Quetiapine extended-release (Seroquel-XR) versus amitriptyline monotherapy for treating patients with fibromyalgia: a 16-week, randomized, flexible-dose, open-label trial

Pharmacological Treatment of Fibromyalgia Syndrome: A Practice-Based Review

PURPOSE OF REVIEW

Fibromyalgia Syndrome (FMS) is a complex chronic pain condition characterized by widespread musculoskeletal pain and numerous other debilitating symptoms. The purpose of this review is to provide a comprehensive overview, based on everyday clinical practice, of the drugs presently employed in the treatment of FMS.

RECENT FINDINGS

The treatment of FMS is based on a multimodal approach, with pharmacologic treatment being an essential pillar. The drugs used include tricyclic antidepressants, serotonin and noradrenaline reuptake inhibitors, other antidepressants, anticonvulsants, myorelaxants, and analgesics. The effectiveness of these medications varies, and the choice of drug often depends on the specific symptoms presented by the patient. Many drugs tend to either address only some domains of the complex FMS symptomatology or have a limited effect on pain. Each treatment option comes with potential side effects and risks that necessitate careful consideration. It may be beneficial to divide patients into clinical subpopulations, such as FMS with comorbid depression, for more effective treatment. Despite the complexities and challenges, the pharmacological treatment remains a crucial part for the management of FMS. This review aims to guide clinicians in prescribing pharmacological treatment to individuals with FMS.

Management of Fibromyalgia: An Update

Fibromyalgia, a chronic pain condition marked by abnormal pain processing, impacts a significant part of the population, leading to reduced quality of life and function. Hallmark symptoms include widespread persistent pain, sleep disturbances, fatigue, cognitive dysfunction, and mood changes. Through this updated review, we aim to contribute to the evolving understanding and management of fibromyalgia, offering insights into the diverse tools available to improve the lives of those affected by this challenging condition. Management begins with educating patients to ultimately relieve them of unnecessary testing and provide reassurance. Treatment emphasizes a comprehensive approach, combining nonpharmacological interventions such as aforementioned education, exercise, and psychotherapy, alongside pharmacologic management-namely duloxetine, milnacipran, pregabalin, and amitriptyline-which have consistent benefits for a range of symptoms across the spectrum of fibromyalgia. Notably, drugs like nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen are generally not recommended due to limited efficacy and associated risks. Lastly, a variety of other medications have shown promise, including NMDA-receptor antagonists, naltrexone, and cannabinoids; however, they should be used with caution due to a small amount of evidence and potential for adverse effects.

Non-invasive brain stimulation for fibromyalgia: current trends and future perspectives

Fibromyalgia, a common and enduring pain disorder, ranks as the second most prevalent rheumatic disease after osteoarthritis. Recent years have witnessed successful treatment using non-invasive brain stimulation. Transcranial magnetic stimulation, transcranial direct current stimulation, and electroconvulsion therapy have shown promise in treating chronic pain. This article reviews the literature concerning non-invasive stimulation for fibromyalgia treatment, its mechanisms, and establishes a scientific basis for rehabilitation, and discusses the future directions for research and development prospects of these techniques are discussed.

Pharmacotherapy for gastric and intestinal cramping pain: ‎ current and emerging therapies

INTRODUCTION

Acute gastrointestinal cramping pain (GICP) is a debilitating condition that affects many people worldwide, significantly reducing their quality of life. As such, prompt treatment is crucial.

AREAS COVERED

This article will explore relevant literature from databases such as PubMed, Scopus, Google Scholar, Cochrane Library, and Web of Science. Additionally, we searched ClinicalTrials.gov and the WHO ICTRP database for the latest clinical trials.

EXPERT OPINION

Consensus dictates that antispasmodics such as hyoscine-N-butyl bromide and mebeverine should be the primary treatment for GICP. If these prove ineffective, patients can switch to an antispasmodic with a different mode of action or add acetaminophen/NSAIDs for more severe cases. Currently, several antispasmodics are undergoing clinical trials, including drotaverine, alverine, pinaverium, otilonium bromide, fenoverine, tiropramide, otilonium bromide, trimebutine, and peppermint oil. Well-designed head-to-head studies are necessary to evaluate current antispasmodics' safety, efficacy, pharmacokinetic, and pharmacoeconomics profiles. Recent studies have shown that fixed-dose combinations of antispasmodics + NSAIDs or two different antispasmodics can improve patient compliance and synergistically reduce GICP. Therefore, it is recommended that the global availability and accessibility of these products be enhanced.

