Fibromyalgia syndrome module at OMERACT 9: domain construct

Effects of bedtime very low dose cyclobenzaprine on symptoms and sleep physiology in patients with fibromyalgia syndrome: a double-blind randomized placebo-controlled study

OBJECTIVE

To determine the effects of bedtime very low dose (VLD) cyclobenzaprine (CBP) on symptoms and sleep physiology of patients with fibromyalgia (FM), unrefreshing sleep, and the α-nonREM sleep electroencephalographic (EEG) anomaly at screening.

METHODS

Of 37 patients with FM in the screened population, 36 were randomized and treated in this 8-week, double-blind, placebo-controlled, dose-escalating study of VLD CBP 1-4 mg at bedtime. We evaluated changes in subjective symptoms including pain, tenderness, fatigue, mood [Hospital Anxiety and Depression Scale (HAD)], and objective EEG sleep physiology (at screening, baseline, and Weeks 2, 4, and 8).

RESULTS

In the VLD CBP-treated group (n = 18) over 8 weeks, musculoskeletal pain and fatigue decreased, tenderness improved; total HAD score and the HAD depression subscore decreased; patient-rated and clinician-rated fatigue improved. In the placebo-treated group (n = 18), none of these outcome measures changed significantly. Compared to placebo at 8 weeks, VLD CBP significantly improved pain, tenderness, and the HAD Depression subscore. Analysis of cyclic alternating pattern (CAP) sleep EEG revealed that significantly more subjects in the VLD CBP group than the placebo group had increased nights of restorative sleep in which CAP(A2+A3)/CAP(A1+A2+A3) = CAP(A2+A3(Norm)) ≤ 33%. For VLD CBP-treated subjects, the increase in nights with CAP(A2+A3(Norm)) ≤ 33% was correlated to improvements in fatigue, total HAD score, and HAD depression score.

CONCLUSION

Bedtime VLD CBP treatment improved core FM symptoms. Nights with CAP(A2+A3(Norm)) ≤ 33% may provide a biomarker for assessing treatment effects on nonrestorative sleep and associated fatigue and mood symptoms in persons with FM.

Efficacy of hypnosis/guided imagery in fibromyalgia syndrome--a systematic review and meta-analysis of controlled trials

Background

Recent systematic reviews on psychological therapies of fibromyalgia syndrome (FMS) did not consider hypnosis/guided imagery (H/GI). Therefore we performed a systematic review with meta-analysis of the efficacy of H/GI in FMS.

Methods

We screened http://ClinicalTrials.gov, Cochrane Library, MEDLINE, PsycINFO and SCOPUS (through December 2010). (Quasi-) randomized controlled trials (CTs) comparing H/GI with controls were analyzed. Outcomes were pain, sleep, fatigue, depressed mood and health-related quality of life (HRQOL). Effects were summarized using standardized mean differences (SMD).

Results

Six CTs with 239 subjects with a median of 9 (range 7-12) H/GI-sessions were analysed. The median number of patients in the H/GI groups was 20 (range 8-26). Three studies performed follow-ups. H/GI reduced pain compared to controls at final treatment (SMD -1.17 [95% CI -2.21, -0.13]; p = 0.03). H/GI did not reduce limitations of HRQOL at final treatment (SMD -0.90 [95% CI -2.55, 0.76]; p = 0.29) compared to controls. Effect sizes on fatigue, sleep and depressed mood at final treatment and follow-up and on pain and HRQOL at follow-up were not calculated because of limited data available. The significant effect on pain at final treatment was associated with low methodological and low treatment quality.

Conclusion

Further studies with better treatment quality and adequate methodological quality assessing all key domains of FMS are necessary to clarify the efficacy of H/GI in FMS.

Improvement in multiple dimensions of fatigue in patients with fibromyalgia treated with duloxetine: secondary analysis of a randomized, placebo-controlled trial

Introduction

Fatigue is one of the most disabling symptoms associated with fibromyalgia that greatly impacts quality of life. Fatigue was assessed as a secondary objective in a 2-phase, 24-week study in outpatients with American College of Rheumatology-defined fibromyalgia.

