Efficacy and safety of tapentadol extended release for the management of chronic low back pain: results of a prospective, randomized, double-blind, placebo- and active-controlled Phase III study

Health-Related Quality of Life in Chronic Pain Treated With Tapentadol Versus Oxycodone/Naloxone and Its Determinants: A Real-World, Single-Center Retrospective Cohort Study in Spain

OBJECTIVES

A substantial proportion of patients with chronic noncancer pain (CNCP) are treated with tapentadol (TAP) or oxycodone/naloxone (OXN) to improve their perceived physical and mental health over time.

METHODS

A cross-sectional study was conducted in 135 CNCP outpatients with usual prescribing (TAP: n = 58, OXN: n = 77) at a tertiary-care Spanish Hospital to compare health-related quality-of-life (HRQoL) records. Health utility was derived from the EQ-5D-3L. Regression models were performed to search for other HRQoL determinants. Pain intensity, relief, analgesic prescription, adverse events, inpatient stays, emergency department visits, and change to painkiller prescriptions were registered from electronic records.

RESULTS

Health utility (0.43 ± 0.24 scores, from -0.654 to 1) was similar for both opioids, although TAP showed a significantly low daily opioid dose requirement, neuromodulators use, and constipation side effect compared with OXN. After multivariable adjustment, the significant predictors of impaired HRQoL were pain intensity (β = -0.227, 95% CI -0-035 to -0.005), number of adverse events (β = -0.201, 95% CI -0.024 to -0.004), and opioid daily dose (β = -0.175, 95% CI -0.097 to -0.012). Male sex (β = -0.044) and pain relief (β = 0.158) should be taken into account for future studies.

CONCLUSIONS

HRQoL was similar for TAP and OXN in real-world patients with CNCP, albeit with a TAP opioid-sparing effect. More work is needed to explore HRQoL determinants in relation to long-term opioid use in CNCP.

Predictors of success of pharmacological management in patients with chronic lower back pain: systematic review

BACKGROUND

Conservative management is recommended as the first therapeutic step in chronic low back pain (LBP), but there is no available evidence regarding the possible effect of patients' baseline characteristics on the therapeutic outcomes. A systematic review of the literature was performed to investigate this point.

METHODS

In February 2024, all the level I studies investigating the role of pharmacological management for chronic LBP were accessed. Data concerning the patient demographic at baseline were collected: number of patients and related mean BMI and age, duration of the symptoms, duration of the follow-up, percentage of females, Numeric Rating Scale (NRS), the Roland Morris Disability Questionnaire (RMQ), Oswestry Disability Index (ODI). The outcomes at the last follow-up were evaluated through NRS, RMQ, and ODI. A multiple linear model regression diagnostic through the Pearson Product-Moment Correlation Coefficient (r) was used.

RESULTS

Data from 47 articles (9007 patients) were obtained. The analysis yielded the following significant associations: age at baseline and NRS at follow-up (r = - 0.22; P = 0.04), NRS at baseline with NRS (r = 0.26; P = 0.03) and RMQ (r = - 0.58; P = 0.02) at follow-up, RMQ at baseline and the same at follow-up (r = 0.69; P = 0.0001).

CONCLUSION

Older age, higher BMI, presence of comorbidities, higher ODI and a long history of symptoms or surgical treatments do not reduce the efficacy of pharmacological management of chronic LBP. However, pharmacological therapy is not an effective option for patients with high baseline RMQ.

LEVEL OF EVIDENCE

I systematic review of RCTs.

Continued Opioid Use and Adverse Events Following Provision of Opioids for Musculoskeletal Pain in the Emergency Department: A Systematic Review and Meta-Analysis

BACKGROUND

The prevalence of continued opioid use or serious adverse events (SAEs) following opioid therapy in the emergency department (ED) for musculoskeletal pain is unclear. The aim of this review was to examine the prevalence of continued opioid use and serious adverse events (SAEs) following the provision of opioids for musculoskeletal pain in the emergency department (ED) or at discharge.

METHODS

Records were searched from MEDLINE, EMBASE and CINAHL from inception to 7 October 2022. We included randomised controlled trials and observational studies enrolling adult patients with musculoskeletal pain who were administered and/or prescribed opioids in the ED. Continued opioid use and opioid misuse data after day 4 since ED discharge were extracted. Adverse events were coded using the Common Terminology Criteria for Adverse Events (CTCAE), and those rated as grades 3-4 (severe or life-threatening) and grade 5 (death) were considered SAEs. Risk of bias was assessed using the Quality in Prognosis Studies (QUIPS) tool.

RESULTS

Seventy-two studies were included. Among opioid-naïve patients who received an opioid prescription, 6.8-7.0% reported recent opioid use at 3-12 months after discharge, 4.4% filled ≥ 5 opioid prescriptions and 3.1% filled > 90-day supply of opioids within 6 months. The prevalence of SAEs was 0.02% [95% confidence interval (CI) 0, 0.2%] in the ED and 0.1% (95% CI 0, 1.5%) within 2 days. One study observed 42.9% of patients misused opioids within 30 days after discharge.

CONCLUSIONS

Around 7% of opioid-naïve patients with musculoskeletal pain receiving opioid therapy continue opioid use at 3-12 months after ED discharge. SAEs following ED administration of an opioid were uncommon; however, studies only monitored patients for 2 days.

PROTOCOL REGISTRATION

10.31219/osf.io/w4z3u.

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.

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.

A novel anti-NGF PEGylated Fab' provides analgesia with lower risk of adverse effects

Nerve growth factor (NGF) has emerged as a key driver of pain perception in several chronic pain conditions, including osteoarthritis (OA), and plays an important role in the generation and survival of neurons. Although anti-NGF antibodies improve pain control and physical function in patients with clinical chronic pain conditions, anti-NGF IgGs are associated with safety concerns such as effects on fetal and postnatal development and the risk of rapidly progressive osteoarthritis. To overcome these drawbacks, we generated a novel anti-NGF PEGylated Fab' antibody. The anti-NGF PEGylated Fab' showed specific binding to and biological inhibitory activity against NGF, and analgesic effects in adjuvant-induced arthritis model mice in a similar manner to an anti-NGF IgG. In collagen-induced arthritis model mice, the anti-NGF PEGylated Fab' showed higher accumulation in inflamed foot pads than the anti-NGF IgG. In pregnant rats and non-human primates, the anti-NGF PEGylated Fab' was undetectable in fetuses, while the anti-NGF IgG was detected and caused abnormal postnatal development. The PEGylated Fab' and IgG also differed in their ability to form immune complexes in vitro. Additionally, while both PEGylated Fab' and IgG showed analgesic effects in sodium monoiodoacetate-induced arthritic model rats, their effects on edema were surprisingly quite different. While the anti-NGF IgG promoted edema over time, the anti-NGF PEGylated Fab' did not. The anti-NGF PEGylated Fab' (ASP6294) may thus be a potential therapeutic candidate with lower risk of adverse effects for various diseases in which NGF is involved such as OA and chronic back pain.

