Allgemeine Behandlungsgrundsätze, Versorgungskoordination und Patientenschulung beim Fibromyalgiesyndrom

[Updated S1 guideline on long/post-COVID: relevant aspects for pain medicine]

BACKGROUND

The S1 guideline on long/post-COVID of the AWMF [German Association of the Medical Scientific Societies] registration number 020-027) was updated in August 2022.

METHODS

Under the coordination of the German Society of Pneumology, the guideline was updated by 21 scientific associations, two professional associations and clinical centers each and one institute and statutory accident insurance each. Each scientific association was responsible for its own chapter. The German Pain Society prepared the chapter "Pain". The coordinators of each chapter performed a selective literature search and also received approval for the chapter within their scientific association. During an internal period of comments, all representatives of the participating institutions could comment on all chapters. The AWMF task force commented on the draft of the guideline, which was then finally approved by the boards of all participating institutions.

RESULTS

Coronavirus disease 2019 (COVID-19) increases the risk of persistent headache and musculoskeletal pain. Long/Post-COVID pain is frequently associated with fatigue and cognitive problems. A specialist assessment might be considered if symptoms with limitations of daily activities persist 3 months after the infection. The diagnostic workup of long/post-COVID-associated pain should be performed according to the standards of pain medicine. Management should follow the pain guidelines of the AWMF.

CONCLUSIONS

The updated S1 guideline on long/post-COVID is a clinical manual which offers orientation for diagnostics and treatment despite limited data.

Effectiveness of non-pharmacological interventions for fibromyalgia and quality of review methods: an overview of Cochrane Reviews

BACKGROUND

Fibromyalgia syndrome (FMS) is defined as chronic widespread pain associated with sleep disorders, cognitive dysfunction, and somatic symptoms present for at least three months and cannot be better explained by another diagnosis.

OBJECTIVES

To examine efficacy and safety of non-pharmacological interventions for FMS in adults reported in Cochrane Reviews, and reporting quality of reviews.

METHODS

Systematic reviews of randomised controlled trials (RCTs) of non-pharmacological interventions for FMS were identified from the Cochrane Database of Systematic Reviews (CDSR 2022, Issue 3 and CDSR 2023 Issue 6). Methodological quality was assessed using the AMSTAR-2 tool and a set of methodological criteria critical for analgesic effects. The primary efficacy outcomes of interest were clinically relevant pain relief, improvement in health-related quality of life (HRQoL), acceptability, safety, and reduction of mobility difficulties as reported by study participants. No pooled analyses were planned. We assumed a clinically relevant improvement was a minimal clinically important difference (MCID) between interventions and controls of 15%, or a SMD of more than 0.2, or a MD of more than 0.5, on a 0 to 10 scale.

RESULTS

Ten Cochrane reviews were eligible, reporting 181 randomized or quasi- randomized trials (11,917 participants, average trial size 66 participants). The reviews examined exercise training, acupuncture, transcutaneous electrical nerve stimulation, and psychological therapies. One review was rated moderate according to AMSTAR 2, seven were rated low and two were rated critically low. All reviews met most of the additional methodological quality criteria. All reviews included studies with patient-reported outcomes for pain. We found low certainty evidence of clinically relevant positive effects of aerobic and mixed exercise training and for cognitive behavioural therapies (CBTs) at reducing mobility difficulties and for mixed exercise training and CBTs for improving HRQoL at the end of the intervention. Number needed to treat for an additional beneficial outcome (NNTB) values for a MCID of 15% ranged between 4 and 9. We found low certainty evidence that was clinically relevant for mixed exercise and CBTs for reducing mobility difficulties at an average follow up of 24 weeks. We found low certainty evidence of clinically relevant positive effects of mixed exercise on HRQoL at an average follow up of 24 weeks. NNTB values for a MCID of 15% ranged from 5 to 11. The certainty of evidence of the acceptability (measured by dropouts) of the different non-pharmacological interventions ranged from very low to moderate and the dropout rate for any reason did not differ across the interventions or the controls, except for biofeedback and movement therapies. All the systematic reviews stated that the reporting of adverse events was inconsistent in the studies analysed (very low certainty evidence).