Methods

Patients were randomized to duloxetine 60-120 mg/d (N = 263) or placebo (N = 267) for the 12-week acute phase. At Week 12, all placebo-treated patients were switched to double-blind treatment with duloxetine for the extension phase. Fatigue was assessed at baseline and every 4 weeks with the Multidimensional Fatigue Inventory (MFI) scales: General Fatigue, Physical Fatigue, Mental Fatigue, Reduced Activity, and Reduced Motivation. Other assessments that may be associated with fatigue included Brief Pain Inventory (BPI) average pain, numerical scales to rate anxiety, depressed mood, bothered by sleep difficulties, and musculoskeletal stiffness. Treatment-emergent fatigue-related events were also assessed. Changes from baseline to Week 12, and from Week 12 to Week 24, were analyzed by mixed-effects model repeated measures analysis.

Results

At Week 12, duloxetine versus placebo significantly (all p < .05) reduced ratings on each MFI scale, BPI pain, anxiety, depressed mood, and stiffness. Improvement in ratings of being bothered by sleep difficulties was significant only at Weeks 4 and 8. At Week 24, mean changes in all measures indicated improvement was maintained for patients who received duloxetine for all 24 weeks (n = 176). Placebo-treated patients switched to duloxetine (n = 187) had significant within-group improvement in Physical Fatigue (Weeks 16, 20, and 24); General Fatigue (Weeks 20 and 24); Mental Fatigue (Week 20); and Reduced Activity (Weeks 20 and 24). These patients also experienced significant within-group improvement in BPI pain, anxiety, depressed mood, bothered by sleep difficulties, and stiffness. Overall, the most common (> 5% incidence) fatigue-related treatment-emergent adverse events were fatigue, somnolence, and insomnia.

Conclusions

Treatment with duloxetine significantly improved multiple dimensions of fatigue in patients with fibromyalgia, and improvement was maintained for up to 24 weeks.

Trial registration

ClinicalTrials.gov registry NCT00673452.

A confirmatory study of the Combined Index of Severity of Fibromyalgia (ICAF*): factorial structure, reliability and sensitivity to change

Background

Fibromyalgia (FM) is a complex syndrome that affects many aspects of the patients life and it is very difficult to evaluate in clinical practice. A recent study has developed the Combined Index of Severity of Fibromyalgia (ICAF), an instrument that evaluates diverse aspects of FM and offers five indices: emotional, physical, active coping, passive coping and total. The objective of this study is to confirm the structure of the ICAF, check its test-retest reliability, assess its sensitivity to change, and compare the results obtained in a sample of patients with fibromyalgia with another sample of healthy controls.

Methods

A total of 232 patients took part in the study, 228 women and 4 men, with a mean age of 47.73 years of age (SD = 8.61) and a time of disease evolution since diagnosis of 4.28 years (SD = 4.03). The patients from the FM group completed the ICAF. Between one and two weeks later, they again attended the clinic and complete the 59 items on the ICAF (retest) and immediately afterwards they began treatment (according to daily clinical practice criteria). A sample of healthy subjects was also studied as a control group: 110 people were included (106 women and 4 men) with a mean age of 46.01 years of age (SD = 9.35). The study was conducted in Spain.

Results

The results obtained suggest that the four-factor model obtained in the previous study adequately fits the data obtained in this study. The test-retest reliability and internal consistency were all significant and show a high degree of correlation for all the factors as well as in overall score. With the exception of the passive coping factor, all the other scores, including the overall score, were sensitive to change after the therapeutic intervention. The ICAF scores of the patients with fibromyalgia compared with those of the control group were markedly different.

