Around-the-clock, controlled-release oxycodone therapy for osteoarthritis-related pain: placebo-controlled trial and long-term evaluation

Effectiveness of an anti-inflammatory diet versus low-fat diet for knee osteoarthritis: the FEAST randomised controlled trial protocol

INTRODUCTION

Chronic inflammation plays a key role in knee osteoarthritis pathophysiology and increases risk of comorbidities, yet most interventions do not typically target inflammation. Our study will investigate if an anti-inflammatory dietary programme is superior to a standard care low-fat dietary programme for improving knee pain, function and quality-of-life in people with knee osteoarthritis.

METHODS AND ANALYSIS

The eFEct of an Anti-inflammatory diet for knee oSTeoarthritis study is a parallel-group, assessor-blinded, superiority randomised controlled trial. Following baseline assessment, 144 participants aged 45-85 years with symptomatic knee osteoarthritis will be randomly allocated to one of two treatment groups (1:1 ratio). Participants randomised to the anti-inflammatory dietary programme will receive six dietary consultations over 12 weeks (two in-person and four phone/videoconference) and additional educational and behaviour change resources. The consultations and resources emphasise nutrient-dense minimally processed anti-inflammatory foods and discourage proinflammatory processed foods. Participants randomised to the standard care low-fat dietary programme will receive three dietary consultations over 12 weeks (two in-person and one phone/videoconference) consisting of healthy eating advice and education based on the Australian Dietary Guidelines, reflecting usual care in Australia. Adherence will be assessed with 3-day food diaries. Outcomes are assessed at 12 weeks and 6 months. The primary outcome will be change from baseline to 12 weeks in the mean score on four Knee injury and Osteoarthritis Outcome Score (KOOS4) subscales: knee pain, symptoms, function in daily activities and knee-related quality of life. Secondary outcomes include change in individual KOOS subscale scores, patient-perceived improvement, health-related quality of life, body mass and composition using dual-energy X-ray absorptiometry, inflammatory (high-sensitivity C reactive protein, interleukins, tumour necrosis factor-α) and metabolic blood biomarkers (glucose, glycated haemoglobin (HbA1c), insulin, liver function, lipids), lower-limb function and physical activity.

ETHICS AND DISSEMINATION

The study has received ethics approval from La Trobe University Human Ethics Committee. Results will be presented in peer-reviewed journals and at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12622000440729.

Narcotic analgesics

There is documentation of the use of opium derived products in the ancient history of the Assyrians: the Egyptians; in the sixth century AD by the Roman Dioscorides; and by Avicenna (980-1037). Reference to opium like products is made by Paracelsus and by Shakespeare. Charles Louis Derosne and Fredrich Wilhelm Adam Serturner isolated morphine from raw opium in 1802 and 1806 respectively, and it was Sertürner who named the substance morphine, after Morpheus, the Greek God of dreams. By the middle 1800s, Opium and related opioid derived products were the source of a major addiction in USA, and to some extent in the United Kingdom. Opioid products are of major therapeutic value in the treatment of pain from injury, post surgery, intractable pain conditions, and some forms of terminal cancer.

The United States opioid crisis: Big pharma alone is not to blame."

OBJECTIVE

The opioid crisis in the United States continues essentially unabated, fueled by fentanyl contamination of the heroin supply and resulting in 79,770 reported opioid-involved overdose deaths in the calendar year 2022. To prevent another such crisis emerging, it is necessary to fully identify its root causes.

METHODS

Despite the well-recognized role the pharmaceutical industry played in facilitating the crisis via the aggressive marketing of prescription opioids, several other less appreciated but perhaps more influential factors were also contributors, and the overall goal of this review is to ensure that these are not be lost to history in a concerted effort to blame opioid manufacturers and distributors. Presented is a historical review of research and regulatory documents beginning with the loosening of opioid prescription for chronic pain through current thought and practice today. Beginning with a necessary decoupling of the current opioid crisis from the increased use of opioids to treat chronic pain, this review will examine these contributing factors.

RESULTS

Clinical concerns about under- or untreated pain, practice guidelines from standard-setting organizations and government entities, and a health system-wide move away from specialty interdisciplinary pain programs together set the stage for an over-reliance on opioids in chronic pain care.

CONCLUSIONS

This review reminds the health care community that despite the deep pockets of the pharmaceutical industry and highly the organized efforts of the drug cartels, additional self-reflection is warranted to fully understand the true root causes of the current epidemic and ways to prevent similar epidemics in the future.

A randomized, placebo-controlled, double-blinded mechanistic clinical trial using endotoxin to evaluate the relationship between insomnia, inflammation, and affective disturbance on pain in older adults: A protocol for the sleep and Healthy Aging Research for pain (SHARE-P) study

Chronic pain is prevalent in older adults. Treatment, especially with opioids, is often ineffective and poses considerable negative consequences in this population. To improve treatment, it is important to understand why older adults are at a heightened risk for developing chronic pain. Insomnia is a major modifiable risk factor for chronic pain that is ubiquitous among older adults. Insomnia can also lead to heightened systemic inflammation and affective disturbance, both of which may further exacerbate pain conditions in older adults. Endotoxin exposure can be used as an experimental model of systemic inflammation and affective disturbance. The current study aims to understand how insomnia status and endotoxin-induced changes in inflammation and affect (increased negative affect and decreased positive affect) may interact to impact pain facilitatory and inhibitory processes in older adults. Longitudinal data will also assess how pain processing, affective, and inflammatory responses to endotoxin may predict the development of pain and/or depressive symptoms. The current study is a randomized, double-blinded, placebo-controlled, mechanistic clinical trial in men and women, with and without insomnia, aged 50 years and older. Participants were randomized to either 0.8ng/kg endotoxin injection or saline placebo injection. Daily diaries were used to collect variables related to sleep, mood, and pain at two-week intervals during baseline and 3-, 6-, 9-, and 12-months post-injection. Primary outcomes during the experimental phase include conditioned pain modulation, temporal summation, and affective pain modulation ∼5.5 hours after injection. Primary outcomes for longitudinal assessments are self-reported pain intensity and depressive symptoms. The current study uses endotoxin as an experimental model for pain. In doing so, it aims to extend the current literature by: (1) including older adults, (2) investigating insomnia as a potential risk factor for chronic pain, (3) evaluating the role of endotoxin-induced affective disturbances on pain sensitivity, and (4) assessing sex differences in endotoxin-induced hyperalgesia.

Clinicaltrialsgov

NCT03256760.

Trial sponsor

NIH R01AG057750-01.

Management of chronic non-cancer pain: a framework

Aim: Since publication of the CDC 2016 Guideline, opioid-related mortality in the USA has doubled and a crisis has developed among the 15-20 million Americans with chronic, moderate-to-severe, noncancer pain. Our aim was to develop a comprehensive alternative approach to management of chronic pain. Methods: Analytic review of the clinical literature. Results: Published science provides a solid framework for the management of chronic non-cancer pain, detailed here, even as it leaves many knowledge gaps, which we fill with insights from clinical experience. Conclusion: There is a sufficient basis in science and in clinical experience to achieve adequate control of chronic pain in nearly all patients in a way that adequately balances benefits and potential harms.