AUTHORS' CONCLUSIONS

There is low certainty evidence of clinically relevant reduction of mobility difficulties and of improvement of HRQoL among individuals with FMS by aerobic and mixed exercise training and by CBTs at the end of the intervention. There is low certainty evidence that CBTs and mixed exercise training reduces mobility difficulties post-treatment and that mixed exercise training improves HRQoL at follow-up by clinically meaningful scores.

Investigating the Influential Factors of Mild Water-Filtered Infrared-A Whole-Body Hyperthermia for Pain Relief in Fibromyalgia: A Mixed-Methods Approach Focusing on Predictors and Patient Perspectives

Fibromyalgia syndrome (FMS) is a chronic condition characterized by chronic widespread pain, persistent fatigue, and disrupted sleep, significantly impacting well-being. Mild water-filtered infrared-A (wIRA) whole-body hyperthermia (WBH) is emerging as a promising pain management approach to FMS. Within the present randomized controlled trial (ClinicalTrials ID: NCT05135936), FMS patients underwent six sessions of mild wIRA-WBH over 3 weeks. Their pain levels were assessed at baseline and at week 12, while body core temperature and plateau phase duration were monitored during WBH. Qualitative interviews were conducted at week 12. Results from this mixed-methods study revealed that baseline pain intensity and plateau phase duration significantly predicted pain intensity at week 12. Thematic analysis of the interviews revealed diverse patient experiences with the treatment, with all patients reporting improvements in perceived pain and overall well-being. The onset and duration of pain relief varied among individuals. Overall, the findings suggest that the duration of the plateau phase may serve as an indicator for long-term pain reduction, although individual factors may influence treatment outcomes. Despite varying experiences, a prevailing trend of positive patient evaluations emerged. This study sheds light on the potential of wIRA-WBH as a therapeutic option for alleviating pain for and enhancing the well-being of FMS patients.

The Challenge of Fibromyalgia Efficacy of Hypnosis in Alleviating the Invisible Pain: A Narrative Review

Fibromyalgia syndrome (FMS) is a multifaceted and incapacitating functional pain syndrome characterized by continuous, severe, widespread musculoskeletal pain. FMS is associated with other symptoms such as fatigue, nonrestorative sleep, cognitive/emotional dysfunction, and diminished health-related quality of life. The pathogenesis of FMS is still not fully understood, but an increasing amount of evidence supports the link between childhood/adulthood emotional, physical, sexual abuse or neglect and the development of FMS. Managing and treating FMS patients can be challenging because the syndrome is refractory to most treatments. However, psychological interventions, particularly hypnotherapy, have been shown to be effective in the cognitive modulation of fibromyalgic pain. FMS patients may benefit from hypnotherapy alone or in combination with standard medical therapy. Symptom-oriented hypnosis aims to reduce pain, fatigue, sleep problems, anxiety, and depression, while hypnotherapy focuses on resolving emotional conflicts and unresolved traumas associated with FMS. In conclusion, hypnosis may be a useful and safe adjunct tool for managing chronic pain and dysfunctional symptoms in challenging fibromyalgic patients.

Mild Water-Filtered Infrared-A Whole-Body Hyperthermia Reduces Pain in Patients with Fibromyalgia Syndrome-A Randomized Sham-Controlled Trial

The challenging treatment situation of patients with fibromyalgia syndrome (FMS) requires additional therapy options. The effects of water-filtered infrared-A whole-body hyperthermia (WBH) versus sham hyperthermia on pain intensity were investigated in an outpatient setting within a two-armed randomized sham-controlled trial. n = 41 participants aged between 18 and 70 years with a medically confirmed diagnosis of FMS were randomized to WBH (intervention; n = 21) or sham hyperthermia (control; n = 20). Six treatments with mild water-filtered infrared-A WBH over a period of three weeks with at least one day in between treatments were applied. On average, the maximum temperature was 38.7 °C for a duration of approximately 15 min. The control group received exactly the same treatment except that an insulating foil between the patient and the hyperthermia device blocked most of the radiation. Primary outcome was pain intensity measured by the Brief Pain Inventory at week 4. Secondary outcomes included blood cytokine levels and FMS-related core symptoms and quality of life. Pain intensity at week 4 was significantly different between the groups in favor of WBH (p = 0.015). A statistically significant pain reduction in favor of WBH was also found at week 30 (p = 0.002). Mild water-filtered infrared-A WBH effectively reduced pain intensity at the end of treatment and follow-up.

