Efficacy and safety of duloxetine in patients with chronic low back pain

Association of Aromatase Inhibitor-Induced Musculoskeletal Symptoms with Central Sensitization-Related Symptoms: A Cross-Sectional Study

Introduction

Aromatase inhibitor (AI)-induced musculoskeletal symptoms (AIMSS) can decrease health-related quality of life and lead to discontinuation of AI therapy for postmenopausal women with breast cancer (BC). Although central sensitization (CS) may contribute to AIMSS, the relevance of CS-related symptoms to AIMSS has not been fully clarified. This study aimed to investigate the relationship between AIMSS and CS-related symptoms in women with BC who received AI therapy.

Methods

This cross-sectional study recruited women who underwent BC surgery before at least 1 year and were taking AI for at least 6 months. Participants were assessed for joint pain and CS-related symptoms using the central sensitization inventory (CSI). The severity of CS-related symptoms was classified into three groups, and the prevalence of AIMSS was calculated. Multiple logistic regression analysis was used to assess the relationship between AIMSS and factors of possible relevance to AIMSS, including CSI severity.

Results

Of the 73 women who were included in this study, 31 (42.4%) were categorized into the AIMSS group and 42 (57.6%) into the non-AIMSS group. Participants with a history of chemotherapy and higher CSI score were significantly more likely to have AIMSS. Multiple logistic regression analysis showed that a history of chemotherapy (odds ratio = 4.21) and higher CSI severity (odds ratio = 13.43) had significantly associated with AIMSS.

Conclusion

CS-related symptoms assessed using CSI may be strongly associated with AIMSS. Further longitudinal studies to investigate the causal relationship and effectiveness of CS-targeted interventions are needed to prevent and treat AIMSS effectively.

Effectiveness of Duloxetine versus Other Therapeutic Modalities in Patients with Diabetic Neuropathic Pain: A Systematic Review and Meta-Analysis

Objectives: Diabetic peripheral neuropathy (DPN) is a chronic complication of diabetes mellitus (DM) with symptoms like intense pain and impaired quality of life. This condition has no treatment; instead, the pain is managed with various antidepressants, including duloxetine. The aim of this study is to analyze the evidence on the efficacy of duloxetine in the management of DPN. Methods: A systematic search in different databases was conducted using the keywords "diabetic neuropathy", "duloxetine therapy", "neuropathic pain", and "Diabetes Mellitus". Finally, eight studies were included in this meta-analysis. Results: All articles comparing duloxetine at different doses vs. a placebo reported significant differences in favor of duloxetine on pain scales like 24 h Average Pain Severity (standardized mean difference [SMD] = -1.06, confidence interval [CI] = -1.09 to -1.03, and p < 0.00001) and BPI Severity (SMD = -0.70, CI = -0.72 to -0.68, and p < 0.00001), among others. A total of 75% of the meta-analyses of studies comparing duloxetine at different doses showed a tendency in favor of the 120 mg/d dose. There were significant differences in favor of duloxetine when compared to routine care on the Euro Quality of Life (SMD = -0.04, CI = -0.04 to -0.03, and p < 0.00001) and SF-36 Survey (SMD = -5.86, CI = -6.28 to -5.44, and p < 0.00001) scales. There were no significant differences on the visual analog scale (VAS) when comparing duloxetine and gabapentin. Conclusions: Duloxetine appears to be effective in the management of DPN in different pain, symptom improvement, and quality of life scales.

Efficacy of Duloxetine With Arthrocentesis in the Management of TMJ Internal Derangement

Temporomandibular joint (TMJ) arthrocentesis is one of the most commonly used non-invasive surgical interventions in the treatment of refractory pain and dysfunction associated with internal derangement. Several adjunctive therapies have been used in combination with arthrocentesis in an attempt to increase its efficacy and long-term maintenance. Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor which is used in different chronic pain conditions. This study aimed to assess the efficacy of duloxetine in combination with arthrocentesis compared with arthrocentesis alone. Twenty-eight patients with chronic TMJ pain were included and randomly allocated into 2 groups (control and study groups). The control group included patients who underwent TMJ arthrocentesis only, and the study group included patients who underwent arthrocentesis followed by giving duloxetine (30 mg) orally twice daily for 3 months. Pain, maximum mouth opening, and level of anxiety and depression were assessed preoperatively and followed at regular intervals of 1 week, 1 month, 3 months, and 6 months postoperatively. Pain was significantly reduced in both groups at all postoperative intervals and was significantly lower in the study group than the control group at 6 months. Maximum mouth opening increased significantly in both groups, but the difference between them was not significant. Level of anxiety and depression was significantly decreased in both groups, with no statistically significant difference between them. The results of this study indicate that duloxetine in combination with arthrocentesis may provide effective and long-term pain control; however, its use is associated with a higher risk of adverse events.

Probable chronic pain, brain structure, and Alzheimer's plasma biomarkers in older men

Chronic pain leads to tau accumulation and hippocampal atrophy in mice. In this study, we provide one of the first assessments in humans, examining the associations of probable chronic pain with hippocampal volume, integrity of the locus coeruleus (LC)-an upstream site of tau deposition-and Alzheimer's Disease-related plasma biomarkers. Participants were mostly cognitively unimpaired men. Probable chronic pain was defined as moderate-to-severe pain in 2+ study waves at average ages 56, 62, and 68. At age 68, 424 participants underwent structural magnestic resonance imaging (MRI) of hippocampal volume and LC-sensitive MRI providing an index of LC integrity (LC contrast-to-noise ratio). Analyses adjusted for confounders including major health conditions, depressive symptoms, and opioid use. Models showed that men with probable chronic pain had smaller hippocampal volume and lower rostral-middle-but not caudal-LC contrast-to-noise ratio compared to men without probable chronic pain. Men with probable chronic pain also had higher levels of plasma total tau, beta-amyloid-42, and beta-amyloid-40 compared to men without probable chronic pain. These findings suggest that probable chronic pain is associated with tau accumulation and reduced structural brain integrity in regions affected early in the development of Alzheimer's Disease. PERSPECTIVE: Probable chronic pain was associated with plasma biomarkers and brain regions that are affected early in Alzheimer's disease (AD). Reducing pain in midlife and elucidating biological mechanisms may help to reduce the risk of AD in older adults.

The effect of duloxetine on postoperative pain and opium consumption in spine surgery: A systematic review

Background

Postoperative pain after spinal surgery is a major problem that can impact patients' quality of life. Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI) with analgesic effect in different pain disorders. In this study, we aim to evaluate the safety and analgesic effect of duloxetine on acute and chronic pain following spine surgery.

Methods

A systematic search was completed on MEDLINE, PsycINFO, and Embase through OVID from inception to April 2023 to find relevant articles. We used Cochrane methodology to evaluate the bias of included studies. Investigated outcomes included postoperative pain, opioid consumption, and adverse events.

Results

Seven articles involving 487 participants were included in our systematic review. Out of 7 papers, 5 were randomized clinical trials, 1 was a pilot trial and 1 was a retrospective observational study. The results of these studies indicated the analgesic effect of duloxetine on postoperative pain, which was measured using numeric rating scale, verbal numeric scale, brief pain inventory, and visual analogue scale. Duloxetine was generally safe without serious adverse events. The most common reported adverse events included headache, nausea, vomiting, itching, dizziness, and drowsiness.

Conclusions

Duloxetine may be an effective treatment option for postoperative pain following spine surgery, but further rigorously designed and well-controlled randomized trials are required.

Comparative Efficacy and Safety of Antidepressants for Patients with Chronic Back Pain: A Network Meta-Analysis

Various antidepressants have introduced in clinical practice for pain management, but it is important to understand how to properly use them. We therefore performed a systematic review and network meta-analysis to compare and rank the efficacy and safety of antidepressants for patients with chronic back pain. We identified eligible randomized controlled trials (RCTs) that investigated the efficacy and safety of antidepressants for chronic back pain from PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov, searching from inception to May 2023. Six categories of antidepressants for the treatment of chronic back pain were included, and the surface under the cumulative ranking probabilities was applied to rank the treatment strategies. Overall, we selected 19 RCTs recruiting 2903 patients for the meta-analysis. Tricyclic antidepressants presented the best relative effects for relief in pain score (surface under the cumulative ranking, 84.4%). The results of pairwise comparison analyses found the use of serotonin-noradrenaline reuptake inhibitors (SNRIs) significantly reduced pain score and low disability score compared with placebo, irrespective of treatment duration. Noradrenaline-dopamine reuptake inhibitors (relative risk [RR], 2.80; 95% confidence interval [CI], 1.30-6.03; P = .008) and SNRIs (RR, 1.17; 95% CI, 1.07-1.27; P < .001) significantly increased the risk of adverse events. SNRIs were associated with an increased risk of withdrawal due to adverse events (RR, 2.37; 95% CI, 1.64-3.43; P < .001). This study found that antidepressants are more efficacious than placebos for treating chronic back pain, and tricyclic antidepressants are the most likely medications that lead to pain relief.

Impact of central sensitization on pain, disability and psychological distress in patients with knee osteoarthritis and chronic low back pain

BACKGROUND

Central sensitization (CS) is becoming increasingly recognized as a significant factor in many chronic pain conditions, including knee osteoarthritis (KOA) and chronic low back pain (CLBP). Yet it presently remains unclear how strong is the involvement of CS in KOA and CLBP and which factors are involved in CS in these two chronic disabling diseases.