Effects of quetiapine on sleep: A systematic review and meta-analysis of clinical trials

Quetiapine is a common off-label antipsychotic drug for treating insomnia. Its effects in different disease conditions and dosages remain unclear. We conducted a systematic review and meta-analysis in clinical trials examining the efficacy of low-dose quetiapine in sleep. We obtained 21 clinical trials. Mean difference (MD), standard mean difference (SMD), and odds ratio (OR) were used to estimate the effect sizes using a random-effects model. The pooled results showed that quetiapine improved sleep quality compared with placebo (SMD: -0.57 [95%CI: -0.75, -0.4]). The SMD of sleep quality was correlated with age (coefficient: -0.0174) and sex (coefficient: -0.012). The significant effects were observed in the general anxiety disorder (SMD: -0.59 [95%CI: -0.92, -0.27]), major depressive disorder (SMD: -0.47 [95%CI: -0.66, -0.28]), and healthy (SMD: -1.33, [95%CI [-2.12, -0.54]) subgroups, at the dosage of 50 mg (SMD: -0.36 [95%CI: -0.36, -0.11]), 150 mg (SMD: -0.4 [95%CI: -0.52, -0.29]), and 300 mg (SMD: -0.17 [95%CI: -0.31,-0.04]). Quetiapine increased total sleep time compared with placebo (MD: 47.91 [95%CI: 28.06, 67.76]) but not when compared with other psychiatric drugs (MD: -4.19 [95%CI: -19.43, 11.05]). Adverse events (AEs) and discontinuation due to AEs were common among the quetiapine users. Quetiapine is effective as a sleep-helping drug. Precaution is suggested when interpreting the results on the elderly due to the high heterogeneity caused by incorporating patients over 66 years in the meta-analyses. We recommend an initial dosage of 50-150 mg/day with priority consideration for the elderly with GAD or MDD while monitoring its potential AEs.

Review of Fibromyalgia (FM) Syndrome Treatments

BACKGROUND

Fibromyalgia (FM) is a disease characterized by widespread musculoskeletal chronic pain that impairs the patient's quality of life and is considered a somatization disorder. The symptoms of the disease also affect the patient mentally, mainly since invisible pain is the only thing that indicates its existence. A typical symptom that characterizes FM patients is the lack of acceptance of the disease since its pathophysiology is not elucidated, hence the deficiencies in its management, or rather, cognitively, the belief that there is no disease to manage. The current paper aims to shed light on the new treatment methods at a holistic level, that is, cognitive, physical, and pharmacological therapies.

METHOD

A literature review was carried out that discusses treatment methods that help alleviate the pain, accept it, and manage the symptoms of the disease.

RESULTS

FM symptoms can be treated by taking a broad view of treatment that will include a response to the mind through pain management, response to the body through physical activity, and response to the pain through pharmacological treatment.

CONCLUSIONS

Today, there is an evolutionary view that accepts FM and chronic pain diseases as syndromes in which the pain is the disease; therefore, the response to this disease can be applied through three channels: physical, bodily, and mental.

Efficacy and Safety Considerations With Second-Generation Antipsychotics as Adjunctive Analgesics: A Review of Literature

Objective: To determine the efficacy and safety of second-generation antipsychotics (SGAs) as adjunctive analgesics. Data Sources: A comprehensive literature review was conducted between August 2020 and January 2021 on PubMed, Scopus, and ProQuest Central. Study Selection and Data Extraction: Keyword and Boolean phrase searches using the following terminology were conducted: "Quetiapine" OR "Risperidone" OR "Olanzapine" OR "Ziprasidone" AND "Analgesia" NOT "Psychosis" NOT "Psych." Articles that involved human adult patients who received any of the SGAs mentioned in the searching filter with an opioid were included. Articles that described pediatrics, pregnant women, patients who received any of these agents for treatment of psychosis and articles that were not in English, or readily translatable to English, were excluded. Data Synthesis: Three articles were selected for inclusion in this review, with 2 articles detailing reports with olanzapine and 1 article describing a randomized, controlled trial with extended-release quetiapine. Both olanzapine and quetiapine were able to decrease pain scores on the numeric rating scale, indicating a reduction pain experienced, and additionally reduced opioid craving behavior in patients. Depression scores and quality-of-life indicators improved with quetiapine, though those metrics were not studied with olanzapine. Conclusions: Select SGAs, specifically extended-release quetiapine and olanzapine, may serve as an appropriate adjunctive analgesic choice in select patients. Further research is required in a clinical setting to determine the exact role of this drug class in pain management.

