The efficacy of duloxetine, non-steroidal anti-inflammatory drugs, and opioids in osteoarthritis: a systematic literature review and meta-analysis

Current advances in the pain treatment and mechanisms of Traditional Chinese Medicine

Traditional Chinese Medicine (TCM), as a unique medical model in China, has been shown to be effective in the treatment of many diseases. It has been proven that TCM can increase the pain threshold, increase the level of endorphins and enkephalins in the body, and reduce the body's response to adverse stimuli. In recent years, TCM scholars have made valuable explorations in the field of pain treatment, using methods such as internal and external application of TCM and acupuncture to carry out research on pain treatment and have achieved more satisfactory results. TCM treats pain in a variety of ways, and with the discovery of a variety of potential bioactive substances for pain treatment. With the new progress in the research of other TCM treatment methods for pain, TCM will have greater potential in the clinical application of pain.

Predictors of Multiwave Opioid Use Among Older American Adults

Background and Objectives

Despite limited analgesic benefits, long-term opioid therapy (L-TOT) is common among older adults with chronic pain. Extended opioid use poses a threat to older adults as aging metabolisms retain opioids for longer, increasing the risk of injury, overdose, and other negative health outcomes. In contrast to predictors of general opioid use, predictors of L-TOT in older adults are not well documented. We aimed to identify such predictors using all available data on self-reported opioid use in the Health and Retirement Study.

Research Design and Methods

Using 5 waves of data, respondents (N = 10,713) aged 51 and older were identified as reporting no opioid use (n = 8,621), a single wave of use (n = 1,410), or multiple waves of use (n = 682). We conducted a multinomial logistic regression to predict both single- and multiwave opioid use relative to no use. Demographic, socioeconomic, geographic, health, and health care-related factors were included in our model.

Results

Multivariable findings show that, relative to nonusers, both single- and multiwave users were significantly more likely to be younger (relative risk ratio [RRR] = 1.33; RRR = 2.88); report lower household wealth (RRR = 1.47; RRR = 2.88); live in the U.S. Midwest (RRR = 1.29; RRR = 1.56), South (RRR = 1.34; RRR = 1.58), or West (RRR = 1.46; RRR = 2.34); experience interfering pain (RRR = 1.59; RRR = 3.39), back pain (RRR = 1.35; RRR = 1.53), or arthritic pain (RRR = 1.46; RRR = 2.32); and see the doctor frequently (RRR = 1.50; RRR = 2.02). Multiwave users were less likely to be Black (RRR = 0.69) or Hispanic (RRR = 0.45), and less likely to be never married (RRR = 0.52).

Discussion and Implications

We identified demographic, socioeconomic, geographic, and health care-related predictors of chronic multiyear opioid use. Our focus on individuals taking opioids for this extended duration is novel. Differences in opioid use by geographic region and frequency of doctor visits particularly warrant attention from policy-makers and researchers. We make additional recommendations based on a sensitivity analysis limited to 2016-2020 data.

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.

Antidepressants for hip and knee osteoarthritis

BACKGROUND

Although pain is common in osteoarthritis, most people fail to achieve adequate analgesia. Increasing acknowledgement of the contribution of pain sensitisation has resulted in the investigation of medications affecting pain processing with central effects. Antidepressants contribute to pain management in other conditions where pain sensitisation is present.

OBJECTIVES

To assess the benefits and harms of antidepressants for the treatment of symptomatic knee and hip osteoarthritis in adults.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was January 2021.

