Safety and efficacy of oxycodone/naloxone vs. oxycodone vs. morphine for the treatment of chronic low back pain: results of a 12 week prospective, randomized, open-label blinded endpoint streamlined study with prolonged-release preparations

Rationale and design of a multicenter, double-blinded, randomized, placebo-controlled trial to investigate the effects of naldemedine on opioid-induced constipation for patients with cancer pain: A study protocol

Background

It is unclear which laxatives are appropriate to prevent opioid-induced constipation (OIC). This study will evaluate whether prophylactic use of naldemedine prevents OIC in patients with cancer who start opioid administration.

Methods

This study is a multicenter, double-blinded, randomized, placebo-controlled trial. Patients who meet the eligibility criteria and give consent will be randomly assigned to the naldemedine or placebo group. Both groups will take each drug once a day after breakfast for 14 days.

Results

The primary endpoint is the proportion of patients with a Bowel Function Index of less than 28.8 on Day 14. The secondary endpoints include assessment scales of the impact of constipation on comprehensive quality of life.

Conclusions

This is the first study proposed to assess the superiority of naldemedine over placebo in the prevention of OIC. If naldemedine is found to be effective in reducing OIC compared with the placebo, it will be regarded as a new standard for OIC prophylaxis at opioid initiation.

Trial registration

jRCT identifier: jRCTs031200397. Registered March 5, 2021, https://rctportal.niph.go.jp/en/detail?trial_id=jRCTs031200397.

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.

Prevalence of drug-induced constipation and severity of associated biopsychosocial effects in patients with nonmalignant pain: a cross-sectional review of depersonalized data from the German Pain e-Registry

BACKGROUND

Drug-induced constipation (DIC) is a well-known comorbidity of cancer pain, however, data on its prevalence in nonmalignant pain (NMP) and its biopsychosocial effects are few.

OBJECTIVE

To assess the prevalence and impact of DIC in patients with NMP.

METHODS

Exploratory noninterventional, retrospective, cross-sectional analysis of depersonalized routine data of the German Pain e-Registry on 150,488 NMP patients (EUPAS identifier: 42286).

RESULTS

DIC affects 33.5% of NMP patients. The most prevalent risk factors were the use of strong opioid analgesics and analgesic polymedication. Patients with DIC presented with significantly worse biopsychosocial scores as well as significantly higher percentages of individuals with severe deterioration of pain, daily life activities, physical and mental quality of life, mood, and overall wellbeing. Among patients with DIC, those who reported constipation as a clinical symptom and who documented bowel-function index (BFI) scores above the reference range were significantly more affected compared to those who either reported only constipation as an adverse event or elevated BFI scores. 55.9% of patients with DIC reported the use of laxatives, mostly over-the-counter preparations (43.6%), whereas prescription laxatives were taken by only 29.3%.

CONCLUSIONS

DIC is a frequent comorbidity of pain management and affects around one-third of patients with NMP. It interferes significantly with pain-related biopsychosocial effects and has to be addressed specifically to improve the overall burden in affected patients. However, the use of laxatives was significantly less frequent than recommended indicating significant room for improvement.

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.

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.

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.

Opioid-induced bowel dysfunction: suggestions from a multidisciplinary expert Board

Constipation, one of the adverse effects of opioid therapy with a major impact on quality of life, is still an unmet need for cancer patients, particularly those with an advanced and progressive disease, and for non-cancer patients chronically treated with opioids. The awareness of this condition is poor among healthcare providers, despite the recent publication of guidelines and consensus conferences. An early multidisciplinary approach of opioid-induced bowel dysfunction (OIBD), based on available therapies of proven effectiveness, could support clinicians in managing this condition, thus increasing patients’ adherence to pain therapy. Several Italian experts involved in the management of patients suffering from pain (anaesthesia pain therapy, oncology, haematology, palliative care, gastroenterology) joined in a Board in order to draw up an expert opinion on OIBD. The most frequent and still unsolved issues in this field were examined, including a more comprehensive definition of OIBD, the benefits of early intervention to prevent its occurrence and the most appropriate use of peripherally acting mu-opioid receptor antagonists (PAMORAs). The use of the recently introduced PAMORA naloxegol was analysed, in light of the current literature. The Board proposed a solution for each open issue in the form of recommendations, integrated with the contribution of representatives from different disciplines and often accompanied by procedural algorithms immediately usable and applicable in daily clinical practice. Safety and quality of life of the patient suffering from pain and from the adverse effects of pain therapies have been the mainstays of this expert opinion, in cooperation with general practitioners and caregivers.

