Comparing duloxetine and pregabalin for treatment of pain and depression in women with fibromyalgia: an open-label randomized clinical 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.

Effectiveness of primary care interventions in conjointly treating comorbid chronic pain and depression: a systematic review and meta-analysis

BACKGROUND

Chronic pain and depression are highly comorbid, but the lack of consensus on the best treatment strategies puts patients at high risk of suboptimal care-coordination as well as health and social complications. Therefore, this study aims to quantitatively assesses how effective different primary care interventions have been in treating the comorbid state of chronic pain and depression. In particular, this study evaluates both short-term outcomes-based specifically on measures of chronic pain and depression during an intervention itself-and long-term outcomes or measures of pain and depression in the months after conclusion of the formal study intervention.

METHODS

This study is a systematic review and meta-analysis of randomised-controlled trials (RCTs) enrolling patients with concurrent chronic pain and depression. Intensity and severity of pain and depression symptoms were the primary outcomes. The main inclusion criteria were RCTs that: (i) enrolled patients diagnosed with depression and chronic pain, (ii) occurred in primary care settings, (iii) reported baseline and post-intervention outcomes for chronic pain and depression, (iv) lasted at least 8 weeks, and (v) used clinically validated outcome measures. Risk of bias was appraised with the Risk of Bias 2 tool, and GRADE guidelines were used to evaluate the quality of evidence.

RESULTS

Of 692 screened citations, 7 multicomponent primary care interventions tested across 891 patients were included. Meta-analyses revealed significant improvements in depression at post-intervention (SMD = 0.44, 95% CI [0.17, 0.71], P = 0.0014) and follow-up (SMD = 0.41, 95% CI [0.01, 0.81], P = 0.0448). Non-significant effects were observed for chronic pain at post-intervention (SMD = 0.27, 95% CI [-0.08, 0.61], P = 0.1287) and follow-up (SMD = 0.13, 95% CI [-0.3, 0.56], P = 0.5432).

CONCLUSIONS

Based on the results of the meta-analysis, primary care interventions largely yielded small to moderate positive effects for depressive symptoms and no significant effects on pain. In one study, stepped-care to be more effective in treatment of comorbid chronic pain and depression than other interventions both during the intervention and upon post-intervention follow-up. As such, depression appears more amenable to treatment than pain, but the number of published RCTs assessing both conditions is limited. More research is needed to further develop optimal treatment strategies.

Pharmacotherapeutic advances in fibromyalgia: what's new on the horizon?

INTRODUCTION

This review delves into Fibromyalgia Syndrome (FMS), a chronic pain condition demanding thorough understanding for precise diagnosis and treatment. Yet, a definitive pharmacological solution for FMS remains elusive.

AREAS COVERED

In this article, we systematically analyze various pharmacotherapeutic prospects for FMS treatment, organized into sections based on the stage of drug development and approval. We begin with an overview of FDA-approved drugs, discussing their efficacy in FMS treatment. Next, we delve into other medications currently used for FMS but still undergoing further study, including opioids and muscle relaxants. Further, we evaluate the evidence behind medications that are currently under study, such as cannabinoids and naltrexone. Lastly, we explore new drugs that are in phase II trials. Our research involved a thorough search on PUBMED, Google Scholar, and clinicaltrials.gov. We also discuss the action mechanisms of these drugs and their potential use in specific patient groups.

EXPERT OPINION

A focus on symptom-driven, combination therapy is crucial in managing FMS. There is also a need for ongoing research into drugs that target neuroinflammation, immunomodulation, and the endocannabinoid system. Bridging the gap between benchside research and clinical application is challenging, but it holds potential for more targeted and effective treatment strategies.