SELECTION CRITERIA

We included randomised controlled trials of adults with osteoarthritis that compared use of antidepressants to placebo or alternative comparator. We included trials that focused on efficacy (pain and function), treatment-related adverse effects and had documentation regarding discontinuation of participants. We excluded trials of less than six weeks of duration or had participants with concurrent mental health disorders.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Major outcomes were pain; responder rate; physical function; quality of life; and proportion of participants who withdrew due to adverse events, experienced any adverse events or had serious adverse events. Minor outcomes were proportion meeting the OARSI (Osteoarthritis Research Society International) Response Criteria, radiographic joint structure changes and proportion of participants who dropped out of the study for any reason. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Nine trials (2122 participants) met the inclusion criteria. Seven trials examined only knee osteoarthritis. Two also included participants with hip osteoarthritis. All trials compared antidepressants to placebo, with or without non-steroidal anti-inflammatory drugs. Trial sizes were 36 to 388 participants. Most participants were female, with mean ages of 54.5 to 65.9 years. Trial durations were 8 to 16 weeks. Six trials examined duloxetine. We combined data from nine trials in meta-analyses for knee and hip osteoarthritis. One trial was at low risk of bias in all domains. Five trials were at risk of attrition and reporting bias. High-certainty evidence found that antidepressants resulted in a clinically unimportant improvement in pain compared to placebo. Mean reduction in pain (0 to 10 scale, 0 = no pain) was 1.7 points with placebo and 2.3 points with antidepressants (mean difference (MD) -0.59, 95% confidence interval (CI) -0.88 to -0.31; 9 trials, 2122 participants). Clinical response was defined as achieving a 50% or greater reduction in 24-hour mean pain. High-certainty evidence demonstrated that 45% of participants receiving antidepressants had a clinical response compared to 28.6% receiving placebo (RR 1.55, 95% CI 1.32 to 1.82; 6 RCTs, 1904 participants). This corresponded to an absolute improvement in pain of 16% more responders with antidepressants (8.9% more to 26% more) and a number needed to treat for an additional beneficial effect (NNTB) of 6 (95% CI 4 to 11). High-certainty evidence showed that the mean improvement in function (on 0 to 100 Western Ontario and McMaster Universities Arthritis Index, 0 = best function) was 10.51 points with placebo and 16.16 points with antidepressants (MD -5.65 points, 95% CI -7.08 to -4.23; 6 RCTs, 1909 participants). This demonstrates a small, clinically unimportant response. Moderate-certainty evidence (downgraded for imprecision) showed that quality of life measured using the EuroQol 5-Dimension scale (-0.11 to 1.0, 1.0 = perfect health) improved by 0.07 points with placebo and 0.11 points with antidepressants (MD 0.04, 95% CI 0.01 to 0.07; 3 RCTs, 815 participants). This is clinically unimportant. High-certainty evidence showed that total adverse events increased in the antidepressant group (64%) compared to the placebo group (49%) (RR 1.27, 95% CI 1.15 to 1.41; 9 RCTs, 2102 participants). The number needed to treat for an additional harmful outcome (NNTH) was 7 (95% CI 5 to 11). Low-certainty evidence (downgraded twice for imprecision for very low numbers of events) found no evidence of a difference in serious adverse events between groups (RR 0.94, 95% CI 0.46 to 1.94; 9 RCTs, 2101 participants). The NNTH was 1000.  Moderate-certainty evidence (downgraded for imprecision) showed that 11% of participants receiving antidepressants withdrew from trials due to an adverse event compared to 5% receiving placebo (RR 2.15, 95% CI 1.56 to 2.97; 6 RCTs, 1977 participants). The NNTH was 17 (95% CI 10 to 35).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that use of antidepressants for knee osteoarthritis leads to a non-clinically important improvement in mean pain and function. However, a small number of people will have a 50% or greater important improvement in pain and function. This finding was consistent across all trials. Pain in osteoarthritis may be due to a variety of causes that differ between individuals. It may be that the cause of pain that responds to this therapy is only present in a small number of people. There is moderate-certainty evidence that antidepressants have a small positive effect on quality of life with heterogeneity between trials. High-certainty evidence indicates antidepressants result in more adverse events and moderate-certainty evidence indicates more withdrawal due to adverse events. There was little to no difference in serious adverse events (low-certainty evidence due to low numbers of events). This suggests that if antidepressants were being considered, there needs to be careful patient selection to optimise clinical benefit given the known propensity for adverse events with antidepressant use. Future trials should include alternative antidepressant agents or phenotyping of pain in people with osteoarthritis, or both.

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.

Effectiveness and safety of non-steroidal anti-inflammatory drugs and opioid treatment for knee and hip osteoarthritis: network meta-analysis

OBJECTIVE

To assess the effectiveness and safety of different preparations and doses of non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and paracetamol for knee and hip osteoarthritis pain and physical function to enable effective and safe use of these drugs at their lowest possible dose.

DESIGN

Systematic review and network meta-analysis of randomised trials.

DATA SOURCES

Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, regulatory agency websites, and ClinicalTrials.gov from inception to 28 June 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised trials published in English with ≥100 patients per group that evaluated NSAIDs, opioids, or paracetamol (acetaminophen) to treat osteoarthritis.

OUTCOMES AND MEASURES

The prespecified primary outcome was pain. Physical function and safety outcomes were also assessed.

REVIEW METHODS

Two reviewers independently extracted outcomes data and evaluated the risk of bias of included trials. Bayesian random effects models were used for network meta-analysis of all analyses. Effect estimates are comparisons between active treatments and oral placebo.