Etiology, Evaluation, and Treatment of Failed Back Surgery Syndrome

The study aimed to review the etiology of failed back surgery syndrome (FBSS) and to propose a treatment algorithm based on a systematic review of the current literature and individual experience. FBSS is a term that groups the conditions with recurring low back pain after spine surgery with or without a radicular component. Since the information on FBSS incidence is limited, data needs to be retrieved from old studies. It is generally accepted that its incidence ranges between 10% and 40% after lumbar laminectomy with or without fusion. Although the etiology of FBSS is not completely understood, it is possibly multifactorial, and the causative factors may be categorized into preoperative, operative, and postoperative factors. The evaluation of patients with FBSS symptoms should ideally initiate with reviewing the patients’ clinical history (observing “red flags”), followed by a detailed clinical examination and imaging (whole-body X-ray, magnetic resonance imaging, and computed tomography). FBSS is a complex and difficult pathology, and its accurate diagnosis is of utmost importance. Its management should be multidisciplinary, and special attention should be provided to cases of recurrent disc herniation and postoperative spinal imbalance.

Oxycodone/Naloxone Prolonged Release: A Review in Severe Chronic Pain

Oral oxycodone/naloxone prolonged release (PR) [Targin^®, Targinact^®, Targiniq^®] is a 12-hourly opioid receptor agonist and opioid receptor antagonist fixed-dose combination product that is approved in countries in the EU for the management of severe pain (adequately manageable only with opioid analgesics) in adults. Oral naloxone prevents oxycodone from binding to μ-receptors in the gastrointestinal (GI) tract, thereby counteracting opioid-induced constipation (OIC). In short-term (5- to 12-week) clinical trials of adults with moderate to severe, chronic pain and OIC (OXN3001, OXN3006, OXN3506), oxycodone/naloxone PR significantly improved OIC while providing noninferior analgesia relative to oxycodone PR; results were consistent between cancer and non-cancer patients in OXN3506. Analgesia and improvements in bowel function were sustained with an additional 24-52 weeks of oxycodone/naloxone PR treatment in long-term extension studies. Results in real-world studies were consistent with those in clinical trials. Oxycodone/naloxone PR was generally well tolerated, with nausea, hyperhidrosis, and diarrhoea (generally transient) reported as the most commonly occurring adverse events. Thus, oxycodone/naloxone PR is a useful treatment option to consider in adults with severe chronic pain that can be adequately managed only with opioid analgesics, particularly in those with OIC.

Prolonged-release oxycodone/naloxone reduces opioid-induced constipation and improves quality of life in laxative-refractory patients: results of an observational study

Background

Opioids are an effective treatment for moderate-to-severe pain. However, they are associated with a number of gastrointestinal side effects, most commonly constipation. Laxatives do not target the underlying mechanism of opioid-induced constipation (OIC), so many patients do not have their symptoms resolved. Fixed-dose prolonged-release (PR) oxycodone/naloxone (OXN) tablets contain the opioid agonist oxycodone and the opioid antagonist naloxone. Nal-oxone blocks the action of oxycodone in the gut without compromising its analgesic effects.

Aim

To evaluate the effectiveness of PR OXN in patients with severe pain who had laxative-refractory OIC with their previous opioid.

Methods

The study was carried out in 13 centers across the UK and Ireland, using a bespoke online tool to capture patients’ data. Patients were reviewed according to normal clinical practice of each center and rated any changes in their constipation and quality of life (QoL) since starting PR OXN. Any change in patients’ laxative use was also recorded.

Results

One hundred and seven patients were entered into the database, and 81 went on to attend at least one review. Of these, 54 (66.7%) reported an improvement in constipation and 50 (61.7%) reported an improvement in QoL since starting PR OXN. Fifty-seven patients (70.4%) said they had reduced laxative intake; 48 (59.3%) only needed laxatives as required.