Expert review and recommendations for the management of acute, chronic, and neuropathic pain in Qatar

BACKGROUND

Pain management is an evolving area of expertise in Qatar. Gaps in knowledge, inadequate training for physicians and nurses, and the absence of policies/guidelines are the main barriers to effective pain management in Qatar. In addition, the use of certain pain medication, especially opioids, is highly regulated, limiting their availability in outpatient pain management. These factors are responsible for the undertreatment of pain in Qatar. This study aimed to standardize evidence-based local recommendations for pharmacological treatment of pain in Qatar.

METHODS

An expert panel of physicians from different disciplines, with experience in diagnosis and treatment of the three pain types (i.e., acute, chronic, and neuropathic), was convened for two face-to-face meetings in Doha, Qatar, on November 29, 2019, and on February 22, 2020, with subsequent virtual meetings. A literature search was performed on Medline and Google Scholar databases from inception till December 2019, and all relevant articles were selected. Based on these articles and repeated feedback from the authors, the final pain treatment protocols were developed.

RESULTS

Recommendations for the treatment of acute pain, based on pain severity, followed three approaches: acetaminophen/paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) for mild pain and moderate pain and referral to a pain specialist for severe pain. Acetaminophen/paracetamol or NSAIDs is recommended for chronic pain, and the use of opioids was strongly discouraged because of its long-term side effects. For neuropathic pain, tricyclic antidepressants or gabapentin or pregabalin or serotonin-norepinephrine reuptake inhibitors were recommended first-line agents. Non-responders must be referred to neurologists or a pain specialist.

CONCLUSION

The expert panel provides recommendations for the management of acute, chronic, and neuropathic pain based on international guidelines adapted to local practice and treatment availability in Qatar. More importantly, the panel has recommended taking extreme caution in the use of opioids for long-term management of chronic pain and to refer the patient to a pain specialist clinician as required.

Does the Rural Environment Influence Symptomatology and Optimize the Effectiveness of Disease Acceptance? A Study Among Women With Fibromyalgia

The present study aims to explore whether the symptoms associated with fibromyalgia are contextually influenced by the area of residence (rural/urban). Furthermore, it is analyzed whether the effect of the acceptance of the disease on the emotional, cognitive and physical symptoms is moderated by the patients' place of residence. Using a cross-sectional design, a total of 234 women with fibromyalgia (mean age = 56.91 years; SD = 8.94) were surveyed, of which 55.13% resided in rural areas and 44.87% in urban areas. Self-reported questionnaires were used to assess pain severity, anxiety and depression, functional limitation, physical and mental fatigue and acceptance of the disease. The results show significant differences in acceptance (p = 0.040), pain (p < 0.001), and physical and mental fatigue (p = 0.003 and p = 0.004, respectively) between patients from rural and urban areas. The rural area patients presented higher levels of acceptance and pain and lesser levels of physical and mental fatigue compared to the urban area. The moderation analysis add that, only in patients from the rural area, the variables of physical symptoms (pain, functional limitation, and physical fatigue) were significantly and negatively associated with acceptance. This study addresses for the first time the role of the place of residence in suffering from fibromyalgia, suggesting that the rural or urban environment plays a relevant role in the severity and/or management of symptoms in fibromyalgia women. Limitations and practical implications are also discussed.