METHODS

This is a cross-sectional study in which included a total of 178 patients with KOA and 118 patients with CLBP. Inclusion criteria for eligible participants for the KOA group were a confirmed diagnosis of KOA according to the American College of Rheumatology criteria, and for the CLBP group a chronic low back pain for more than 3 months. Subjects were excluded if they presented with a diagnosed psychiatric disorder or if they lacked the capacity to provide informed consent, understand study questionnaires or perform physical performance tests. In each group, were assessed; CS-related symptoms using the Central Sentization Inventory (CSI); demographic and clinical characteristics such as disease duration, pain intensity on a visual analog scale, self-reported function using the Lequesne index for KOA patients and the Oswestry Disability index for CLBP patients, and physical performance with the 6 minutes' walk test; as well as psychosocial risk factors using the Patient Health Questionnaire for depression (PHQ-9), the Generalized Anxiety Disorder (GAD-7) and the Pain Catastrophizing Scale (PCS).

RESULTS

CSI scores significantly correlated with pain intensity and disability in KOA and CLBP patients, and were highly correlated with self-reported symptoms of depression, anxiety and pain catastrophizing. Depression significantly predicted the CSI score in both groups.

CONCLUSION

These findings provide further evidence for the impact of CS on pain, function and physical performance in KOA and CLBP patients. Psychosocial symptoms such as pain catastrophizing, anxiety and depression should also be considered as they are also associated with CS.

Measures of sleep disturbance are not routinely captured in trials for chronic low back pain: a systematic scoping review of 282 trials

STUDY OBJECTIVES

To investigate the extent to which sleep measures are reported in intervention trials for chronic low back pain.

METHODS

A systematic scoping review was conducted. Ovid MEDLINE, Cochrane CENTRAL, and CINAHL were queried for trials published between January 2010 and December 2022 using keywords related to chronic low back pain. Two reviewers screened and reviewed abstracts and full texts for eligibility criteria and extracted data. Randomized intervention trials with the aim to treat pain or disability related to chronic low back pain in adults were included. Data were pooled and synthesized from trials that included a measure of sleep.

RESULTS

Two hundred eighty-two trials conducted in 40 different countries were included in the final review. Twenty-six trials (9.2%) assessed any sleep measure, and 13 (4.6%) collected a formal sleep disturbance measure at multiple time points. Three trials analyzed the mediating effects of sleep disturbance on pain. Reporting of sleep measures was no better in more recently published trials; trials published in 2010 (22%; n = 2/9) and 2022 (23%; n = 3/13) had the highest reporting rates.

CONCLUSIONS

The poor adherence to guideline recommendations for capturing measures of sleep quality or disturbance limits clinicians' and researchers' understanding of how sleep may influence treatment effects for chronic low back pain. There is an opportunity to improve the understanding of the relationship between sleep and pain with improved collection and reporting of sleep disturbance measures.

CITATION

Neilson BD, Dickerson C, Young JL, Shepherd MH, Rhon DI. Measures of sleep disturbance are not routinely captured in trials for chronic low back pain: a systematic scoping review of 282 trials. J Clin Sleep Med. 2023;19(11):1961-1970.

#Scoliosis: an analysis of patient perception of scoliosis on TikTok

Background

Social media presents an opportunity to analyze popular opinion about patient experiences. Idiopathic scoliosis is a spinal pathology commonly identified in younger patients who are the largest users of social media.

Objective

To analyze posts on the social media platform, TikTok, to better understand the scoliotic patient condition.

Methods

TikTok posts were searched manually by screening for "#Scoliosis." Variables assessed included number of likes, conveyed tone, gender, activities of daily living, incisional scar, imaging, involved spine level, spinal curvature, pain, formal physical therapy, multiple operations/reoperation, brace use, self-image, mobility, and educational/awareness posts. Number of responses per category were evaluated for the total they represented and the percentage of available posts containing those elements. Odds ratios with 95% confidence intervals were calculated for each collected variable.

Results

More posts were positive than negative (P < 0.001) and from female users than male users (P < 0.001). Self-image was the most prevalent subject, with many posts not mentioning activities of daily living, incisional scars, imaging, pain, physical therapy, timing, awareness/education, or involved spine levels.

Conclusions

More females post about scoliosis than males, with most posts containing positive self-image-related themes. This may represent a positive public attitude about scoliosis; however, further research is needed.

Unravelling Impaired Hypoalgesia at Rest and in Response to Exercise in Patients with Chronic Whiplash-Associated Disorders: Effects of a Single Administration of Selective Serotonin Reuptake Inhibitor versus Selective Norepinephrine Reuptake Inhibitor

(1) Background: Noradrenaline and serotonin have modulatory roles in pain signaling and in exercise-induced hypoalgesia. Patients with chronic whiplash-associated disorders often show impaired exercise-induced hypoalgesia. Therefore, this study aimed to examine the isolated effect of activating serotonergic or noradrenergic descending pathways on hypoalgesia at rest and in response to exercise in patients with chronic WAD by using respectively a single dose of a selective serotonin reuptake inhibitor (SSRI) and a selective norepinephrine reuptake inhibitor (NRI). (2) Methods: Twenty-five people with chronic WAD participated in this double-blind randomized controlled crossover experiment. Serotonin and noradrenaline concentrations were modulated by the oral ingestion of a single dose of citalopram (i.e., SSRI) or atomoxetine (i.e., SNRI). Quantitative sensory testing (including pressure pain thresholds and conditioned pain modulation) was measured before and after exercise in combination with no medication (1), atomoxetine (2), or citalopram (3) at three different test days. (3) Results: Random-intercept linear mixed models analysis was used to analyze pain outcomes (i.e., pain at rest and exercise-induced hypoalgesia) before and after exercise over the three conditions in patients with chronic WAD. No differences in pain at rest were found between the three conditions before exercise. The effect of exercise on pain outcome measures was not influenced by medication intake. The occupational status of the participants had a significant influence on the effect of exercise and medication on pain outcomes (p < 0.05). Patients working full-time had some positive effect of atomoxetine on pain facilitation (p < 0.05). Unemployed patients had some negative effect of citalopram on pain tolerance and experienced exercise-induced hypoalgesia (p < 0.05). (4) Conclusions: A single dose of citalopram or atomoxetine did not result in changes in hypoalgesia at rest and in response to exercise. These results do not support the use of SSRI or selective NRI to overcome impaired hypoalgesia at rest or in response to exercise in people with chronic WAD. Effect of exercise and medication on pain in patients with chronic WAD is influenced by the occupational status.

Pregabalin and gabapentin for chronic low back pain without radiculopathy: a systematic review

BACKGROUND

 Chronic low back pain (CLBP) is a global health problem, and gabapentin and pregabalin are often used in the treatment of patients without associated radiculopathy or neuropathy. Therefore, determining their efficacy and safety is of enormous value.

OBJECTIVE

To examine the efficacy and safety of using gabapentin and pregabalin for CLBP without radiculopathy or neuropathy.

METHODS

 We performed a search on the CENTRAL, MEDLINE, EMBASE, LILACS, and Web of Science data bases for clinical trials, cohorts, and case-control studies that evaluated patients with CLBP without radiculopathy or neuropathy for at least eight weeks. The data were extracted and inserted into a previously-prepared Microsoft Excel spreadsheet; the outcomes were evaluated using the Cochrane RoB 2 tool, and the quality of evidence, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

 Of the 2,230 articles identified, only 5 were included, totaling 242 participants. In them, pregabalin was slightly less efficacious than amitriptyline, the combination of tramadol/acetaminophen, and celecoxib, and pregabalin added to celecoxib showed no benefit when compared to celecoxib alone (very low evidence for all). On the other hand, although one study with gabapentin did not support its use in a general sample of patients with low back pain, another found a reduction in the pain scale and improved mobility (moderate evidence). No serious adverse events were observed in any of the studies.

CONCLUSION

 Quality information to support the use of pregabalin or gabapentin in the treatment of CLBP without radiculopathy or neuropathy is lacking, although results may suggest gabapentin as a viable option. More data is needed to fill this current gap in knowledge.

Between guidelines and clinical trials: evidence-based advice on the pharmacological management of non-specific chronic low back pain

The pharmacological management of nonspecific chronic low back pain (NCLBP) aims to restore patients' daily activities and improve their quality of life. The management of NCLBP is not well codified and extremely heterogeneous, and residual symptoms are common. Pharmacological management should be considered as co-adjuvant to non-pharmacological therapy, and should be guided by the symptoms reported by the patients. Depending on the individual severity of NCLPB, pharmacological management may range from nonopioid to opioid analgesics. It is important to identify patients with generalized sensory hypersensitivity, who may benefit from dedicated therapy. This article provides an evidence-based overview of the principles of pharmacological management of NCLPB.

Antidepressants for pain management in adults with chronic pain: a network meta-analysis

BACKGROUND

Chronic pain is common in adults, and often has a detrimental impact upon physical ability, well-being, and quality of life. Previous reviews have shown that certain antidepressants may be effective in reducing pain with some benefit in improving patients' global impression of change for certain chronic pain conditions. However, there has not been a network meta-analysis (NMA) examining all antidepressants across all chronic pain conditions.

OBJECTIVES

To assess the comparative efficacy and safety of antidepressants for adults with chronic pain (except headache).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, AMED and PsycINFO databases, and clinical trials registries, for randomised controlled trials (RCTs) of antidepressants for chronic pain conditions in January 2022.