Conclusion

PR OXN reduced symptoms of constipation, improved QoL and reduced laxative intake in patients with OIC. It has a potential place early in any treatment strategy for severe pain in patients using opioids, particularly in patients who may be predisposed to constipation.

Prolonged release oxycodone and naloxone treatment counteracts opioid-induced constipation in patients with severe pain compared to previous analgesic treatment

OBJECTIVE

Treatment with prolonged-release oxycodone/naloxone (PR OXN) has been shown to improve opioid induced constipation (OIC) in constipated patients. This publication reports on a real-life observational study investigating the efficacy of PR OXN with regard to bowel function in patients switching to PR OXN from WHO step 1, step 2 and step 3 opioids.

METHODS

Patients with chronic pain experiencing insufficient pain relief and/or unacceptable side effects were switched to PR OXN and monitored in this observational study with respect to efficacy regarding bowel function and efficacy regarding pain relief in comparison with previous analgesic therapy. A patient was considered a responder with respect to efficacy if this assessment was "slightly better", "better" or "much better" compared with previous therapy. Bowel function index, pain intensity, quality of life, laxative medication use, and safety analgesic were also evaluated.

RESULTS

A total of 1338 patients (mean [SD] age 64.3 [14.9], 63% female) were observed for 43 [3-166] days (median [range]) during treatment with PR OXN. Overall response rate regarding bowel function efficacy was 82.5%. Patients with symptoms of constipation at study entry obtained a clinically relevant improvement of the bowel function index (BFI) within the first 2 weeks of PR OXN treatment. Non-constipated patients at study entry maintained normal bowel function despite switching to treatment with the opioid PR OXN.

CONCLUSION

In conclusion, treatment with PR OXN results in a significant and clinically relevant improvement of bowel function. During the observation of the treatment with PR OXN patients reported an improvement of quality of life (QoL). More interestingly, non-constipated patients maintained a normal bowel function, showing prevention of constipation despite the use of an opioid.

Opioid-Induced Constipation Relief From Fixed-Ratio Combination Prolonged-Release Oxycodone/Naloxone Compared With Oxycodone and Morphine for Chronic Nonmalignant Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

CONTEXT

Opioid-induced constipation (OIC) is one of the most frequent and severe adverse events (AEs) after treatment with opioids. Recent studies have indicated that fixed-ratio combination prolonged-release oxycodone/naloxone (OXN PR) could decrease OIC with similar pain relief compared with other opioids.

OBJECTIVES

We systematically reviewed (PROSPERO registration numbers: CRD42016036244) the constipation relief of OXN PR compared with other opioids regardless of formulation, prolonged release, or extended release used for the relief of chronic pain.

METHODS

Relevant studies were identified by searching PubMed, EMBASE, Web of Science, and the Cochrane library from inception to May 2016, with an update to December 2016. We quantitatively analyzed OIC (assessed by bowel function index [BFI]), pain intensity, and AEs.

RESULTS

A total of 167 articles were identified from the databases. Finally seven studies with 3217 patients were included in our meta-analysis, including 1322 patients in OXN PR treatment groups and 1885 patients in prolonged-release oxycodone (OXY PR) or prolonged-release morphine (MOR PR) control group. The relative risk (RR) of OIC was decreased in OXN PR (RR 0.52, 95% CI 0.44; 0.62). Whether BFI was better or worse at baseline, the mean difference (MD) of BFI -17.48 95% CI -21.60; -13.36) was better after treatment with OXN PR with clinical importance at the end of intervention; moreover, the BFI of the OXN PR-treated group was closer to normal BFI scores. However, clinical BFI change from baseline to the end measurement only existed in patients when the baseline BFI was high (mean [SDs] 61.0 [23.39]-67.40 [19.51]), and the MD of the BFI was -15.96 (95% CI -25.56; -15.48). The RR of AEs was also smaller (RR 0.80; 95% CI 0.69-0.93), but the severity or duration of AEs was not reported. Pain intensity was also significantly decreased in the OXN PR treatment groups (MD -3.84, 95% CI -7.14; -0.55), although there was no clinically meaningful difference.