RESULTS

192 trials comprising 102 829 participants examined 90 different active preparations or doses (68 for NSAIDs, 19 for opioids, and three for paracetamol). Five oral preparations (diclofenac 150 mg/day, etoricoxib 60 and 90 mg/day, and rofecoxib 25 and 50 mg/day) had ≥99% probability of more pronounced treatment effects than the minimal clinically relevant reduction in pain. Topical diclofenac (70-81 and 140-160 mg/day) had ≥92.3% probability, and all opioids had ≤53% probability of more pronounced treatment effects than the minimal clinically relevant reduction in pain. 18.5%, 0%, and 83.3% of the oral NSAIDs, topical NSAIDs, and opioids, respectively, had an increased risk of dropouts due to adverse events. 29.8%, 0%, and 89.5% of oral NSAIDs, topical NSAIDs, and opioids, respectively, had an increased risk of any adverse event. Oxymorphone 80 mg/day had the highest risk of dropouts due to adverse events (51%) and any adverse event (88%).

CONCLUSIONS

Etoricoxib 60 mg/day and diclofenac 150 mg/day seem to be the most effective oral NSAIDs for pain and function in patients with osteoarthritis. However, these treatments are probably not appropriate for patients with comorbidities or for long term use because of the slight increase in the risk of adverse events. Additionally, an increased risk of dropping out due to adverse events was found for diclofenac 150 mg/day. Topical diclofenac 70-81 mg/day seems to be effective and generally safer because of reduced systemic exposure and lower dose, and should be considered as first line pharmacological treatment for knee osteoarthritis. The clinical benefit of opioid treatment, regardless of preparation or dose, does not outweigh the harm it might cause in patients with osteoarthritis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO number CRD42020213656.

Is There Any Role for Opioids in the Management of Knee and Hip Osteoarthritis? A Systematic Review and Meta-Analysis

OBJECTIVE

Opioids have long been prescribed for chronic pain conditions, including osteoarthritis (OA). However, there is little information about their temporal efficacy, or differences in efficacy and safety between opioids with strong versus weak/intermediate μ opioid receptor-binding affinity. To explore these research questions, we conducted a systematic review and meta-analyses of randomized controlled trials (RCTs) conducted in patients with knee and/or hip OA.

METHODS

We searched Medline, Embase, PubMed Central, and the Cochrane Central Register of Controlled Trials from inception to December 2019 and sought unpublished data. Placebo-controlled RCTs of oral opioids in patients with knee and/or hip OA were included. Standardized mean differences (SMDs) were calculated for pain and function at 2, 4, 8, and 12 weeks. Subgroup analyses for strong and weak/intermediate opioids were conducted. Meta-regression was performed to assess the impact of dosage (morphine equivalency) on pain relief. Risk ratios were calculated for safety at the final follow-up.

RESULTS

A total of 18 RCTs (9,283 participants) were included. Opioids demonstrated small benefits on pain at each time point, with SMDs ranging from -0.28 (95% confidence interval [95% CI] -0.38, -0.17) to -0.19 (95% CI -0.29, -0.08); similar effects were observed for function. Strong opioids demonstrated consistently inferior efficacy and overall worse safety than weak/intermediate opioids. Meta-regression revealed that incremental pain relief achieved beyond 20-50-mg doses was not substantial in the context of increased safety risks.

CONCLUSION

Opioids provide minimal relief of OA symptoms within a 12-week period, and they are known to cause discomfort in a majority of patients. Clinicians and policy makers should reconsider the utility of opioids in the management of OA.

Curcumenol mitigates chondrocyte inflammation by inhibiting the NF‑κB and MAPK pathways, and ameliorates DMM‑induced OA in mice

At present, an increasing number of individuals are affected by osteoarthritis (OA), resulting in a heavy socioeconomic burden. OA in knee joints is caused by the release of inflammatory cytokines and subsequent biomechanical and structural deterioration. To determine its anti‑inflammatory function, the current study investigated the use of the plant‑derived medicine, curcumenol, in OA treatment. Curcumenol was not cytotoxic to ATDC5 chondrocytes and primary chondrocytes, as determined using a cell viability test. When these cells were treated with TNF‑α and IL‑1β to induce inflammation, curcumenol treatment inhibited the progression of inflammation by inactivating the NF‑κB and MAPK signaling pathways, as well as decreasing the expression levels of MMP3 (as indicated by reverse transcription‑quantitative PCR and western blotting). Moreover, to analyze metabolic and catabolic status in high‑density and pellet culture, catalytic changes and the degradation of the extracellular matrix induced by TNF‑α and IL‑1β, were evaluated by alcian blue staining. These catalytic deteriorations were ameliorated by curcumenol. Using curcumenol in disease management, the mechanical and metabolic disruption of cartilage caused in the destabilization of medial meniscus (DMM) model was prevented in vivo. Thus, curcumenol mitigated inflammation in ATDC5 chondrocytes and primary mice chondrocytes, and also ameliorated OA in a DMM‑induced mouse model.