Pharmacological Advances in Opioid Therapy: A Review of the Role of Oliceridine in Pain Management

Problems with the treatment of acute pain may arise when a patient is opioid-tolerant, such as those on chronic therapy with opioids or opiate replacement therapy, those who misuse opioids, and those who are in recovery. While some of the adverse effects of opioid medications are well known, it is also important to recognize the roles of tolerance and hyperalgesia. Oliceridine can target and modulate a novel μ-receptor pathway. The G protein-biased agonism of oliceridine allows for effective re-sensitization and desensitization of the mu-opioid receptor, which decreases the formation of opioid tolerance in patients. Oliceridine has been demonstrated to be an effective and relatively safe intravenous analgesic for the treatment of postoperative pain and is generally well tolerated with a favorable side effect profile when compared to morphine. As the prevalence of pain increases, it is becoming increasingly important to find safe and effective analgesics.

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.

Opioids and Chronic Pain: An Analytic Review of the Clinical Evidence

We conducted an analytic review of the clinical scientific literature bearing on the use of opioids for treatment of chronic non-cancer pain in the United States. There is substantial, albeit not definitive, scientific evidence of the effectiveness of opioids in treating pain and of high variability in opioid dose requirements and side effects. The estimated risk of death from opioid treatment involving doses above 100 MMED is ~0.25%/year. Multiple large studies refute the concept that short-term use of opioids to treat acute pain predisposes to development of opioid use disorder. The prevalence of opioid use disorder associated with prescription opioids is likely <3%. Morbidity, mortality, and financial costs of inadequate treatment of the 18 million Americans with moderate to severe chronic pain are high. Because of the absence of comparative effectiveness studies, there are no scientific grounds for considering alternative non-pharmacologic treatments as an adequate substitute for opioid therapy but these treatments might serve to augment opioid therapy, thereby reducing dosage. There are reasons to question the ostensible risks of co-prescription of opioids and benzodiazepines. As the causes of the opioid crisis have come into focus, it has become clear that the crisis resides predominantly in the streets and that efforts to curtail it by constraining opioid treatment in the clinic are unlikely to succeed.

Model-based Meta-analysis to Compare Primary Efficacy-endpoint, Efficacy-time Course, Safety, and Tolerability of Opioids Used in the Management of Osteoarthritic Pain in Humans

BACKGROUND

Despite recent therapeutic advances, osteoarthritis continues to be a challenging health problem, especially in the elderly population. Opioids, which are potent analgesics, have shown an extraordinary ability to reduce intense pain in many osteoarthritic clinical trials; however, there is an increased need for a study to integrate the reported outcomes and utilize them to achieve a better understanding. Herein, efficacy and safety aspects of opioids used to manage osteoarthritic pain were assessed and compared using a model-based meta-analysis (MBMA).

METHODS

To perform the analysis, a comprehensive database consisting of pain relief compounds with information on summary-level of efficacy over time, adverse events and dropout rates was compiled from multiple sources. MBMA was conducted using a nonlinear mixed-effects modeling approach.

RESULTS

The results of primary efficacy endpoint analysis indicated that the doses of oxycodone, oxymorphone, and tramadol required to produce 50% of the maximum effect were 47, 84, and 247 mg per day, respectively. Efficacytime course analysis showed that opioids had rapid time to efficacy onset, suggesting potentially powerful painrelieving effects. It was also found that gastrointestinal adverse events were the most opioid-associated and dosedependent adverse effects. In addition, the analysis revealed that opioids were well-tolerated at low to moderate doses.

CONCLUSION

This MBMA provides clinically meaningful insights into the efficacy and safety profiles of oxycodone, oxymorphone, and tramadol. Resultantly, the presented framework analysis can have an impact in the clinic on drug development where it can guide: the optimization of doses of opioids required to manage osteoarthritic pain; the making of precise key decisions for the positioning of new drugs, and; the design of more efficient trials.

A 20-year study of the bidirectional relationship between anxious and depressive symptomology and pain medication usage

Aim: To investigate the 20-year relationship between anxiety, depression and pain medication use. Patients: A total of 521 individuals reporting chronic pain from the National Survey of Midlife Development in the USA (MIDUS) study. Methods: Structural equation modeling of 20-year longitudinal survey data. Results: Over 20 years, a bidirectional relationship between depression and anxiety in individuals with chronic pain was indicated. Pain medication utilization predicted later use at 10 years. Pain medication use was not strongly related to later anxiety; however, heightened anxiety was associated with later use. Conclusion: Depression and anxiety show an extensive long-term bidirectional relationship. While there was little indication of a relationship between pain medication use and later negative mood, anxiety was associated with subsequent pain medication use.

Efficacy and harms of long-term opioid therapy in chronic non-cancer pain: Systematic review and meta-analysis of open-label extension trials with a study duration ≥26 weeks

BACKGROUND AND OBJECTIVE

This updated systematic review evaluated the efficacy, acceptability and safety of long-term opioid therapy (LTOT) for chronic non-cancer pain (CNCP).

DATABASES AND DATA TREATMENT

Clinicaltrials.gov, CENTRAL and MEDLINE until June 2019. We included open-label extension trials with a study duration ≥26 weeks of RCTs with ≥2 weeks duration. Pooled estimates of event rates of categorical data and standardized mean differences (SMD) of continuous variables were calculated using a random effects model.

RESULTS

We added four new studies with 1,154 participants for a total of 15 studies with 3,590 participants. Study duration ranged between 26 and 156 weeks. Studies included patients with low back, osteoarthritis and neuropathic pain. The quality of evidence for every outcome was very low. 31.1% (95% Confidence interval [CI] 23.0%-40.7%) of patients randomized at baseline finished the open label period. 14.1% (95% CI 10.9%-19.4%) of patients dropped out to due adverse events. In 6.3% (95 CI 3.9%-10.1%) of patients serious adverse events and in 2.7% (95% CI 1.5%-4.7%) aberrant drug behaviour were noted. 0.5% (95% CI 0.2%-1.4%) of patients died.

CONCLUSIONS

Within the context of open-label extension studies, opioids maintain reduction of pain and disability and are rather well tolerated and safe. LTOT can be considered in carefully selected and monitored patients with low back, osteoarthritis and neuropathic pain who experience a clinically meaningful pain reduction with at least tolerable adverse events in short-term opioid therapy.

SIGNIFICANCE

There is very low quality evidence of the long-term efficacy, tolerability and safety of opioids for chronic low back, osteoarthritis and diabetic polyneuropathic pain within the context of open-label extension studies of randomized controlled trials. Drop out rate due to adverse events and deaths increase with study duration. One-third of patients profit from LTOT. Long-term opioid therapy can be considered in some carefully selected and monitored patients.