Low Dose Pregabalin Improves Gastrointestinal Symptoms of Crohn's Disease

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are lifelong conditions with no definite cure. Several studies demonstrated that patients with IBD more frequently experience symptoms of common mental disorders, such as anxiety and depression, because of bidirectional communication through the gut-brain axis and the chronicity of symptoms, as well as because of impaired quality of life and reduced social functioning. However, psychological conditions of affected patients are often underestimated and not fully considered. Herein, we present the case of a 37-year-old woman with Crohn's disease and a mild depressive condition, characterized by anxious distress, tachycardia, tachypnea, tremors, sweating, avoidant behaviors, and intestinal somatizations (diarrhea), who was treated with Pregabalin upon indication of the referring psychiatrist. Following the beginning of the treatment, the patient rapidly reported an improvement in the overall clinical symptoms as well as a better management of psychic and physical anxiety with a marked reduction in diarrheal discharges under stress at work. After 6 months of Pregabalin therapy, we additionally observed an improvement in Crohn's disease activity, both clinically, in the laboratory, and endoscopically. Our case showed that patients with Crohn's disease and anxiety problems may benefit from low-dose Pregabalin medication to improve both their mental and physical condition.

Correlation between levels of perceived stress and depressive symptoms in the functional disability of patients with fibromyalgia

OBJECTIVE

The aim of this study was to evaluate the factors that are most correlated with the levels of functional disability in patients with fibromyalgia.

METHODS

This is a cross-sectional descriptive study in which 42 patients diagnosed with fibromyalgia according to the criteria of the American College of Rheumatology reported their status using the following questionnaires: the Beck Depression Inventory, the Perceived Stress Scale 14, the Revised Fibromyalgia Impact Questionnaire, the Visual Analog Pain Scale, and the Health Assessment Questionnaire.

RESULTS

Moderate to severe levels of depression (Beck Depression Inventory: 22.35±10.39), moderate to severe functional disability (Health Assessment Questionnaire: 1.28±0.58), and high levels of stress (Perceived Stress Scale 14: 31.59±10.02) were found. The correlation adjusted by multiple regression as a function of the Health Assessment Questionnaire indicated a negligible to weak positive correlation with perceived stress (r=0.11), while a moderately strong positive correlation was observed with the Visual Analog Pain Scale (r=0.55). Regarding physical exercise, one of the pillars of the treatment, a moderate negative correlation was found with the Health Assessment Questionnaire (r=-0.4).

CONCLUSION

The pain levels were moderately influenced by depression severity. The factors most linked to functional disability are due to the pain levels but not to the perception of stress.

Electroacupuncture attenuates chronic inflammatory pain and depression comorbidity by inhibiting hippocampal neuronal apoptosis via the PI3K/Akt signaling pathway

In chronic inflammatory pain (CIP) and depression, neuroapoptosis has been identified as a contributing factor. Electroacupuncture (EA) shows promise as an alternative therapy for this comorbidity. However, the underlying mechanism remains unclear. This study aimed to investigate the effects of EA on hippocampal neuronal apoptosis in rats with CIP and depression. Rats received plantar injections of complete Freund's adjuvant (CFA) on days 0 and 14. They were then divided into groups: sham operation, model, EA, and duloxetine. EA was administered at Hegu (LI4) and Taichong (LR3) from days 15 to 28, while the duloxetine group received duloxetine and distilled water daily (0.1 mg/ml). Pain behavior was assessed using the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) tests. Depression-like behavior was evaluated through the sucrose preference test (SPT), open-field test (OFT), and forced swim test (FST). Hematoxylin and eosin (HE) staining was employed to assess pathological changes in the hippocampus. Nerve cell apoptosis was determined using TUNEL fluorescence staining. Western blot analysis was conducted to measure the protein expression of Bcl-2, Bax, p-PI3K/PI3K, and p-Akt/Akt. EA demonstrated significant pain intensity reduction and alleviation of pain-related depressive symptoms. Our findings from the HE staining confirmed that CIP induced by CFA led to morphological changes in the hippocampus, while EA effectively reversed these pathological alterations. Moreover, EA intervention remarkably reduced neuronal apoptosis and exhibited an upregulation of Bcl-2 protein expression accompanied by a decrease in Bax expression. Additionally, EA activated the PI3K/Akt signaling pathway. Overall, our study suggests that EA holds the potential to improve pain and depressive behaviors in rats with CIP and depression comorbidity, potentially mediated through the activation of the PI3K/Akt pathway, leading to a reduction in hippocampal neuronal apoptosis.