CONCLUSION

For people with chronic pain, treatment with OXN PR decreases the incidence of OIC and provides intermediate-term bowel function improvement with clinical importance; in addition, pain relief is not weakened. The OIC after treatment with OXN PR for cancer-related pain and over the long term remains unknown.

Tolerability of Opioid Analgesia for Chronic Pain: A Network Meta-Analysis

Aim of this study was to study the tolerability of opioid analgesia by performing a network meta-analysis (NMA) of randomized-controlled trials (RCTs) which investigated effectiveness of opioids for the management of chronic pain. Research articles reporting outcomes of RCT/s comparing 2 or more opioid analgesics for the management of chronic pain were obtained by database search. Bayesian NMAs were performed to combine direct comparisons between treatments with that of indirect simulated evidence. Study endpoints were: incidence of adverse events, incidence of constipation, trial withdrawal rate, and patient satisfaction with treatment. Outcomes were also compared with conventional meta-analyses. Thirty-two studies investigating 10 opioid drugs fulfilled the eligibility criteria. Tapentadol treatment was top-ranking owing to lower incidence of overall adverse events, constipation, and least trial withdrawal rate. Tapentadol was followed by oxycodone-naloxone combination in providing better tolerability and less trial withdrawal rate. Patient satisfaction was found to be higher with oxycodone-naloxone followed by fentanyl and tapentadol. These results were in agreement with those achieved with conventional meta-analyses. Tapentadol and oxycodone-naloxone are found to exhibit better tolerability characteristics in comparison with other opioid drugs for the management of chronic pain and are associated with low trial withdrawal rate and better patient satisfaction.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Peripherally acting μ-opioid receptor antagonists as treatment options for constipation in noncancer pain patients on chronic opioid therapy

Opioid-induced constipation (OIC), a prevalent and distressing side effect of opioid therapy, does not reliably respond to treatment with conventional laxatives. OIC can be a treatment-limiting adverse event. Recent advances in medications with peripherally acting μ-opioid receptor antagonists, such as methylnaltrexone, naloxegol, and alvimopan, hold promise for treating OIC and thus extending the benefits of opioid analgesia to more chronic pain patients. Peripherally acting μ-opioid receptor antagonists have been clinically tested to improve bowel symptoms without compromise to pain relief, although there are associated side effects, including abdominal pain. Other treatment options include fixed-dose combination products of oxycodone analgesic together with naloxone.

Intravenous morphine titration as a rapid and efficient analgesia for adult patients with femoral shaft fractures after injury

This study aimed to compare the analgesic effects of intravenous ibuprofen and intravenous morphine titration for femoral shaft fractures in adult patients. In total, 293 participants were enrolled and randomly received intravenous ibuprofen or intravenous morphine titration. Their visual analogue scale (VAS) results were recorded every 5 minutes after the first administration. The VAS scores before and during transport were also measured. Meanwhile, the type and frequency of the adverse effects were also recorded in both groups. Patients treated with morphine showed a faster and greater reduction in the VAS than those in the ibuprofen group within 1 hour after the first administration. Interestingly, intravenous morphine titration provided consistent analgesia even during the further transport. No significant immediate adverse event was observed in all of the participants, except for sedation, which might be beneficial for keeping the patient quiet and might not be arbitrarily attributed to adverse effects. No addiction was noted in the morphine group. This study demonstrated that intravenous morphine titration is a faster and more efficient analgesia for femoral shaft fractures than ibuprofen in adult patients immediately after injury.

Analgesic effectiveness and tolerability of oral oxycodone/naloxone and pregabalin in patients with lung cancer and neuropathic pain: an observational analysis

INTRODUCTION

Cancer-related pain has a severe negative impact on quality of life. Combination analgesic therapy with oxycodone and pregabalin is effective for treating neuropathic cancer pain. We investigated the efficacy and tolerability of a dose-escalation combination therapy with prolonged-release oxycodone/naloxone (OXN-PR) and pregabalin in patients with non-small-cell lung cancer and severe neuropathic pain.