Conclusions

The findings suggest that the ICAF is a valid, reliable, sensitive to change instrument with the added advantage that it offers some additional domains (factors) that provide very valuable information regarding the most delicate aspects of the patient, which must be addressed at the time of treatment in daily clinical practice.

Trazodone plus pregabalin combination in the treatment of fibromyalgia: a two-phase, 24-week, open-label uncontrolled study

Background

Although trazodone is frequently used by fibromyalgia patients, its efficacy on this disease has not been adequately studied. If effective, pregabalin, whose beneficial effects on pain and sleep quality in fibromyalgia have been demonstrated, could complement the antidepressant and anxiolytic effects of trazodone. The aim of the present study was to assess the effectiveness of trazodone alone and in combination with pregabalin in the treatment of fibromyalgia.

Methods

This was an open-label uncontrolled study. Trazodone, flexibly dosed (50-300 mg/day), was administered to 66 fibromyalgia patients during 12 weeks; 41 patients who completed the treatment accepted to receive pregabalin, also flexibly dosed (75-450 mg/day), added to trazodone treatment for an additional 12-week period. Outcome measures included the Fibromyalgia Impact Questionnaire (FIQ), the Pittsburgh Sleep Quality Index (PSQI), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory (BPI), the Short-Form Health Survey (SF-36), and the Patients' Global Improvement scale (PGI). Emergent adverse reactions were recorded. Data were analyzed with repeated measures one-way ANOVA and paired Student's t test.

Results

Treatment with trazodone significantly improved global fibromyalgia severity, sleep quality, and depression, as well as pain interference with daily activities although without showing a direct effect on bodily pain. After pregabalin combination additional and significant improvements were seen on fibromyalgia severity, depression and pain interference with daily activities, and a decrease in bodily pain was also apparent. During the second phase of the study, only two patients dropped out due to side effects.

Conclusions

Trazodone significantly improved fibromyalgia severity and associated symptomatology. Its combination with pregabalin potentiated this improvement and the tolerability of the drugs in association was good.

Trial Registration

ClinicalTrials.gov: NCT00791739

Longitudinal evaluation of health care utilization and costs during the first three years after a new diagnosis of fibromyalgia

OBJECTIVE

To evaluate health care resource utilization and costs 1 year before and 3 years after a fibromyalgia (FM) diagnosis.

METHODS

This retrospective cohort analysis used claims from Humana to identify newly diagnosed FM patients ≥18 years of age based on ≥2 medical claims for ICD-9 CM code 729.1 and 729.0 between June 1, 2002 and March 1, 2005. Prevalence of comorbidities, as well as utilization and costs of pharmacotherapy and health care services were examined for 12 months preceding (pre-diagnosis) and 36 months following (post-diagnosis) the date of first FM diagnosis. These periods were subdivided into 6-month blocks to better observe patterns of change.

RESULTS

We identified 2613 FM patients who had a mean age at diagnosis of 58.5 ± 15.3 years and a mean Charlson Comorbidity Index of 0.48 ± 1.05. Of those, 73% were female. The use and costs of pain-related medications rose from pre-diagnosis and remained stable after the 6-month post-diagnosis period, while the use of non-pain-related medications steadily rose from pre-diagnosis to 3 years post-diagnosis. This increase was concomitant with an increase in the presence of conditions that may account for higher resource utilization. The use of recommended FM therapies (i.e., antidepressants and anticonvulsants) increased post-diagnosis but remained less common than other pain-related therapies. Total resource utilization and costs increased during the period up to 6 months after diagnosis. This increase was followed by a decline (7-12 months post-diagnosis), and plateau, with an increase during the final 6 months of the study period. Total mean per patient costs were $3481 for the 6-month post-diagnosis period, and $3588 for the final 6 months. Limitations include potential errors in coding and recording, and an inability of claims analyses to determine causality between resource utilization and the specific diagnosis of interest.