Comparison of the antinociceptive profiles of morphine and oxycodone in two models of inflammatory and osteoarthritic pain in rat

Oxycodone and morphine are two opioid drugs commonly used for the treatment of moderate to severe pain. However, their use in the management of noncancer pain remains a controversial issue and, in this respect, the evidence on their effectiveness and safety, particularly in osteoarthritis, is being questioned. In order to analyse their analgesic profile, two different pain models in rats were used: the formalin-induced inflammatory pain and the monosodium iodoacetate (MIA)-induced knee osteoarthritic pain. Drugs were administered systemically (i.p.) and their antinociceptive effect and potency were assessed. In the formalin test, both morphine and oxycodone produced a dose-dependent antinociceptive effect, but oxycodone outdid morphine in terms of effectiveness and potency (nearly two times) in the early (acute nociceptive) as in the late phase (inflammatory). In the osteoarthritis model, both drugs reduced movement-evoked pain (knee-bend test), mechanical allodynia (von Frey test) and heat hyperalgesia (Plantar test). Pretreatment with naloxone and naloxone methiodide reduced morphine and oxycodone effects. Peripheral mu-opioid receptors play a crucial role in the antinociceptive effect of both drugs on movement-evoked pain and heat hyperalgesia, but not on tactile allodynia. The main finding of our study is that oxycodone has a better antinociceptive profile in the inflammatory and osteoarthritic pain, being more effective than morphine at 14 days post-MIA injection (phase with neuropathic pain); it overcame the morphine effect by improving the movement-induced pain, tactile allodynia and heat hyperalgesia. Therefore, oxycodone could be an interesting option to treat patients suffering from knee osteoarthritis when opioids are required.

Management of Pain in the United States-A Brief History and Implications for the Opioid Epidemic

Pain management in the United States reflects attitudes to those in pain. Increased numbers of disabled veterans in the 1940s to 1960s led to an increased focus on pain and its treatment. The view of the person in pain has moved back and forth between a physiological construct to an individual with pain where perception may be related to social, emotional, and cultural factors. Conceptually, pain has both a medical basis and a political context, moving between, for example, objective evidence of disability due to pain and subjective concerns of malingering. In the 20th century, pain management became predominately pharmacologic. Perceptions of undertreatment led to increased use of opioids, at first for those with cancer-related pain and then later for noncancer pain without the multidimensional care that was intended. The increased use was related to exaggerated claims in the medical literature and by the pharmaceutical industry, of a lack of addiction in the setting of noncancer pain for these medications-a claim that was subsequently found to be false and deliberatively deceptive; an epidemic of opioid prescribing began in the 1990s. An alarming rise in deaths due to opioids has led to several efforts to decrease use, both in patients with noncancer conditions and in those with cancer and survivors of cancer.

Efficacy and Safety of Oral and Transdermal Opioid Analgesics for Musculoskeletal Pain in Older Adults: A Systematic Review of Randomized, Placebo-Controlled Trials

This systematic review with meta-analysis was performed to evaluate the efficacy and safety of using opioid analgesics in older adults with musculoskeletal pain. We searched Cochrane Library, MEDLINE, EMBASE, Web of Science, AMED, CINAHL, and LILACS for randomized controlled trials with mean population age of 60 years or older, comparing the efficacy and safety of opioid analgesics with placebo for musculoskeletal pain conditions. Reviewers extracted data, assessed risk of bias, and evaluated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Random effects models were used to calculate standardized mean differences (when different scales were used across trials), mean differences and odds ratios with respective 95% confidence intervals (CIs). Meta-regressions were carried out to assess the influence of opioid analgesic daily dose and treatment duration on our main outcomes. We included 23 randomized placebo-controlled trials in the meta-analysis. Opioid analgesics had a small effect on decreasing pain intensity (standardized mean difference = -.27; 95% CI = -.33 to -.20) and improving function (standardized mean difference = -.27, 95% CI = -.36 to -.18), which was not associated with daily dose or treatment duration. The odds of adverse events were 3 times higher (odds ratio = 2.94; 95% CI = 2.33-3.72) and the odds of treatment discontinuation due to adverse events 4 times higher (odds ratio = 4.04; 95% CI = 3.10-5.25) in patients treated with opioid analgesics. The results show that in older adults suffering from musculoskeletal pain, using opioid analgesics had only a small effect on pain and function at the cost of a higher odds of adverse events and treatment discontinuation. For this specific population, the opioid-related risks may outweigh the benefits.

PERSPECTIVE

The systematic review shows that, in older adults suffering from musculoskeletal conditions, opioid analgesics have only a small effect on pain and disability. Conversely, this population is at higher risk of adverse events. The results may reflect age-related physiological changes in pain processing, pharmacokinetics, and pharmacodynamics.

Chronic Pain and the Opioid Conundrum

Opioids prescribed for chronic cancer and noncancer pain have been embroiled in public policy debates as to effectiveness and potential for contributing to society's problem with misuse, addiction, and overdose mortality. The conundrum of opioid prescribing is to determine who will most likely benefit from opioids and how medical practitioners may safely provide chronic opioid therapy, while also identifying patients who are unlikely to benefit or could divert illicit pharmaceuticals into society. Risk assessment and monitoring are essential to meet the standard of care, as is compliance with federal controlled substances law as well as state regulations.

[Long-term opioid therapy in chronic noncancer pain. A systematic review and meta-analysis of efficacy, tolerability and safety in open-label extension trials with study duration of at least 26 weeks]

BACKGROUND

The efficacy and safety of long-term (≥ 6 months) opioid therapy (LtOT) in chronic noncancer pain (CNCP) is under debate. A systematic review with meta-analysis of the efficacy and harms of opioids in open-label extension studies of randomized controlled trials (RCTs) has not been conducted until now.

METHODS

We screened MEDLINE and clinicaltrials.gov (through to December 2013), as well as reference sections of systematic reviews of long-term RCTs of opioids in CNCP. We included open-label extension trials with a study duration ≥ 26 weeks of RCTs of ≥ 2 weeks duration. Using a random effects model, pooled estimates of event rates for categorical data and standardized mean differences (SMD) for continuous variables were calculated.

RESULTS

We included 11 open-label extension studies with 2445 participants with nociceptive (low back, osteoarthritis) and neuropathic (radicular, polyneuropathy) pain. Median study duration was 26 (range 26-108) weeks. Four studies tested oxycodone, two studies tramadol and buprenorphine; hydromorphone, morphine, oxymorphone and tapentadol were each tested in one study. Of the patients randomized at baseline, 28.5 % (95 % confidence interval, CI, 17.9-39.2 %) finished the open-label period; 53.5 % (95 % CI 38.1-68.2 %) of patients entering the open-label period finished the open-label period. In sum, the total loss was 71.5 % (95 % CI 60.9-83.1 %) of all patients primarily included into the RCT. A total of 4.9 % (95 % CI 2.9-8.2 %) of patients dropped out due lack of efficacy; 16.8 % (95 % CI 11.0-24.8 %) dropped out to due adverse events (AE) in the open-label period and 0.08 % (95 % CI 0.001-0.05 %) of patients died during the open-label period. Only one study systematically assessed aberrant drug behavior of the patients: 5.7 % (95 % CI 3.4-9.6 %) showed aberrant drug behavior in the opinion of the investigators and 2.6 % (95 % CI 1.2-5.8 %) were judged to show aberrant drug behavior by independent expert assessment. There was no significant change (p = 0.50) in pain intensity between the end of the randomized period and the end of open-label phase (SMD 0.19 [- 0.03, 0.41]; six studies with 1360 participants).