Pharmacologic Management of Cancer-Related Pain in Pregnant Patients

Despite being an essential part of whole-person care, patients with cancer often experience complex and under-treated pain. Managing cancer-related pain in patients who are also pregnant compounds the challenge for adequate pain management, as studies have largely excluded this population. Therapy for pain management should be guided by the cause and mechanism of pain. The objective of this review is to provide clinicians with an understanding of pain experienced by pregnant patients with cancer and medications that may be used to help manage cancer-related pain. Nociceptive pain results from damage to somatic or visceral tissues that may be directly caused by cancer. This type of pain can be managed in pregnant patients using acetaminophen and/or nonsteroidal antiinflammatory drugs as first-line agents. In nociceptive pain not managed by non-opioid analgesics, buprenorphine is recommended for those requiring chronic opioids to help manage their pain. Neuropathic pain that results from damage to the peripheral or central nervous system may also be directly caused by cancer, particularly chemotherapy. In pregnant patients, duloxetine and gabapentin should be considered first. Venlafaxine, pregabalin, tricyclic antidepressants, and sodium channel blockers should be avoided, if possible. Nociplastic pain is not directly caused by cancer but may be caused by ongoing peripheral nociceptive input or a condition that predates the cancer diagnosis. Duloxetine and gabapentin are reasonable agents to consider for treatment of nociceptive pain in pregnant patients. Cyclobenzaprine may also be helpful for nociplastic pain.

Efficacy and safety of duloxetine in chronic musculoskeletal pain: a systematic review and meta-analysis

BACKGROUND

Chronic musculoskeletal pain (CMP) is a complex condition that is mainly treated with analgesic drugs. However, antidepressant intervention is also an important factor in the treatment of CMP. Duloxetine is an effective treatment option for patients with CMP as its antidepressant effect. The purpose of this article is to evaluate the efficacy and safety of duloxetine in treating CMP.

DATABASES AND DATA TREATMENT

We searched PubMed, Web of Science, Embase, Cochrane Library from inception to May, 2022. Randomized controlled trials (RCTs) evaluating the efficacy and safety of duloxetine versus placebo in patients with CMP were included. We identified 13 articles and studied a population of 4201 participants in 4 countries.

RESULTS

This meta-analysis showed that the duloxetine has statistically significant compared with the placebo control, benefits on 24-hour average pain, living quality, physical function, and global impressions and there was no difference in the incidence of serious adverse event. In general, duloxetine can improve mood and pain level at the same time.

CONCLUSIONS

This review shows a significant contribution of duloxetine to CMP symptom relief. This meta-analysis improved that duloxetine can significantly reduce the pain level of patients, improve depressive symptoms and global impression, and has no obvious serious adverse reactions. However, additional studies are required to confirm the relationship between psychological diseases and chronic pain and explore their internal links.

Tolerability and efficacy of duloxetine for the prevention of persistent musculoskeletal pain after trauma and injury: a pilot three-group randomized controlled trial

ABSTRACT

This study investigated the tolerability and preliminary efficacy of duloxetine as an alternative nonopioid therapeutic option for the prevention of persistent musculoskeletal pain (MSP) among adults presenting to the emergency department with acute MSP after trauma or injury. In this randomized, double-blind, placebo-controlled study, eligible participants (n = 78) were randomized to 2 weeks of a daily dose of one of the following: placebo (n = 27), 30 mg duloxetine (n = 24), or 60 mg duloxetine (n = 27). Tolerability, the primary outcome, was measured by dropout rate and adverse effects. Secondary outcomes assessed drug efficacy as measured by (1) the proportion of participants with moderate to severe pain (numerical rating scale ≥ 4) at 6 weeks (pain persistence); and (2) average pain by group over the six-week study period. We also explored treatment effects by type of trauma (motor vehicle collision [MVC] vs non-MVC). In both intervention groups, duloxetine was well tolerated and there were no serious adverse events. There was a statistically significant difference in pain over time for the 60 mg vs placebo group ( P = 0.03) but not for the 30 mg vs placebo group ( P = 0.51). In both types of analyses, the size of the effect of duloxetine was larger in MVC vs non-MVC injury. Consistent with the role of stress systems in the development of chronic pain after traumatic stress, our data indicate duloxetine may be a treatment option for reducing the transition from acute to persistent MSP. Larger randomized controlled trials are needed to confirm these promising results.