Pain reduction in fibromyalgia syndrome through pairing transcranial direct current stimulation and mindfulness meditation: A randomized, double-blinded, sham-controlled pilot clinical trial

Background

This double-blinded, randomized and sham-controlled pilot clinical trial aimed to investigate the preliminary clinical efficacy and feasibility of combining mindfulness meditation (MM) and transcranial direct current stimulation (tDCS) for pain and associated symptoms in patients with fibromyalgia syndrome (FMS).

Methods

Included FMS patients (age: 33 to 70) were randomized to three different groups to receive either ten daily sessions of anodal tDCS over the left primary motor cortex paired with MM for 20 min (active + MM, n = 10), sham tDCS combined with MM (sham + MM, n = 10) or no intervention (NoT, n = 10). Patients in the bimodal therapy groups received a week of training in MM prior to the stimulation. Participants reported pain intensity, the primary outcome, by filling in a pain diary daily throughout the whole study. They were also evaluated for quality of life, pressure pain sensitivity, psychological wellbeing, sleep quality and sleep quantity. Assessments were performed at three time points (baseline, immediately after treatment and one-month follow-up).

Results

Participants in the active + MM group did not exhibit reduced pain intensity following the bimodal therapy compared to controls. Patients in active group demonstrated clinically meaningful and significantly higher quality of life following the therapeutic intervention than other groups. There was no significant difference among groups regarding pressure pain sensitivity, sleep parameters and psychological scales. The combined treatment was well tolerated among participants, with no serious adverse effects.

Conclusion

This study was the first to pair these two effective non-pharmacological therapies for pain management in FMS. In the light of an underpowered sample size, repetitive anodal tDCS combined with MM did not improve pain or FMS-associated symptoms. However, patients in the active + MM group reported higher quality of life than the control groups. Studies with more participants and longer follow-ups are required to confirm our findings.

Clinical trial registration

[www.drks.de], identifier [DRKS00023490].

The Role of Nutrient Supplementation in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

The multifaceted clinical presentation of fibromyalgia (FM) supports the modern understanding of the disorder as a more global condition than one simply affecting pain sensation. The main pharmacologic therapies used clinically include anti-epileptics and anti-depressants. Conservative treatment options include exercise, myofascial release, psychotherapy, and nutrient supplementation.

METHODS

Narrative review.

RESULTS

Nutrient supplementation is a broadly investigated treatment modality as numerous deficiencies have been linked to FM. Additionally, a proposed link between gut microbiome patterns and chronic pain syndromes has led to studies investigating probiotics as a possible treatment. Despite positive results, much of the current evidence regarding this topic is of poor quality, with variable study designs, limited sample sizes, and lack of control groups.

CONCLUSIONS

The etiology of FM is complex, and has shown to be multi-factorial with genetics and environmental exposures lending influence into its development. Preliminary results are promising, however, much of the existing evidence regarding diet supplementation is of poor quality. Further, more robust studies are needed to fully elucidate the potential of this alternative therapeutic option.

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.

The Role of Vitamin D in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

Fibromyalgia (FM) is a complex disorder characterized primarily by chronic, widespread musculoskeletal pain. Currently, the Food and Drug Administration (FDA) has approved the use of three medications to treat FM: pregabalin, duloxetine, and milnacipran. The pharmaceutical intervention has lacked consistent pain relief among all patients. Therefore, the investigation into alternative treatment options has grown in interest. This narrative review aims to evaluate the evidence regarding vitamin D for the treatment of FM.

METHODS

Narrative review.

RESULTS

Low serum vitamin D has been linked to various chronic pain states. An association between vitamin D deficiency and FM has been reported but is controversial in the literature. Some studies have documented the beneficial effects of vitamin D supplementation on reducing pain symptoms and improving the overall quality of life in those with FM. Despite these positive findings, many of the studies regarding this topic lack adequate power to make substantial conclusions about the effects of vitamin D on FM.

CONCLUSION

Existing studies provide promising results. However, additional high-quality data on vitamin D supplementation is needed before recommendations for pain management can be made. Vitamin D supplementation is inexpensive, has minimal side effects, and can benefit FM patients regardless of its efficacy in pain control. Additionally, high-quality studies are warranted to fully elucidate the potential of vitamin D to manage chronic pain in FM.