Appropriate use of tapentadol: focus on the optimal tapering strategy

OBJECTIVE

Due to its opioid and non-opioid mechanism of action, tapentadol is considered an atypical opioid with improved gastrointestinal tolerability versus traditional opioids. As for all opioid analgesics it is important to understand how to discontinue a treatment when it is not needed anymore. The aim of this article was to provide an overview of opioid therapy in non-cancer pain, with a specific focus on tapering of tapentadol in patients with chronic non-cancer pain, and suggestions on how to achieve tapering.

METHODS

Studies for this narrative review were identified via PubMed using a structured search strategy, focusing on management of chronic non-cancer pain with opioids, and the efficacy, tolerability, and pharmacology of tapentadol prolonged release. Publications were limited to English-language articles published within the last ∼10 years.

RESULTS

The review discusses the use and discontinuation of opioids in general, as well clinical data on discontinuation of tapentadol specifically. We provide a flow chart, which can be used by clinicians in the context of their own clinical experience to appropriately taper tapentadol in patients with chronic non-cancer pain. The flow chart can be easily tailored to individual patient characteristics, duration of tapentadol treatment, response to progressive dosage reduction, and likelihood of withdrawal symptom occurrence.

CONCLUSIONS

While tapentadol is associated with a low frequency of opioid withdrawal symptoms after abrupt discontinuation, use of a tapering strategy is prudent. Tapering strategies developed for opioids in general can potentially be safely individualized in tapentadol-treated patients, although research on tapering strategies for tapentadol is required.

An Updated Overview of Low Back Pain Management

We aimed to determine the recommendation level for the treatment of acute and chronic low back pain (LBP). A systematic review (SR) of the literature was performed and all English-language articles that discuss acute and chronic LBP, including MEDLINE and the Cochrane Database of Systematic Reviews, were searched. Of the 873 searched literature reports, 259 articles, including 131 clinical trials, 115 SRs, nine meta-analyses, and four clinical guidelines were analyzed. In these articles, high-quality randomized controlled trials, SRs, and used well-written clinical guidelines were reviewed. The results indicated multiple acute and chronic LBP treatment methods in the literature, and these reports when reviewed included general behavior, pharmacological therapy, psychological therapy, specific exercise, active rehabilitation and educational interventions, manual therapy, physical modalities, and invasive procedures. The Trial conclusions and SRs were classified into four categories of A, B, C, and D. If there were not enough high-quality articles, it was designated as "I" (insufficient). This review and summary of guidelines may be beneficial for physicians to better understand and make recommendations in primary care.

Benefits and harms of treatments for chronic non-specific low back pain without radiculopathy: Systematic review and meta-analysis

BACKGROUND CONTEXT

Currently, there are no published studies that compare non-pharmacological, pharmacological and invasive treatments for chronic low back pain in adults and provide summary statistics for benefits and harms.

PURPOSE

The aim of this review was to compare the benefits and harms of treatments for the management of chronic low back pain without radiculopathy and to report the findings in a format that facilitates direct comparison (Benefit-Harm Scale: level 1 to 7).

DESIGN

Systematic review and meta-analysis of randomized controlled trials, including trial registries, from electronic databases up to 23^rd May 2022.

PATIENT SAMPLE

Adults with non-specific chronic low back pain, excluding radicular pain in any clinical setting.

OUTCOME MEASURES

Comparison of pain at immediate-term (≤2 weeks) and short-term (>2 weeks to ≤12 weeks) and serious adverse events using the Benefit-Harm Scale (level 1 to 7).

METHODS

This was a registered systematic review and meta-analysis of randomized controlled trials. Interventions included non-pharmacological (acupuncture, spinal manipulation), pharmacological and invasive treatments compared to placebo. Best evidence criteria was used. Two independent reviewers conducted eligibility assessment, data extraction and quality appraisal.

RESULTS

The search retrieved 17,362 records. Three studies provided data on the benefits of interventions, and 30 provided data on harms. Studies included interventions of acupuncture (n=8); manipulation (n=2); pharmacological therapies (n=9), including NSAIDs and opioid analgesics; surgery (n=8); and epidural corticosteroid injections (n=3). Acupuncture (standardized mean difference (SMD) -0.51, 95%CI -0.88 to -0.14, n=1 trial, moderate quality of evidence, benefit rating of 3) and manipulation (SMD -0.39, 95%CI -0.56 to -0.21, n=2 trials, moderate quality of evidence, benefit rating of 5) were effective in reducing pain intensity compared to sham. The benefit of the other interventions was scored as uncertain due to not being effective, statistical heterogeneity preventing pooling of effect sizes, or the absence of relevant trials. The harms level warnings were at the lowest (eg, indicating rarer risk of events) for acupuncture, spinal manipulation, NSAIDs, combination ingredient opioids, and steroid injections, while they were higher for single ingredient opioid analgesics (level 4) and surgery (level 6).

CONCLUSIONS

There is uncertainty about the benefits and harms of all the interventions reviewed due to the lack of trials conducted in patients with chronic non-specific low back pain without radiculopathy. From the limited trials conducted, non-pharmacological interventions of acupuncture and spinal manipulation provide safer benefits than pharmacological or invasive interventions. However, more research is needed. There were high harms ratings for opioids and surgery.

Comparative benefits and harms of individual opioids for chronic non-cancer pain: a systematic review and network meta-analysis of randomised trials

BACKGROUND

Most systematic reviews of opioids for chronic pain have pooled treatment effects across individual opioids under the assumption they provide similar benefits and harms. We examined the comparative effects of individual opioids for chronic non-cancer pain through a network meta-analysis of randomised controlled trials.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials to March 2021 for studies that enrolled patients with chronic non-cancer pain, randomised them to receive different opioids, or opioids vs placebo, and followed them for at least 4 weeks. Certainty of evidence was evaluated using the GRADE approach.

RESULTS

We identified 82 eligible trials (22 619 participants) that evaluated 14 opioids. Compared with placebo, several opioids showed superiority to others for analgesia and improvement in physical function; however, when restricted to pooled-effect estimates supported by moderate certainty evidence, no differences between opioids were evident. Among opioids with moderate certainty evidence, all increased the risk of gastrointestinal adverse events compared with placebo, although no opioids were more harmful than others. Low to very low certainty evidence suggests that extended-release vs immediate-release opioids may provide similar benefits for pain relief and physical functioning, and gastrointestinal harms.

CONCLUSIONS

Our findings support the pooling of effect estimates across different types and formulations of opioids to inform effectiveness for chronic non-cancer pain.

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.

Efficacy and safety of strong opioids for chronic noncancer pain and chronic low back pain: a systematic review and meta-analyses

ABSTRACT

In recent years, long-term prescribing and use of strong opioids for chronic noncancer pain (CNCP) has increased in high-income countries. Yet existing uncertainties, controversies, and differing recommendations make the rationale for prolonged opioid use in CNCP unclear. This systematic review and meta-analyses compared the efficacy, safety, and tolerability of strong opioids with placebo or nonopioid therapy in CNCP, with a special focus on chronic low back pain (CLBP). Systematic literature searches were performed in 4 electronic databases (MEDLINE, Web of Science, Cochrane Library, and CINAHL) in July 2019 and updated by regular alerts until December 2020. We included 16 placebo-controlled randomized controlled trials for CLBP and 5 studies (2 randomized controlled trials and 3 nonrandomized studies) of opioids vs nonopioids for CNCP in the quantitative and qualitative synthesis. Random effects pairwise meta-analyses were performed for efficacy, safety, and tolerability outcomes and subgroup analyses for treatment duration, study design, and opioid experience status. Very low to low certainty findings suggest that 4 to 15 weeks (short or intermediate term) opioid therapy in CLBP (compared with placebo) may cause clinically relevant reductions in pain but also more gastrointestinal and nervous system adverse events, with likely no effect on disability. By contrast, long-term opioid therapy (≥6 months) in CNCP may not be superior to nonopioids in improving pain or disability or pain-related function but seems to be associated with more adverse events, opioid abuse or dependence, and possibly an increase in all-cause mortality. Our findings also underline the importance and need for well-designed trials assessing long-term efficacy and safety of opioids for CNCP and CLBP.