SELECTION CRITERIA

We included RCTs that examined antidepressants for chronic pain against any comparator. If the comparator was placebo, another medication, another antidepressant, or the same antidepressant at different doses, then we required the study to be double-blind. We included RCTs with active comparators that were unable to be double-blinded (e.g. psychotherapy) but rated them as high risk of bias. We excluded RCTs where the follow-up was less than two weeks and those with fewer than 10 participants in each arm.  DATA COLLECTION AND ANALYSIS: Two review authors separately screened, data extracted, and judged risk of bias. We synthesised the data using Bayesian NMA and pairwise meta-analyses for each outcome and ranked the antidepressants in terms of their effectiveness using the surface under the cumulative ranking curve (SUCRA). We primarily used Confidence in Meta-Analysis (CINeMA) and Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) to assess the certainty of the evidence. Where it was not possible to use CINeMA and ROB-MEN due to the complexity of the networks, we used GRADE to assess the certainty of the evidence. Our primary outcomes were substantial (50%) pain relief, pain intensity, mood, and adverse events. Our secondary outcomes were moderate pain relief (30%), physical function, sleep, quality of life, Patient Global Impression of Change (PGIC), serious adverse events, and withdrawal.

MAIN RESULTS

This review and NMA included 176 studies with a total of 28,664 participants. The majority of studies were placebo-controlled (83), and parallel-armed (141). The most common pain conditions examined were fibromyalgia (59 studies); neuropathic pain (49 studies) and musculoskeletal pain (40 studies). The average length of RCTs was 10 weeks. Seven studies provided no useable data and were omitted from the NMA. The majority of studies measured short-term outcomes only and excluded people with low mood and other mental health conditions. Across efficacy outcomes, duloxetine was consistently the highest-ranked antidepressant with moderate- to high-certainty evidence. In duloxetine studies, standard dose was equally efficacious as high dose for the majority of outcomes. Milnacipran was often ranked as the next most efficacious antidepressant, although the certainty of evidence was lower than that of duloxetine. There was insufficient evidence to draw robust conclusions for the efficacy and safety of any other antidepressant for chronic pain.  Primary efficacy outcomes Duloxetine standard dose (60 mg) showed a small to moderate effect for substantial pain relief (odds ratio (OR) 1.91, 95% confidence interval (CI) 1.69 to 2.17; 16 studies, 4490 participants; moderate-certainty evidence) and continuous pain intensity (standardised mean difference (SMD) -0.31, 95% CI -0.39 to -0.24; 18 studies, 4959 participants; moderate-certainty evidence). For pain intensity, milnacipran standard dose (100 mg) also showed a small effect (SMD -0.22, 95% CI -0.39 to 0.06; 4 studies, 1866 participants; moderate-certainty evidence). Mirtazapine (30 mg) had a moderate effect on mood (SMD -0.5, 95% CI -0.78 to -0.22; 1 study, 406 participants; low-certainty evidence), while duloxetine showed a small effect (SMD -0.16, 95% CI -0.22 to -0.1; 26 studies, 7952 participants; moderate-certainty evidence); however it is important to note that most studies excluded participants with mental health conditions, and so average anxiety and depression scores tended to be in the 'normal' or 'subclinical' ranges at baseline already. Secondary efficacy outcomes Across all secondary efficacy outcomes (moderate pain relief, physical function, sleep, quality of life, and PGIC), duloxetine and milnacipran were the highest-ranked antidepressants with moderate-certainty evidence, although effects were small. For both duloxetine and milnacipran, standard doses were as efficacious as high doses. Safety There was very low-certainty evidence for all safety outcomes (adverse events, serious adverse events, and withdrawal) across all antidepressants. We cannot draw any reliable conclusions from the NMAs for these outcomes.

AUTHORS' CONCLUSIONS

Our review and NMAs show that despite studies investigating 25 different antidepressants, the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose. There is also promising evidence for milnacipran, although further high-quality research is needed to be confident in these conclusions. Evidence for all other antidepressants was low certainty. As RCTs excluded people with low mood, we were unable to establish the effects of antidepressants for people with chronic pain and depression. There is currently no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for the safety of antidepressants for chronic pain at any time point.

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.

Effects of pharmacotherapy on sleep-related outcomes in adults with chronic low back pain: A systematic review and meta-analysis of randomised controlled trials

Background

Adults with chronic low back pain (CLBP) suffer impaired sleep. Medications for CLBP can impact sleep which in turn may influence treatment outcomes. This systematic review and meta-analysis examined the effects of pharmacotherapy (any type) on sleep in adults with CLBP.

Methods

In this systematic review and meta-analysis, we searched PubMed, CINAHL, SPORTDiscus, PsycINFO, EMBASE, and CENTRAL from inception to 10 July 2022. Randomised controlled trials that investigated the effects of pharmacotherapy on sleep in adults with CLBP were included. Manual citation search of relevant systematic reviews and included studies were also conducted. Mean change from baseline for sleep outcomes (e.g., sleep quality, total sleep time, wake after sleep onset) was the effect of interest. Pairwise inverse-variance random effect meta-analysis was performed to impute pooled estimates (Hedges' g or risk ratios). The Hartung-Knapp-Sidik-Jonkman method was used where there were ≤5 studies. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used for evaluating the certainty of evidence. This study was registered with PROSPERO (CRD42022309419).

Findings

Assessment of 3959 records resulted in nine studies (n = 2927) being included. Pharmacotherapy for CLBP management had a small, yet unlikely clinically significant, effect on improving sleep in adults with CLBP, when compared to placebo (g [95% CI]: -0.23 [-0.37, -0.09], p = .0009; I 2  = 30.1%; n = 1433; studies: n = 8; GRADE: low). Notably, no eligible studies investigated the effect of sleep medications in this population, despite being within the scope of this review.

Interpretation

Pharmacotherapy used to manage CLBP provided improvements in sleep in adults with CLBP. Given that these effects were small and unlikely clinically significant, clinicians could consider alternative treatments (e.g., non-pharmacological interventions) for managing sleep in adults with CLBP. However, low to very low certainty of evidence precluded strong conclusions. To improve certainty of evidence and confidence in the effect estimates, future research needs to use robust method to minimise bias. Additional research evaluating multiple sleep characteristics, using both validated objective and subjective measures, is also warranted to further investigate the influence of distinct sleep parameters.

Funding

The Summer Research Scholarship from the Appleton Institute, Central Queensland University, Australia.

Choosing the appropriate pharmacotherapy for nonspecific chronic low back pain

The pharmacological management of nonspecific chronic low back pain (NCLBP) aims to restore daily activities and improve the quality of life. No magic bullet exists for NCLBP; interventions to reduce pain and disability are available, but long-term results are unpredictable. Education in this regard needs to improve. This is often hard to accept for clinicians and patients, and provides a fertile soil to quacks, faith healers, and gurus to promote miraculous non-evidence-based solutions. The management of NCLBP is not well codified and extremely heterogeneous, and residual symptoms are common. Depending on the individual severity of NCLPB, pharmacological management may range from nonopioid to opioid analgesics. It is important to identify patients with generalized sensory hypersensitivity, who may benefit from a dedicated therapy. In this editorial, we provide an evidenced-based overview of the principles of pharmacological management of NCLPB.

A bibliometric analysis of self-efficacy in low back pain from 1980 to 2021

BACKGROUND

Self-efficacy is one of the important factors affecting chronic diseases. In the current epidemiological context of low back pain (LBP), LBP self-efficacy has become a topic of great practical interest for researchers. However, no bibliometric analysis related to LBP self-efficacy has been performed to date. The purpose of this study was to conduct and explore the current state of research in LBP self-efficacy from 1980 to 2021, by using bibliometric analysis and scientific mapping.

METHODS

Raw data were selected from the Web of Science (WOS) database, relevant literature on LBP self-efficacy was retrieved, and data were de-duplicated and cleaned. Excel was used for data processing. CiteSpace 5.8.R3 was used for bibliometric analysis and scientific mapping in publications and country, institution, journals, authors, references, and keywords. Statistical analysis was performed using IBM SPSS 25.0.

RESULTS

There were 822 references included. For this period, the total publication numbers were increased. A total of 103 regions had researchers in this area; the United States was the country with the largest volume of research. There were 94 disciplines, mainly in neuroscience. More research is likely to burst and develop quickly in general and internal medicine in the future. Spine was the most recognized journal. Cognitive-behavioral manifestations and older adults with LBP might be the frontiers and trends.

CONCLUSION

The volume of literature on LBP self-efficacy has increased linearly over the past 41 years and will continue to increase. The field of study has become more refined. This bibliometric analysis provides valuable support for future directions and research trends in LBP self-efficacy.

Pharmacological treatments of fibromyalgia in adults; overview of phase IV clinical trials

Background: Fibromyalgia is a chronic neurological condition characterized by widespread pain. The effectiveness of current pharmacological treatments is limited. However, several medications have been approved for phase IV trials in order to evaluate them.

Aim: To identify and provide details of drugs that have been tested in completed phase IV clinical trials for fibromyalgia management in adults, including the primary endpoints and treatment outcomes. This article was submitted to Neuropharmacology, a section of the journal Frontiers in Pharmacology.

Method: Publicly available and relevant phase IV trials registered at ClinicalTrials.gov were analyzed. The uses of the trialed drugs for fibromyalgia were reviewed.

Results: As of 8 August 2022, a total of 1,263 phase IV clinical trials were identified, of which 121 were related to fibromyalgia. From these, 10 clinical trials met the inclusion criteria for the current study. The drugs used in phase IV trials are milnacipran, duloxetine, pregabalin, a combination of tramadol and acetaminophen, and armodafinil. The effectiveness of the current pharmacological treatments is apparently limited.