Multitargeting the sleep-pain interaction with pharmacological approaches: A narrative review with suggestions on new avenues of investigation

The multimorbidity formed by sleep disturbances and pain conditions is highly prevalent and has a significant impact in global health and in the socioeconomic system. Although different approaches have been directed toward its management, evidence regarding an optimal treatment is lacking, and pharmacological options are often preferred. Health professionals (e.g., pain and sleep clinicians) tend to focus on their respective expertise, targeting a single symptom with a single drug. This may increase polypharmacy and the risk of drug interactions, adverse events, and mortality. Hence, the use of medications that can directly or indirectly improve sleep, pain, and other possible accompanying conditions without exacerbating them becomes especially relevant. The objectives of this comprehensive review are to: a) describe the beneficial or deleterious effects that some commonly used medications to manage pain have on sleep and sleep disorders; and b) describe the beneficial or deleterious effects that frequently prescribed medications for sleep may have on pain. Moreover, medications targeting some specific sleep-pain interactions will be suggested and future directions for improving sleep and alleviating pain of these patients will be provided with clinical and research perspectives.

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.

Current and Emerging Pharmacotherapy for Fibromyalgia

Introduction. Fibromyalgia syndrome (FMS) is a pain disorder with an estimated prevalence of 1–5%. It is associated with a variety of somatic and psychological disorders. Its exact pathogenesis is still unclear but is involved with neural oversensitization and decreased conditioned pain modulation (CPM), combined with cognitive dysfunction, memory impairment, and altered information processing. Connectivity between brain areas involved in pain processing, alertness, and cognition is increased in the syndrome, making its pharmacologic therapy complex. Only three drugs, pregabalin, duloxetine, and milnacipran are currently FDA-approved for FM treatment, but many other agents have been tested over the years, with varying efficacy. Areas Covered. The purpose of this review is to summarize current clinical experience with different pharmacologic treatments used for fibromyalgia and introduce future perspectives in developing therapies. Expert Opinion. Future insights into the fields of cannabinoid and opioid research, as well as an integrative approach towards the incorporation of genetics and functional imaging combined with additional fields of research relevant towards the study of complex CNS disorders, are likely to lead to new developments of novel tailor-made treatments for FMS patients.

A Systematic Review of Atypical Antipsychotics in Chronic Pain Management: Olanzapine Demonstrates Potential in Central Sensitization, Fibromyalgia, and Headache/Migraine

INTRODUCTION

Many psychopharmacologic agents are used as primary or adjuncts in pain management. Atypical antipsychotics (AAs) have also been used as adjuncts in pain management regimens in a variety of manners; however, their efficacy in this capacity is unclear.

METHODS

A systematic review of all studies examining AA use for pain was conducted. Three literature databases were utilized to search for word combinations of "pain" and a variety of commonly prescribed AAs ie, (olanzapine, quetiapine, risperidone, aripiprazole, ziprasidone, clozapine, paliperidone, iloperidone, lurasidone). Articles chosen for review included retrospective analyses, randomized control trials, and case series/reports. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses diagram illustrates the study selection process.

RESULTS

Olanzapine, quetiapine, risperidone, aripiprazole, and ziprasidone are the only AAs with published studies in pain management. Among these, olanzapine and quetiapine have the most studies (11 and 6, respectively). Olanzapine shows preliminary and consistent efficacy in fibromyalgia and headache/migraine, although only 1 study was a randomized controlled trial with level I evidence of efficacy. Other AAs eg, (quetiapine) fail to demonstrate efficacy in pain syndromes and/or lack robust study designs.

CONCLUSIONS

Few studies have been conducted to evaluate the analgesic effects of AAs. The collective findings of multiple studies evaluating olanzapine in pain syndromes suggest a high, yet preliminary level of evidence of efficacy, warranting prospective studies in various pain syndrome contexts. Pharmacological mechanisms of AA action are elaborated, and the findings of this review are discussed. Risk and benefits of using AAs in chronic pain are described, and investigational implications and future directions are explored.

Psychotropics, Antidepressants, and Visceral Analgesics in Functional Gastrointestinal Disorders

Purpose of Review

The functional gastrointestinal disorders, or disorders of gut-brain interaction as defined by the Rome IV criteria, are the most common diagnostic entities in gastroenterology. Treatments that address the dysregulation of gut-brain interaction with these disorders are increasingly gaining interest as a better option than for example traditional analgesics, particularly opioids. Antidepressants, antianxiety and antipsychotic medications, and visceral analgesics, now termed neuromodulators, are included in this update addressing the evidence of treatment benefit in disorders of brain-gut interaction.