Formulation of Japanese Orthopaedic Association (JOA) clinical practice guideline for the management of low back pain- the revised 2019 edition

BACKGROUND

The latest clinical guidelines are mandatory for physicians to follow when practicing evidence-based medicine in the treatment of low back pain. Those guidelines should target not only Japanese board-certified orthopaedic surgeons, but also primary physicians, and they should be prepared based entirely on evidence-based medicine. The Japanese Orthopaedic Association Low Back Pain guideline committee decided to update the guideline and launched the formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline with the latest data of evidence-based medicine.

METHODS

The Japanese Orthopaedic Association Low Back Pain guideline formulation committee revised the previous guideline based on a method for preparing clinical guidelines in Japan proposed by Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Two key phrases, "body of evidence" and "benefit and harm balance" were focused on in the revised version. Background and clinical questions were determined, followed by literature search related to each question. Appropriate articles were selected from all the searched literature. Structured abstracts were prepared, and then meta-analyses were performed. The strength of both the body of evidence and the recommendation was decided by the committee members.

RESULTS

Nine background and nine clinical qvuestions were determined. For each clinical question, outcomes from the literature were collected and meta-analysis was performed. Answers and explanations were described for each clinical question, and the strength of the recommendation was decided. For background questions, the recommendations were described based on previous literature.

CONCLUSIONS

The 2019 clinical practice guideline for the management of low back pain was completed according to the latest evidence-based medicine. We strongly hope that this guideline serves as a benchmark for all physicians, as well as patients, in the management of low back pain.

Tapentadol Safety and Patient Characteristics Associated with Treatment Discontinuation in Cancer Therapy: A Retrospective Multicentre Study in Japan

INTRODUCTION

Tapentadol has analgesic effects comparable to those of conventional opioids and is associated with fewer side effects, including gastrointestinal symptoms, drowsiness, and dizziness, than other opioids. However, the safety of tapentadol in the Japanese population remains unclear; the present multicentre study aimed to examine the safety of tapentadol and the characteristics of patients likely to discontinue this treatment owing to adverse events.

METHODS

The safety of tapentadol was assessed retrospectively in patients with any type of cancer treated between August 18, 2014 and October 31, 2019 across nine institutions in Japan. Patients were examined at baseline and at the time of opioid discontinuation. Multivariate analysis was performed to identify factors associated with tapentadol discontinuation owing to adverse events.

RESULTS

A total of 906 patients were included in this study, and 685 (75.6%) cases were followed up until tapentadol cessation for any reason. Among patients who discontinued treatment, 119 (17.4%) did so because of adverse events. Among adverse events associated with difficulty in taking medication, nausea was the most common cause of treatment discontinuation (4.7%), followed by drowsiness (1.8%). Multivariate analysis showed that those who were prescribed tapentadol by a palliative care physician (odds ratio [OR] 2.60, 95% confidence interval [CI] 1.36-4.99, p = 0.004), patients switching to tapentadol due to side effects from previous opioids (OR 2.19, 95% CI 1.05-4.56, p = 0.037), and patients who did not use naldemedine (OR 5.06, 95% CI 2.47-10.37, p < 0.0001) had an increased risk of treatment discontinuation owing to adverse events.

CONCLUSIONS

This study presents the safety profile of tapentadol and the characteristics of patients likely to discontinue this treatment owing to adverse events in the Japanese population. Prospective controlled trials are required to evaluate the safety of tapentadol and validate the present findings.

TRIAL REGISTRATION NUMBER

UMIN 000044282 (University Hospital Medical Information Network).

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.

Tapentadol prolonged release in patients with chronic low back pain: real-world data from the German Pain eRegistry

Aim: Comparison of tapentadol prolonged release (PR) with other oral WHO-III PR opioid analgesics (morphine, oxycodone ± naloxone, hydromorphone) in routine medical care of chronic low back pain. Patients & methods: Noninterventional, retrospective 12-week study using anonymized clinical practice data from the German Pain eRegistry. Six effectiveness, tolerability, and safety criteria were aggregated in a primary composite end point (treatment responder). Propensity scoring matched 2331 datasets per treatment cohort. Results: All six single criteria showed significantly better outcomes for tapentadol PR (all parameters p < 0.001). There were significantly more treatment responders under tapentadol PR (65.7 vs 14.2%; p < 0.001). Conclusion: Tapentadol PR showed significantly better effectiveness and tolerability in severe chronic low back pain unsuccessfully treated with WHO-I/II analgesics compared with the other oral WHO-III PR opioids investigated.

Tapentadol Versus Tramadol: A Narrative and Comparative Review of Their Pharmacological, Efficacy and Safety Profiles in Adult Patients

We conducted a narrative review of the literature to compare the pharmacological, efficacy and safety profiles of tapentadol and tramadol, and to assess the clinical interest of tapentadol in adult patients. Tapentadol and tramadol share a mixed mechanism of action, including both mu-agonist and monoaminergic properties. Tapentadol is approximately two to three times more potent than tramadol and two to three times less potent than morphine. It has no identified analgesically active metabolite and is not significantly metabolised by cytochrome P450 enzymes, thus overcoming some limitations of tramadol, including the potential for pharmacokinetic drug-drug interactions and interindividual variability due to genetic polymorphisms of cytochrome P450 enzymes. The toxicity profiles of tramadol and tapentadol are similar; however tapentadol is likely to result in less exposure to serotoninergic adverse effects (nausea, vomiting, hypoglycaemia) but cause more opioid adverse effects (constipation, respiratory depression, abuse) than tramadol. The safety of tapentadol in real-world conditions remains poorly documented, particularly in at-risk patient subgroups and also in the ability to assess the risk associated with its residual serotonergic activity (serotonin syndrome, seizures). Because of an earlier market introduction, more real-world safety data are available for tramadol, including data from at-risk patient subgroups. The level of evidence on the efficacy of both tramadol and tapentadol for the treatment of chronic pain is globally low. The trials published to date show overall that tapentadol does not provide a clinically significant analgesic improvement compared to existing treatments, for which the safety profile is much better known. In conclusion, tapentadol is not a first-line opioid but represents an additional analgesic in the therapeutic choices, which some patients may benefit from after careful examination of their clinical situation, co-morbidities and co-medications.

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.

Assessment of health-related quality of life and patient's knowledge in chronic non-specific low back pain

BACKGROUND

Chronic non-specific low back pain syndrome (cnsLBP) is a severe health problem in developed countries, which has an important effect on patients' quality of life and is highly determined by socio-demographic factors and low back pain specific knowledge. We examined patients' health-related quality of life according to the results of the Short Form Health Survey (SF-36), low back pain knowledge (LBPKQ) and the social determinants of the participants.