Conclusion: Due to its complexity and association with other functional pain syndromes, treatment options for fibromyalgia only are limited and they are designed to alleviate the symptoms rather than to alter the pathological pathway of the condition itself. Pain management specialists have numerous pharmacologic options available for the management of fibromyalgia.

Pharmacotherapy for Spine-Related Pain in Older Adults

As the population ages, spine-related pain is increasingly common in older adults. While medications play an important role in pain management, their use has limitations in geriatric patients due to reduced liver and renal function, comorbid medical problems, and polypharmacy. This review will assess the evidence basis for medications used for spine-related pain in older adults, with a focus on drug metabolism and adverse drug reactions. A PubMed/OVID search crossing common spine, neck, and back pain terms with key words for older adults and geriatrics was combined with common drug classes and common drug names and limited to clinical trials and age over 65 years. The results were then reviewed with identification of commonly used drugs and drug categories: nonsteroidal anti-inflammatories (NSAIDs), acetaminophen, corticosteroids, gabapentin and pregabalin, antispastic and antispasmodic muscle relaxants, tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tramadol, and opioids. Collectively, 138 double-blind, placebo-controlled trials were the focus of the review. The review found a variable contribution of high-quality studies examining the efficacy of medications for spine pain primarily in the geriatric population. There was strong evidence for NSAID use with adjustments for gastrointestinal and renal risk factors. Gabapentin and pregabalin had mixed evidence for neuropathic pain. SNRIs had good evidence for neuropathic pain and a more favorable safety profile than TCAs. Tramadol had some evidence in older patients, but more so in persons aged < 65 years. Rational therapeutic choices based on geriatric spine pain diagnosis are helpful, such as NSAIDs and acetaminophen for arthritic and myofascial-based pain, gabapentinoids or duloxetine for neuropathic and radicular pain, antispastic agents for myofascial-based pain, and combination therapy for mixed etiologies. Tramadol can be well tolerated in older patients, but has risks of cognitive and classic opioid side effects. Otherwise, opioids are typically avoided in the treatment of spine-related pain in older adults due to their morbidity and mortality risk and are reserved for refractory severe pain. Whenever possible, beneficial geriatric spine pain pharmacotherapy should employ the lowest therapeutic doses with consideration of polypharmacy, potentially decreased renal and hepatic metabolism, and co-morbid medical disorders.

Assessment of Low Back Pain: Reliability and Minimal Detectable Change of the Brief Pain Inventory

IMPORTANCE

The Brief Pain Inventory (BPI) is one of the most widely used measures to assess pain and related impacts among patients with low back pain (LBP). However, its test-retest reliability and minimal detectable change (MDC) have rarely been examined in patients with LBP, interfering with its utility.

OBJECTIVE

To investigate the test-retest reliability and MDC of the BPI among patients with LBP.

DESIGN

Repeated assessments design with a 1-wk interval.

SETTING

Department of Physical Medicine and Rehabilitation in a hospital in Taiwan.

PARTICIPANTS

Fifty-four patients with stable LBP conditions.

OUTCOMES AND MEASURES

The BPI has two subscales-Intensity and Interference-that assess pain intensity and pain interference, respectively. Their test-retest reliability was examined using the intraclass correlation coefficient (ICC), and MDCs were calculated.

RESULTS

The ICCs of the Intensity and Interference subscales were .62 and .76, respectively. The MDC values for the two subscales were 2.57 and 2.34, respectively. For the four Intensity items, the average-pain score had a higher ICC (.60) than scores on the other items (worst, least, and current pain, which had ICCs of about .40).

CONCLUSIONS AND RELEVANCE

The results suggest that although the BPI is a commonly used measure of pain intensity and pain interference among patients with LBP, caution should be exercised in interpreting the Intensity subscale score and its item scores. What This Article Adds: The BPI is widely used to assess pain and related impacts on daily occupation and functioning among patients with LBP. This study provides information regarding its test-retest reliability. Moreover, the MDC values provide clinicians and researchers with the thresholds for determining real improvement (beyond random measurement error).

Validating a biosignature-predicting placebo pill response in chronic pain in the settings of a randomized controlled trial

ABSTRACT

The objective of this study is to validate a placebo pill response predictive model-a biosignature-that classifies chronic pain patients into placebo responders (predicted-PTxResp) and nonresponders (predicted-PTxNonR) and test whether it can dissociate placebo and active treatment responses. The model, based on psychological and brain functional connectivity, was derived in our previous study and blindly applied to current trial participants. Ninety-four chronic low back pain (CLBP) patients were classified into predicted-PTxResp or predicted-PTxNonR and randomized into no treatment, placebo treatment, or naproxen treatment. To monitor analgesia, back pain intensity was collected twice a day: 3 weeks baseline, 6 weeks of treatment, and 3 weeks of washout. Eighty-nine CLBP patients were included in the intent-to-treat analyses and 77 CLBP patients in the per-protocol analyses. Both analyses showed similar results. At the group level, the predictive model performed remarkably well, dissociating the separate effect sizes of pure placebo response and pure active treatment response and demonstrating that these effects interacted additively. Pain relief was about 15% stronger in the predicted-PTxResp compared with the predicted-PTxNonR receiving either placebo or naproxen, and the predicted-PTxNonR successfully isolated the active drug effect. At a single subject level, the biosignature better predicted placebo nonresponders, with poor accuracy. One component of the biosignature (dorsolateral prefrontal cortex-precentral gyrus functional connectivity) could be generalized across 3 placebo studies and in 2 different cohorts-CLBP and osteoarthritis pain patients. This study shows that a biosignature can predict placebo response at a group level in the setting of a randomized controlled trial.

Is Targeting Nerve Growth Factor Antagonist a New Option for Pharmacologic Treatment of Low Back Pain? A Supplemental Network Meta-Analysis of the American College of Physicians Guidelines

Objective: It has been found that targeting nerve growth factor antagonists (ANGF) have excellent effects in the treatment of chronic pain, and the current pharmacologic treatments have very limited effects on low back pain (LBP). Thus we conducted this network meta-analysis (NMA) to study the efficacy and safety of ANGF for the treatment of LBP, and to guide for clinical practice and further research.

Method: PubMed, Scopus, Embase, CNKI, and the Cochrane Library were searched from January 1980 to March 2021. A frequentist framework network meta-analysis with a random-effect model was performed. Ranking effects were calculated by surface under the cumulative ranking analysis (SUCRA) and clusterank analysis.

Results: This NMA identified 30 studies, involving 9,508 patients with LBP. ANGF reported both superior effect on pain relief {SUCRA 82.1%, SMD 0.89, 95% CI [(0.26,1.51)]} and function improvement {SUCRA 77.3%, SMD 0.93, 95% CI [(0.27,1.58)]} than placebo, and did not showed any higher risk of treatment-emergent adverse effects {RR 1.11, 95% CI [(0.97,1.27)]} or serious adverse effects {RR 1.03, 95% CI [(0.54,1.97)]}, but it was associate with a special risk of rapidly progressive osteoarthritis. ANGF displayed the greatest potential to be the most effective and safest treatment (cluster-rank value for function improvement and safety: 4266.96, for pain relief and safety: 4531.92).

Conclusion: ANGF could relieve pain and improve function effectively and are superior to other traditional drugs recommended by guidelines. Although no significant difference in tolerability and safety between ANGFs and placebo was found, the rapid progression of original osteoarthritis which may be related to the use of ANGFs still needs special attention and furtherly verification by clinical trials.

Systematic Review Registration: PROSPERO, identifier [CRD42021258033].

Placebo Response Reduction and Accurate Pain Reporting Training Reduces Placebo Responses in a Clinical Trial on Chronic Low Back Pain: Results From a Comparison to the Literature

OBJECTIVE

A literature review was conducted to compare placebo responses in a recent trial-which implemented an accurate pain reporting (APR) and placebo response reduction (PRR) training program-with placebo responses in similar previous trials in chronic lower back pain (CLBP) that did not use such training.

METHODS

A literature search was performed to find parallel design, randomized, controlled trials of pharmacological treatments administered orally or through intravenous injection for CLBP. Studies were assessed for the proportion of placebo responders, defined as the proportion of patients in the placebo group with ≥30% reduction in pain intensity. A χ analysis was performed on the proportion of responders from the SPRINT trial and from other similar studies.

RESULTS

Of 844 studies identified in the initial screening process, 16 studies were included for comparison. The percentage of placebo responders was statistically significantly lower in the SPRINT study (19.1%) compared with other CLBP trials (38.0%) (P=0.003). Our results show that the placebo response was lower in the SPRINT trial than other comparable studies on CLBP.

DISCUSSION

These findings are consistent with results from other studies showing that neutralizing subject and study staff expectations of therapeutic benefit can decrease the placebo response in clinical trials. The results of this study suggest training participants and staff to improve pain reporting accuracy, neutralize expectations, and decrease external cues that may bias participants' pain ratings in clinical trials may effectively decrease the placebo response leading to increased assay sensitivity.

Non-steroidal anti-inflammatory drugs and gabapentinoids for chronic lumbar pain: a Bayesian network meta-analysis of randomized controlled trials

INTRODUCTION

Several pharmacological therapies have been proposed for the management of chronic low back pain (LBP), but no consensus has been reached yet.

SOURCE OF DATA

Recent published literatures identified accessing PubMed, Google scholar, Embase and Scopus.