CONCLUSION

Only a minority of patients selected for opioid therapy at randomization finished the long-term open-label study. However, sustained effects of pain reduction could be demonstrated in these patients. LtOT can be considered in carefully selected and monitored CNCP patients who experience clinically meaningful pain reduction with at least tolerable AE in short-term opioid therapy. The English full-text version of this article is freely available at SpringerLink (under "Supplementary Material").

Long-Acting Opioid Use Independently Predicts Perioperative Complication in Total Joint Arthroplasty

BACKGROUND

Opioid therapy is an increasingly used modality for treatment of musculoskeletal pain despite multiple associated risks. The purpose of this study was to evaluate how preoperative opioid use affects early outcomes after total joint arthroplasty.

METHODS

A total of 174 patients undergoing total joint arthroplasty were matched by age, gender, and procedure into 3 groups stratified by preoperative opioid use (nonuser, short acting [eg, Vicodin], long acting [eg, Oxycontin]).

RESULTS

Compared to nonusers, preoperative long-acting use was associated with increased postoperative mean opioid consumption (46 mg vs 366 mg mean morphine equivalents, P < .001) and independently predicted complications within 90 days (odds ratio: 6.15, confidence interval: [1.46, 25.95], P = .013).

CONCLUSION

Preoperative opioid use should be disclosed as a risk factor for complication to patients and taken into consideration by physicians before initiating opioid management.

Sleep and Pain in Pediatric Illness: A Conceptual Review

BACKGROUND

Sleep disruption is a common comorbidity of pediatric pain. Consequences of pain and disrupted sleep, evidence for the pain-sleep relation, and how aspects of illness, treatment, and pharmacological pain management may contribute to or exacerbate these issues are presented.

AIMS

This conceptual review explored the relation between pain and sleep in children diagnosed with chronic medical or developmental conditions. The goal of this review is to expand upon the literature by examining common themes in sleep disturbances associated with painful conditions across multiple pediatric illnesses. Populations reviewed include youth with intellectual and developmental disabilities (IDD), migraines, cystic fibrosis (CF), sickle cell disease (SCD), cancer, juvenile idiopathic arthritis (JIA), juvenile fibromyalgia (JFM), and functional gastrointestinal disorders (FGIDs).

RESULTS

Consistent evidence demonstrates that children with medical or developmental conditions are more vulnerable to experiencing pain and subjective sleep complaints than healthy peers. Objective sleep concerns are common but often under-studied. Evidence of the pain-sleep relationship exists, particularly in pediatric SCD, IDD, and JIA, with a dearth of studies directly examining this relation in pediatric cancer, JFM, CF, and FGIDs. Findings suggest that assessing and treating pain and sleep disruption is important when optimizing functional outcomes.

CONCLUSION

It is essential that research further examine objective sleep, elucidate the pain-sleep relationship, consider physiological and psychosocial mechanisms of this relationship, and investigate nonpharmacological interventions aimed at improving pain and sleep in vulnerable pediatric populations.

Pain Management in Elderly Patients

In elderly patients, persistent pain negatively impacts quality of life. An interdisciplinary approach to pain management and emphasis on quality improvement will help to achieve better therapeutic outcomes. Managing pain in the geriatric population is challenging because of age-related changes in pain perception, cognition, pharmacokinetics, and drug effects. Improvement and maintenance of physical and emotional function is the goal. Pharmacotherapy should be initiated conservatively and titrated to effective doses with minimal adverse effects. Milder pain should be treated with non-opioid analgesics with a progression toward opioids and/or adjuvant medications as the pain intensifies. Acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and adjuvant medications represent most of the analgesic agents used in pain management. Knowing the underlying mechanism of pain will help guide pharmacologic therapy. The patient should be monitored initially, with every dose change, and periodically to assess efficacy and severity of adverse effects.

Safety profile of extended-release morphine sulfate with sequestered naltrexone hydrochloride in older patients: pooled analysis of three clinical trials

OBJECTIVE

Clinical trial safety data following chronic administration of extended-release opioids within an older population is limited. Embeda * is an extended-release formulation of morphine sulfate surrounding sequestered naltrexone hydrochloride (MSN) and is designed to deter opioid misuse and abuse. The present analysis compared pooled safety outcomes among patients aged ≥65 years and those aged <65 years from three phase 2/3 studies (ranging from 2 weeks to 12 months) in patients treated with MSN.

RESEARCH DESIGN AND METHODS

Subgroup analysis of patients aged ≥65 years and <65 years was performed on pooled data for adverse events (AEs), potentially clinically significant laboratory values (hematology/chemistry), and signs/symptoms of opioid withdrawal using the Clinical Opiate Withdrawal Scale (COWS) (phase 3 trials only) for patients who received at least one dose (short-term studies, maximum dose was 160 mg/d or 320 mg/d depending on study; long-term study, no maximum dose) of study medication during titration and maintenance phases.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT00420992, NCT00415597.

RESULTS

During titration, 173 (17.1%) of 1012 patients treated with MSN were aged ≥65 years, while during maintenance 76/564 (13.5%) patients were aged ≥65 years. Treatment-emergent AEs were similar in frequency and type between the two cohorts, with the most common being constipation, nausea, and somnolence; no consistent patterns relating to age and only one possibly treatment-related serious AE in patients ≥65 years was noted. No clinically significant differences in laboratory values or COWS scores (average maximum score ≤2.5) were observed between age groups.

CONCLUSIONS

Safety outcomes following daily administration of MSN (2 weeks-12 months) were similar between patients aged ≥65 years and <65 years. Key limitations include the variable study designs and length of treatment (2 weeks-12 months), small sample size, and the inclusion of only those patients who were otherwise in relatively good health with restrictions on concomitant medications.

Long-term Safety and Efficacy of Tapentadol Extended Release Following up to 2 Years of Treatment in Patients With Moderate to Severe, Chronic Pain: Results of an Open-label Extension Trial

PURPOSE

Tapentadol extended release (ER) has demonstrated efficacy and safety for the management of moderate to severe, chronic pain in adults. This study evaluated the long-term safety and tolerability of tapentadol ER in patients with chronic osteoarthritis or low back pain.

METHODS

Patients were enrolled in this 1-year, open-label extension study after completing one of two 15-week, placebo-controlled studies of tapentadol ER and oxycodone controlled release (CR) for osteoarthritis knee pain (NCT00421928) or low back pain (NCT00449176), a 7-week crossover study between tapentadol immediate release and tapentadol ER for low back pain (NCT00594516), or a 1-year safety study of tapentadol ER and oxycodone CR for osteoarthritis or low back pain (NCT00361504). After titrating the drug to an optimal dose, patients received tapentadol ER (100-250 mg BID) for up to 1 year (after finishing treatment in the preceding studies); patients who were previously treated with tapentadol ER in the 1-year safety study received tapentadol ER continuously for up to 2 years in total.