METHODS

We carried out our research in the first half of 2015 in Southern Transdanubia, Hungary. The examination included 1155 respondents living with chronic non-specific low back pain. The confidence interval of 95% was used, and the level of. significance was p < 0.05 using SPSS 22.0 software.

RESULTS

The SF-36 questionnaire is suitable for the examination of patients' health-related quality of life (Cronbach's Alpha> 0.76), as the LBPKQ's Cronbach's Alpha was 0.726 also, which showed good validity. Longer-term disease meant a lower health-related quality of life (p < 0.05). A greater decrease of function (Roland Morris scores (RM)) accounts for a lower HRQoL and higher knowledge level. We found significant differences in LBPKQ scores according to sociodemographic parameters. The general health status was positively correlated with LBPKQ (p = 0.024) adjusted for demographic and pain and functional status.

CONCLUSION

The negative effect of the symptoms on patients' quality of life is proved, which is determined by different socio-demographic parameters furthermore by knowledge. Above all could be useful information for professionals to adopt the right interventions.

Opioids for chronic low back pain management: a Bayesian network meta-analysis

Introduction: Chronic low back pain (LBP) is common, and some patients require opiates therapy. This Bayesian network meta-analysis (NMA) analyzed available randomized clinical trials (RCTs) on the use of opioids for LBP.Methods: All RCTs comparing two or more opioids for chronic LBP and reporting results under the Numeric Rating Scale were included. The following drugs were analyzed: fentanyl, morphine, tapentadol, oxycodone, buprenorphine, oxymorphone, tramadol. The NMA was performed through the STATA routine for Bayesian hierarchical random-effects model analysis, with standardized mean difference (SMD) effect measure. Data regarding the rate of adverse events and different drug formulations were also reported.Results: Data from 2933 patients were obtained, with a mean age of 53.30 ± 6.95 years. The mean duration of symptoms prior to beginning the trial was 95.16 ± 47.29 months. The mean follow-up was 3.29 ± 1.72 months. Among the analyzed compounds, oxymorphone, tapentadol and fentanyl showed the highest efficacy in terms of pain reduction.Conclusion: According to published level I evidence, oxymorphone, tapentadol and fentanyl were the most effective drugs in the treatment of chronic LBP. However, different formulation and pharmacokinetic characteristics need to be taken into consideration when choosing the ideal compound for a given patient.

Effect of tapentadol on experimental model of orofacial pain - a pilot study

Acute orofacial pain is associated with significant disability and has a detrimental impact on quality of life. Although various origins of the pain in trigeminal territory can be identified an odontogenic pathology is the most common cause of acute orofacial pain in patients. Due to complex pathophysiology drugs with multitarget action might provide beneficial effect in pain management. The aim of the present study was to experimentally examine the anti-nociceptive effects of tapentadol, an opioid agonist and a norepinephrine reuptake inhibitor (MOR/NRI), in our animal model of orofacial pain. We tested the effect of tapentadol at gradual doses of 1, 2 and 5 mg/kg during thermal and mechanical stimulation in the trigeminal area of adult rats. We observed that tapentadol exhibits antinociceptive effect at dosages of 2 mg/kg and 5 mg/kg and only in association with mechanical stimulation.

Safety of tapentadol compared with other opioids in chronic pain treatment: network meta-analysis of randomized controlled and withdrawal trials

OBJECTIVE

To assess the relative safety of oral tapentadol PR and other opioid analgesics for moderate or severe chronic pain in adults, we conducted a systematic review and network meta-analysis (NMA).

METHODS

A systematic review was conducted to identify randomized controlled trials (RCTs) and randomized withdrawal trials of tapentadol with other WHO stage II and III opioid analgesics in patients with moderate or severe chronic pain. Searches were conducted in MEDLINE, EMBASE, PubMed, Cochrane databases and trial registries. Feasibility assessment evaluated the trials' suitability for NMA. Outcomes assessed were overall AEs, overall serious adverse events, constipation, nausea, dizziness, somnolence, headache, and discontinuation due to AEs. Randomized withdrawal trials were analyzed separately to other RCTs.

RESULTS

Searches conducted in April 2019 identified 16,604 records. Following screening and feasibility assessment, 29 RCTs and 19 randomized withdrawal trials were identified and included in the NMA. Consistent with existing research, evidence from RCTs suggested that tapentadol is associated with relatively lower odds of adverse events occurring than most active comparators. The withdrawal trial data were less clear, with higher uncertainty around the results, and results that appear to contradict the RCT evidence. There are a number of trial design factors that may be affecting these results.

CONCLUSIONS

RCT evidence suggests that tapentadol can be a useful treatment option for patients suffering from chronic pain and in need of an opioid analgesic. Opioids should be prescribed by a qualified physician only after other analgesics have been considered, taking side effects and misuse risk into account.

Tapentadol treatment results in long-term pain relief in patients with chronic low back pain and associates with reduced segmental sensitization

The endogenous pain system may be used as a biomarker in the pharmacological treatment of patients with CLBP, enabling an individualized, mechanism-based treatment approach.

Introduction:

Chronic low back pain (CLBP) is one of the most common chronic pain conditions in pain practice.

Objectives:

In the current study, we describe phenotypes of patients with CLBP based on the status of their endogenous pain modulatory system.

Methods:

Conditioned pain modulation (a measure of central pain inhibition), temporal summation (TS, a measure of pain facilitation), and offset analgesia (a measure of temporal filtering of nociception) were evaluated in 53 patients with CLBP at painful and nonpainful sites. Next, in a double-blind, randomized, placebo-controlled trial, 40 patients with defective conditioned pain modulation responses received treatment with tapentadol prolonged-release or placebo for 3 months.

Results:

The majority of patients (87%) demonstrated loss of central pain inhibition combined with segmentally increased TS and reduced offset analgesia at the lower back region. During treatment, tapentadol reduced pain intensity more than placebo (tapentadol −19.5 ± 2.1 mm versus placebo −7.1 ± 1.8 mm, P = 0.025). Furthermore, tapentadol significantly decreased pain facilitation by reduction of TS responses at the lower back (tapentadol −0.94 ± 1.9 versus placebo 0.01 ± 1.5, P = 0.020), which correlated with pain reduction (P < 0.001).

Conclusion:

Patients with CLBP demonstrated different phenotypes of endogenous pain modulation. In patients with reduced conditioned pain modulation, tapentadol produced long-term pain relief that coincided with reduction of signs of pain facilitation. These data indicate that the endogenous pain system may be used as a biomarker in the pharmacological treatment of CLBP, enabling an individualized, mechanism-based treatment approach.

Quality of life and functional outcomes with tapentadol prolonged release in chronic musculoskeletal pain: post hoc analysis

Aims: To investigate quality of life (QOL) and functionality changes in chronic pain during tapentadol prolonged release (PR) treatment. Patients & methods: Post hoc analysis of data from three Phase III trials in patients with osteoarthritis knee pain or low back pain. QOL and functionality changes were assessed by SF-36 scores. Results: All SF-36 subdomain scores improved progressively to week 3 of tapentadol titration and were sustained during 12-week maintenance treatment. Improvements in SF-36 scores were similar between tapentadol dose groups (e.g., 200 to <300 mg vs ≥500 mg), with no greater effect from higher doses. QOL and functionality improvements were consistently greater with tapentadol PR than oxycodone controlled release. Conclusion: Tapentadol PR provides consistent, clinically relevant improvements in QOL and functionality in chronic pain.