Association between descending pain modulatory system and cognitive impairment in fibromyalgia: A cross-sectional exploratory study

Background

The successful regulation of sensory input to the central nervous system depends on the descending pain modulatory system (DPMS). For the effective regulation of sensory input to the central nervous system and behavioral responses to pain, the DPMS is required. Its connection to fibromyalgia (FM)-related cognitive dysfunction has not yet been investigated. Therefore, this study tested whether measures of verbal fluency, sustained attention, and short-term and working memory could distinguish FM patients from healthy controls (HC). Additionally, it investigated, using a standardized paradigm, the link between cognitive ability and the function of the DPMS in responders and non-responders to the conditioned pain modulation test (CPM-test).

Materials and methods

We enrolled 21 HC women and 69 FM patients, all of whom ranged in age from 30 to 65. We employed scores from the Trail Making Test (TMTB-A) (sustained and divided attention), the Controlled Oral Word Association Test (COWAT) (orthographic and semantic fluency), and the Digits subtest of the Wechsler Adult Intelligence Scale (WAIS-III) as dependent variables.

Results

A generalized linear model (GLM) adjusted by educational level revealed significantly lower scores in FM than HC on the Span digits forward, COWAT-orthographic, and TMTB-A. For FM patients, multilevel MANCOVA revealed that the cognitive performance of non-responders compared to responders to CPM-test showed lower adjusted scores in Span digits forward (Partial-η² = 0.358, P = 0.001), Span digits backward (Partial-η² = 0.358, P = 0.001), COWAT-orthographic (Partial-η² = 0.551, P = 0.001), COWAR-semantic (Partial-η² = 0.355, P = 0.001), and TMTB-A (Partial-η² = 0.360, P = 0.001). The association between the cognitive tests and the DPMS is moderated by the serum level of brain-derived neurotrophic factor (BDNF). Additionally, these cognitive assessments had a positive correlation with antidepressant use and pain threshold. The cognitive assessments, on the other hand, were conversely associated with a life of quality.

Conclusion

Based on these findings, it can be shown that HC performed substantially better on cognitive exams than FM did. They demonstrated a link between clinical complaints about attention and memory and decreased DPMS effectiveness. Additionally, they demonstrated that the BDNF is a moderating element in a potential relationship between the severity of cognitive impairment and DPMS dysfunction.

Outcomes and Predictors of Response of Duloxetine for the Treatment of Persistent Idiopathic Dentoalveolar Pain: A Retrospective Multicenter Observational Study

Background

Duloxetine has been reported to significantly relieve the pain of persistent idiopathic dentoalveolar pain (PIDP); however, the number of studies available is scarce and no study has identified the predictors of response of duloxetine for the treatment of PIDP.

Objective

To report the efficacy, safety, and identification of positive predictors of duloxetine for PIDP patients through a retrospective multicenter observational study.

Methods

We retrospectively reviewed the clinical database of PIDP patients who were prescribed duloxetine at 3 hospitals between January 2018 and November 2021. Demographic and pain-related baseline data, efficacy of patients after 3 months of medication by visual analog scale (VAS) scores for pain and adverse events were extracted and analyzed. The predictors of pain-relieving effect of duloxetine were identified by logistic regression analysis.

Results

A total of 135 patients were included in this study. Side effects occurred immediately after taking duloxetine in 24 (17.8%) patients, and the treatment with duloxetine was discontinued on 13 of them because they could not tolerate the side effects. Other 11 (8.1%) patients gradually tolerated the side effects within 2 weeks. Ninety-four out of 122 (77.0%) patients obtained pain relief with VAS significantly decreased (p < 0.01) and the other 28 (23.0%) patients stopped taking the drug because of weak efficacy. Binary logistic regression analysis showed that short disease duration (OR = 1.017, 95% CI = 1.004–1.030, P = 0.012) was an independent predictor of the positive response of duloxetine.

Conclusion

This study confirmed that duloxetine can significantly improve chronic pain of PIDP patients, and the safety was tolerable. Patients with shorter disease duration had more benefit from duloxetine.

Limitations

This is a retrospective observational study. Long-term efficacy and safety of duloxetine in the treatment of PIDP patients were not evaluated.