AREAS OF AGREEMENT

Exploring effective conservative alternatives to the surgical intervention is of especial interest.

AREAS OF CONTROVERSY

The efficacy and safety of non-steroidal anti-inflammatory drugs and gabapentinoids for chronic LBP are debated. Several clinical studies showed controversial results, and the most effective and safe class of drugs has not yet been clarified.

GROWING POINTS

The effects of selective and non-selective NSAIDs and gabapentinoids in chronic LBP are probably over-estimated.

AREAS TIMELY FOR DEVELOPING RESEARCH

The effect of behavioural changes, including exercise, should be explored, alone or in combination with drugs.

Duloxetine for the Treatment of Chronic Low Back Pain: A Systematic Review of Randomized Placebo-Controlled Trials

This systematic review determines the efficacy and safety of duloxetine for chronic low back pain (CLBP). We queried the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I and II randomized controlled studies published in the English language investigating the efficacy of duloxetine for chronic low back pain were included. Five studies (832 duloxetine-treated patients, 667 placebo-treated patients, and 41 duloxetine and placebo crossover analysis patients) were analyzed. One study was level I evidence and four studies were level II evidence. All five studies reported statistically significant improvements in more than one back-pain-specific clinical outcome score with duloxetine versus placebo. Four studies found that duloxetine 60 mg daily leads to one or more statistically significant improvements versus placebo in Brief Pain Inventory Severity (BPI-S) scores. All five studies found no significant difference in serious adverse events (AEs) between the duloxetine and placebo groups. One study found a higher rate of total AEs among the duloxetine 120 mg group versus the placebo group; however, the same study did not find a significant difference in total AEs among duloxetine 20 mg and 60 mg groups versus placebo. Duloxetine is a safe and effective first-line option for the treatment of CLBP. Current studies demonstrate that 60 mg taken once daily has the highest efficacy for reducing pain and disability while minimizing minor adverse effects. Further randomized controlled trials with long-term follow-up are necessary to determine its long-term effects.

Comparative safety review of current treatment options for chronic low back pain and unmet needs: a narrative review

Introduction: The healthcare expenditures in the United States are substantial for the management of refractory, chronic low back pain (CLBP). The objective of this review is to summarize and evaluate the safety profiles of different pharmacological treatment options used in the management of CLBP.Areas covered: The authors conducted a search of randomized controlled trials (RCTs) assessing the safety profiles of different pharmacological agents used in the management of CLBP. This narrative review covered corticosteroids, opioids, antidepressants, gabapentinoids, nonsteroidal anti-inflammatory drugs, muscle relaxants, anti-nerve growth factor antibodies and topical agents, as monotherapy or in combination.Expert opinion: The risk-benefit ratio of a particular treatment is a subject driving the ongoing development of pharmaceuticals. The most commonly reported AEs across all drug classes are of gastrointestinal nature, followed by neurological and skin-related. These AEs include nausea, dizziness, constipation, arthralgia, headache, dry mouth, pruritus, etc. The majority of the AEs reported are not life-threatening, although they may lower patients' quality of life, thus, affecting their compliance. One of the biggest limitations of our review stems from the paucity of safety assessments in published RCTs. Advances in our understanding of the neurobiology of pain will promote development of new therapeutic strategies.

Expert consensus of Chinese Association for the Study of Pain on the non-opioid analgesics for chronic musculoskeletal pain

Chronic musculoskeletal pain (CMP) is a common occurrence in clinical practice and there are a variety of options for the treatment of it. However, the pharmacological therapy is still considered to be a primary treatment. The recent years have witnessed the emergence of opioid crisis, yet there are no relevant guidelines on how to treat CMP with non-opioid analgesics properly. The Chinese Medical Association for the Study of Pain convened a panel meeting to develop clinical practice consensus for the treatment of CMP with non-opioid analgesics. The purpose of this consensus is to present the application of nonsteroidal anti-inflammatory drugs, serotonin norepinephrine reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, muscle relaxants, ion channel drugs and topical drugs in CMP.

Efficacy, acceptability, and safety of antidepressants for low back pain: a systematic review and meta-analysis

BACKGROUND

Antidepressant medicines are used to manage symptoms of low back pain. The efficacy, acceptability, and safety of antidepressant medicines for low back pain (LBP) are not clear. We aimed to evaluate the efficacy, acceptability, and safety of antidepressant medicines for LBP.

METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov , the EU Clinical Trials Register, and the WHO International Clinical Trial Registry Platform from inception to May 2020. We included published and trial registry reports of RCTs that allocated adult participants with LBP to receive an antidepressant medicine or a placebo medicine. Pairs of authors independently extracted data in duplicate. We extracted participant characteristics, study sample size, outcome values, and measures of variance for each outcome. We data using random-effects meta-analysis models and calculated estimates of effects and heterogeneity for each outcome. We formed judgments of confidence in the evidence in accordance with GRADE. We report our findings in accordance with the PRISMA statement. We prespecified all outcomes in a prospectively registered protocol. The primary outcomes were pain intensity and acceptability. We measured pain intensity at end-of-treatment on a 0-100 point scale and considered 10 points the minimal clinically important difference. We defined acceptability as the odds of stopping treatment for any reason.

RESULTS

We included 23 RCTs in this review. Data were available for pain in 17 trials and acceptability in 14 trials. Treatment with antidepressants decreased pain intensity by 4.33  points (95% CI - 6.15 to - 2.50) on a 0-100 scale, compared to placebo. Treatment with antidepressants increased the odds of stopping treatment for any reason (OR 1.27 [95% CI 1.03 to 1.56]), compared to placebo.

CONCLUSIONS

Treatment of LBP with antidepressants is associated with small reductions in pain intensity and increased odds of stopping treatment for any reason, compared to placebo. The effect on pain is not clinically important. The effect on acceptability warrants consideration. These findings provide Level I evidence to guide clinicians in their use of antidepressants to treat LBP.

TRIAL REGISTRATION

We prospectively registered the protocol for this systematic review on PROSPERO ( CRD42020149275 ).

Efficacy and safety of antidepressants for the treatment of back pain and osteoarthritis: systematic review and meta-analysis

OBJECTIVE

To investigate the efficacy and safety of antidepressants for back and osteoarthritis pain compared with placebo.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, Cochrane Central Register of Controlled Trials, CINAHL, International Pharmaceutical Abstracts, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform from inception to 15 November and updated on 12 May 2020.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Randomised controlled trials comparing the efficacy or safety, or both of any antidepressant drug with placebo (active or inert) in participants with low back or neck pain, sciatica, or hip or knee osteoarthritis.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data. Pain and disability were primary outcomes. Pain and disability scores were converted to a scale of 0 (no pain or disability) to 100 (worst pain or disability). A random effects model was used to calculate weighted mean differences and 95% confidence intervals. Safety (any adverse event, serious adverse events, and proportion of participants who withdrew from trials owing to adverse events) was a secondary outcome. Risk of bias was assessed with the Cochrane Collaboration's tool and certainty of evidence with the grading of recommendations assessment, development and evaluation (GRADE) framework.

RESULTS

33 trials (5318 participants) were included. Moderate certainty evidence showed that serotonin-noradrenaline reuptake inhibitors (SNRIs) reduced back pain (mean difference -5.30, 95% confidence interval -7.31 to -3.30) at 3-13 weeks and low certainty evidence that SNRIs reduced osteoarthritis pain (-9.72, -12.75 to -6.69) at 3-13 weeks. Very low certainty evidence showed that SNRIs reduced sciatica at two weeks or less (-18.60, -31.87 to -5.33) but not at 3-13 weeks (-17.50, -42.90 to 7.89). Low to very low certainty evidence showed that tricyclic antidepressants (TCAs) did not reduce sciatica at two weeks or less (-7.55, -18.25 to 3.15) but did at 3-13 weeks (-15.95, -31.52 to -0.39) and 3-12 months (-27.0, -36.11 to -17.89). Moderate certainty evidence showed that SNRIs reduced disability from back pain at 3-13 weeks (-3.55, -5.22 to -1.88) and disability due to osteoarthritis at two weeks or less (-5.10, -7.31 to -2.89), with low certainty evidence at 3-13 weeks (-6.07, -8.13 to -4.02). TCAs and other antidepressants did not reduce pain or disability from back pain.

CONCLUSION

Moderate certainty evidence shows that the effect of SNRIs on pain and disability scores is small and not clinically important for back pain, but a clinically important effect cannot be excluded for osteoarthritis. TCAs and SNRIs might be effective for sciatica, but the certainty of evidence ranged from low to very low.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020158521.

Duloxetine for the reduction of opioid use in elective orthopedic surgery: a systematic review and meta-analysis

Background Duloxetine is currently approved for chronic pain management; however, despite some evidence, its utility in acute, postoperative pain remains unclear Aim of the review This systematic review and meta-analysis is to determine if duloxetine 60 mg given perioperatively, is safe and effective at reducing postoperative opioid consumption and reported pain following elective orthopedic surgery. Method CINAHL, Medline, Cochrane Central Registry for Clinical Trials, Google Scholar, and Clinicaltrials.gov were searched using a predetermined search strategy from inception to January 15, 2019. Covidence.org was used to screen, select, and extract data by two independent reviewers. Individual study bias was assessed using the Cochrane Risk of Bias tool. Opioid consumption data were converted to oral morphine milligram equivalents (MME) and exported to RevMan where meta-analysis was conducted using a DerSimonian and Laird random effects model. Results Six randomized-controlled trials were included in the literature review of postoperative pain and adverse effects. Five studies were utilized for the meta-analysis of postoperative opioid consumption; totaling 314 patients. Postoperative pain analysis showed variable statistical significance with overall lower pain scores with duloxetine. Adverse effects included an increase in insomnia with duloxetine but lower rates of nausea and vomiting. Meta-analysis revealed statistically significant [mean difference (95% CI)] lower total opioid use with duloxetine postoperatively at 24 h [- 31.9 MME (- 54.22 to - 9.6), p = 0.005], 48 h [- 30.90 MME (- 59.66 to - 2.15), p = 0.04] and overall [- 31.68 MME (- 46.62 to - 16.74), p < 0.0001]. Conclusion These results suggest that adding perioperative administration duloxetine 60 mg to a multimodal analgesia regimen within the orthopedic surgery setting significantly lowers total postoperative opioid consumption and reduces pain without significant adverse effects.