American Society of Hematology 2020 guidelines for sickle cell disease: management of acute and chronic pain

BACKGROUND

The management of acute and chronic pain for individuals living with sickle cell disease (SCD) is a clinical challenge. This reflects the paucity of clinical SCD pain research and limited understanding of the complex biological differences between acute and chronic pain. These issues collectively create barriers to effective, targeted interventions. Optimal pain management requires interdisciplinary care.

OBJECTIVE

These evidence-based guidelines developed by the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in pain management decisions for children and adults with SCD.

METHODS

ASH formed a multidisciplinary panel, including 2 patient representatives, that was thoroughly vetted to minimize bias from conflicts of interest. The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic reviews. Clinical questions and outcomes were prioritized according to importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel reached consensus on 18 recommendations specific to acute and chronic pain. The recommendations reflect a broad pain management approach, encompassing pharmacological and nonpharmacological interventions and analgesic delivery.

CONCLUSIONS

Because of low-certainty evidence and closely balanced benefits and harms, most recommendations are conditional. Patient preferences should drive clinical decisions. Policymaking, including that by payers, will require substantial debate and input from stakeholders. Randomized controlled trials and comparative-effectiveness studies are needed for chronic opioid therapy, nonopioid therapies, and nonpharmacological interventions.

A systematic review and meta-analysis of health state utility values for osteoarthritis-related conditions

BACKGROUND

Health state utility values (HSUVs) are a key input in health economic modelling but HSUVs of people with osteoarthritis (OA)-related conditions have not been systematically reviewed and meta-analysed.

OBJECTIVE

To systematically review and meta-analyse the HSUVs for people with OA.

METHODS

Searches within health economic/biomedical databases were performed to identify eligible studies reporting OA-related HSUVs. Data on study design, participant characteristics, affected OA joint sites, treatment type, HSUV elicitation method, considered health states, and the reported HSUVs were extracted. HSUVs for people with knee, hip and mixed OA in pre- and post-treatment populations were meta-analysed using random effects models.

RESULTS

One-hundred and fifty-one studies were included in the systematic review, and 88 in meta-analyses. Of 151 studies, 56% were conducted in Europe, 75% were in people with knee and/or hip OA and 79% were based on the EQ-5D. The pooled mean (95% confidence interval [CI]) baseline HSUVs for knee OA core interventions, medication, injection and primary surgery treatments were 0.64 (0.61-0.66), 0.56 (0.45-0.68), 0.58 (0.50-0.66) and 0.52 (0.49-0.55), respectively. These were 0.71 (0.59-0.84) for hip OA core interventions and 0.52 (0.49-0.56) for hip OA primary surgery. For all knee OA treatments and hip OA primary surgery, pooled HSUVs were significantly higher in the post- than the pre- treatment populations.

CONCLUSION

This study provides a comprehensive summary of OA-related HSUVs and generates a HSUVs database for people with different affected OA joint sites undergoing different treatments to guide HSUV choices in future health economic modelling of OA interventions.

Guidelines for the diagnosis and treatment of osteoarthritis in China (2019 edition)

Osteoarthritis (OA) is a degenerative disease of middle-aged and elderly people, contributed a higher burden of disease in China and the world. In 2017, under the support of the Rheumatology and Immunology Expert Committee of the Cross-Strait Medical and Health Exchange Association. The objective was to develop an evidence-based diagnosis and treatment guideline for OA in China based on emerging new evidence. The guideline was registered at International Practice Guidelines Registry Platform (IPGRP-2018CN028). The grading of recommendations assessment, development and evaluation (GRADE) approach was used to rate the quality of evidence and the strength of recommendations, and the RIGHT (Reporting Items for Practice Guidelines in Healthcare) checklist was followed to report the guideline. The guideline provides recommendations for the OA diagnosis, disease risks monitoring and evaluate, treatment purpose and physical, medical and surgical interventions. This guideline is intended to serve as a tool for Chinese clinicians for the best decisions-making on diagnosis and treatment of OA.

Real-World Evidence in Prescription Medication Use Among U.S. Adults with Neck Pain

Introduction

Neck pain is a common condition that leads to serious pain, disability, and increased healthcare costs worldwide. Pharmacotherapy is one of the most common strategies to reduce neck pain in patients. The aim of this study was to analyze the real-world pattern of drugs prescribed for patients with neck pain in the USA.