Thalamocortical bistable switch as a theoretical model of fibromyalgia pathogenesis inferred from a literature survey

Fibromyalgia (FM) is an unsolved central pain processing disturbance. We aim to provide a unifying model for FM pathogenesis based on a loop network involving thalamocortical regions, i.e., the ventroposterior lateral thalamus (VPL), the somatosensory cortex (SC), and the thalamic reticular nucleus (TRN). The dynamics of the loop have been described by three differential equations having neuron mean firing rates as variables and containing Hill functions to model mutual interactions among the loop elements. A computational analysis conducted with MATLAB has shown a transition from monostability to bistability of the loop behavior for a weakening of GABAergic transmission between TRN and VPL. This involves the appearance of a high-firing-rate steady state, which becomes dominant and is assumed to represent pathogenic pain processing giving rise to chronic pain. Our model is consistent with a bulk of literature evidence, such as neuroimaging and pharmacological data collected on FM patients, and with correlations between FM and immunoendocrine conditions, such as stress, perimenopause, chronic inflammation, obesity, and chronic dizziness. The model suggests that critical targets for FM treatment are to be found among immunoendocrine pathways leading to GABA/glutamate imbalance having an impact on the thalamocortical system.

Fibromyalgia and Depression: A Literature Review of Their Shared Aspects

Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread, persistent pain that lasts more than three months without an evident organic lesion. FM has been considered controversial throughout history due to its validity as a diagnosis being constantly in question. Most patients diagnosed with FM are females. FM has been associated with multiple conditions, including irritable bowel and psychiatric disorders. Among all associated conditions, depression has been frequently found in patients with FM. Studies suggest that depression negatively affects the outcome of patients with FM. Moreover, a bidirectional relation between FM and depression has been depicted: depression increases the risk of FM being diagnosed later in life, as well as FM increases the risk of developing depression. In this article, we discussed aspects that FM and depression share and that might link both diseases, such as certain elements they seem to share in their pathophysiology: predisposing and triggering factors, central sensitization and kindling, areas of the brain implicated in both pain modulation and mood regulation, and hypothalamic-pituitary-adrenal axis (HPA axis) alterations. In addition, we highlighted the prevalence of depression in patients with FM, overlapping symptoms between FM and depression and how to assess them, and treatment strategies that have shown effective management of both conditions when concomitant. Due to the improvement of many aspects of FM when depression is appropriately targeted, screening for depression in patients with FM, despite its difficulty, has been encouraged.

Depression: A Modifiable Risk Factor for Poor Outcomes in Fibromyalgia

Background:

About 4 out of 10 fibromyalgia patients suffer from depression. The European Alliance of Associations for Rheumatology (EULAR) guidelines recommend using antidepressants to treat fibromyalgia.

Objective:

To determine predictors of improved outcomes following a multicomponent treatment program.

Design:

We designed this longitudinal treatment outcome study to evaluate the prevalence of depression symptoms in patients diagnosed with fibromyalgia at a tertiary care facility, and the impact of depression on functional outcomes after completing a multicomponent fibromyalgia treatment program.

Setting:

Tertiary care center.

Patients:

This study included 411 adult patients with fibromyalgia who completed a multicomponent treatment program for fibromyalgia. Expert physicians performed comprehensive evaluations following American College of Rheumatology (ACR) criteria to confirm fibromyalgia before referral to the program.

Intervention:

An intensive outpatient multicomponent treatment program consisting of 16 hours of cognitive behavioral strategies served as the intervention.

Measurements:

Functional status was assessed using the Fibromyalgia Impact Questionnaire Revised (FIQR). Depression was evaluated with the Center for Epidemiologic Study of Depression (CES-D) measure. Measures were administered prior to participation in the program and approximately 5 months following completion of the program.

Results:

The cohort had a high prevalence of depressive symptoms (73.2% had depression at admission). Higher depression scores at baseline predicted poorer outcomes following multi-component treatment. Effectively treated depression resulted in improved functioning at follow-up.

Limitations:

Findings limited to tertiary care center cohort of fibromyalgia patients. Patients did not undergo a structured clinical diagnostic interview to diagnose depression.

Conclusions:

The current data links depression to poorer outcomes in patients with fibromyalgia. Depression is an important modifiable factor in the management of fibromyalgia. Guidelines should reflect the importance of assessing and effectively treating depression at the time of diagnosis of fibromyalgia, to improve functional outcomes.

Registration:

Specific registry and specific study registration number—Institutional Review Board—(IRB# 19-000495).

Funding Source:

No funding.