Effectiveness of duloxetine on severity of pain and quality of life in chronic low back pain in patients who had posterior spinal fixation

Background:

In this study, we want to search the effectiveness of Duloxetine on the severity of pain and quality of life in patients with chronic low back pain who had posterior spinal fixation.

Methods:

In this randomized, placebo-controlled trial done in 6 months 50 patients who had CLBP and were candidates for PSF surgery selected and divided into two groups (drug and placebo). They filled the VAS, SF-36, and Hamilton questionnaires before surgery and after 6 weeks from using 30 mg of duloxetine or placebo.

Results:

Significant differences were evidenced among groups for the Visual Analogue Scale (P = 0.005) and Verbal Analogue Scale (p = 0.003). Patients in the Duloxetine group have more visual and verbal pain scores than the placebo group. In the quality of life, there was a significant difference between the two groups before the intervention. Also, significant differences were evidenced among groups for the Hamilton Anxiety Rating Scale (p = 0.17). After the intervention, only the Hamilton Anxiety Rating Scale (p = 0.001) and ‘bodily pain’ and ‘general health’ subscales of quality of life (p = 0.008, 0.004, respectively) have a significant difference between the two groups. There was a significant difference between pre and post-intervention in the Hamilton Anxiety Rating Scale only in the duloxetine group. Also, in terms of quality of life, the subscales of ‘physical role’, ‘emotional role’, ‘physical pain’ and ‘total score of quality of life’ in the duloxetine and placebo groups were significantly different between pre and post-intervention. However, the subscales of ‘physical function’ and ‘general health’ were significantly different only in the duloxetine group between pre and post-intervention.

Conclusion:

The results suggest that the use of duloxetine in patients who had spinal surgery can help to better control back pain, on the other hand, it can cause a better psychological condition that affects the quality of life.

CLINICAL ANALYSIS OF PATIENTS WITH LOW BACK PAIN IN THE EMERGENCY DEPARTMENT

ABSTRACT Objective To describe the daily practice in an emergency service and to provide relevant data for future studies about the treatment of low back pain from the perspective of emergency medicine. Methods Analysis of hospital records and review of medical records. Results 2,434 patients were attended between January 1 and December 31, 2017 with the complaint of low back pain. Radiographs of the spine were performed in 15.7% of patients and computerized tomography scans in 7.6%. Eighty-five patients required hospitalization, with a mean hospital stay of 8.3 days. The rate of use was 52.7% for tricyclic or antiepileptic drugs and 12% for strong opioids among hospitalized patients. Conclusions A high prevalence of low back complaints was observed in the emergency care service (4.6% of total emergency room visits during the year), with low hospitalization potential. The rates of hospitalization and tomographic examinations were higher than those observed in similar studies, with a lower proportion of radiograph and strong opioid use as compared with the same studies. The paucity of national and international data for more in-depth comparisons makes clear the need for further studies and development of new recommendations specifically targeting this subset of patients. Level of evidence IV; Prognostic studies.

Animal models of pain: Diversity and benefits

Chronic pain is a maladaptive neurological disease that remains a major health problem. A deepening of our knowledge on mechanisms that cause pain is a prerequisite to developing novel treatments. A large variety of animal models of pain has been developed that recapitulate the diverse symptoms of different pain pathologies. These models reproduce different pain phenotypes and remain necessary to examine the multidimensional aspects of pain and understand the cellular and molecular basis underlying pain conditions. In this review, we propose an overview of animal models, from simple organisms to rodents and non-human primates and the specific traits of pain pathologies they model. We present the main behavioral tests for assessing pain and investing the underpinning mechanisms of chronic pathological pain. The validity of animal models is analysed based on their ability to mimic human clinical diseases and to predict treatment outcomes. Refine characterization of pathological phenotypes also requires to consider pain globally using specific procedures dedicated to study emotional comorbidities of pain. We discuss the limitations of pain models when research findings fail to be translated from animal models to human clinics. But we also point to some recent successes in analgesic drug development that highlight strategies for improving the predictive validity of animal models of pain. Finally, we emphasize the importance of using assortments of preclinical pain models to identify pain subtype mechanisms, and to foster the development of better analgesics.

Spezielle Schmerztherapie bei rheumatischen Erkrankungen

Schmerz als Hauptsymptom vieler chronisch-entzündlicher Erkrankungen stellt für den Patienten, aber auch für den behandelnden Arzt besonders in seiner chronifizierten Form eine große Herausforderung dar. Es gibt leider keine „Wunderpille“ mit der man Schmerzen für jeden gleich zuverlässig beseitigen kann. Es gibt aber viele Ansätze pharmakologischer als auch nicht-pharmakologischer Art und deren Kombination, um für den einzelnen Patienten wirksame Behandlungsstrategien zu finden. Um diese Strategien für jeden Patienten individuell optimal festzulegen, bedarf es zum einen eines fundamentierten Wissens über das Spektrum zur Verfügung stehender Mittel, zum anderen aber auch Erkenntnis darüber, wie diese sinnvoll nach Art der vorliegenden Schmerzformen einzusetzen sind. In dieser Übersicht wird beides behandelt, mit einem Fokus auf die medikamentöse Therapie von Schmerzen bei entzündlich-rheumatischen Erkrankungen. Dabei wird herausgearbeitet, dass es für die in diesem Zusammenhang relevantesten Formen des Schmerzes, akut-entzündlich nozizeptiv, neuropathisch und durch periphere und zentrale Sensibilisierung chronifizierte Schmerzen, jeweils andere wirksame Konzepte gibt.

The pharmacological management of chronic lower back pain

INTRODUCTION

Treating chronic low back pain (LBP) can be challenging, and the most effective pharmacological therapy is controversial. The present systematic review investigated the efficacy of various pharmacological compounds to achieve pain relief and improve disability in chronic LBP patients. The present study focused on acetaminophen, amoxicillin, flupirtine, baclofen, tryciclic antidepressants (TCAs), duloxetine, topiramate, gabapentinoids, non-steroid anti-inflammatory drugs (NSAIDs) and opioids.

AREAS COVERED

All randomized clinical trials comparing two or more drug treatments for chronic low back pain were accessed. Studies reporting outcomes concerning patients with neurologic or mechanic, specific or aspecific low back pain with or without radiculopathy were included. LBP was considered chronic if pain had lasted more than 6 weeks. Data from 47 articles (9007 patients: mean age: 52.62 ± 7.0 years; mean BMI: 28.26 ± 2.8; mean follow-up: 3.23 ± 3.2 months) were obtained.

EXPERT OPINION

According to published level I evidence, only baclofen, duloxetine, NSAIDs, and opiates showed to improve pain and disability levels in patients with LBP. However, the patients' demographics are heterogeneous, and the results must be interpreted with caution and in the light of possible adverse events connected to the use of these drugs.

Measuring the impact of chronic low back pain on everyday functioning: content validity of the Roland Morris disability questionnaire

BACKGROUND

Robust outcome measures are needed to assess and monitor the impact of chronic low back pain (CLBP) on physical functioning. The Roland Morris Disability Questionnaire (RMDQ) is a well-established measure designed to capture the impacts of back pain on everyday functioning, with a particular emphasis on physical functioning. It has documented evaluation of psychometric properties. However, there is no documented qualitative evidence to confirm the content validity of the tool, nor have changes made for electronic administration been debriefed in participants with CLBP.

METHODS

In-depth, semi-structured, concept elicitation and cognitive debriefing interviews were conducted with 23 US participants with confirmed CLBP. Interviews allowed participants to describe the impact of CLBP on their day-to-day functioning and discuss comprehension and suitability of the RMDQ. Interviews were transcribed verbatim and analyzed using thematic analysis.

RESULTS

Concept elicitation and cognitive debriefing revealed the substantial burden associated with CLBP, highlighting 15 key areas of functional impact. These were grouped into overarching themes of mobility (walking, stairs, sitting/standing, bending/kneeling, lifting, lying down), activities (chores/housework, dressing, washing, driving, work) and other (relationships/socializing, mood, sleep, appetite), which are consistent with those evaluated within the RMDQ. All participants found the RMDQ to be relevant with most reporting that the instructions, recall period, and response options were suitable. A few suggested minor changes, however, none were consistent or necessary to support content validity. Updates to the measure for electronic administration and to clarify the response options were well received.

CONCLUSION

The qualitative data from individuals with CLBP confirmed that the RMDQ has content validity and, alongside documented psychometric evidence, supports the use of the RMDQ as a reliable and valid tool to assess the impact of CLBP on physical functioning.