METHODS

This was a 4-week, open-label, observational study. Patients were treated with OXN-PR and pregabalin. Average pain intensity ([API] measured on a 0-10 numerical rating scale) and neuropathic pain (Douleur Neuropathique 4) were assessed at study entry and at follow-up visits. The primary endpoint was response to treatment, defined as a reduction of API at T28 ≥30% from baseline. Secondary endpoints included other efficacy measures, as well as patient satisfaction and quality of life (Brief Pain Inventory Short Form), Hospital Anxiety and Depression Scale, and Symptom Distress Scale; bowel function was also assessed.

RESULTS

A total of 56 patients were enrolled. API at baseline was 8.0±0.9, and decreased after 4 weeks by 48% (4.2±1.9; P<0.0001 vs baseline); 46 (82.1%) patients responded to treatment. Significant improvements were also reported in number/severity of breakthrough cancer pain episodes (P=0.001), Brief Pain Inventory Short Form (P=0.0002), Symptom Distress Scale (P<0.0001), Hospital Anxiety and Depression Scale depression (P=0.0006) and anxiety (P<0.0001) subscales, and bowel function (P=0.0003). At study end, 37 (66.0%) patients were satisfied/very satisfied with the new analgesic treatment. Combination therapy had a good safety profile.

CONCLUSION

OXN-PR and pregabalin were safe and highly effective in a real-world setting of severe neuropathic cancer pain, with a high rate of satisfaction, without interference on bowel function.

Pharmacokinetic and pharmacodynamic evaluation of oxycodone and naltrexone for the treatment of chronic lower back pain

INTRODUCTION

Chronic low back pain (CLBP) is a common and difficult illness to manage. Some individuals with CLBP have pain processing disorders and are also at risk for opioid abuse, misuse; addiction and diversion. Guidelines have been published to guide management; neuromodulation, exercise, mindfulness-based stress reduction and cognitive behavior therapies among other non-pharmacological reduce the pain of CLBP with minimal toxicity. Pharmacological management includes acetaminophen, NSAIDs and antidepressants, mainly duloxetine. Abuse-deterrent opioids have been developed which have been shown to reduce pain and opioid abuse risk. ALO-02 is a tamper-resistant sustained release opioid consisting of extended release oxycodone and sequestered naltrexone. Pivotal studies of ALO-02 have centered on patients with CLBP.

AREAS COVERED

This manuscript will review CLBP, the pivotal analgesic and clinical abuse potential studies of ALO-02. The opinion will cover whether opioids should be used for CLBP, when they should be used and opioid choices.

EXPERT OPINION

ALO-02 is one of several opioids which can be considered in the management of CLBP. The outcome to a trial of opioids should be function rather than analgesia. Most analgesic trials for CLBP have had analgesia as the primary outcome and function has not been vigorously studied as an outcome. Opioids should be considered as a trial only when other non-opioid analgesics have failed to improve analgesia and function. Universal precautions should be routinely part of phase III analgesic trial particularly for chronic non-malignant pain.

Quality of life under oxycodone/naloxone, oxycodone, or morphine treatment for chronic low back pain in routine clinical practice

OBJECTIVE

To compare the quality of life of patients with moderate-to-severe chronic low back pain under treatment with the WHO-step III opioids oxycodone/naloxone, oxycodone, or morphine in routine clinical practice.

STUDY DESIGN

Prospective, 12-week, randomized, open-label, blinded end-point study in 88 medical centers in Germany.

PATIENTS AND METHODS

A total of 901 patients requiring around-the-clock pain treatment with a WHO-step III opioid were randomized to either morphine, oxycodone, or oxycodone/naloxone (1:1:1). Changes from baseline to week 12 in quality of life were assessed using different validated tools (EuroQoL-5 Dimensions [EQ-5D], Short Form 12 [SF-12], quality of life impairment by pain inventory [QLIP]).