FINDINGS

Of the 1,154 patients in the safety population, 82.7% were aged >65 years and 57.9% were female; 50.1% had mild baseline pain intensity. Mean (SD) pain intensity scores (11-point numerical rating scale) were 3.9 (2.38) at baseline (end of preceding study) and 3.7 (2.42) at end point, indicating that pain relief was maintained during the extension study. Improvements in measures of quality of life (eg, EuroQol-5 Dimension and the 36-item Short Form Health Survey [SF-36]) health status questionnaires) achieved during the preceding studies were maintained during the open-label extension study. Tapentadol ER was associated with a safety and tolerability profile comparable to that observed in the preceding studies. The most common treatment-emergent adverse events (incidence ≥10%; n = 1154) were headache (13.1%), nausea (11.8%), and constipation (11.1%). Similar efficacy and tolerability results were shown for patients who received up to 2 years of tapentadol ER treatment.

IMPLICATIONS

Pain relief and improvements in quality of life achieved during the preceding studies were maintained throughout this extension study, during which tapentadol ER was well tolerated for the long-term treatment of chronic osteoarthritis or low back pain over up to 2 years of treatment. (ClinicalTrials.gov identifier: NCT00487435.).

Efficacy and tolerability of a hydrocodone extended-release tablet formulated with abuse-deterrence technology for the treatment of moderate-to-severe chronic pain in patients with osteoarthritis or low back pain

This double-blind, placebo-controlled study evaluated the efficacy and safety of hydrocodone extended release (ER) developed with abuse-deterrence technology to provide sustained pain relief and limit effects of alcohol and tablet manipulation on drug release. Eligible patients with chronic moderate-to-severe low back or osteoarthritis pain were titrated to an analgesic dose of hydrocodone ER (15-90 mg) and randomized to placebo or hydrocodone ER every 12 hours. The primary efficacy measure was change from baseline to week 12 in weekly average pain intensity (API; 0=no pain, 10=worst pain imaginable). Secondary measures included percentage of patients with >33% and >50% increases from baseline in weekly API, change from baseline in weekly worst pain intensity, supplemental opioid usage, aberrant drug-use behaviors, and adverse events. Overall, 294 patients were randomized and received ≥1 dose of placebo (n=148) or hydrocodone ER (n=146). Weekly API did not differ significantly between hydrocodone ER and placebo at week 12 (P=0.134); although, in post hoc analyses, the change in weekly API was significantly lower with hydrocodone ER when excluding the lowest dose (15 mg; least squares mean, -0.20 vs 0.40; P=0.032). Significantly more patients had >33% and >50% increase in weekly API with placebo (P<0.05), and mean weekly worst pain intensity was significantly lower with hydrocodone ER at week 12 (P=0.026). Supplemental medication usage was higher with placebo (86%) than hydrocodone ER (79%). Incidence of aberrant drug-use behaviors was low, and adverse events were similar between groups. This study did not meet the primary endpoint, although results support the effectiveness of this hydrocodone ER formulation in managing chronic low back or osteoarthritis pain. Use of the hydrocodone ER 15-mg dose, a robust placebo response, and use of supplemental analgesics, particularly in the placebo group, may have limited detection of a statistically significant treatment effect, and additional research is needed to clarify these findings.

Opioids for chronic noncancer pain: To prescribe or not to prescribe-What is the question?

The recent American Academy of Neurology position paper by Franklin, "Opioids for chronic noncancer pain," suggests that the benefits of opioid treatment are very likely to be substantially outweighed by the risks and recommends avoidance of doses above 80-120 mg/day morphine equivalent. However, close reading of the primary literature supports a different conclusion: opioids have been shown in randomized controlled trials (RCTs) to be highly effective in the treatment of chronic nonmalignant pain; long-term follow-up studies have shown that this effectiveness can be maintained; and effectiveness has been limited in many clinical trials by failure to take into account high variability in dose requirements, failure to adequately treat depression, and use of suboptimal outcome measures. Frequency of side effects in many RCTs has been inflated by overly rapid dose titration and failure to appreciate the high interindividual variability in side effect profiles. The recent marked increase in incidence of opioid overdose is of grave concern, but there is good reason to believe that it has been somewhat exaggerated. Potential causes of overdose include inadequately treated depression; inadequately treated pain, particularly when compounded by hopelessness; inadvertent overdose; concurrent use of alcohol; and insufficient practitioner expertise. Effective treatment of pain can enable large numbers of patients to lead productive lives and improve quality of life. Effective alleviation of suffering associated with pain falls squarely within the physician's professional obligation. Existing scientific studies provide the basis for many improvements in pain management that can increase effectiveness and reduce risk. Many potentially useful areas of further research can be identified.

WITHDRAWN: Botulinum toxin for subacute/chronic neck pain

Withdrawn due to non‐compliance with The Cochrane Collaboration’s Commercial Sponsorship Policy

The editorial group responsible for this previously published document have withdrawn it from publication.

WITHDRAWN: Medicinal and injection therapies for mechanical neck disorders

Withdrawn due to non‐compliance with The Cochrane Collaboration’s Commercial Sponsorship Policy

The editorial group responsible for this previously published document have withdrawn it from publication.

Health care experiences when pain and substance use disorder coexist: "just because i'm an addict doesn't mean i don't have pain"

OBJECTIVE

To report the health care experiences of 34 individuals with coexisting substance use disorder (SUD) and chronic pain.

DESIGN

Narrative inquiry qualitative study of 90-minute interviews.

SETTING

Midwest metropolitan methadone clinic.

SUBJECTS

All individuals had SUD and were treated for SUD with methadone. They all self-identified as having pain longer than 6 months.

METHODS

This qualitative design allowed exploration of how participants made sense of events related to living with SUD and chronic pain. Narrative inquiry gives a consistent story from the participants' perspective, and researchers can perform additional analysis using the storyline. Thematic analysis occurred of their health care experiences.

RESULTS

Results revealed that participants 1) spoke about how they used deception to obtain opioids when their drug cravings were out of control; 2) were disturbed by health care providers having little understanding or ability to help them with their painful condition; 3) felt they wanted to abuse opioids again when receiving poor treatment by the health care team; 4) related what went well in their health care to help them maintain their sobriety; and 5) recommended improvements on health care interventions that included effective treatment of pain.

CONCLUSIONS

Coexisting chronic pain and SUD create unique health care needs by mutually activating and potentiating the other. There are very few comparable studies exploring the experiences of individuals when pain and SUD coexist. The health care team can better develop treatment plans and test interventions sensitive to their unique needs when they understand the experiences of this population.