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.

Guideline summary review: an evidence-based clinical guideline for the diagnosis and treatment of low back pain

BACKGROUND CONTEXT

The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016.

PURPOSE

The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition.

STUDY DESIGN

This is a guideline summary review.

METHODS

This guideline is the product of the Low Back Pain Work Group of NASS' Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors.

RESULTS

Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature.

CONCLUSIONS

The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx.

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.

Modulation of sensitization processes in the management of pain and the importance of descending pathways: a role for tapentadol?

Objective: This paper presents and discusses recent evidence on the pathophysiological mechanisms of pain. The role of tapentadol - an opioid characterized by an innovative mechanism of action (i.e. µ-opioid receptor [MOR] agonism and inhibition of noradrenaline [NA] reuptake [NRI]) - in the modulation of pain, and the most recent pharmacological evidence on this molecule (e.g. the µ-load concept) are also presented and commented upon.Methods: Narrative review.Results: Solid evidence has highlighted the importance of central sensitization in the transition from acute to chronic pain. In particular, the noradrenergic system holds a major role in limiting central sensitization and the progression to chronic pain. Therefore, pharmacological modulation of the noradrenergic system appears to be a well-grounded strategy for the control of chronic pain. Tapentadol is characterized by a to-date-unique mechanism of action, since it acts both as a MOR agonist and as an inhibitor of NA reuptake. The synergistic interaction of these two mechanisms allows a strong analgesic effect by acting on both ascending and descending pathways. Of note, the reduced µ-load of tapentadol limits the risk of opioid-related adverse events, such as gastrointestinal disturbances. Moreover, the NA component becomes predominant, at least, in some types of pain, with consequent specific clinical efficacy in the treatment of neuropathic and chronic pain.Conclusions: According to these characteristics, tapentadol appears suitable in the treatment of severe uncontrolled chronic pain characterized by both a nociceptive and a neuropathic component, such as osteoarthritis or back pain.

Modulation of sensitization processes in the management of pain and the importance of descending pathways: a role for tapentadol?

Objective: This paper presents and discusses recent evidence on the pathophysiological mechanisms of pain. The role of tapentadol - an analgesic molecule characterized by an innovative mechanism of action (i.e. µ-opioid receptor [MOR] agonism and inhibition of noradrenaline [NA] reuptake [NRI]) - in the modulation of pain, and the most recent pharmacological evidence on this molecule (e.g. the µ-load concept) are also presented and commented upon.Methods: Narrative review.Results: Solid evidence has highlighted the importance of central sensitization in the transition from acute to chronic pain. In particular, the noradrenergic system holds a major role in limiting central sensitization and the progression to chronic pain. Therefore, pharmacological modulation of the noradrenergic system appears to be a well-grounded strategy for the control of chronic pain. Tapentadol is characterized by a to-date-unique mechanism of action since it acts both as a MOR agonist and as an inhibitor of NA reuptake. The synergistic interaction of these two mechanisms allows a strong analgesic effect by acting on both ascending and descending pathways. Of note, the reduced µ-load of tapentadol has two important consequences: first, it limits the risk of opioid-related adverse events, as well as the risk of dependence; second, the NA component becomes predominant at least in some types of pain with consequent specific clinical efficacy in the treatment of neuropathic and chronic pain.Conclusions: According to these characteristics, tapentadol appears suitable in the treatment of chronic pain conditions characterized by both a nociceptive and a neuropathic component, such as osteoarthritis or back pain.

Pain assessment for chronic lower back pain: performance of the PAL-S and PAL-I patient-reported measures for symptoms and impacts

Objective: The Patient Assessment for Low Back Pain-Symptoms (PAL-S) and the Patient Assessment for Low Back Pain-Impacts (PAL-I) were developed to incorporate patient perspective of treatment benefit in chronic low back pain (cLBP) trials. This study documents psychometric measurement properties of the PAL-S and PAL-I.Methods: In this multicenter, observational study, eligible participants clinically diagnosed with cLBP provided sociodemographic information and completed PAL measures and other patient-reported outcome measures of pain and/or disability. Confirmatory factor analyses (CFA), construct validity, and reliability were assessed.Results: The 104 participants were 61% female, 89% white, and mean age of 55 years; mean cLBP duration was 11.4 (range 0-47) years. Using painDETECT scores, 36.5% reported small likelihood of neuropathic pain, 30.8% reported unclear likelihood, and 32.7% reported definite likelihood. Persistent pain with pain attacks was reported by 38.5% of participants. CFA confirmed single components with adequate fit indices. Cronbach's alpha was 0.83 (PAL-S) and 0.87 (PAL-I), indicating reliable scales. Intraclass correlation coefficients (test-retest reproducibility, n = 44) were 0.81 (PAL-S) and 0.85 (PAL-I). PAL-S score correlation was 0.49 with Roland-Morris Disability Questionnaire (RMDQ) and 0.77 with Neuropathic Pain Symptom Inventory (NPSI). PAL-I correlated at 0.73 with RMDQ and -0.60 with Medical Outcomes Study (MOS)-36 Bodily Pain. Both measures significantly differentiated between pain intensity levels (based on numeric response scale) and painDETECT groups.Conclusion: The PAL-S and PAL-I generated highly reliable scores with substantial evidence of construct validity. Routine use of these measures in treatment trials will enhance comparability of LBP-related symptom and impact results, including patient perspective of treatment benefit.

Adult Cancer Pain, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology

In recent years, the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Adult Cancer Pain have undergone substantial revisions focusing on the appropriate and safe prescription of opioid analgesics, optimization of nonopioid analgesics and adjuvant medications, and integration of nonpharmacologic methods of cancer pain management. This selection highlights some of these changes, covering topics on management of adult cancer pain including pharmacologic interventions, nonpharmacologic interventions, and treatment of specific cancer pain syndromes. The complete version of the NCCN Guidelines for Adult Cancer Pain addresses additional aspects of this topic, including pathophysiologic classification of cancer pain syndromes, comprehensive pain assessment, management of pain crisis, ongoing care for cancer pain, pain in cancer survivors, and specialty consultations.

Outcomes Associated with Treatment of Chronic Pain with Tapentadol Compared with Morphine and Oxycodone: A UK Primary Care Observational Study

Introduction

This study compared adverse outcomes and resource use for patients with a diagnosis of pain treated with tapentadol prolonged-release (PR) versus those treated with morphine controlled-release (CR) and oxycodone CR.

Methods

Data were sourced from the Clinical Practice Research Datalink (CPRD), a database derived from UK primary care. Patients prescribed tapentadol PR between May 2011 and December 2016 were selected and matched to two groups of controls treated with either morphine CR or oxycodone CR on gender, age, pain duration, pain site, pain aetiology, Charlson index and prior analgesia. Times to first adverse event (constipation or nausea/vomiting) were compared within a Cox proportional hazards model. Rates of primary care contacts, accident and emergency contacts and, for a subset of patients linked to Hospital Episode Statistics (HES), inpatient admissions and outpatient contacts were compared using incidence rate ratios (IRRs) derived from Poisson regression.