An Updated Systematic Review and Meta-analysis of Duloxetine for Knee Osteoarthritis Pain

OBJECTIVE

We conducted the updated systematic review and meta-analysis of the best available quantitative and qualitative evidence to evaluate the effects and safety of duloxetine for the treatment of knee osteoarthritis (OA) pain.

METHODS

A comprehensive literature search used 3 English and 4 Chinese biomedical databases from inception through July 10, 2020. We included randomized controlled trials of duloxetine with intervention duration of 2 weeks or longer for knee OA. The primary outcome was pain intensity measured by Brief Pain Inventory and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Secondary outcome measurements included 36-Item Short Form Health Survey, Patient's Global Impression of Improvement, Clinical Global Impressions of Severity, and adverse events (AEs). The quality of all included studies was evaluated using the Cochrane risk-of-bias criteria. The review was registered in the PROSPERO (CRD 42020194072).

RESULTS

Six studies totaling 2059 patients met the eligibility criteria. Duloxetine had significant reductions in Brief Pain Inventory 24 hours average pain (mean difference [MD]=-0.74; 95% confidence interval [CI], -0.92 to -0.57; P<0.00001; I2=13%; 5 trials; 1695 patients); patient general activity (MD=-0.76; 95% CI, -0.96 to -0.56; P<0.00001; I2=0%; 5 trials; 1694 patients) WOMAC physical function subscale (MD=-4.22; 95% CI, -5.14 to -3.30; P<0.00001; I2=26%; 5 trials; 1986 patients); Patient's Global Impression of Improvement (MD=-0.48; 95% CI, -0.58 to -0.37; P<0.00001; I2=29%; 5 trials; 1741 patients); and Clinical Global Impressions of Severity (MD=-0.34; 95% CI, -0.44 to -0.24; P<0.00001; I2=0%; 4 trials; 1178 patients) compared with placebo control. However, no difference on WOMAC pain subscale (standard mean difference=-1.68; 95% CI, -3.45 to 0.08; P=0.06; I2=100%; 3 trials; 1104 patients) and in serious AEs (risk ratio=0.92; 95% CI, 0.40-2.11; P=0.84; I2=0%; 5 trials; 1762 patients) between duloxetine and placebo. Furthermore, duloxetine failed to show superior effects for improving the life quality and demonstrated more treatment-emergent AEs.

CONCLUSION

Duloxetine may be an effective treatment option for knee OA patients but further rigorously designed and well-controlled randomized trials are warranted.

Placebo effect in pharmacological management of fibromyalgia: a meta-analysis

INTRODUCTION

The management of fibromyalgia involves a combination of pharmacological and non-pharmacological treatments.

SOURCE OF DATA

Recently published literature in PubMed, Google Scholar and Embase databases.

AREAS OF AGREEMENT

Several pharmacological and non-pharmacological strategies have been proposed for the management of fibromyalgia. However, the management of fibromyalgia remains controversial. The administration of placebo has proved to be more effective than no treatment in many clinical settings and evidence supports the 'therapeutic' effects of placebo on a wide range of symptoms.

AREAS OF CONTROVERSY

The placebo effect is believed to impact the clinical outcomes, but its actual magnitude is controversial.

GROWING POINTS

A meta-analysis comparing pharmacological management versus placebo administration for fibromyalgia was conducted.

AREAS TIMELY FOR DEVELOPING RESEARCH

Drug treatment resulted to be more effective than placebo administration for the management of fibromyalgia. Nevertheless, placebo showed a beneficial effect in patients with fibromyalgia. Treatment-related adverse events occurred more frequently in the drug treatment.

LEVEL OF EVIDENCE

I, Bayesian network meta-analysis of double-blind randomized clinical trials.

No effect of approved fibromyalgia drugs on the social pain (invalidation) contrary to physical pain: an open-label short-term randomized clinical trial

OBJECTIVES

The social pain or invalidation denoting painful feeling following social conflicts or misunderstanding about illness legitimacy has been proposed as a salient disabling symptom besides physical pain or non-pain symptoms in fibromyalgia (FM). We sought to evaluate the effect of 1-month administration of duloxetine or pregabalin on the invalidation dimensions in FM patients with respect to the comparison of these two drugs on this issue.