Fighting insomnia and battling lethargy: the yin and yang of palliative care

There is an interdependent relationship between insomnia and fatigue in the medical literature, but both remain distinct entities. Insomnia entails problematic sleep initiation, maintenance, or restoration with an accompanying decrease in perceived daytime function. Lethargy is a symptom that has a wide differential diagnosis that heavily overlaps with cancer-related fatigue; however, insomnia may contribute to worsened fatigue and lethargy in cancer patients. Insomnia is a major risk factor for mood disturbances such as depression, which may also contribute to lethargy in this at-risk population. The pathophysiology of fatigue and insomnia is discussed in this review, including their differential diagnoses as well as the emerging understanding of the roles of neurotransmitters, branched-chain amino acids, and inflammatory cytokines. Treatment approaches for insomnia and fatigue are also discussed and reviewed, including the role of hypnotics, psychotropics, hormonal agents, and alternative therapies.

Oral or transdermal opioids for osteoarthritis of the knee or hip

BACKGROUND

Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in older people. Opioids may be a viable treatment option if people have severe pain or if other analgesics are contraindicated. However, the evidence about their effectiveness and safety is contradictory. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effects on pain, function, safety, and addiction of oral or transdermal opioids compared with placebo or no intervention in people with knee or hip osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL (up to 28 July 2008, with an update performed on 15 August 2012), checked conference proceedings, reference lists, and contacted authors.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials that compared oral or transdermal opioids with placebo or no treatment in people with knee or hip osteoarthritis. We excluded studies of tramadol. We applied no language restrictions.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate. We calculated standardised mean differences (SMDs) and 95% confidence intervals (CI) for pain and function, and risk ratios for safety outcomes. We combined trials using an inverse-variance random-effects meta-analysis.

MAIN RESULTS

We identified 12 additional trials and included 22 trials with 8275 participants in this update. Oral oxycodone was studied in 10 trials, transdermal buprenorphine and oral tapentadol in four, oral codeine in three, oral morphine and oral oxymorphone in two, and transdermal fentanyl and oral hydromorphone in one trial each. All trials were described as double-blind, but the risk of bias for other domains was unclear in several trials due to incomplete reporting. Opioids were more beneficial in pain reduction than control interventions (SMD -0.28, 95% CI -0.35 to -0.20), which corresponds to a difference in pain scores of 0.7 cm on a 10-cm visual analogue scale (VAS) between opioids and placebo. This corresponds to a difference in improvement of 12% (95% CI 9% to 15%) between opioids (41% mean improvement from baseline) and placebo (29% mean improvement from baseline), which translates into a number needed to treat (NNTB) to cause one additional treatment response on pain of 10 (95% CI 8 to 14). Improvement of function was larger in opioid-treated participants compared with control groups (SMD -0.26, 95% CI -0.35 to -0.17), which corresponds to a difference in function scores of 0.6 units between opioids and placebo on a standardised Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability scale ranging from 0 to 10. This corresponds to a difference in improvement of 11% (95% CI 7% to 14%) between opioids (32% mean improvement from baseline) and placebo (21% mean improvement from baseline), which translates into an NNTB to cause one additional treatment response on function of 11 (95% CI 7 to 14). We did not find substantial differences in effects according to type of opioid, analgesic potency, route of administration, daily dose, methodological quality of trials, and type of funding. Trials with treatment durations of four weeks or less showed larger pain relief than trials with longer treatment duration (P value for interaction = 0.001) and there was evidence for funnel plot asymmetry (P value = 0.054 for pain and P value = 0.011 for function). Adverse events were more frequent in participants receiving opioids compared with control. The pooled risk ratio was 1.49 (95% CI 1.35 to 1.63) for any adverse event (9 trials; 22% of participants in opioid and 15% of participants in control treatment experienced side effects), 3.76 (95% CI 2.93 to 4.82) for drop-outs due to adverse events (19 trials; 6.4% of participants in opioid and 1.7% of participants in control treatment dropped out due to adverse events), and 3.35 (95% CI 0.83 to 13.56) for serious adverse events (2 trials; 1.3% of participants in opioid and 0.4% of participants in control treatment experienced serious adverse events). Withdrawal symptoms occurred more often in opioid compared with control treatment (odds ratio (OR) 2.76, 95% CI 2.02 to 3.77; 3 trials; 2.4% of participants in opioid and 0.9% of participants control treatment experienced withdrawal symptoms).

AUTHORS' CONCLUSIONS

The small mean benefit of non-tramadol opioids are contrasted by significant increases in the risk of adverse events. For the pain outcome in particular, observed effects were of questionable clinical relevance since the 95% CI did not include the minimal clinically important difference of 0.37 SMDs, which corresponds to 0.9 cm on a 10-cm VAS.

Chronic pain treatment with opioid analgesics: benefits versus harms of long-term therapy

Chronic non-cancer pain (CNCP) is a disabling chronic condition with a high prevalence rate around the world. Opioids are routinely prescribed for treatment of chronic pain (CP). In the past two decades there has been a massive increase in the number of opioid prescriptions, prescribed daily opioid doses and overall opioid availability. Many more patients with CNCP receive high doses of long-acting opioids on a long-term basis. Yet CP and related disability rates remain high, and majority of the patients with CNCP are dissatisfied with their treatments. Intersecting with the upward trajectory in opioid use are the increasing trends in opioid related adverse effects, especially prescription drug abuse, addiction and overdose deaths. This complex situation raises questions on the relevance of opioid therapy in the treatment of CNCP. This article reviews current evidence on opioid effectiveness, the benefits and harms of long-term therapy in CNCP.

Safety and tolerability of tapentadol extended release in moderate to severe chronic osteoarthritis or low back pain management: pooled analysis of randomized controlled trials

INTRODUCTION

This analysis of pooled data from four randomized, controlled-dose adjustment, phase 3 studies (three 15-week, double-blind, placebo- and active-controlled studies and a 1-year, open-label, active-controlled safety study) in patients with chronic osteoarthritis hip or knee pain or low back pain evaluated the safety and tolerability of tapentadol extended release (ER) for the management of moderate to severe, chronic pain.

METHODS

In the three 15-week studies, patients were randomized (1:1:1) to twice-daily (bid) doses of placebo, tapentadol ER (100-250 mg), or oxycodone hydrochloride (HCl) controlled release (CR; 20-50 mg). In the 1-year safety study, patients were randomized (4:1) to tapentadol ER (100-250 mg bid) or oxycodone HCl CR (20-50 mg bid). Adverse events (AEs) and discontinuations were recorded in each study; pooled results were analyzed by treatment group.