Results

A total of 1907 patients prescribed tapentadol PR were identified and 1791 (93.9%) had a pain diagnosis. Of these 1246 (65.3%) were matched to morphine controls and 829 (43.4%) to oxycodone controls. Compared to controls, gastrointestinal adverse events with tapentadol PR treatment were reduced; aHR = 0.532 (0.402–0.703; p < 0.001) versus morphine CR and 0.517 (0.363–0.735; p < 0.001) versus oxycodone CR. Compared with morphine CR, primary care contacts [IRR = 0.831 (0.802–0.861)], accident and emergency attendance [0.739 (0.572–0.951)], outpatient contacts [0.917 (0.851–0.989)] and inpatients contacts [0.789 (0.664–0.938)] were reduced. For oxycodone, the respective figures were 0.735 (0.703–0.768), 0.971 (0.699–1.352), 0.877 (0.799–0.962) and 0.748 (0.601–0.932).

Conclusion

Tapentadol PR was associated with significantly fewer adverse gastrointestinal events than morphine CR and oxycodone CR in patients with a diagnosis of pain. There was also significantly reduced primary and secondary care resource use. As with all observational studies, potential bias due to residual confounding and confounding by indication should be considered.

Funding

Grünenthal Ltd.

Electronic supplementary material

The online version of this article (10.1007/s12325-019-00932-7) contains supplementary material, which is available to authorized users.

Opioid Use and Potency Are Associated With Clinical Features, Quality of Life, and Use of Resources in Patients With Gastroparesis

BACKGROUND & AIMS

Many patients with gastroparesis are prescribed opioids for pain control, but indications for opioid prescriptions and the relationship of opioid use to gastroparesis manifestations are undefined. We characterized associations of use of potent vs weaker opioids and presentations of diabetic and idiopathic gastroparesis.

METHODS

We collected data on symptoms, gastric emptying, quality of life, and health care resource use from 583 patients with gastroparesis (>10% 4-h scintigraphic retention) from the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Consortium, from January 2007 through November 2016. Patients completed medical questionnaires that included questions about opioid use. The opioid(s) were categorized for potency relative to oral morphine. Symptom severities were quantified by Patient Assessment of Upper Gastrointestinal Disorders Symptoms questionnaires. Subgroup analyses compared patients on potent vs weaker opioids and opioid effects in diabetic vs idiopathic etiologies.

RESULTS

Forty-one percent of patients were taking opioids; 82% of these took potent agents (morphine, hydrocodone, oxycodone, methadone, hydromorphone, buprenorphine, or fentanyl). Abdominal pain was the reason for prescription for 61% of patients taking opioids. Mean scores for gastroparesis, nausea/vomiting, bloating/distention, abdominal pain, and constipation scores were higher in opioid users (P ≤ .05). Opioid use was associated with greater levels of gastric retention, worse quality of life, increased hospitalization, and increased use of antiemetic and pain modulator medications compared with nonusers (P ≤ .03). Use of potent opioids was associated with worse gastroparesis, nausea/vomiting, upper abdominal pain, and quality-of-life scores, and more hospitalizations compared with weaker opioids (tapentadol, tramadol, codeine, or propoxyphene) (P ≤ .05). Opioid use was associated with larger increases in gastric retention in patients with idiopathic vs diabetic gastroparesis (P = .008).

CONCLUSIONS

Opioid use is prevalent among patients with diabetic or idiopathic gastroparesis, and is associated with worse symptoms, delays in gastric emptying, and lower quality of life, as well as greater use of resources. Potent opioids are associated with larger effects than weaker agents. These findings form a basis for studies to characterize adverse outcomes of opioid use in patients with gastroparesis and to help identify those who might benefit from interventions to prevent opioid overuse.

Tapentadol for neuropathic pain: a review of clinical studies

Neuropathic pain (NP) is an enormous burden for patients, caregivers and society. NP is a pain state that may develop after injury of the peripheral or central nervous system because of a wide range of diseases and traumas. A NP symptom component can be found also in several types of chronic pain. Many NP patients are substantially disabled for years. Due to its chronicity, severity and unpredictability, NP is difficult to treat. Tapentadol is a central-acting oral analgesic with combined opioid and noradrenergic properties, which make it potentially suitable for a wide range of pain conditions, particularly whenever a NP component is present or cannot be excluded. In randomized controlled trials, tapentadol has proved to be effective in relieving NP in diabetic peripheral neuropathy and in chronic low back pain. In observational studies, tapentadol reduced NP in chemotherapy-induced peripheral neuropathies, blood and solid cancers, and the NP component in neck pain and Parkinson's disease. This narrative review aims to provide clinicians with a broad overview of tapentadol effects on NP.

Tapentadol: an effective option for the treatment of back pain

Back pain, including low back pain and neck pain, is the leading cause of disability worldwide. This type of pain is challenging to treat, since it presents both a nociceptive and a neuropathic component. The latter also contributes to the evolution of pain toward chronification. Treatment selection should therefore consider the ability to prevent this event. Tapentadol is characterized by a unique and innovative peculiar mechanism of action that makes it the first representative of a new class of central strong analgesics referred to as MOR-NRI. This molecule acts both on the nociceptive and neuropathic components of pain, and it can therefore be effective in the treatment of a mixed pain condition such as back pain. This narrative review discusses the rationale for the use of tapentadol in both low back pain and neck pain and presents available clinical data. Overall, data show that tapentadol prolonged release is a well-grounded treatment for chronic back pain, sustained by a strong mechanistic rationale and robust evidence. Given also the availability of long-term efficacy and safety data, we believe that this molecule should be considered as an elective therapy for chronic back pain.

Tapentadol: an overview of the safety profile

Long-term opioid therapy may be associated with analgesic efficacy and also predictable adverse events, including cardiovascular and pulmonary events, gastrointestinal disorders, endocrinological harms, psychological problems, impairment of driving ability, and risk of abuse. These effects of opioids are mostly due to the wide expression of the mu receptor. Tapentadol, a centrally acting analgesic, is the first agent of a new class of drugs (MOR-NRI), since it combines two mechanisms of action, namely µ-opioid receptor (MOR) agonism and noradrenaline reuptake inhibition. Noteworthy, MOR activation with tapentadol is markedly lower compared with that exerted by classical opioids, thus likely resulting in fewer opioid-related adverse effects. In this review, we discuss current safety data on tapentadol, with a focus on some specific events, risk of abuse, and driving ability, a well-accepted proxy of the ability of taking critical decisions.

Harms and benefits of opioids for management of non-surgical acute and chronic low back pain: a systematic review

Background

Consequences of prescription opioid use involve harms, addiction, tolerance and death. Despite routine prescription, opioids are not recommended for initial intervention by any major multidisciplinary low back pain (LBP) guideline.

Objective

Our primary purpose was to improve overall understanding of the harms and benefits associated with oral opioid interventions prescribed for treatment of acute or chronic back pain. Our second goal was to evaluate pain intensity and to compare and contrast these data with the harms. Our last objective was to evaluate conflicts of interest among the study authors and the findings.

