reference lists of other reviews and trials registries.

SELECTION CRITERIA

Double-blind, randomised controlled trials comparing combinations of two or more drugs to placebo or other comparators, or both, for the treatment of fibromyalgia pain.

DATA COLLECTION AND ANALYSIS

From all studies, we extracted data on: participant-reported pain relief of 30% or 50% or greater; patient global impression of clinical change (PGIC) much or very much improved or very much improved; any other pain-related outcome of improvement; withdrawals (lack of efficacy, adverse events), participants experiencing any adverse event, serious adverse events, and specific adverse events (e.g. somnolence and dizziness). The primary comparison was between combination and one or all single-agent comparators. We also assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We identified 16 studies with 1474 participants. Three studies combined a non-steroidal anti-inflammatory drug (NSAID) with a benzodiazepine (306 participants); two combined amitriptyline with fluoxetine (89 participants); two combined amitriptyline with a different agent (92 participants); two combined melatonin with an antidepressant (164 participants); one combined carisoprodol, paracetamol (acetaminophen), and caffeine (58 participants); one combined tramadol and paracetamol (acetaminophen) (315 participants); one combined malic acid and magnesium (24 participants); one combined a monoamine oxidase inhibitor with 5-hydroxytryptophan (200 participants); and one combined pregabalin with duloxetine (41 participants). Six studies compared the combination of multiple agents with each component alone and with inactive placebo; three studies compared combination pharmacotherapy with each individual component but did not include an inactive placebo group; two studies compared the combination of two agents with only one of the agents alone; and three studies compared the combination of two or more agents only with inactive placebo.Heterogeneity among studies in terms of class of agents evaluated, specific combinations used, outcomes reported, and doses given prevented any meta-analysis. None of the combinations of drugs found provided sufficient data for analysis compared with placebo or other comparators for our preferred outcomes. We therefore provide a narrative description of results. There was no or inadequate evidence in any comparison for primary and secondary outcomes. Two studies only reported any primary outcomes of interest (patient-reported pain relief of 30%, or 50%, or greater). For each 'Risk of bias' item, only half or fewer of studies had unequivocal low risk of bias. Small size and selective reporting were common as high risk of bias.Our GRADE assessment was therefore very low for primary outcomes of pain relief of 30% or 50% or greater, PGIC much or very much improved or very much improved, any pain-related outcome, participants experiencing any adverse event, any serious adverse event, or withdrawing because of an adverse event.Three studies found some evidence that combination pharmacotherapy reduced pain compared to monotherapy; these trials tested three different combinations: melatonin and amitriptyline, fluoxetine and amitriptyline, and pregabalin and duloxetine. Adverse events experienced by participants were not serious, and where they were reported (in 12 out of 16 studies), all participants experienced them, regardless of treatment. Common adverse events were nausea, dizziness, somnolence, and headache.

AUTHORS' CONCLUSIONS

There are few, large, high-quality trials comparing combination pharmacotherapy with monotherapy for fibromyalgia, consequently limiting evidence to support or refute the use of combination pharmacotherapy for fibromyalgia.

Chronic pain patients can be classified into four groups: Clustering-based discriminant analysis of psychometric data from 4665 patients referred to a multidisciplinary pain centre (a SQRP study)

OBJECTIVE

To subgroup chronic pain patients using psychometric data and regress the variables most responsible for subgroup discrimination.

DESIGN

Cross-sectional, registry-based study.

SETTING AND SUBJECTS

Chronic pain patients assessed at a multidisciplinary pain centre between 2008 and 2015.

METHODS

Data from the Swedish quality registry for pain rehabilitation (SQRP) were retrieved and analysed by principal component analysis, hierarchical clustering analysis, and partial least squares-discriminant analysis.

RESULTS

Four subgroups were identified. Group 1 was characterized by low "psychological strain", the best relative situation concerning pain characteristics (intensity and spreading), the lowest frequency of fibromyalgia, as well as by a slightly older age. Group 2 was characterized by high "psychological strain" and by the most negative situation with respect to pain characteristics (intensity and spreading). Group 3 was characterized by high "social distress", the longest pain durations, and a statistically higher frequency of females. The frequency of three neuropathic pain conditions was generally lower in this group. Group 4 was characterized by high psychological strain, low "social distress", and high pain intensity.

CONCLUSIONS

The identification of these four clusters of chronic pain patients could be useful for the development of personalized rehabilitation programs. For example, the identification of a subgroup characterized mainly by high perceived "social distress" raises the question of how to best design interventions for such patients. Differentiating between clinically important subgroups and comparing how these subgroups respond to interventions is arguably an important area for further research.

Gastrointestinal and Hepatic Disease in Fibromyalgia

Fibromyalgia (FM) has historically been associated with several diseases in gastroenterology and hepatology. The most substantiated evidence pertains to irritable bowel syndrome (IBS). The pathogeneses of FM and IBS remain unclear, but it is likely related to dysregulation within the brain-gut axis, resulting in a hyperalgesic state. IBS and FM share other similarities, including a female predominance, fatigue, insomnia, and susceptibility to psychiatric state. These common manifestations and pathogeneses serve as a foundation for overlapping, multidisciplinary treatment modalities.