Recent Findings

By a careful selection based on a multidimensional clinical profile, a decreased symptom burden, particularly regarding abdominal pain, nausea, and vomiting, as well as improved social function and quality of life, can be obtained by use of neuromodulators. There is good evidence for the peripheral neuromodulators from studies in bowel disorders, and the central neuromodulators both from indirect evidence in chronic pain disorders as well as selected disorders of brain-gut interaction.

Summary

Basic knowledge about the pharmacologic properties and clinical use of neuromodulators in disorders of brain-gut interaction improves the treatment outcome and avoids use of traditional analgesics.

Neuromodulators for Functional Gastrointestinal Disorders (Disorders of Gut-Brain Interaction): A Rome Foundation Working Team Report

BACKGROUND & AIMS

Central neuromodulators (antidepressants, antipsychotics, and other central nervous system-targeted medications) are increasingly used for treatment of functional gastrointestinal disorders (FGIDs), now recognized as disorders of gut-brain interaction. However, the available evidence and guidance for the use of central neuromodulators in these conditions is scanty and incomplete. In this Rome Foundation Working Team report, a multidisciplinary team summarized available research evidence and clinical experience to provide guidance and treatment recommendations.

METHODS

The working team summarized the literature on the pharmacology of central neuromodulators and their effects on gastrointestinal sensorimotor function and conducted an evidence-based review on their use for treating FGID syndromes. Because of the paucity of data for FGIDs, we included data for non-gastrointestinal painful disorders and specific symptoms of pain, nausea, and vomiting. This information was combined into a final document comprising a synthesis of available evidence and recommendations for clinical use guided by the research and clinical experience of the experts on the committee.

RESULTS

The evidence-based review on neuromodulators in FGID, restricted by the limited available controlled trials, was integrated with open-label studies and case series, along with the experience of experts to create recommendations using a consensus (Delphi) approach. Due to the diversity of conditions and complexity of treatment options, specific recommendations were generated for different FGIDs. However, some general recommendations include: (1) low to modest dosages of tricyclic antidepressants provide the most convincing evidence of benefit for treating chronic gastrointestinal pain and painful FGIDs and serotonin noradrenergic reuptake inhibitors can also be recommended, though further studies are needed; (2) augmentation, that is, adding a second treatment (adding quetiapine, aripiprazole, buspirone α2δ ligand agents) is recommended when a single medication is unsuccessful or produces side effects at higher dosages; (3) treatment should be continued for 6-12 months to potentially prevent relapse; and (4) implementation of successful treatment requires effective communication skills to improve patient acceptance and adherence, and to optimize the patient-provider relationship.

CONCLUSIONS

Based on systematic and selectively focused review and the consensus of a multidisciplinary panel, we have provided summary information and guidelines for the use of central neuromodulators in the treatment of chronic gastrointestinal symptoms and FGIDs. Further studies are needed to confirm and refine these recommendations.

An update on emerging drugs for fibromyalgia treatment

INTRODUCTION

Fibromyalgia (FM) is a chronic disorder whose symptoms of pain, fatigue, sleep disturbances and depression have a devastating effect on patients' lives as it limits their ability to engage in everyday working and social activities, and make it difficult to maintain normal relationships with family, friends and employers. None of the currently available drugs are fully effective against the whole spectrum of symptoms. The aim of this narrative review is to summarise the data relating to the new therapeutic options that have become available over the last few years. Areas covered: Increasing efforts by the pharmaceutical industry have led to the introduction of new investigational drugs and new formulations of older drugs, and studies have been carried out in order to investigate the possibility of using drugs that are currently used for other diseases. Expert opinion: Slight improvements in the health of FM patients treated with drugs targeting a range of molecular mechanisms have been observed, but there is still no single drug that is capable of offering substantial efficacy against all of the characteristic symptoms of FM. The identification of new and improved therapies for FM requires consideration of the heterogeneity of the condition, which suggests the existence of different patient subgroups, a relationship between central and peripheral aspects of the pathophysiology, and the need for combined treatment with drugs targeting multiple molecular mechanisms.