CONCLUSIONS

An FM diagnosis was associated with increased utilization and pain-related medication cost up to the first 6 months post-diagnosis followed by stabilization over 3 years post-diagnosis. Less use of recommended therapies relative to other therapies suggests that further dissemination of treatment guidelines is needed. An increase in non-pain medications over the observation period accounted for the majority of pharmacy costs. These pharmacy costs may be related to an increasing prevalence of comorbid conditions.

Fibromyalgia criteria and severity scales for clinical and epidemiological studies: a modification of the ACR Preliminary Diagnostic Criteria for Fibromyalgia

OBJECTIVE

To develop a fibromyalgia (FM) survey questionnaire for epidemiologic and clinical studies using a modification of the 2010 American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia (ACR 2010). We also created a new FM symptom scale to further characterize FM severity.

METHODS

The ACR 2010 consists of 2 scales, the Widespread Pain Index (WPI) and the Symptom Severity (SS) scale. We modified these ACR 2010 criteria by eliminating the physician's estimate of the extent of somatic symptoms and substituting the sum of 3 specific self-reported symptoms. We also created a 0-31 FM Symptom scale (FS) by adding the WPI to the modified SS scale. We administered the questionnaire to 729 patients previously diagnosed with FM, 845 with osteoarthritis (OA) or with other noninflammatory rheumatic conditions, 439 with systemic lupus erythematosus (SLE), and 5210 with rheumatoid arthritis (RA).

RESULTS

The modified ACR 2010 criteria were satisfied by 60% with a prior diagnosis of FM, 21.1% with RA, 16.8% with OA, and 36.7% with SLE. The criteria properly identified diagnostic groups based on FM severity variables. An FS score ≥ 13 best separated criteria+ and criteria- patients, classifying 93.0% correctly, with a sensitivity of 96.6% and a specificity of 91.8% in the study population.

CONCLUSION

A modification to the ACR 2010 criteria will allow their use in epidemiologic and clinical studies without the requirement for an examiner. The criteria are simple to use and administer, but they are not to be used for self-diagnosis. The FS may have wide utility beyond the bounds of FM, including substitution for widespread pain in epidemiological studies.

Do We Need Core Sets of Fibromyalgia Domains? The Assessment of Fibromyalgia (and Other Rheumatic Disorders) in Clinical Practice

Objective.

An OMERACT consensus process recommended domains for investigation in fibromyalgia (FM) clinical trials. We used patient data to investigate variable importance in the determination of patient global and health-related quality of life (HRQOL) in FM and non-FM patients to determine whether variables were valued differently in FM compared with non-FM states.

Methods.

We used ACR 2010 diagnostic FM criteria modified for epidemiological and clinical research to identify patients with rheumatoid arthritis (RA; N = 5884) with and without FM, and also characterized previously diagnosed patients with FM (N = 808) as to current criteria status. We measured variable importance by multivariable regression, decomposing regression variance by averaging over model orderings. We examined the distributions of key variables in the various disorders, and the distributions as a function of a FM severity index (fibromyalgianess).

Results.

Out of 9 measures, pain, Health Assessment Questionnaire disability index, and fatigue explained more than 50% of explainable variance (50.49%–56.59%). Explained variance was similar across all disorders and diagnostic groups. In addition, the SF-36 physical component summary score varied across disorders as a function of fibromyalgianess.

Conclusion.

The main determinants of global severity and HRQOL in FM are pain, function, and fatigue. But these variables are also the main determinants in RA and other rheumatic diseases. The content and impact of FM, whether measured by discrete variables or a fibromyalgianess scale, seems to be independent of diagnosis. These data argue for a common set of variables rather than disease-specific variables. Clinical use is supported and enhanced by simple measures.