Are Opioids Needed to Treat Chronic Low Back Pain? A Review of Treatment Options and Analgesics in Development

The continued prevalence of chronic low back pain (CLBP) is a testament to our lack of understanding of the potential causes, leading to significant treatment challenges. CLBP is the leading cause of years lived with disability and the fifth leading cause of disability-adjusted life-years. No single non-pharmacologic, pharmacologic, or interventional therapy has proven effective as treatment for the majority of patients with CLBP. Although non-pharmacologic therapies are generally helpful, they are often ineffective as monotherapy and many patients lack adequate access to these treatments. Noninvasive treatment measures supported by evidence include physical and chiropractic therapy, yoga, acupuncture, and non-opioid and opioid pharmacologic therapy; data suggest a moderate benefit, at most, for any of these therapies. Until our understanding of the pathophysiology and treatment of CLBP advances, clinicians must continue to utilize rational multimodal treatment protocols. Recent Centers for Disease Control and Prevention guidelines for opioid prescribing recommend that opioids not be utilized as first-line therapy and to limit the doses when possible for fear of bothersome or dangerous adverse effects. In combination with the current opioid crisis, this has caused providers to minimize or eliminate opioid therapy when treating patients with chronic pain, leaving many patients suffering despite optimal nonopioid therapies. Therefore, there remains an unmet need for effective and tolerable opioid receptor agonists for the treatment of CLBP with improved safety properties over legacy opioids. There are several such agents in development, including opioids and other agents with novel mechanisms of action. This review critiques non-pharmacologic and pharmacologic treatment modalities for CLBP and examines the potential of novel opioids and other analgesics that may be a useful addition to the treatment options for patients with chronic pain.

Efficacy and safety of duloxetine in osteoarthritis or chronic low back pain: a Systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of duloxetine in the treatment of patients with osteoarthritis (OA) or chronic low back pain (CLBP).

METHODS

Relevant randomized controlled trials (RCTs) were searched in PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Included RCTs compared the efficacy and safety of duloxetine vs placebo in the treatment of OA or CLBP. Weighted mean difference (WMD) were calculated for continuous outcomes while risk ratio (RR) were calculated for dichotomous outcomes.

RESULTS

Nine RCTs were included in our meta-analysis. Duloxetine had significant improvement over placebo in Brief Pain Inventory 24-h average pain [WMD: -0.67; 95% confidence interval (CI):-0.80, -0.53], weekly mean of the 24-h average pain (WMD: -0.65; 95% CI: -0.79, -0.52), Patient's Global Impression of Improvement (WMD: -0.41; 95% CI: -0.49, -0.32), Clinical Global Impression of Severity (WMD: -0.32; 95% CI: -0.38, -0.25), European Quality of Life Questionnaire-5 Dimension (WMD: 0.04; 95% CI: 0.02, 0.07). In addition, duloxetine is associated with more treatment-emergent adverse events (TEAEs) (RR: 1.25; 95% CI: 1.17, 1.33) and discontinuations for adverse events (AEs) (RR: 2.31; 95% CI: 1.81, 2.94). However, there was no statistically significant difference in serious AEs between duloxetine and placebo.

CONCLUSION

Duloxetine had modest to moderate effects on pain relief, function improvement, mood regulation and improvement in quality of life with mild AEs in the treatment of OA or CLBP. Future RCTs should focus on comparing duloxetine with other oral drugs and assessing the long-term safety of duloxetine.

Duloxetine and cardiovascular adverse events: A systematic review and meta-analysis

Duloxetine has been increasingly administered, but the associated cardiovascular adverse event risk is not clearly understood. Therefore, we identified the association between duloxetine and cardiovascular adverse events through an analysis of heart rate and blood pressure change. We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and psycINFO in June 2019. The title, abstract, and full text were checked in order to obtain articles. A meta-analysis was conducted with random effect model and quality of articles was evaluated using Cochrane Risk of Bias 2.0. The manuscript has been written according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) harm checklist. A total of 4009 studies were screened by the title and abstract. After reviewing 186 full texts, 17 studies were finally selected for the meta-analysis. Nine of the 17 studied duloxetine given for mood disorders and 8 for pain control. The duration of 14 studies was under 13 weeks. Cardiovascular adverse events (hypertension, myocardial infarction, transient ischemic attack, tachycardia atrial fibrillation, and cerebrovascular accident) were reported. The meta-analysis demonstrated that duloxetine increased heart rate by 2.22 beats/min (95% confidence intervals [CIs]: 1.53, 2.91) and diastolic blood pressure by 0.82 mmHg (95% CI: 0.17, 1.47). Our findings may be the signal for the safety of cardiovascular disease for short-term use of duloxetine. Well-designed pharmaco-epidemiological studies evaluating the causal relationship between long-term use of duloxetine and cardiovascular disease is still necessary.

AAPT Diagnostic Criteria for Chronic Low Back Pain

Chronic low back pain (CLBP) conditions are highly prevalent and constitute the leading cause of disability worldwide. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION) public-private partnership with the US Food and Drug Administration and the American Pain Society (APS), have combined to create the ACTTION-APS Pain Taxonomy (AAPT). The AAPT initiative convened a working group to develop diagnostic criteria for CLBP. The working group identified 3 distinct low back pain conditions which result in a vast public health burden across the lifespan. This article focuses on: 1) the axial predominant syndrome of chronic musculoskeletal low back pain, 2) the lateralized, distally-radiating syndrome of chronic lumbosacral radicular pain 3) and neurogenic claudication associated with lumbar spinal stenosis. This classification of CLBP is organized according to the AAPT multidimensional framework, specifically 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors. PERSPECTIVE: An evidence-based classification of CLBP conditions was constructed for the AAPT initiative. This multidimensional diagnostic framework includes: 1) core diagnostic criteria; 2) common features; 3) medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

Reduction in anxiety during treatment with exercise and duloxetine is related to improvement of low back pain-related disability in patients with non-specific chronic low back pain

Background:

Non-invasive treatment is generally recommended for patients with non-specific chronic low back pain (CLBP). However, the impact of combination therapy with physical exercise and a serotonin-norepinephrine reuptake inhibitor has not been clarified in patients with non-specific CLBP. This study assessed the efficacy of combination treatment with exercise and duloxetine on non-specific CLBP and aimed to identify factors that contributed to improvement of LBP-induced disability.

Methods:

This prospective study was conducted on consecutive outpatients with non-specific CLBP. Patients received a supervised home-based exercise program and duloxetine administration for 15 weeks. The Roland-Morris Disability Questionnaire (RDQ), Numerical Rating Scale (NRS), Hospital Anxiety and Depression Scale (HADS), and Pain Catastrophizing Scale (PCS) were assessed at baseline and 15 weeks. Multiple logistic regression modeling was used to identify factors associated with an improvement in RDQ.

Results:

Forty-two patients were enrolled. Overall, scores on the RDQ, NRS, and PCS (total score, magnification, helplessness) were significantly reduced at 15 weeks (p < 0.01 for all). An improvement of disability was confirmed in 22 patients (52%). A higher HADS depression score before and after the intervention was significantly associated with a lack of improvement in disability (p < 0.01). Further, a reduction in HADS anxiety score over 15 weeks was a significant factor associated with an improvement in disability (odds ratio: 1.99;95% CI: 1.26-3.65).

Conclusions:

Supervised exercise plus duloxetine resulted in favorable outcomes and an improvement of LBP-related disability in approximately 50% of patients. A reduction in anxiety over treatment was associated with the improved disability.

Relationship Between Pain Alleviation and Disease-specific Health-related Quality of Life Measures in Patients With Chronic Low Back Pain Receiving Duloxetine: Exploratory Post Hoc Analysis of a Japanese Phase 3 Randomized Study

This post hoc analysis of a Japanese phase 3 randomized study (ClinicalTrials.gov identifier: NCT01855919) investigated relationships between pain severity (assessed by the Brief Pain Inventory [BPI]) and disease-specific health-related quality of life (assessed by the 24-item Roland-Morris Disability Questionnaire [RDQ-24]) in duloxetine-treated patients with chronic low back pain (CLBP).

A Subgroup of Chronic Low Back Pain Patients With Central Sensitization

BACKGROUND

Our knowledge of central sensitization (CS) in chronic low back pain (CLBP) is limited. 2011 fibromyalgia criteria and severity scales (2011 FM survey) have been used to determine FM positive as a surrogate of CS. The major features of CS including widespread hyperalgesia and dysfunction of the descending inhibitory pathways can be identified by pressure pain threshold (PPT) and conditioned pain modulation (CPM) tests. The purpose of the study was to examine neurophysiological characteristics and psychosocial symptoms in a subgroup of FM-positive CLBP compared with FM-negative CLBP patients.

METHODS

A total of 46 participants with CLBP and 22 pain-free controls completed outcome measures of the 2011 FM survey, PPT and CPM tests, and psychosocial questionnaires. Differences between FM-positive and FM-negative CLBP participants on these measures and correlations were analyzed.

RESULTS

The 2011 FM survey identified 22 (48%) participants with CLBP as FM positive. FM-positive CLBP participants showed lower PPT values of the thumbnail (P=0.011) and lower back (P=0.003), lower CPM values of the thumbnail (P=0.002), and more severe pain catastrophizing, anxiety, and depression symptoms (P<0.05) than FM-negative CLBP participants. The 2011 FM scores were significantly correlated with the PPT and CPM values of the thumbnail and with psychosocial symptoms (P<0.001).

DISCUSSION

Our findings suggest a subgroup of CLBP patients exhibiting with signs and symptoms of CS. Associations between subjective and objective CS measures indicate that the 2011 FM survey can be utilized to identify the presence of CS in CLBP in clinical practice.