A Brief Review of the Pharmacology of Amitriptyline and Clinical Outcomes in Treating Fibromyalgia

Fibromyalgia is a complex chronic condition characterized by pain, physical fatigue, sleep disorder and cognitive impairment. Evidence-based guidelines recommend antidepressants as treatments of fibromyalgia where tricyclics are often considered to have the greatest efficacy, with amitriptyline often being a first-line treatment. Amitriptyline evokes a preferential reduction in pain and fatigue of fibromyalgia, and in the Fibromyalgia Impact Questionnaire (FIQ) score, which is a quality of life assessment. The multimodal profile of the mechanisms of action of amitriptyline include monoamine reuptake inhibition, receptor modulation and ion channel modulation. Several of the actions of amitriptyline on multiple nociceptive and sensory processes at central and peripheral locations have the potential to act cumulatively to suppress the characteristic symptoms of fibromyalgia. Greater understanding of the role of these mechanisms of action of amitriptyline could provide further clues to the pathophysiology of fibromyalgia and to a preferable pharmacological profile for future drug development.

Centrally Targeted Pharmacotherapy for Chronic Abdominal Pain: Understanding and Management

Chronic abdominal pain has a widespread impact on the individual and the society. Identifying and explaining mechanisms of importance for the pain experience within a biopsychosocial context are central in order to select treatment that has a chance for symptom reduction. With current knowledge of brain-gut interactions, chronic abdominal pain, which mostly appears in functional gastrointestinal disorders, to a large extent involves pain mechanisms residing within the brain. As such, the use of centrally targeted pharmacotherapy as an effective treatment option is obvious in a selected number of patients. The antidepressants are most common, but also other classes of medications can be used, either alone or in combination. The latter option refers to when there is insufficient effect of one drug alone or side effects limiting dosage, and when combined in lower doses, certain drugs give rise to augmentation effects. This chapter outlines basic mechanisms of importance for the understanding of chronic abdominal pain and the pharmacologic treatment options.

Potential drug therapies for the treatment of fibromyalgia

INTRODUCTION

Fibromyalgia (FM) is a common, complex chronic widespread pain condition is characterized by fatigue, sleep disturbance and cognitive dysfunction. Treatment of FM is difficult, requiring both pharmacological and non-pharmacological approaches, with an empiric approach to drug therapy focused toward individual symptoms, particularly pain. The effectiveness of current medications is limited with many patients discontinuing use.

AREAS COVERED

A systemic database search has identified 26 molecular entities as potential emerging drug therapies. Advances in the understanding of the pathophysiology of FM provides clues to targets for new medications. Investigation of bioamine modulation and α2δ ligands and novel targets such as dopamine receptors, NMDA receptors, cannabinoid receptors, melatonin receptors and potassium channels has identified potential drug therapies.

EXPERT OPINION

Modest improvement of health status in patients with FM has been observed with drugs targeting a diverse range of molecular mechanisms. No single drug, however, offered substantial efficacy against all the symptoms characteristic of FM. Identification of new and improved therapies for FM needs to address the heterogeneity of the condition, which suggests existence of patient subgroups, the relationship of central and peripheral aspects of the pathophysiology and a requirement of combination therapy with drugs targeting multiple molecular mechanisms.

Antipsychotics for fibromyalgia in adults

BACKGROUND

This review is one of a series on drugs used to treat fibromyalgia. Fibromyalgia is a clinically well-defined chronic condition of unknown aetiology characterised by chronic widespread pain that often co-exists with sleep problems and fatigue. It affects approximately 2% of the general population. Up to 70% of patients with fibromyalgia meet the criteria for a depressive or anxiety disorder. People often report high disability levels and poor health-related quality of life. Drug therapy focuses on reducing key symptoms and disability, and improving health-related quality of life. Antipsychotics might reduce fibromyalgia and associated mental health symptoms.

OBJECTIVES

To assess the efficacy, tolerability and safety of antipsychotics in fibromyalgia in adults.

SEARCH METHODS

We searched CENTRAL (2016, Issue 4), MEDLINE and EMBASE to 20 May 2016, together with reference lists of retrieved papers and reviews and two clinical trial registries. We also contacted trial authors.