Design/data/eligibility criteria

Studies incorporating oral prescription opioid management of non-surgical LBP were evaluated. After systematic assessment, no studies that met inclusion included participants with specifically acute LBP. Therefore, extracted data reflects only populations with subacute and chronic LBP. Data on reported harms, severe harms, pain outcomes and withdrawal rates were extracted and meta-analyses were completed for opioid versus placebo trials and opioids versus non-opioid trials.

Results

Fourteen studies met inclusion/exclusion requirements. All trials involved short-term management with limited follow-up. A high percentage of harms were identified across most studies. Opioids were not shown to be superior to other medications, and only showed superiority to placebo comparators (at cost of additional harms).

Conclusion

This review identified trends of higher harms rates and higher percentages of severe harms in opioid arms for the management of subacute and chronic LBP. The majority of trials that demonstrated benefits with opioids also had potential conflicts of interest. Lastly, non-opioid medications demonstrated statistically significant pain improvement compared with opioids. We feel that the results of the trial are supportive of current LBP guidelines and do not condone the initial use of opioids in management of subacute or chronic LBP.

Trial registration number

CRD42017070914

Tapentadol: an analgesic that differs from classic opioids due to its noradrenergic mechanism of action

Chronic pain treatment represents one of the most complex clinical challenges and even though opioids exhibit particular efficacy on nociceptive pain, their use must be controlled to avoid the risk of adverse reactions. A useful approach, aimed at maintaining analgesia and mitigating side effects, is represented by the use of a new class of analgesics endowed of µ-opioid (MOR) receptor agonism and noradrenaline reuptake inhibition (NRI) mechanisms. Tapentadol is the progenitor of this new class of drugs called MOP-NRI. A literature review has been conducted to gain information about the efficacy and the tolerability profile of tapentadol shifting from MOR agonism (acute pain) to NRI activity (chronic pain). The tolerability and therapeutic safety of tapentadol in neuropathic pain models, as well as in clinical settings, has been analyzed showing a good gastrointestinal tolerability profile, a moderate effect on hormone levels (in healthy volunteers and in patients) and on cognitive performance, a lack of significant alteration of the electrocardiogram recording and no changes of the QT/QTc interval, a minimal effect on serotonin reuptake in vivo with a low risk of serotonin syndrome, a longer time for the onset of analgesic tolerance and a less occurrence of abuse liability compared to formulations containing other comparator compounds. Tapentadol represents a great innovation in chronic pain therapy with a unique analgesic profile different form classical opioids, therefore, thanks to its synergistic MOR-NRI action, it may be a good option for the treatment of chronic, neuropathic and mixed pain.

Opioids for Chronic Noncancer Pain: A Systematic Review and Meta-analysis

IMPORTANCE

Harms and benefits of opioids for chronic noncancer pain remain unclear.

OBJECTIVE

To systematically review randomized clinical trials (RCTs) of opioids for chronic noncancer pain.

DATA SOURCES AND STUDY SELECTION

The databases of CENTRAL, CINAHL, EMBASE, MEDLINE, AMED, and PsycINFO were searched from inception to April 2018 for RCTs of opioids for chronic noncancer pain vs any nonopioid control.

DATA EXTRACTION AND SYNTHESIS

Paired reviewers independently extracted data. The analyses used random-effects models and the Grading of Recommendations Assessment, Development and Evaluation to rate the quality of the evidence.

MAIN OUTCOMES AND MEASURES

The primary outcomes were pain intensity (score range, 0-10 cm on a visual analog scale for pain; lower is better and the minimally important difference [MID] is 1 cm), physical functioning (score range, 0-100 points on the 36-item Short Form physical component score [SF-36 PCS]; higher is better and the MID is 5 points), and incidence of vomiting.

RESULTS

Ninety-six RCTs including 26 169 participants (61% female; median age, 58 years [interquartile range, 51-61 years]) were included. Of the included studies, there were 25 trials of neuropathic pain, 32 trials of nociceptive pain, 33 trials of central sensitization (pain present in the absence of tissue damage), and 6 trials of mixed types of pain. Compared with placebo, opioid use was associated with reduced pain (weighted mean difference [WMD], -0.69 cm [95% CI, -0.82 to -0.56 cm] on a 10-cm visual analog scale for pain; modeled risk difference for achieving the MID, 11.9% [95% CI, 9.7% to 14.1%]), improved physical functioning (WMD, 2.04 points [95% CI, 1.41 to 2.68 points] on the 100-point SF-36 PCS; modeled risk difference for achieving the MID, 8.5% [95% CI, 5.9% to 11.2%]), and increased vomiting (5.9% with opioids vs 2.3% with placebo for trials that excluded patients with adverse events during a run-in period). Low- to moderate-quality evidence suggested similar associations of opioids with improvements in pain and physical functioning compared with nonsteroidal anti-inflammatory drugs (pain: WMD, -0.60 cm [95% CI, -1.54 to 0.34 cm]; physical functioning: WMD, -0.90 points [95% CI, -2.69 to 0.89 points]), tricyclic antidepressants (pain: WMD, -0.13 cm [95% CI, -0.99 to 0.74 cm]; physical functioning: WMD, -5.31 points [95% CI, -13.77 to 3.14 points]), and anticonvulsants (pain: WMD, -0.90 cm [95% CI, -1.65 to -0.14 cm]; physical functioning: WMD, 0.45 points [95% CI, -5.77 to 6.66 points]).

CONCLUSIONS AND RELEVANCE

In this meta-analysis of RCTs of patients with chronic noncancer pain, evidence from high-quality studies showed that opioid use was associated with statistically significant but small improvements in pain and physical functioning, and increased risk of vomiting compared with placebo. Comparisons of opioids with nonopioid alternatives suggested that the benefit for pain and functioning may be similar, although the evidence was from studies of only low to moderate quality.

Tapentadol Prolonged Release: A Review in Pain Management

Tapentadol prolonged release (tapentadol PR) [Palexia® SR in EU] is a long-acting tablet formulation of the strong central analgesic tapentadol, which acts as both a μ-opioid receptor (MOR) agonist and a noradrenaline reuptake inhibitor. Tapentadol PR is approved for chronic pain in various countries, with its EU indication (severe chronic pain manageable only with opioid analgesics) being the focus here. Well-designed trials and clinical practice data support tapentadol PR use in this setting. Short term, tapentadol PR was an effective and generally well tolerated analgesic for moderate to severe pain of varying aetiologies, including neuropathic pain. It provided analgesia at least as good as that of conventional strong opioids and appeared more favourable in terms of gastrointestinal tolerability, likely due to less potent MOR binding. Severe back pain with a neuropathic component responded well to moderate-dose tapentadol PR in some patients, while for others, an increase to the maximum recommended tapentadol PR dosage provided analgesia at least as good as that of moderate-dose tapentadol PR plus pregabalin and appeared to have some CNS tolerability benefits. Data also support the use of tapentadol PR in opioid rotation, including when conventional opioids are intolerable. Longer-term data in musculoskeletal pain conditions indicate continued benefit over up to 2 years' treatment with tapentadol PR with no evidence of tolerance. Thus, tapentadol PR is a useful option for the management of severe chronic pain.