Internet-enhanced management of fibromyalgia: a randomized controlled trial

Both pharmacological and non-pharmacological interventions have demonstrated efficacy in the management of fibromyalgia (FM). Non-pharmacological interventions however are far less likely to be used in clinical settings, in part due to limited access. This manuscript presents the findings of a randomized controlled trail of an Internet-based exercise and behavioral self-management program for FM designed for use in the context of a routine clinical care. 118 individuals with FM were randomly assigned to either (a) standard care or (b) standard care plus access to a Web-Enhanced Behavioral Self-Management program (WEB-SM) grounded in cognitive and behavioral pain management principles. Individuals were assessed at baseline and again at 6 months for primary endpoints: reduction of pain and an improvement in physical functioning. Secondary outcomes included fatigue, sleep, anxiety and depressive symptoms, and a patient global impression of improvement. Individuals assigned to the WEB-SM condition reported significantly greater improvement in pain, physical functioning, and overall global improvement. Exercise and relaxation techniques were the most commonly used skills throughout the 6 month period. A no-contact, Internet-based, self-management intervention demonstrated efficacy on key outcomes for FM. While not everyone is expected to benefit from this approach, this study demonstrated that non-pharmacological interventions can be efficiently integrated into routine clinical practice with positive outcomes.

Trazodone for the treatment of fibromyalgia: an open-label, 12-week study

Background

Despite its frequent use as a hypnotic, trazodone has not been systematically assessed in fibromyalgia patients. In the present study have we evaluated the potential effectiveness and tolerability of trazodone in the treatment of fibromyalgia.

Methods

A flexible dose of trazodone (50-300 mg/day), was administered to 66 fibromyalgia patients for 12 weeks. The primary outcome measure was the Pittsburgh Sleep Quality Index (PSQI). Secondary outcome measures included the Fibromyalgia Impact Questionnaire (FIQ), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory (BPI), the Short-Form Health Survey (SF-36), and the Patients' Global Improvement Scale (PGI). Trazodone's emergent adverse reactions were recorded. Data were analyzed with repeated measures one-way ANOVA and paired Student's t test.

Results

Trazodone markedly improved sleep quality, with large effect sizes in total PSQI score as well on sleep quality, sleep duration and sleep efficiency. Significant improvement, although with moderate effect sizes, were also observed in total FIQ scores, anxiety and depression scores (both HADS and BDI), and pain interference with daily activities. Unexpectedly, the most frequent and severe side effect associated with trazodone in our sample was tachycardia, which was reported by 14 (21.2%) patients.

Conclusions

In doses higher than those usually prescribed as hypnotic, the utility of trazodone in fibromyalgia management surpasses its hypnotic activity. However, the emergence of tachycardia should be closely monitored.

Trial registration

This trial has been registered with ClinicalTrials.gov number NCT-00791739.

Efficacy of Cognitive-Behavioral Therapies in Fibromyalgia Syndrome — A Systematic Review and Metaanalysis of Randomized Controlled Trials

Objective.

We performed the first systematic review with metaanalysis of the efficacy of cognitive-behavioral therapies (CBT) in fibromyalgia syndrome (FM).

Methods.

We screened Cochrane Library, Medline, PsychINFO, and Scopus (through June 2009) and the reference sections of original studies and systematic reviews for CBT in FM. Randomized controlled trials (RCT) comparing CBT to controls were analyzed. Primary outcomes were pain, sleep, fatigue, and health-related quality of life (HRQOL). Secondary outcomes were depressed mood, self-efficacy pain, and healthcare-seeking behavior. Effects were summarized using standardized mean differences (SMD).

Results.

A total of 14 out of 27 RCT with 910 subjects with a median treatment time of 27 hours (range 6–75) over a median of 9 weeks (range 5–15) were included. CBT reduced depressed mood (SMD −0.24, 95% CI −0.40, −0.08; p = 0.004) at posttreatment. Sensitivity analyses showed that the positive effect on depressed mood could not be distinguished from some risks of bias. There was no significant effect on pain, fatigue, sleep, and HRQOL at posttreatment and at followup. There was a significant effect on self-efficacy pain posttreatment (SMD 0.85, 95% CI 0.25, 1.46; p = 0.006) and at followup (SMD 0.90, 95% CI 0.14, 1.66; p = 0.02). Operant behavioral therapy significantly reduced the number of physician visits at followup (SMD −1.57, 95% CI −2.00, −1.14; p < 0.001).