SELECTION CRITERIA

We selected controlled trials of at least four weeks duration of any formulation of antipsychotics used for the treatment of fibromyalgia in adults.

DATA COLLECTION AND ANALYSIS

We extracted the data from all included studies and two review authors independently assessed study risks of bias. We resolved discrepancies by discussion. We performed analysis using three tiers of evidence. We derived first tier evidence from data meeting current best standards and subject to minimal risk of bias (outcome equivalent to substantial pain intensity reduction, intention-to-treat analysis without imputation for drop-outs, at least 200 participants in the comparison, eight to 12 weeks duration, parallel design), second tier evidence from data that failed to meet one or more of these criteria and that we considered at some risk of bias but with adequate numbers in the comparison, and third tier evidence from data involving small numbers of participants that we considered very likely to be biased or used outcomes of limited clinical utility, or both. We rated the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included a total of four studies with 296 participants.Three studies with 206 participants compared quetiapine, an atypical (second-generation) antipsychotic, with placebo. One study used a cross-over design and two studies a parallel-group design. Study duration was eight or 12 weeks. Quetiapine was used in all studies with a bedtime dosage between 50 and 300 mg/day. All studies had one or more sources of potential major bias and we judged them to be at moderate risk of bias overall. The primary outcomes in this review were participant-reported pain relief of 50% or greater, Patient Global Impression of Change (PGIC) much or very much improved, withdrawal due to adverse events (tolerability) and serious adverse events (safety).Second tier evidence indicated that quetiapine was not statistically superior to placebo in the number of participants with a 50% or more pain reduction (very low quality evidence). No study reported data on PGIC. A greater proportion of participants on quetiapine reported a 30% or more pain reduction (risk difference (RD) 0.12, 95% confidence interval (CI) 0.00 to 0.23; number needed to treat for an additional benefit (NNTB) 8, 95% CI 5 to 100) (very low quality evidence). A greater proportion of participants on quetiapine reported a clinically relevant improvement of health-related quality of life compared to placebo ( RD 0.18, 95% CI 0.05 to 0.31; NNTB 5, 95% CI 3 to 20) (very low quality evidence). Quetiapine was statistically superior to placebo in reducing sleep problems (standardised mean difference (SMD) -0.67, 95% CI -1.10 to -0.23), depression (SMD -0.39, 95% CI -0.74 to -0.04) and anxiety (SMD -0.40, 95% CI -0.69 to -0.11) (very low quality evidence). Quetiapine was statistically superior to placebo in reducing the risk of withdrawing from the study due to a lack of efficacy (RD -0.14, 95% CI -0.23 to -0.05) (very low quality evidence). There was no statistically significant difference between quetiapine and placebo in the proportion of participants withdrawing due to adverse events (tolerability) (very low quality evidence), in the frequency of serious adverse events (safety) (very low quality evidence) and in the proportion of participants reporting dizziness and somnolence as an adverse event (very low quality evidence). In more participants in the quetiapine group a substantial weight gain was noted (RD 0.08, 95% CI 0.02 to 0.15; number needed to treat for an additional harm (NNTH) 12, 95% CI 6 to 50) (very low quality evidence). We downgraded the quality of evidence by three levels to a very low quality rating because of limitations of study design, indirectness (patients with major medical diseases and mental disorders were excluded) and imprecision (fewer than 400 patients were analysed).One parallel design study with 90 participants compared quetiapine (50 to 300 mg/day flexible at bedtime) to amitriptyline (10 to 75 mg/day flexible at bedtime). The study had three major risks of bias and we judged it to be at moderate risk of bias overall. We downgraded the quality of evidence by two levels to a low quality rating because of indirectness (patients with major medical diseases and mental disorders were excluded) and imprecision (fewer than 400 patients were analysed). Third tier evidence indicated no statistically significant differences between the two drugs. Both drugs did not statistically significantly differ in the reduction of average scores for pain, fatigue, sleep problems, depression, anxiety and for limitations of health-related quality of life and in the proportion of participants reporting dizziness, somnolence and weight gain as a side effect (low quality evidence). Compared to amitriptyline, more participants left the study due to adverse events (low quality evidence). No serious adverse events were reported (low quality evidence).We found no relevant study with other antipsychotics than quetiapine in fibromyalgia.