A theoretical framework to improve the construct for chronic pain disorders using fibromyalgia as an example

Fibromyalgia (FM) is a frequent, complex condition of chronic musculoskeletal pain with no evidence for biological correlates. For this reason, despite many efforts from the medical community, its construct still appears ill defined. Promising candidate biomarkers are critically reviewed. A research agenda is proposed for developing a clearer construct of FM. The ideal theoretical framework is one of overcoming the illness–disease dichotomy and considering reciprocal interactions between biology and behaviour. This approach may foster research in other fields of pain medicine and of medicine in general.

Suicidal Ideation Profiles in Patients with Fibromyalgia Using Transdiagnostic Psychological and Fibromyalgia-Associated Variables

Several studies have emphasized the heterogeneity of fibromyalgia patients. Furthermore, fibromyalgia patients are considered a high-risk suicide group. The ideation-to-action framework proposes a set of transdiagnostic psychological factors involved in the development of suicidal ideation. The present study aims to explore the existence of different subgroups according to their vulnerability to suicidal ideation through these transdiagnostic psychological variables and a set of variables typically associated with fibromyalgia. In this cross-sectional study, 151 fibromyalgia patients were assessed through the Revised Fibromyalgia Impact Questionnaire, Beck Depression Inventory-II, Plutchik Suicide Risk Scale, Interpersonal Needs Questionnaire, Defeat Scale, Entrapment Scale, Psychache Scale, and Beck Hopelessness Scale. A K-means cluster analysis identified two clusters, one (45.70%) according to a low vulnerability, and a second (54.30%) with a high vulnerability to suicidal ideation. These clusters showed statistically significant differences in suicidal ideation and suicide risk. However, no differences were observed in most socio-demographic variables. In conclusion, fibromyalgia patients who present a clinical condition characterized by a moderate-high degree of physical dysfunction, overall disease impact and intensity of fibromyalgia-associated symptoms, along with a high degree of perceived burdensomeness, thwarted belongingness, defeat, entrapment, psychological pain and hopelessness, form a homogeneous group at high risk for suicidal ideation.

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.

Pharmacological therapies for fibromyalgia in adults ‐ an overview of Cochrane Reviews

This is a protocol for a Cochrane Review (Overview). The objectives are as follows:

To provide an overview of the therapeutic efficacy of pharmacological therapies for fibromyalgia, and to report on adverse events associated with their use. The major comparison of interest will be with placebo.

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.

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

BACKGROUND

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

METHODS

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

RESULTS AND CONCLUSION

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

Serotonin and noradrenaline reuptake inhibitors (SNRIs) for fibromyalgia

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Unravelling Fibromyalgia-Steps Toward Individualized Management

The heterogeneity of the clinical presentation and the pathophysiologic mechanisms associated with fibromyalgia (FM), and the modest results on average for any therapy, call for a more individualized management strategy. Individualized treatment can be on the basis of subgrouping of patients according to associated conditions (mental health problems, chronic overlapping pain conditions, other somatic diseases) or on disease severity. Categorizing FM as mild, moderate, or severe can be on the basis of clinical assessment (eg, degree of daily functioning) or on questionnaires. Shared decision-making regarding treatment options can be directed according to patient preferences, comorbidities, and availability in various health care settings. The European League Against Rheumatism guidelines recommend a tailored approach directed by FM key symptoms (pain, sleep disorders, fatigue, depression, disability), whereas the German guidelines recommend management tailored to disease severity, with mild disease not requiring any specific treatment, and more severe disease requiring multicomponent therapy (combination of drug treatment with aerobic exercise and psychological treatments). When indicated, treatments should follow a stepwise approach beginning with easily available therapies such as aerobic exercise and amitriptyline. Successful application of a tailored treatment approach that is informed by individual patient characteristics should improve outcome of FM.

PERSPECTIVE

This article presents suggestions for an individualized treatment strategy for FM patients on the basis of subgroups and disease severity. Categorizing FM as mild, moderate, or severe can be on the basis of clinical assessment (eg, degree of daily functioning) or questionnaires. Subgroups can be defined according to mental health and somatic comorbidities.