Methods

Data on individuals who reported current neck pain in the 2009−2010 US National Health and Nutrition Examination Survey (NHANES) and with a history of persistent pain for at least 6 weeks or 3 months were extracted from the NHANES database. Those included in the study were divided into three groups based on the duration of pain: the without neck pain group (Group A); subacute group (Group B) with a history of 6 weeks of neck pain; and the chronic neck pain group (Group C) with a history of 3 months of neck pain. The use and duration of medication prescribed for Group A, B, and C patients were compared.

Results

The analysis revealed that opioid use was significantly more prevalent in the subacute and chronic neck pain group than in the without neck pain group (Group A) (adjusted odds ratio [aOR] 4.20, 95% confidence interval [CI] 2.07–8.52 and aOR 7.00, 95% CI 4.32–11.33, respectively). The factors strongly associated with higher opioid use included older age, low education level, and low family income. In the chronic neck group, opioids, followed in decreasing order of frequency by acetaminophen and nonsteroidal anti-infammatory drugs, were the most common analgesics used in combination with other analgesics.

Conclusion

Our analysis of the data shows that the long-term excessive use of opioids and the underutilization of other analgesics are two major issues in the treatment of neck pain in the USA. Possible improvements include improved education of patients by healthcare professionals on the use of opioids and more consideration given to non-pharmacotherapy options. Our results reveal the potential problem in pharmacotherapy choices for neck pain treatment and may help improve the current clinical practice in the USA and other countries.

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.

What is the selection process for osteoarthritis pharmacotherapy?

Osteoarthritis is the most prevalent joint condition that continues to increase with an ever-aging population and the rising tide of obesity. There are multiple recommendations/guidelines for the management of osteoarthritis. The basis of management should focus on self-management and education, lifestyle modifications, exercise and when appropriate, weight loss. Pharmacotherapy is targeted toward pain palliation with no agents available presently to target prevention and disease modification. The selection of pharmacotherapy should be tailored to the individual, taking into account of personal preferences and interactions with underlying co-morbidities. This editorial provides a guide to the selection process of presently available pharmacotherapy in osteoarthritis.

Do β-adrenoreceptor blocking drugs associate with reduced risk of symptomatic osteoarthritis and total joint replacement in the general population? A primary care-based, prospective cohort study using the Clinical Practice Research Datalink

INTRODUCTION

To investigate if β-adrenoreceptor blocking drug (β-blocker) prescription reduces the risk of knee or hip osteoarthritis, total joint replacement and analgesic prescription.

SETTING

Primary care.

METHODS AND ANALYSIS

This is a cohort study using data from the Clinical Practice Research Datalink. Two separate analyses will be performed. Study 1 will be on the association between β-blocker prescription and incident knee/hip osteoarthritis. Inclusion criteria will be age ≥40 years. Exposed participants will be those with ≥2 continuous β-blocker prescriptions, and the index date will be the date of the first prescription of β-blocker. Unexposed participants will include up to four controls matched for age, sex, general practice surgery and propensity score for β-blocker prescription. Exclusion criteria will include contraindications to β-blockers, consultations for osteoarthritis or potent analgesic prescription before the index date. Outcomes will be knee osteoarthritis (primary outcome), hip osteoarthritis, knee pain and hip pain. Study 2 will be on the association between β-blocker prescription and total joint replacement and analgesic prescription in people with osteoarthritis. Inclusion criteria will be age ≥40 years, knee or hip osteoarthritis, and index date will be as in study 1. Unexposed participants will be as in study 1, additionally matched for consultation for knee or hip osteoarthritis prior to the index date. Exclusion criteria will include contraindications to β-blockers and osteoarthritis in other joints prior to the index date. Outcomes will be total knee replacement (primary outcome), total hip replacement and new analgesic prescription.

STATISTICAL ANALYSIS

Kaplan-Meier curves will be plotted, and Cox proportional HRs and 95% CIs will be calculated. Stratified analysis will be performed by class of β-blocker, intrinsic sympathomimetic effect and indication(s) for prescription.

ETHICS AND DISSEMINATION

This study was ethically approved by the Independent Scientific Advisory Committee of the Medicines and Healthcare Authority (Ref 18_227R). The results of this study will be published in peer-reviewed journals and presented at conferences.

SUMMARY

This prospective cohort study will evaluate the analgesic potential of commonly used drugs for osteoarthritis pain.