Conclusion.

CBT can be considered to improve coping with pain and to reduce depressed mood and healthcare-seeking behavior in FM.

Effects of sodium oxybate on sleep physiology and sleep/wake-related symptoms in patients with fibromyalgia syndrome: a double-blind, randomized, placebo-controlled study

OBJECTIVE

To determine the effects of sodium oxybate (SXB) on sleep physiology and sleep/wake-related symptoms in patients with fibromyalgia syndrome (FM).

METHODS

Of 304 patients with FM (American College of Rheumatology tender point criteria) in the screened study population, 209 underwent polysomnography, 195 were randomized, and 151 completed this 8-week, double-blind, placebo-controlled study of SXB 4.5 g and 6 g/night. We evaluated changes in objective sleep measures and subjective symptoms, including daytime sleepiness [Epworth Sleepiness Scale (ESS)], fatigue visual analog scale (FVAS), sleep [Jenkins Scale for Sleep (JSS)], and daytime functioning [Functional Outcome of Sleep Questionnaire (FOSQ), SF-36 Vitality domain, and Fibromyalgia Impact Questionnaire (FIQ) general and morning tiredness].

RESULTS

Pretreatment screening revealed an elevated incidence of maximum alpha EEG-intrusion > 24 min/hour of sleep (66%), periodic limb movements of sleep (20.1% ≥ 5/hour), and moderate to severe obstructive sleep apnea disorder (15.3% apnea-hypopnea index ≥ 15/hour). Compared with placebo, both doses of SXB achieved statistically significant improvements in ESS, morning FVAS, JSS, FOSQ, SF-36 Vitality, and FIQ general and morning tiredness; both doses also demonstrated decreased rapid eye movement (REM) sleep (all p ≤ 0.040). SXB 6 g/night improved afternoon, evening and overall FVAS, reduced wakefulness after sleep onset, and increased Stage 2, slow-wave, and total non-REM sleep (all p ≤ 0.032) versus placebo. Moderate correlations (≥ 0.40) were noted between changes in subjective sleep and pain measures. Adverse events occurring significantly more frequently with SXB than placebo were nausea, pain in extremity, nervous system disorders, dizziness, restlessness, and renal/urinary disorders (including urinary incontinence).

CONCLUSION

This large cohort of patients with FM demonstrated that SXB treatment improved EEG sleep physiology and sleep-related FM symptoms.

Milnacipran: a selective serotonin and norepinephrine dual reuptake inhibitor for the management of fibromyalgia

Milnacipran, a serotonin and norepinephrfrine reuptake inhibitor with preferential inhibition of norepinephrine reuptake over serotonin, is approved in the United States for the management of fibromyalgia. Owing to its effects on norepinephrine and serotonin, as well as its lack of activity at other receptor systems, it was hypothesized that milnacipran would provide improvements in pain and other fibromyalgia symptoms without some of the unpleasant side effects associated with other medications historically used for treating fibromyalgia. The clinical safety and efficacy of milnacipran 100 and 200 mg/day in individuals with fibromyalgia has been investigated in four large, randomized, double-blind, placebo-controlled studies and three long-term extension studies. The clinical studies used composite responder analyses to identify the proportion of individual patients reporting simultaneous and clinically significant improvements in pain, global status, and physical function, in addition to assessing improvement in various symptom domains such as fatigue and dyscognition. In the clinical studies, patients receiving milnacipran reported significant improvements in pain and other symptoms for up to 15 months of treatment. Most adverse events were mild to moderate in severity and were related to the intrinsic pharmacologic properties of the drug. Long-term exposure to milnacipran did not result in any new safety concerns. As with other serotonin and norepinephrine reuptake inhibitors, increases in heart rate and blood pressure have been observed in some patients with milnacipran treatment.