Does 'Strong Analgesic' Equal 'Strong Opioid'? Tapentadol and the Concept of 'µ-Load'

INTRODUCTION

The distinct properties of the centrally-acting analgesic tapentadol derive from the combined contributions of an opioid component and a nonopioid component. However, the opioid component's relative contribution to analgesic and adverse effects has not previously been elucidated. Tapentadol's analgesic effect derives from the combined contribution of an opioid mechanism and a nonopioid mechanism, the extent of which can vary for different pains. Likewise, the interaction can vary for various adverse effects. Hence, the contribution of each mechanism to adverse effects can be different from the contribution to analgesia. We here estimate the percent contribution of each component of the mechanism of action to analgesia and to adverse effects.

AREAS COVERED

Several approaches to in vitro and in vivo data to estimate the contribution of tapentadol's opioid component to analgesia and to the two important opioid adverse effects, respiratory depression and constipation. The results are then compared with clinical data.

EXPERT OPINION

Traditional opioids, such as morphine, oxycodone, and others, produce their analgesic effects primarily through a single mechanism-the activation of µ-opioid receptors (MOR). Therefore, the contribution of the opioid component to adverse effects is 100%. In contrast, the newer strong analgesic tapentadol produces its analgesic effect via two separate and complementary analgesic mechanisms, only one of which is µ-opioid. We applied standard drug-receptor theory and novel techniques to in vitro and in vivo data to estimate by several different ways the μ-load of tapentadol (the % contribution of the opioid component to the adverse effect magnitude relative to a pure/classical µ-opioid at equianalgesia) in respiratory depression and constipation, and we compared the results to clinical evidence. The estimate is remarkably consistent over the various approaches and indicates that the μ-load of tapentadol is ≤ 40% (relative to pure MOR agonists, which have, by definition, a µ-load of 100%).

FUNDING

Grünenthal GmbH.

Toxicity of tapentadol: a systematic review

BACKGROUND

Tapentadol is a novel atypical opioid. Anecdotal evidence suggests that tapentadol has a lower toxicity than conventional opioids.

OBJECTIVES

To evaluate all single-drug mortality due to tapentadol and assess serious adverse events caused by tapentadol.

METHODS

The Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) reporting guidelines, an evidence-based minimum set of items for reporting in systematic reviews, were followed in this systematic review.

RESULTS

 24 peer-reviewed papers were identified. They indicate that tapentadol toxicity can cause mortality and serious adverse effects.

CONCLUSION(S)

At least four confirmed fatalities, and serious adverse effects have been documented for individuals abusing or using tapentadol as prescribed. Serious adverse effects of tapentadol use may include respiratory depression, confusion, coma, hallucination/delusion, seizures, tachycardia, hypertension, agitation, tremor, miosis, hypotension, dyspnea, electrolyte abnormality, atrial fibrillation or severe upper abdominal pain. Tapentadol is unlikely to cause serotonin syndrome. The toxicity of tapentadol is significantly less than pure mu opioids, such as oxycodone.

Chronic low back pain: a mini-review on pharmacological management and pathophysiological insights from clinical and pre-clinical data

Globally, low back pain (LBP) is one of the most common health problems affecting humans. The lifetime prevalence of non-specific LBP is approximately 84%, with the chronic prevalence at about 23%. Chronic LBP in humans is defined as LBP that persists for more than 12 weeks without a significant pain improvement. Although there are numerous evidence-based guidelines on the management of acute LBP, this is not the case for chronic LBP, which is regarded as particularly difficult to treat. Research aimed at discovering new drug treatments for alleviation of chronic mechanical LBP is lacking due to the paucity of knowledge on the pathobiology of this condition, despite its high morbidity in the affected adult population. For a debilitating condition such as chronic LBP, it is necessary to assess the sustained effects of pharmacotherapy of various agents spanning months to years. Although many rodent models of mechanical LBP have been developed to mimic the human condition, some of the major shortcomings of many of these models are (1) the presence of a concurrent neuropathic component that develops secondary to posterior intervertebral disc puncture, (2) severe model phenotype, and/or (3) use of behavioural endpoints that have yet to be validated for pain. Hence, there is a great, unmet need for research aimed at discovering new biological targets in rodent models of chronic mechanical LBP for use in drug discovery programs as a means to potentially produce new highly effective and well-tolerated analgesic agents to improve relief of chronic LBP. On a cautionary note, it must be borne in mind that because humans and rats display orthograde and pronograde postures, respectively, the different mechanical forces on their spines add to the difficulty in translation of promising rodent data to humans.

Tapentadol Extended Release in the Treatment of Severe Chronic Low Back Pain and Osteoarthritis Pain

Tapentadol is a novel pain reliever with apparently synergistic dual mechanisms of action, capable of addressing both nociceptive and neuropathic components of chronic pain. As an effective analgesic with good tolerability, tapentadol may be appropriate for patients suffering from severe chronic pain associated with low back pain (LBP) or osteoarthritis (OA). Efficacy studies of tapentadol in populations of patients with severe chronic LBP or OA pain suggest that tapentadol is non-inferior to oxycodone. Its tolerability, especially with respect to gastrointestinal (GI) side effects, may be better than that of other strong opioids in clinical trials and analyses of multiple trials. Patient satisfaction with tapentadol extended release for chronic noncancer pain syndromes is good. Although tapentadol has an opioid component with abuse liability, it appears to be a difficult opioid for tampering with less appeal to abusers than other opioids. For patients with severe LBP and OA pain, tapentadol appears to hold promise as a safe, effective therapeutic option.

Assessment and manifestation of central sensitisation across different chronic pain conditions

Different neuroplastic processes can occur along the nociceptive pathways and may be important in the transition from acute to chronic pain and for diagnosis and development of optimal management strategies. The neuroplastic processes may result in gain (sensitisation) or loss (desensitisation) of function in relation to the incoming nociceptive signals. Such processes play important roles in chronic pain, and although the clinical manifestations differ across condition processes, they share some common mechanistic features. The fundamental understanding and quantitative assessment of particularly some of the central sensitisation mechanisms can be translated from preclinical studies into the clinic. The clinical perspectives are implementation of such novel information into diagnostics, mechanistic phenotyping, prevention, personalised treatment, and drug development. The aims of this paper are to introduce and discuss (1) some common fundamental central pain mechanisms, (2) how they may translate into the clinical signs and symptoms across different chronic pain conditions, (3) how to evaluate gain and loss of function using quantitative pain assessment tools, and (4) the implications for optimising prevention and management of pain. The chronic pain conditions selected for the paper are neuropathic pain in general, musculoskeletal pain (chronic low back pain and osteoarthritic pain in particular), and visceral pain (irritable bowel syndrome in particular). The translational mechanisms addressed are local and widespread sensitisation, central summation, and descending pain modulation.

Significance

Central sensitisation is an important manifestation involved in many different chronic pain conditions. Central sensitisation can be different to assess and evaluate as the manifestations vary from pain condition to pain condition. Understanding central sensitisation may promote better profiling and diagnosis of pain patients and development of new regimes for mechanism based therapy. Some of the mechanisms underlying central sensitisation can be translated from animals to humans providing new options in development of therapies and profiling drugs under development.