METHOD

This open-label randomized clinical trial study was performed on FM patients whose diagnoses were confirmed by a rheumatologist based on the 2016 American College of Rheumatology (ACR). Primary outcome measure (Illness Invalidation Inventory (3*I)) and secondary outcome measures (Beck Depression Inventory-II (BDI-II), widespread pain index (WPI), and polysymptomatic distress scale (PSD)) were compared before and after treatment, using paired t test or Wilcoxon signed test.

RESULTS

Of 81 eligible FM patients, 44 patients in the duloxetine arm and 27 patients in the pregabalin arm completed the study protocol. Overall, no significant improvement was seen in 3*I scores after treatment with either duloxetine or pregabalin, except in the lack of understanding of medical professionals which improved after treatment with pregabalin (2.43 ± 1.38 to 1.79 ± 0.94, p value: 0.01). There were no intragroup and intergroup differences in the effects of duloxetine and pregabalin on 3*I scores when adjusted with the cofounders. Both duloxetine and pregabalin improved WPI, BDI-II, and PSD scores significantly.

CONCLUSIONS

Short-term FM pharmacological treatment had no effect on social pain. This finding was regardless of drug type, improvement of physical pain, and depression.

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.

BMI but not age and sex negatively impact on the outcome of pharmacotherapy in fibromyalgia: a systematic review

INTRODUCTION

The impact of sex, age, body mass index (BMI) in fibromyalgia is still unclear. A systematic review was conducted to investigate whether sex, age and BMI influence the clinical outcomes and rate of adverse events.

METHODS

The present study was performed according to the PRISMA guidelines. The literature search was performed in February 2021. All the RCTs investigating pharmacological strategies for fibromyalgia were accessed.

RESULTS

Data from 51 RCTs (17,311 patients) were collected. Short Form 36 emotional, Social function and physical role subscales showed evidence of a negative association with BMI (P = 0.02, P = 0.002 and P = 0.0001, respectively). Depression and anxiety subscales of the Hospital Anxiety and Depression score demonstrated evidence of a positive association with age (P = 0.04 and P = 0.001, respectively) and sex (P = 0.00005 and P = 0.0001, respectively). Visual analog scale evidenced a positive association with BMI (P = 0.04). Clinical Global Impression Severity scale demonstrated evidence of a negative association with BMI (P = 0.02).

CONCLUSION

Irrespective from the pharmacological approach, a higher BMI is negatively associated with a favorable outcome in patients with fibromyalgia. The association with sex and age remains controversial.

LEVEL OF EVIDENCE

I, systematic review of RCTs.

Urinary side effects of psychotropic drugs: A systematic review and metanalysis

OBJECTIVE

To evaluate the effects of psychotropic drugs on bladder function.

MATERIALS AND METHODS

A systematic review was carried out by searching PubMed and Embase databases for randomized controlled trials enrolling patients treated with psychotropic drugs with available information on treatment-related urinary disorders.

RESULTS

A total of 52 studies was selected. In antidepressant therapy, bladder voiding symptoms, rather than storage symptoms, were more frequently observed. Pooled analysis demonstrated a higher odds ratio (OR) of voiding  disorders in comparison with placebo (OR: 3.30; confidence interval [CI]: 1.90-5.72; 7856 participants; p < 0.001). Odds for voiding dysfunction was higher for tricyclic antidepressants and for Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) when compared to Selective Serotonin Reuptake Inhibitors (SSRIs). Treatment with antipsychotics was associated with heterogeneous urinary disorders  including emptying and storage disorders. OR for incontinence in patients with dementia taking  antipsychotics was higher than placebo (OR: 4.09; CI: 1.71-9.79, p = 0.002) with no difference between different atypical antipsychotics. Rate of voiding disorders was not different between conventional and atypical antipsychotics (OR: 1.64; CI: 0.79-3.39, p = 0.19), although quetiapine showed higher odds to cause voiding dysfunction than other atypical antipsychotics (OR: 2.14; CI: 1.41-3.26; p > 0.001).

CONCLUSIONS

In patients taking tricyclic antidepressants or SNRIs, bladder voiding disorders, could be the side effects of therapy rather than symptoms of a urological disease. Patients treated with these drugs should be actively monitored for the appearance of urinary symptoms. Antipsychotic treatment is associated with various urinary side effects requiring a tailored approach.