Study protocol for a randomised, double-blind, placebo-controlled clinical trial of duloxetine for the treatment and prevention of musculoskeletal pain: altering the transition from acute to chronic pain (ATTAC pain)

INTRODUCTION

Chronic musculoskeletal pain affects a substantial portion of adults visiting the emergency department (ED). Current treatment is limited in scope and does not effectively reduce musculoskeletal pain in patients. The study will evaluate the use of duloxetine, a serotonin-norepinephrine reuptake inhibitor Food and Drug Administration approved for the treatment of chronic pain, as a promising option in its prevention. The proposed study may present a well-tolerated and effective non-opioid treatment for patients with acute musculoskeletal pain that may also be effective in preventing the transition to persistent or chronic musculoskeletal pain.

METHODS AND ANALYSIS

The primary outcome of this study will be to assess the tolerability and preliminary effectiveness of duloxetine in patients with acute musculoskeletal pain. The study will take place at two EDs in Rhode Island, USA. The study will involve randomisation to one of three arms: duloxetine 30 mg, duloxetine 60 mg or placebo. Tolerability will be assessed by comparing the proportion of participants that report an adverse event and that drop-out across the three study arms. Effectiveness will be determined by self-reported pain over 6 weeks of follow-up. Specifically, we will compare the proportion of participants with persistent pain (ongoing pain at 6-week follow-up), across the three study arms. 60 adults (aged 18-59) presenting to the ED with acute axial musculoskeletal pain within 7 days of onset are expected to be enrolled in the proposed study.

ETHICS AND DISSEMINATION

Ethics approval was obtained by the Institutional Review Board (IRB). These results will be published in a peer reviewed scientific journal and presented at one or more scientific conferences.

TRIAL REGISTRATION NUMBER

NCT03315533.

The uptake of Bayesian methods in biomedical meta-analyses: A scoping review (2005-2016)

AIM

Bayesian statistical methods can allow for more complete and accurate incorporation of evidence in meta-analyses. However, these methods remain under-utilized.

METHODS

A scoping review was conducted to examine the proportion of biomedical meta-analyses that used Bayesian methods in the period 2005-2016. The review also examined the reproducibility of the work, the cited sources, the reasons for it, its success or failure, the type of model and prior distributions, and whether a mixture of Bayesian and frequentist methods were employed.

RESULTS

We found that 1% of meta-analyses are Bayesian and that the reporting and conduct of these were often poor. Data were published in 41% of analyses, and programs to run the analysis in 18%. Network meta-analysis was the most common reason and became increasingly popular in recent years. In the majority of papers, models and distributions were either not reported or explained in such brief and ambiguous terms as to be uninformative.

CONCLUSIONS

More use needs to be made of Bayesian meta-analysis, and reporting needs to be improved. Greater awareness of these methods and access to training in them is essential.

Technological development of microemulsions with perspectives for pain treatment: a patent review

INTRODUCTION

Microemulsions are thermodynamically stable translucent systems widely used for systemic delivery of drugs. The present study is the first to analyze the biotechnological potential of microemulsion systems for therapeutic purposes, through transdermal route, for pain treatment.

AREAS COVERED

Patents were searched in the World Intellectual Property Organization (WIPO), European Patent Office (Espacenet), United States Patent and Trademark Office (USPTO) and National Institute of Intellectual Property (INPI). The inclusion criteria were published patents containing the keywords; 'microemulsion' and 'transdermal' in their title or abstract. 208 patents were found. However, only those patents which mentioned in their abstract or in their description the use of microemulsion system (object of invention) for pain treatment were selected. Were excluded duplicate patents and those that did not report pharmacological use of MEs specifically for pain treatment. Thus, sixteen patents were selected and described in the present study.

EXPERT OPINION

Patents were found that focused specifically on the development process of microemulsion systems, the inclusion of essential oils in microemulsions, which place microemulsions as delivery systems for NSAIDs and other substances, as well as microemulsions for transdermal administration. These studies reinforce the therapeutic applicability of MEs in the treatment of acute and chronic pain.

The longitudinal relationship between hand, hip and knee osteoarthritis and cardiovascular events: a population-based cohort study

OBJECTIVE

In this population-based cohort study, we examined the association between the presence of symptomatic osteoarthritis (OA) and risk for cardiovascular (CV) events.

METHOD

A cohort aged ≥55 years recruited from 1996 to 98 was followed through provincial health administrative data to 2014. Demographics, joint complaints and functional limitations were collected. Hip, knee and hand OA were defined using a validated definition. Using Cox-regressions, the relationship between OA and a composite CV outcome (myocardial infarction (MI), stroke, angina, heart failure, revascularization) was assessed controlling for age, body mass index (BMI), sex, pre-existing metabolic factors, comorbidities, income status, primary care exposure and functional limitations.