RESULTS

In the placebo (n = 993), tapentadol ER (n = 1,874), and oxycodone CR (n = 1,224) groups, respectively, 40.7%, 48.4%, and 62.3% of patients discontinued treatment prematurely and 58.7%, 79.0%, and 86.6% of patients experienced ≥ 1 treatment-emergent AE (TEAE). Incidences of gastrointestinal TEAEs in the placebo, tapentadol ER, and oxycodone CR groups, respectively, were 26.6%, 47.3%, and 65.4%; incidences of nervous system TEAEs were 22.5%, 42.6%, and 45.1%, respectively. Moderate or severe gastrointestinal TEAEs were reported for 10.9% of patients who received placebo, 25.3% of patients who received tapentadol ER, and 42.3% of patients who received oxycodone CR, and moderate or severe nervous system TEAEs were reported for 10.6%, 22.1%, and 25.2% of patients, respectively. In the placebo, tapentadol ER, and oxycodone CR groups, respectively, incidences of gastrointestinal TEAEs leading to study discontinuation were 2.1%, 8.3%, and 24.1%; incidences of nervous system TEAEs leading to discontinuation were 1.4%, 7.9%, and 16.3%, respectively.

CONCLUSION

Results from this large patient population showed that tapentadol ER (100-250 mg bid) had improved gastrointestinal tolerability compared with oxycodone CR, based on the overall incidence of gastrointestinal TEAEs, the incidence of moderate or severe gastrointestinal TEAEs, and the incidence of gastrointestinal TEAEs leading to discontinuation.

Effectiveness of polymer-coated extended-release morphine sulfate capsules in older patients with persistent moderate-to-severe pain: A subgroup analysis of a large, open-label, community-based trial

Abstract.

BACKGROUND

Opioid analgesics may offer benefits over nonopioids in some older patients, especially those with moderate-to-severe pain. Polymer-coated extended-release morphine sulfate (P-ERMS) has been found to be efficacious and well tolerated in patients with chronic, moderate-to-severe, nonmalignant pain when used QD or BID.

OBJECTIVE

The purpose of this analysis was to determine the effectiveness of P-ERMS in older patients (aged >65 years) with persistent, moderate-to-severe, inadequately controlled, nonmalignant pain.

METHODS

This was a subgroup analysis of the older population from an openlabel trial in community-based pain clinics in which patients underwent treatment with P-ERMS for persistent, moderate-to-severe, inadequately controlled, nonmalignant pain (≥4 on a scale of 0-10). Patients received P-ERMS at a dose determined by the investigator based on their previous analgesic regimen, QD (morning or evening) for a 4-week treatment period. Dose increases were permitted after weeks 1 and 2; switching to BID was allowed after week 2, if needed. Measurements included changes in pain and sleep scores (0-10 scale), quality of life (QOL) scores (physical and mental component summaries [PCS and MCS, respectively] of the 36-Item Short-Form Health Survey instrument), and patient and clinician assessments of current treatment based on a 9-point scale ranging from -4 to +4.

RESULTS

One hundred forty-eight older patients (mean [SD]age, 73.4 [5.5] years) began treatment with P-ERMS; 86 (58.1%) of those patients completed the study. Pain and sleep scores significantly improved (decreased) from baseline to week 4 (7.4 vs 5.0 and 5.0 vs 3.2, respectively; both, P < 0.001). PCS and MCS scores significantly improved (increased) from baseline (27.7 vs 31.6 and 37.6 vs 40.8, respectively; both, P < 0.05), as did patient and clinician global assessments (-1.2 vs 1.1 and -1.5 vs 1.4; both, P < 0.001). Results found in these older patients were similar to those observed in the younger patients (aged ≤65 years). A majority (71.4%) of the older patients remained on QD administration and took significantly lower mean daily doses than younger patients (77.0 vs 105.2 mg/d, respectively; P = 0.001). The dropout rate for the subgroup was 41.1%, which was similar to that reported in previous studies in mixed-age populations taking other extended-release morphine formulations. Of the patients who discontinued (n = 60), adverse events (AEs) were the most prevalent reason (n = 29). The most common treatment-related AEs were constipation (19.6%) and nausea (9.5%).

CONCLUSIONS

This subgroup analysis of a previously published study revealed that the older patients in that study who were receiving P-ERMS for persistent, moderate-to-severe, inadequately controlled, nonmalignant pain who completed the study attained significant improvements in pain, sleep, and QOL scores compared with baseline. Patient and clinician satisfaction with treatment increased significantly from baseline to study end. Older patients utilized significantly lower mean daily doses than younger patients (P < 0.001), and >70% remained on a QD administration regimen for the duration of the study.

One, two, or three? Constructs of the brief pain inventory among patients with non-cancer pain in the outpatient setting

CONTEXT

Either a two-factor representation (pain intensity and interference) or a three-factor representation (pain intensity, activity interference, and affective interference) of the modified Brief Pain Inventory (BPI) is appropriate among cancer patients.

OBJECTIVES

To evaluate the extent to which a three-factor representation (pain intensity, activity interference, and affective interference) is appropriate for BPI among patients with noncancer pain seen in an outpatient setting.

METHODS

We conducted a prospective, multicenter, observational, nonrandomized study using patient pain registry data from outpatient settings. Seven hundred forty-one patients with acute episodes of noncancer pain requiring treatment with a prescription medication containing oxycodone immediate-release on an as-needed basis for at least five days participated. Baseline measurements included the modified BPI pain intensity (right now, average, and worst in 24 hours) and pain interference with general activities, walking, work, mood, relations with others, sleep, and life enjoyment. Confirmatory factor analysis was conducted for the overall sample and among postoperative patients (n = 133), patients with back and neck pain (n = 202), patients with arthritis (n = 148), and patients with injury or trauma (n = 204).

RESULTS

Both the two-factor and three-factor models were statistically better than the one-factor model (P < 0.05), with the two-factor model performing better than the three-factor model. Configural invariance, but not metric invariance by patient cohort group was demonstrated.

CONCLUSION

Consistent with analyses among cancer patients, a two-factor representation of BPI is appropriate for noncancer patients seen in an ambulatory setting. This work lends additional support for the psychometric properties of BPI.

The individual and societal burden of chronic pain in Europe: the case for strategic prioritisation and action to improve knowledge and availability of appropriate care

BACKGROUND

Chronic pain is common in Europe and elsewhere and its under treatment confers a substantial burden on individuals, employers, healthcare systems and society in general. Indeed, the personal and socioeconomic impact of chronic pain is as great as, or greater, than that of other established healthcare priorities. In light of review of recently published data confirming its clinical and socioeconomic impact, this paper argues that chronic pain should be ranked alongside other conditions of established priority in Europe. We outline strategies to help overcome barriers to effective pain care resulting in particular from deficiencies in education and access to interdisciplinary pain management services. We also address the confusion that exists between proper clinical and scientific uses of opioid medications and their potential for misuse and diversion, as reflected in international variations in the access to, and availability of, these agents.

DISCUSSION

As the economic costs are driven in part by the costs of lost productivity, absenteeism and early retirement, pain management should aim to fully rehabilitate patients, rather than merely to relieve pain. Accredited education of physicians and allied health professionals regarding state-of-the-art pain management is crucial. Some progress has been made in this area, but further provision and incentivization is required. We support a tiered approach to pain management, whereby patients with pain uncontrolled by non-specialists are able to consult a physician with a pain competency or a specialist in pain medicine, who in turn can recruit the services of other professionals on a case-by-case basis. A fully integrated interdisciplinary pain service should ideally be available to patients with refractory pain. Governments and healthcare systems should ensure that their policies on controlled medications are balanced, safeguarding public health without undue restrictions that compromise patient care, and that physician education programmes support these aims.