Neuroimmune Mechanisms as Novel Treatment Targets for Substance Use Disorders and Associated Comorbidities

Recent studies examining the neurobiology of substance abuse have revealed a significant role of neuroimmune signaling as a mechanism through which drugs of abuse induce aberrant changes in synaptic plasticity and contribute to substance abuse-related behaviors. Immune signaling within the brain and the periphery critically regulates homeostasis of the nervous system. Perturbations in immune signaling can induce neuroinflammation or immunosuppression, which dysregulate nervous system function including neural processes associated with substance use disorders (SUDs). In this review, we discuss the literature that demonstrates a role of neuroimmune signaling in regulating learning, memory, and synaptic plasticity, emphasizing specific cytokine signaling within the central nervous system. We then highlight recent preclinical studies, within the last 5 years when possible, that have identified immune mechanisms within the brain and the periphery associated with addiction-related behaviors. Findings thus far underscore the need for future investigations into the clinical potential of immunopharmacology as a novel approach toward treating SUDs. Considering the high prevalence rate of comorbidities among those with SUDs, we also discuss neuroimmune mechanisms of common comorbidities associated with SUDs and highlight potentially novel treatment targets for these comorbid conditions. We argue that immunopharmacology represents a novel frontier in the development of new pharmacotherapies that promote long-term abstinence from drug use and minimize the detrimental impact of SUD comorbidities on patient health and treatment outcomes.

Efficacy of pregabalin as a monotherapy versus combined pregabalin and milnacipran in the management of fibromyalgia

AIM

To compare the efficacy and tolerability of combined pregabalin (PGB) and milnacipran (MLN) in female patients with fibromyalgia (FM) versus PGB as a monotherapy.

METHODS

The present randomized open study included 58 female patients diagnosed with FM (registered on 4/2/19: NCT03905486). Patients were randomly divided into 2 groups (2:2); group 1 included 29 patients who received PGB monotherapy (150 mg twice daily) and group 2 included 29 patients who received combined PGB (150 mg twice daily) and MLN (50 mg twice daily) for 3 months. At the initial visit, patients were subjected to demographic data collection and assessed by the visual analog scale (VAS) for pain and the FM impact questionnaire (FIQ). Outcome measures after 3 months: FIQ, VAS and Leeds Sleep Evaluation Questionnaire.

RESULTS

The median disease duration was 2 years in group 1 (6 months to 5 years) and 2 years in group 2 (6 months to 12 years). The dropout rate was 20.7% in group 1 (n = 6) and 10.3% in group 2 (n = 3). At the follow-up evaluation, a statistically significant improvement was observed in VAS and FIQ scores in both groups (P < 0.001). Although the percentage of patients demonstrating significant improvement in pain, disease impact and sleep pattern were higher in group 2, this did not reach statistical significance.

CONCLUSION

Although PGB as a monotherapy and in combination with MLN have both shown adequate efficacy in the treatment of patients with FM, the combined therapy did not demonstrate superiority over the monotherapy.

Myalgia in myositis and myopathies

Myalgia is a common symptom of various neuromuscular disorders: myalgia occurs in metabolic muscle diseases, inflammatory muscle diseases, dystrophic myopathies and myotonic muscle disorders. Myalgia leads to a significantly reduced quality of life. Other muscular symptoms that are present along with myalgia often provide the clue towards a diagnosis and include weakness, cramps and myotonia as well as the type of pain. In addition, extramuscular symptoms like an erythema in dermatomyositis can lead to the correct diagnosis. Basic diagnostic workup includes a detailed medical history, full neurologic assessment, laboratory tests, EMG and nerve conduction studies. Muscle imaging, genetic testing and muscle biopsy may be required to make a diagnosis. Whenever possible, treatment should aim to improve or correct the underlying cause for myalgia such as inflammation or hypothyroidism. Symptomatic therapy includes different avenues: Myotonia can be treated with mexiletine. Carbamazepine or phenytoin can be used in myotonic syndromes, particularly with muscle cramps. Pregabalin, gabapentin, or amitriptyline can be tried in conditions with myalgic pain. This review summarizes the symptoms, diagnostic strategies, and therapeutic approach in neuromuscular disorders that present with myalgia.