AUTHORS' CONCLUSIONS

Very low quality evidence suggests that quetiapine may be considered for a time-limited trial (4 to 12 weeks) to reduce pain, sleep problems, depression and anxiety in fibromyalgia patients with major depression. Potential side effects such as weight gain should be balanced against the potential benefits in shared decision making with the patient.

An update on pharmacotherapy for the treatment of fibromyalgia

INTRODUCTION

Fibromyalgia is a syndrome characterized by chronic generalized pain in addition to different symptoms such as fatigue, sleep disturbances, stiffness, cognitive impairment, and psychological distress. Multidisciplinary treatment combining pharmacological and nonpharmacological therapies is advised.

AREAS COVERED

Publications describing randomized controlled trials and long-term extension studies evaluating drug treatment for fibromyalgia were searched in PubMed and Scopus and included in this review.

EXPERT OPINION

Different drugs are recommended for the treatment of fibromyalgia by different published guidelines, although only three of them have been approved for this indication by the US FDA, and none have been approved by the European Medicines Agency. According to the available evidence, pregabalin, duloxetine and milnacipran should be the drugs of choice for the treatment of this disease, followed by amitriptyline and cyclobenzaprine. Other drugs with at least one positive clinical trial include some selective serotonin reuptake inhibitors, moclobemide, pirlindole, gabapentin, tramadol, tropisetron, sodium oxybate and nabilone. None of the currently available drugs are fully effective against the whole spectrum of fibromyalgia symptoms, namely pain, fatigue, sleep disturbances and depression, among the most relevant symptoms. Combination therapy is an option that needs to be more thoroughly investigated in clinical trials.

Fibromyalgia

Fibromyalgia is a common illness characterized by chronic widespread pain, sleep problems (including unrefreshing sleep), physical exhaustion and cognitive difficulties. The definition, pathogenesis and treatment are controversial, and some even contest the existence of this disorder. In 1990, the American College of Rheumatology (ACR) defined classification criteria that required multiple tender points (areas of tenderness occurring in muscles and muscle-tendon junctions) and chronic widespread pain. In 2010, the ACR preliminary diagnostic criteria excluded tender points, allowed less extensive pain and placed reliance on patient-reported somatic symptoms and cognitive difficulties. Fibromyalgia occurs in all populations worldwide, and symptom prevalence ranges between 2% and 4% in the general population. The prevalence of people who are actually diagnosed with fibromyalgia ('administrative prevalence') is much lower. A model of fibromyalgia pathogenesis has been suggested in which biological and psychosocial variables interact to influence the predisposition, triggering and aggravation of a chronic disease, but the details are unclear. Diagnosis requires the history of a typical cluster of symptoms and the exclusion of a somatic disease that sufficiently explains the symptoms by medical examination. Current evidence-based guidelines emphasize the value of multimodal treatments, which encompass both non-pharmacological and selected pharmacological treatments tailored to individual symptoms, including pain, fatigue, sleep problems and mood problems. For an illustrated summary of this Primer, visit: http://go.nature.com/LIBdDX.

Centrally targeted pharmacotherapy for chronic abdominal pain

BACKGROUND

Chronic abdominal pain in the context of the functional gastrointestinal disorders departs from a more traditional approach to treating gastrointestinal symptoms. Chronic abdominal pain involves a dysregulation of brain-gut modulation of afferent signaling, so treatments directed toward the gut are not usually sufficient to achieve a clinical response. Rather the methods of treatment depend on re-establishing central pain regulation.

PURPOSE

A conceptual model of predisposing, precipitating, and perpetuating factors is used to explain how a situation of chronic pain develops and it provides the evidence for central neuron degeneration as relevant to this chain of events. The rationale for centrally targeted medications, in particular antidepressants, is discussed with regard to effects independent of their role in treating psychiatric disorders: with regard to downregulation of afferent pain signals and their potential role in neuron proliferation. Finally, guiding examples of which drug to use and treatment combinations involving multiple drugs, augmentation treatment, are outlined and some brief clinical cases of centrally targeted pharmacotherapy.