RESULTS

EQ-5D weighted index scores significantly improved over the 12-week treatment period under all three opioids (P<0.001) with significantly greater improvements under oxycodone/naloxone (65.2% vs 49.6% for oxycodone and 48.2% for morphine, P<0.001). The proportion of patients without EQ-5D complaints was also significantly higher under oxycodone/naloxone (P<0.001). Although quality of life ratings with the QLIP inventory showed significant improvements in all the three treatment arms, improvements were significantly higher under oxycodone/naloxone than under oxycodone and morphine (P<0.001): 90.7% of all oxycodone/naloxone patients achieved ≥30% improvements in quality of life, 72.8% had ≥50%, and 33.2% ≥70% improvements. Similarly, both physical and mental SF-12 component scores showed significantly greater improvements under oxycodone/naloxone with both scores close to the German population norm after 12 weeks.

CONCLUSION

Treatment with morphine, oxycodone, or oxycodone/naloxone under routine daily practice conditions significantly improved state of health and quality of life of patients with moderate-to-severe low back pain over a 12-week treatment period. Comparison between the treatment groups showed significantly greater improvements for oxycodone/naloxone than for the other two opioids.

Low-dose oral prolonged-release oxycodone/naloxone for chronic pain in elderly patients with cognitive impairment: an efficacy-tolerability pilot study

OBJECTIVE

This pilot study evaluated the efficacy and safety of prolonged-release oxycodone/naloxone (OXN-PR) in older subjects with chronic pain and mild-to-moderate cognitive impairment.

METHODS

This was a prospective, observational, open-label study of 45-day duration. Patients with moderate-to-severe chronic pain and naïve to strong opioids were recruited from nursing homes and Alzheimer's disease centers. OXN-PR was initiated at low doses (5 mg od or bid) and increased to a maximum of 20 mg bid. The primary efficacy endpoint was a pain intensity reduction of ≥30% from baseline (T0) to 15 days after OXN-PR initiation, as assessed by a numerical rating scale or the Pain Assessment in Advanced Dementia scale. Other assessments included the Barthel activities of daily living index, Neuropsychiatric Inventory, Bowel Function Index, and adverse events.

RESULTS

The analysis included 53 patients (mean age, 83.0 years; mean Mini-Mental State Examination score, 18.6) with severe pain (median Numerical Rating Scale/Pain Assessment in Advanced Dementia 6) and substantial impairment in daily functioning (mean Barthel index, 32.2). The primary endpoint was achieved by 92.4% of patients. OXN-PR significantly reduced mean pain intensity from baseline to study end (numerical rating scale, 6.6±1.0 vs 2.3±1.1, P<0.0001; Pain Assessment in Advanced Dementia, 6.9±1.6 vs 0.9±0.8, P<0.0001). Substantial improvements from T0 to T45 in daily functioning (mean Barthel index, 32.2±16.8 vs 53.7±23.9, P<0.0001) and neuropsychiatric symptoms (mean Neuropsychiatric Inventory, 25.5±27.3 vs 8.8±9.0, P<0.0001) were also reported. OXN-PR was well tolerated and did not worsen bowel function.

CONCLUSION

In this pilot study, OXN-PR was effective in improving pain and other symptoms associated with dementia, with a favorable safety and tolerability profile. Large-scale trials in people with dementia are needed to improve clinical guidance for the assessment and treatment of pain in these fragile individuals.

Efficacy and tolerability of oral oxycodone and oxycodone/naloxone combination in opioid-naïve cancer patients: a propensity analysis

Background

World Health Organization step III opioids are required to relieve moderate-to-severe cancer pain; constipation is one of the most frequent opioid-induced side effects. A fixed combination, prolonged-release oxycodone/naloxone (OXN), was developed with the aim of reducing opioid-related gastrointestinal side effects. The objective of this study was to compare the efficacy and safety of prolonged-release oxycodone (OXY) alone to OXN in opioid-naïve cancer patients with moderate-to-severe pain.

Methods

Propensity analysis was utilized in this observational study, which evaluated the efficacy, safety, and quality of life.