The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity

OBJECTIVE

To develop simple, practical criteria for clinical diagnosis of fibromyalgia that are suitable for use in primary and specialty care and that do not require a tender point examination, and to provide a severity scale for characteristic fibromyalgia symptoms.

METHODS

We performed a multicenter study of 829 previously diagnosed fibromyalgia patients and controls using physician physical and interview examinations, including a widespread pain index (WPI), a measure of the number of painful body regions. Random forest and recursive partitioning analyses were used to guide the development of a case definition of fibromyalgia, to develop criteria, and to construct a symptom severity (SS) scale.

RESULTS

Approximately 25% of fibromyalgia patients did not satisfy the American College of Rheumatology (ACR) 1990 classification criteria at the time of the study. The most important diagnostic variables were WPI and categorical scales for cognitive symptoms, unrefreshed sleep, fatigue, and number of somatic symptoms. The categorical scales were summed to create an SS scale. We combined the SS scale and the WPI to recommend a new case definition of fibromyalgia: (WPI > or =7 AND SS > or =5) OR (WPI 3-6 AND SS > or =9).

CONCLUSION

This simple clinical case definition of fibromyalgia correctly classifies 88.1% of cases classified by the ACR classification criteria, and does not require a physical or tender point examination. The SS scale enables assessment of fibromyalgia symptom severity in persons with current or previous fibromyalgia, and in those to whom the criteria have not been applied. It will be especially useful in the longitudinal evaluation of patients with marked symptom variability.

Role and rationale for the use of milnacipran in the management of fibromyalgia

Fibromyalgia (FM) is a complex syndrome characterized by chronic widespread musculoskeletal pain which is often accompanied by multiple other symptoms, including fatigue, sleep disturbances, decreased physical functioning, and dyscognition. Due to these multiple symptoms, as well as high rates of comorbidity with other related disorders, patients with FM often report a reduced quality of life. Although the pathophysiology of FM is not completely understood, patients with FM experience pain differently from the general population, most likely due to dysfunctional pain processing in the central nervous system leading to both hyperalgesia and allodynia. In many patients with FM, this aberrant pain processing, or central sensitization, appears to involve decreased pain inhibition within the spinal tract, which is mediated by descending pathways that utilize serotonin, norepinephrine, and other neurotransmitters. The reduced serotonin and norepinephrine levels observed in patients with FM suggest that medications which increase the levels of these neurotransmitters, such as serotonin and norepinephrine reuptake inhibitors (SNRIs), may have clinically beneficial effects in FM and other chronic pain conditions. Milnacipran is an SNRI that has been approved for the management of FM. In clinical trials, treatment with milnacipran for up to 1 year has been found to improve the pain and other symptoms of FM. Because FM is characterized by multiple symptoms that all contribute to the decreased quality of life and ability to function, the milnacipran pivotal trials implemented responder analyses. These utilized a single composite endpoint to identify the proportion of patients who reported simultaneous and clinically significant improvements in pain, global disease status, and physical function. Other domains assessed during the milnacipran trials include fatigue, multidimensional functioning, mood, sleep quality, and patient-reported dyscognition. This review article provides information intended to help clinicians make informed decisions about the use of milnacipran in the clinical management of patients with FM. It draws primarily on results from 2 of the pivotal clinical trials that formed the basis of approval of milnacipran in the United States by the Food and Drug Administration.

A European Multicenter Randomized Double-blind Placebo-controlled Monotherapy Clinical Trial of Milnacipran in Treatment of Fibromyalgia

Objective.

This randomized, double-blind, placebo-controlled, multicenter study investigated the efficacy and safety of milnacipran in the treatment of fibromyalgia (FM) in a European population.

Methods.