RESULTS

18,490 participants were included: median age was 68 years, 60.3% were female; 24.4% met criteria for OA (10.0% hip, 15.3% knee, 16.0% hand), 16.3% self-reported limitation in grip and 25.4% in walking. Over a median 13.4 years, 31.9% experienced a CV event. Controlling for all but walking limitation, a dose-response relationship was observed between number of joints affected by knee/hip OA and CV risk (HR 2 hips/knees vs none: 1.13, 95% CI 1.03-1.23; 3+ hips/knees: 1.22, 95% CI 1.09-1.36). This relationship became non-significant additionally controlling for difficulty walking. Self-reported difficulty walking was associated with a 30% increased hazard for CV events. The effect of hand OA was not significant.

CONCLUSION

In a large population cohort, a greater burden of hip/knee OA was associated with higher CV risk; the relationship was explained by OA-related difficulty walking. Increased attention to management of OA with a view to improving mobility has potential to reduce CV events.

Is duloxetine an alternative in the treatment of osteoarthritis?

INTRODUCTION

Many osteoarthritis patients continue to present symptoms despite nonsurgical treatment. Duloxetine might be a viable alternative for such cases, but real clinical relevance remains unclear.

METHODS

A literature review was conducted in Epistemonikos, the largest database for systematic reviews in health that compiles multiple sources, including MEDLINE, EMBASE, and Cochrane, among others. Relevant data were extracted, and information from the primary studies was reanalyzed. A subsequent meta-analysis was conducted, and summary of findings tables were constructed using the GRADE methodology.

RESULTS AND CONCLUSIONS

Four systematic reviews including four randomized trials, were identified. In conclusion, while duloxetine slightly improves pain and functionality in osteoarthritis patients, its use is associated with frequent adverse side effects. Therefore, the benefit/risk balance appears unfavorable.

Efficacy and safety of duloxetine in Chinese breast cancer patients with paclitaxel-induced peripheral neuropathy

Objective

Chemotherapy with paclitaxel is associated with significant neurotoxicity that may offset patients' quality of life and therapeutic benefits. This prospective, non-randomized control study evaluated the efficacy and safety of an antidepressant drug, duloxetine, at 30 or 60 mg/d, in the treatment of paclitaxel-induced peripheral neuropathy (PIPN) in Chinese breast cancer patients.

Methods

A total of 102 patients with a median age of 50 (range, 25-60) years, treated in the Department of Medical Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, between November 2014 and January 2017 were finally enrolled. Stratified by baseline characteristics, the patients were classified into two groups, receiving either duloxetine or alternative anti-neurotoxicity drugs. During the course of the paclitaxel regimen, the eligibility criteria included sensory neuropathy, as evaluated by the National Cancer Institute-Common Toxicity Criteria for Adverse Events. The treatment consisted of receiving 30 mg duloxetine (for the first 4 weeks) and 60 mg duloxetine for an additional 8 weeks, or any other anti-neurotoxicity drug daily during the same crossover period. The improvement associated with PIPN from the patient's perspective were assessed by the Functional Assessment of Cancer Therapy-Taxane (FACT-Tax) Scales, which contained questions scored from 0 to 4 (0, not at all; 4, very much; total score range, 0-44).

Results

Duloxetine was more effective in decreasing PIPN (odds ratio=5.426; 95% confidence interval, 1.898-15.514; P=0.002). Between duloxetine group and control group, the median (25th-75th percentiles) decreasing difference in the FACT-Tax pain score was 4 (2-6) vs. 1 (0-4) (P=0.005).

Conclusions

Duloxetine is a promising and safe option with tolerable toxicity at a dose of 60 mg/d for Chinese breast cancer patients with PIPN. Non-neuropathy adverse events were mild and similar in both groups. The major toxicities of duloxetine included nausea, constipation, somnolence, dizziness and distention of the eyes. Further examination of the benefits of duloxetine in the prevention of PIPN is required.

Intra-articular therapies for osteoarthritis

INTRODUCTION

Conventional medical therapies for osteoarthritis are mainly palliative in nature, aiming to control pain and symptoms. Traditional intra-articular therapies are not recommended in guidelines as first line therapy, but are potential alternatives, when conventional therapies have failed.

AREAS COVERED

Current and future intra-articular drug therapies for osteoarthritis are highlighted, including corticosteroids, hyaluronate, and more controversial treatments marketed commercially, namely platelet rich plasma and mesenchymal cell therapy. Intraarticular disease modifying osteoarthritis drugs are the future of osteoarthritis treatments, aiming at structural modification and altering the disease progression. Interleukin-1β inhibitor, bone morphogenic protein-7, fibroblast growth factor 18, bradykinin B2 receptor antagonist, human serum albumin, and gene therapy are discussed in this review. The evolution of drug development in osteoarthritis is limited by the ability to demonstrate effect. High quality trials are required to justify the use of existing intra-articular therapies and to advocate for newer, promising therapies.