Topical loperamide for the treatment of localized neuropathic pain: a case report and literature review

Peripheral nerve damage can result in neuronal hyperexcitability, resulting in neuropathic pain. Localized neuropathic pain is confined to a specific area not larger than a letter-size piece of paper. Topical analgesics are increasingly popular for the treatment of localized neuropathic pain because systemic agents for managing neuropathic pain often produce undesirable and intolerable side effects. Commonly used agents for topical use are amitriptyline, baclofen, ketamine and lidocaine; however, these agents do not always give the desired analgesic effect in some patients. We report for the first time a patient with chronic idiopathic axonal polyneuropathy and intractable localized neuropathic pain treated successfully with loperamide 5% cream. After application of loperamide 5% cream, the patient reported a complete reduction of pain within 30 mins, lasting for 2.5 hrs. Subsequently, the patient was able to reduce his daily intake of oxycodone, while using topical loperamide for pain relief. Loperamide is a nonprescription opioid agonist, commonly used against diarrhea. As a topical formulation, it is preferable over other opioids due to its low systemic bioavailability and low risk of crossing the blood–brain barrier. Peripheral upregulation and sensitization of opioid receptors at peripheral nerve endings and perhaps at other cell populations in the epidermis might be targets of topical loperamide.

Maintenance of effect of duloxetine in Chinese patients with pain due to osteoarthritis: 13-week open-label extension data

Background

The objectives of this study were to assess the maintenance of effect of duloxetine 60 mg once-daily (QD) in Chinese patients with chronic pain due to osteoarthritis (OA) of the knee or hip and to provide additional long-term safety data.

Methods

This was an open-label, extension phase of a randomized, double-blind, placebo-controlled clinical trial. Eligible patients were outpatients who met the American College of Rheumatology clinical and radiographic criteria for OA with a rating ≥4 on Brief Pain Inventory (BPI) 24-h average pain. After completing the 13-week placebo-controlled phase, patients originally assigned to placebo were titrated to duloxetine 60 mg QD (PLA_DLX), whereas patients originally assigned to duloxetine 60 mg QD remained on the same dose of duloxetine (DLX_DLX) for another 13 weeks. The maintenance effect of duloxetine 60 mg QD during the extension phase was evaluated by a 1-sided 97.5% confidence interval (CI) of the baseline-to-endpoint change in the extension phase for patients who took duloxetine and reported ≥30% reduction in BPI average pain at the end of placebo-controlled phase (placebo-controlled phase duloxetine responders). Other BPI severity and interference items, as well as safety and tolerability, were assessed.

Results

Of 342 patients entering the extension phase, 162 (97.6%) DLX_DLX-treated patients and 157 (89.2%) PLA_DLX-treated patients completed this phase. Most patients (76.0%) were female. Mean age was 60.6 years. Mean BPI average pain was 5.5 at baseline of the placebo-controlled phase. Among 113 placebo-controlled phase duloxetine responders, mean change in BPI average pain during the extension phase was − 0.59 (from 2.47 to 1.88); the upper bound of the 1-sided 97.5% CI was − 0.31 and less than the pre-specified non-inferiority margin of a 1.5-point increase (p < 0.001). Significant within-group improvements in all BPI items were observed for both PLA_DLX and DLX_DLX groups during the extension phase (all p < 0.01). No deaths or suicide-related events occurred. Seven (4.0%) PLA_DLX-treated patients and no DLX_DLX-treated patients discontinued due to an adverse event.

Conclusion

The analgesic effect of duloxetine 60 mg QD among treatment responders was maintained for the entire duration of the extension phase. Duloxetine 60 mg QD was well tolerated during the extension phase.

Trial registration

ClinicalTrials.gov identification number NCT01931475. Registered 29 August 2013.

An Open-Label, 52-Week, Phase III Trial of Duloxetine in Japanese Patients with Chronic Low Back Pain

Objective

To evaluate the safety and efficacy of duloxetine treatment for 52 weeks.

Design

Multicenter, open-label, phase III clinical study.

Setting

Forty-one medical institutions in Japan.

Subjects

Japanese patients with chronic low back pain (CLBP).

Methods

Duloxetine 60 mg once-daily was administered for 52 weeks. Safety was evaluated based on adverse events (AEs), vital signs, laboratory test values, electrocardiogram, Columbia-Suicide Severity Rating Scale, and occurrence of falls. The efficacy outcome measures were the Brief Pain Inventory (BPI; average pain, worst pain, least pain, and pain right now), BPI Interference, Patient’s Global Impression of Improvement (PGI-I), Clinical Global Impressions of Severity (CGI-S), Roland-Morris Disability Questionnaire–24 (RDQ-24), 36-Item Short-Form Health Survey (SF-36), and European Quality of Life-5 Dimensions Questionnaire (EQ-5D).

Results

In total, 151 patients (83 who completed a 14-week placebo-controlled superiority trial and 68 newly registered patients) were enrolled. The incidence rates of AEs and adverse drug reactions (ADRs) were 86.1% and 50.3%, respectively. ADRs with an incidence of ≥5% were somnolence, constipation, nausea, and dry mouth. Treatment discontinuation for AEs occurred in 16 patients. A significant reduction in the BPI average pain score (mean ± SD) was observed at all assessment time points from week 2 (−1.02 ± 1.37) to week 50 (−2.26 ± 1.63), compared with baseline. BPI pain severity (worst pain, least pain, and pain right now), BPI Interference, PGI-I, CGI-S, RDQ-24, SF-36, and EQ-5D showed significant improvement.

Conclusion

Japanese patients with CLBP had significant pain reduction over 52 weeks without new safety concerns.

Prescription Medication Use Among Community-Based U.S. Adults With Chronic Low Back Pain: A Cross-Sectional Population Based Study

Many classes of medications have been evaluated in chronic low back pain (cLBP), however their utilization in the community remains unclear. We examined patterns of prescription medication use among Americans with cLBP in a nationally representative, community-based sample. The Back Pain Survey was administered to a representative sample of U.S. adults aged 20 to 69 years (N = 5,103) during the 2009 to 2010 cycle of the National Health and Nutrition Examination Survey. cLBP was defined as self-reported pain in the area between the lower posterior margin of the ribcage and the horizontal gluteal fold on most days for at least 3 months (N = 700). Home-based interviews with pill bottle verification were used to capture commonly prescribed medications for chronic pain. Among the sample of U.S. adults with cLBP aged 20 to 69 years, 36.9% took at least 1 prescription pain medication in the past 30 days; of them, 18.8% used opioids, 9.7% nonsteroidal anti-inflammatory drugs, 8.5% muscle relaxants, and 6.9% gabapentin or pregabalin. Nonpain antidepressants and hypnotics were used by 17.8% and 4.7%, respectively. Opioids were used long-term in 76.9% of cases (median = 2 years) and were frequently coadministered with antidepressants, benzodiazepines, or hypnotics. Ninety-four percent of prescription opioids in the cLBP population were used by individuals with less than a college education. Opioids were the most widely used prescription analgesic class in community-based U.S. adults with cLBP and were often coadministered with other central nervous system-active medications. Opioid use was highly prevalent among less educated Americans with cLBP.

PERSPECTIVE

Because prescription opioid use is an issue of national concern, we examined pain-related prescription medication use in community-dwelling U.S. adults with cLBP. Opioids were the most common prescription pain medication, typically used long-term, in combination with other central nervous system-active agents, and disproportionately among individuals with less than a college education.

Why are there no drugs indicated for sciatica, the most common chronic neuropathic syndrome of all?

This review examines the stark contrast between the successes and failures of the clinical development of analgesics for different types of chronic low back pain (CLBP) syndrome over the past three decades. Multiple drugs with differing mechanisms of action have been developed for nonspecific axial-predominant low back syndromes and yet not a single therapy is indicated for any neuropathic low back pain syndrome (e.g., sciatica). Clinician findings have informed the entry criteria for neuropathic low back pain clinical trials, whereas entry criteria of axial CLBP trials have prioritized only patient reports of pain. This key difference could account for the lack of success in developing therapies for neuropathic low back pain in an era marked by successful development of analgesics for other types of CLBP as well as many chronic pain syndromes associated with nerve injury, such as post-herpetic neuralgia (PHN).

Impact of adherence to antidepressants on long-term prescription opioid use cessation

BACKGROUND

Depression contributes to persistent opioid analgesic use (OAU). Treating depression may increase opioid cessation. Aims To determine if adherence to antidepressant medications (ADMs) v. non-adherence was associated with opioid cessation in patients with a new depression episode after >90 days of OAU.

METHOD

Patients with non-cancer, non-HIV pain (n = 2821), with a new episode of depression following >90 days of OAU, were eligible if they received ≥1 ADM prescription from 2002 to 2012. ADM adherence was defined as >80% of days covered. Opioid cessation was defined as ≥182 days without a prescription refill. Confounding was controlled by inverse probability of treatment weighting.

RESULTS

In weighted data, the incidence rate of opioid cessation was significantly (P = 0.007) greater in patients who adhered v. did not adhered to taking antidepressants (57.2/1000 v. 45.0/1000 person-years). ADM adherence was significantly associated with opioid cessation (odds ratio (OR) = 1.24, 95% CI 1.05-1.46).

CONCLUSIONS

ADM adherence, compared with non-adherence, is associated with opioid cessation in non-cancer pain. Opioid taper and cessation may be more successful when depression is treated to remission. Declaration of interest None.