Outpatients diagnosed with FM according to 1990 American College of Rheumatology criteria (N = 884) were randomized to placebo (n = 449) or milnacipran 200 mg/day (n = 435) for 17 weeks (4-week dose escalation, 12-week stable dose, 9-day down-titration), followed by a 2-week posttreatment period. The primary efficacy criterion was a 2-measure composite responder analysis requiring patients to achieve simultaneous improvements in pain (≥ 30% improvement from baseline in visual analog scale, 24-hour morning recall) and a rating of “very much” or “much” improved on the Patient Global Impression of Change scale. If responder analysis was positive, Fibromyalgia Impact Questionnaire (FIQ) was included as an additional key primary efficacy measure.

Results.

At the end of the stable dose period (Week 16), milnacipran 200 mg/day showed significant improvements from baseline relative to placebo in the 2-measure composite responder criteria (p = 0.0003) and FIQ total score (p = 0.015). Significant improvements were also observed in multiple secondary efficacy endpoints, including Short-Form 36 Health Survey (SF-36) Physical Component Summary (p = 0.025), SF-36 Mental Component Summary (p = 0.007), Multidimensional Fatigue Inventory (p = 0.006), and Multiple Ability Self-Report Questionnaire (p = 0.041). Milnacipran was safe and well tolerated; nausea, hyperhidrosis, and headache were the most common adverse events.

Conclusion.

Milnacipran is an effective and safe treatment for pain and other predominant symptoms of FM. Registered as trial no. NCT00436033.

Fibromyalgia: key clinical domains, comorbidities, assessment and treatment

In discussion of the best practices for patients with fibromyalgia (FM), it is key to Introduce commentary about what FM is as a clinical condition, how clinicians should assess for FM, and the pharmacologic approaches to management.

The first widely accepted criteria for the classification for FM were published in 1990 as the American College of Rheumatology criteria for FM. However, the condition has long been described in medical history. In the 1800s, a condition similar to FM was labeled “neurasthenia” and was further defined by researchers in the medical literature. During the early 1900s, symptoms associated with FM were labeled “fibrositis,” which was based on the mistaken idea that there were inflammatory changes in peripheral connective tissue. It was not until the mid-1970s when pioneering work by Smythe and Moldofsky defined central nervous system abnormalities, including significant sleep pathology, in patients with this condition that led to the increased recognition by researchers and clinicians that FM was a central pain phenomenon.

Following this critical development, use of the term “fibromyalgia” began and was codified in the 1990 criteria, intended for use in research settings to standardize classification of FM. The 1990 criteria classify the condition as involving chronic widespread pain for at least 3 months. Patients must also exhibit tenderness of at least 11 of 18 tender points.

Content and criterion validity of the preliminary core dataset for clinical trials in fibromyalgia syndrome

OBJECTIVE

Increasing research interest and emerging new therapies for treatment of fibromyalgia (FM) have led to a need to develop a consensus on a core set of outcome measures that should be assessed and reported in all clinical trials, to facilitate interpretation of the data and understanding of the disease. This aligns with the key objective of the Outcome Measures in Rheumatology (OMERACT) initiative to improve outcome measurement through a data driven, interactive consensus process.

METHODS

Through patient focus groups and Delphi processes, working groups at previous OMERACT meetings identified potential domains to be included in the core data set. A systematic review has shown that instruments measuring these domains are available and are at least moderately sensitive to change. Most instruments have been validated in multiple languages. This pooled analysis study aims to develop the core data set by analyzing data from 10 randomized controlled trials (RCT) in FM.

RESULTS

Results from this study provide support for the inclusion of the following in the core data set: pain, tenderness, fatigue, sleep, patient global assessment, and multidimensional function/health related quality of life. Construct validity was demonstrated with outcome instruments showing convergent and divergent validity. Content and criterion validity were confirmed by multivariate analysis showing R square values between 0.4 and 0.6. Low R square value is associated with studies in which one or more domains were not assessed.

CONCLUSION

The core data set was supported by high consensus among attendees at OMERACT 9. Establishing an international standard for RCT in FM should facilitate future metaanalyses and indirect comparisons.