EXPERT OPINION

Challenges in osteoarthritis therapy research are fundamentally related to the complexity of the pathological mechanisms of osteoarthritis. Novel drugs offer hope in a disease with limited medical therapy options. Whether these future intra-articular therapies will provide clinically meaningful benefits, remains unknown.

Pain Relief for an Osteoarthritic Knee in the Elderly: A Practical Guide

In view of the increasing prevalence of knee osteoarthritis (OA) in the population worldwide, optimal management is critical to decrease the burden of this condition and minimize disability and personal suffering. Current care is based on a sequence of non-pharmacological, pharmacological, and surgical modalities, targeted to improving pain and function in the elderly population. The aim of this article is to provide a practical view of the efficacy of therapeutic options available along with clinically relevant considerations on the management of knee OA in this demographic group.

Comparative pain reduction of oral non-steroidal anti-inflammatory drugs and opioids for knee osteoarthritis: systematic analytic review

OBJECTIVE

Summarize the comparative effectiveness of oral non-steroidal anti-inflammatory drugs (NSAIDs) and opioids in reducing knee osteoarthritis (OA) pain.

METHODS

Two reviewers independently screened reports of randomized controlled trials (RCTs), published in English between 1982 and 2015, evaluating oral NSAIDs or opioids for knee OA. Included studies were at least 8 weeks duration, conducted in Western Europe, the Americas, New Zealand, or Australia, and reported baseline and follow-up pain using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain subscale (0-100, 100-worst). Effectiveness was evaluated as reduction in pain, accounting for study dropout and heterogeneity.

RESULTS

Twenty-seven treatment arms (nine celecoxib, four non-selective NSAIDs [diclofenac, naproxen, piroxicam], eleven less potent opioids [tramadol], and three potent opioids [hydromorphone, oxycodone]) from 17 studies were included. NSAID and opioid studies reported similar baseline demographics and efficacy withdrawal rates; NSAID studies reported lower baseline pain and toxicity withdrawal rates. Accounting for efficacy-related withdrawals, all drug classes were associated with similar pain reductions (NSAIDs: -18; less potent opioids: -18; potent opioids: -19). Meta-regression did not reveal differential effectiveness by drug class but found that study cohorts with a higher proportion of male subjects and worse mean baseline pain had greater pain reduction. Similarly, results of the network meta-analysis did not find a significant difference in WOMAC Pain reduction for the three analgesic classes.

CONCLUSION

NSAIDs and opioids offer similar pain relief in OA patients. These data could help clinicians and patients discuss likely benefits of alternative analgesics.

An Overview of Pharmacologic Management of Chronic Pain

Patients with chronic pain can be challenging to manage and historically providers have relied on opiates to treat pain. Recent studies have brought into question the safety and efficacy of chronic opiate therapy in the noncancer population. There is a vast amount of literature to support the use of nonsteroidal anti-inflammatory medications, antidepressants, anticonvulsants, topical agents, cannabinoids, and botulinum toxin either in conjunction with or in lieu of opioids. Intrathecal drug delivery systems can deliver some of these medications directly to their primary site of action while minimizing the side effects seen with systemic administration.

Strong opioids for noncancer pain due to musculoskeletal diseases: Not more effective than acetaminophen or NSAIDs

The classification of morphine as a step III analgesic, based on pharmacological data, creates a strong bias toward a belief in the efficacy of this drug. However, double-blind emergency-room trials showed similar levels of pain relief with intravenous acetaminophen as with intravenous morphine in patients with renal colic, low back pain or acute limb pain. In patients with chronic noncancer low back pain, morphine and other strong opioids in dosages of up to 100mg/day were only slightly more effective than their placebos, no more effective than acetaminophen, and somewhat less effective than nonsteroidal anti-inflammatory drugs (NSAIDs). In patients with osteoarthritis, strong opioids were not more effective than NSAIDs and, in some studies, than placebos. The only randomized controlled trial in patients with sciatica found no difference with the placebo. Chronic use of strong opioids can induce hyperalgesia in some patients. Hyperpathia with increased sensitivity to cold leading the patient to request higher dosages should suggest opioid-induced hyperalgesia. Pain specialists in the US have issued a petition asking that strong opioids be used in dosages no higher than 100mg/day of morphine-equivalent, in an effort to decrease the high rate of mortality due to the misuse and abuse of strong opioids (10,000 deaths/year in the US). Healthcare providers often overestimate the efficacy of step III analgesics, despite pain score decreases of only 0.8 to 1.2 points.