SUMMARY

Strategic prioritization and co-ordinated actions are required nationally and internationally to address the unacceptable and unnecessary burden of uncontrolled chronic pain that plagues European communities and economies. An appreciation of the 'return on investment' in pain management services will require policymakers to adopt a long-term, cross-budgetary approach.

Opioid therapy for chronic pain in the United States: promises and perils

Opioid therapy offers the promise of reducing the burden of chronic pain in not just individual patients, but among the broad population of patients with chronic pain. Randomized trials have demonstrated that opioid therapy for up to 12-16weeks is superior to placebo, but have not addressed longer-term use. In the United States, opioid sales have quadrupled during 2000-2010, with parallel increases in opioid accidental overdose deaths and substance abuse admissions. Clinical use of long-term opioid therapy is characterized by a pattern of adverse selection, where high-risk patients are prescribed high-risk opioid regimens. This adverse selection may link these trends in use, abuse, and overdose. Long-term opioid therapy appears to be associated with iatrogenic harm to the patients who receive the prescriptions and to the general population. The United States has, in effect, conducted an experiment of population-wide treatment of chronic pain with long-term opioid therapy. The population-wide benefits have been hard to demonstrate, but the harms are now well demonstrated.

Effectiveness and tolerability of tapentadol prolonged release compared with prior opioid therapy for the management of severe, chronic osteoarthritis pain

BACKGROUND

Tapentadol prolonged release (PR; 100-250 mg twice daily) has been efficacious and well tolerated for managing moderate-to-severe, chronic osteoarthritis hip or knee pain in phase 3 studies with washout of previous analgesic treatment.

OBJECTIVE

The objective of this study was to evaluate the effectiveness and tolerability of tapentadol PR (50-250 mg twice daily) after direct rotation from World Health Organization (WHO) step III opioids in patients with severe osteoarthritis knee pain who previously responded to WHO step III therapy but showed poor tolerability.

METHODS

This open-label, phase 3b study (NCT00982280) was conducted from October 2009 through June 2010 (prematurely terminated due to slow recruitment and study drug shortages) in clinical care settings in Europe and Australia. The study population included patients with severe, chronic osteoarthritis knee pain who had taken WHO step III opioids daily for ≥2 weeks before screening, responded to therapy (average pain intensity [11-point numerical rating scale-3 (NRS-3)] ≤5 at screening), and reported opioid-related adverse effects as their reason for changing analgesics. Patients switched directly from WHO step III therapy to tapentadol. Patients received oral tapentadol PR (50-250 mg twice daily) during 5-week titration and 7-week maintenance periods. Oral tapentadol immediate release (IR) was permitted (≤twice/day, ≥4 h apart) for acute pain episodes due to index pain or withdrawal symptoms following discontinuation of previous opioids (combined dose of tapentadol [PR and IR] ≤500 mg/day). This study was planned to evaluate conversion to tapentadol PR, based on responder rate 1 (percentage of patients with same/less pain [NRS-3] versus Week -1) at Week 6 (primary endpoint), adverse events (AEs), and discontinuation rates. Equianalgesic ratios were calculated for tapentadol prior to WHO step III opioids (PR and PR plus IR formulations).

RESULTS

Of 82 patients enrolled, 63 received study medication. In the per-protocol population, responder rate 1 at Week 6 (last observation carried forward) was 94.3 % (50/53; P < 0.0001 vs. the null hypothesis rate [<60 %]). Mean (standard deviation) pain intensity scores were 4.7 (0.66) at baseline, 2.5 (1.46) at Week 6, and 1.8 (1.41) at Week 12 in the main analysis population (change from baseline at Weeks 6 and 12, P < 0.0001). Tapentadol to transdermal buprenorphine equianalgesic ratios (PR [n = 48], 262.9:1; PR plus IR [n = 48], 281.1:1) and tapentadol to oral oxycodone equianalgesic ratios (PR [n = 4], 4.3:1; PR plus IR [n = 6], 4.6:1) were calculated for the main analysis population. In the safety population, prevalence of AEs reported as associated with prior opioids at Week -1 (reasons for rotation) and related to tapentadol treatment at Week 12 decreased over time; the most common were nausea (46.0 vs. 24.1 %) and constipation (31.7 vs. 7.4 %). Overall, 14.3 % of patients discontinued the study early; reasons included AEs (9.5 %), lack of efficacy (3.2 %), and withdrawal of consent (1.6 %).

CONCLUSIONS

Significant improvements in effectiveness were observed for tapentadol PR (50-250 mg twice daily) versus WHO step III opioids in patients with severe, chronic osteoarthritis knee pain who previously responded to WHO step III therapy. Equianalgesic ratios were calculated for tapentadol to transdermal buprenorphine and oral oxycodone and were in line with observations from previous phase 3 studies.

What are we treating with chronic opioid therapy?

The recent increase in the number of patients taking opioids chronically for pain has not yielded the expected benefits in reduction of symptoms and improved function. Chronic pain patients typically respond well initially to opioid medications, but regular use is associated with adverse psychological and physical effects. Patients with significant psychiatric comorbidity and substance use issues are more likely to stay on opioids and to receive higher doses. In the common rheumatological conditions of fibromyalgia and osteoarthritis, opioid treatment is of limited benefit because of lack of efficacy and prominent side effects. Chronic opioid therapy may be more usefully regarded as a form of comfort care, reserved for those patients who have exhausted other treatments and prospects of recovery.

[Recommendations for symptomatic therapy of rheumatic pain with opioid analgetics]

The treatment of musculoskeletal pain is often difficult. For this reason opioids are increasingly being used for chronic musculoskeletal complaints despite poor or lacking evidence for their pain relieving and function improving effects. However, side effects are common and can be severe. Opioid-induced hyperalgesia can lead to higher doses and stronger pain and increase the risk of side effects. Long-term treatment of rheumatic pain with opioids should be carried out with caution.

Primary care considerations of the pharmacokinetics and clinical use of extended-release opioids in treating patients with chronic noncancer pain

Extended-release (ER) opioid analgesics are associated with prolonged analgesia and greater stability in pain relief compared with immediate-release formulations. Due to the pharmacokinetic (PK) characteristics of ER opioids and additional clinical advantages, the use of ER opioids for patients with moderate-to-severe chronic noncancer pain has increased. Primary care physicians are the major prescribers of opioids and require an in-depth understanding of the risks and benefits of opioid treatment in pain management. With appropriate knowledge of PK profiles and clinical outcomes of commonly prescribed ER opioids, primary care physicians can safely and effectively manage this patient population. In addition, the development of ER opioids with abuse-deterrent features marks an important milestone in potentially reducing abuse and may be factored into the clinical decision-making process. This article provides a comprehensive review of the PK and clinical effects of ER opioids and discusses novel ER opioid formulations that may limit abuse potential.