Results

Out of the 210 patients recruited, 146 were matched using propensity scores and included in the comparative analysis. In both groups, pain intensity decreased by ≈3 points after 60 days, indicating comparable analgesic efficacy. Responder rates were similar between groups. Analgesia was achieved and maintained with similarly low and stable dosages over time (12.0–20.4 mg/d for OXY and 11.5–22.0 mg/d for OXN). Bowel Function Index (BFI) and laxative use per week improved from baseline at 30 days and 60 days in OXN recipients (−16, P<0.0001 and −3.5, P=0.02, respectively); BFI worsened in the OXY group. The overall incidence of drug-related adverse events was 28.9% in the OXY group and 8.2% in the OXN group (P<0.01); nausea and vomiting were two to five times less frequent with OXN. Quality of life improved to a significantly greater extent in patients receiving OXN compared to OXY (increase in Short Form-36 physical component score of 7.1 points vs 3.2 points, respectively; P<0.001).

Conclusion

In patients with chronic cancer pain, OXN provided analgesic effectiveness that is similar to OXY, with early and sustained benefits in tolerability. The relationship between responsiveness to OXN and clinical characteristics is currently being investigated.

Physicians Experience with and Expectations of the Safety and Tolerability of WHO-Step III Opioids for Chronic (Low) Back Pain: Post Hoc Analysis of Data from a German Cross-Sectional Physician Survey

Objective. To describe physicians' daily life experience with WHO-step III opioids in the treatment of chronic (low) back pain (CLBP). Methods. Post hoc analysis of data from a cross-sectional online survey with 4.283 Germany physicians. Results. With a reported median use in 17% of affected patients, WHO-step III opioids play a minor role in treatment of CLBP in daily practice associated with a broad spectrum of positive and negative effects. If prescribed, potent opioids were reported to show clinically relevant effects (such as ≥50% pain relief) in approximately 3 of 4 patients (median 72%). Analgesic effects reported are frequently related with adverse events (AEs). Only 20% of patients were reported to remain free of any AE. Most frequently reported AE was constipation (50%), also graded highest for AE-related daily life restrictions (median 46%). Specific AE countermeasures were reported to be necessary in approximately half of patients (median 45%); nevertheless AE-related premature discontinuation rates reported were high (median 22%). Fentanyl/morphine were the most/least prevalently prescribed potent opioids mentioned (median 20 versus 8%). Conclusion. Overall, use of WHO-step III opioids for CLBP is low. AEs, especially constipation, are commonly reported and interfere significantly with analgesic effects in daily practice. Nevertheless, beneficial effects outweigh related AEs in most patients with CLBP.

Development of opioid-induced constipation: post hoc analysis of data from a 12-week prospective, open-label, blinded-endpoint streamlined study in low-back pain patients treated with prolonged-release WHO step III opioids

BACKGROUND

Opioid-induced constipation is the most prevalent patient complaint associated with longer-term opioid use and interferes with analgesic efficacy, functionality, quality of life, and patient compliance.

OBJECTIVES

We aimed to compare the effects of prolonged-release (PR) oxycodone plus PR naloxone (OXN) vs PR oxycodone (OXY) vs PR morphine (MOR) on bowel function under real-life conditions in chronic low-back pain patients refractory to World Health Organization (WHO) step I and/or II analgesics.

RESEARCH DESIGN AND METHODS

This was a post hoc analysis of the complete data set from a prospective, randomized, open-label, blinded endpoint (PROBE) streamlined study (German pain study registry: 2012-0012-05; European Union Drug Regulating Authorities Clinical Trials [EudraCT]: 2012-001317-16), carried out in 88 centers in Germany, where a total of 901 patients requiring WHO step III opioids to treat low-back pain were enrolled and prospectively observed for 3 months. Opioid allocation was based on either optional randomization (n=453) or physician decision (n=448). In both groups, treatment doses could be adjusted as per the German prescribing information, and physicians were free to address all side effects and tolerability issues as usual. The primary endpoint was the proportion of patients maintaining normal bowel function throughout the complete treatment period, assessed with the Bowel Function Index (BFI). Secondary analyses addressed absolute and relative BFI changes, complete spontaneous bowel movements, use of laxatives, treatment emergent adverse events, analgesic effects, and differences between randomized vs nonrandomized patient groups.

RESULTS

BFI changed significantly with all three WHO step III treatments, however significantly less with OXN vs OXY and MOR despite a significantly higher use of laxatives with the latter ones (P<0.001). The percentage of patients who maintained normal BFI scores despite opioid treatment was 54.5% (164/301) with OXN and was significantly superior to those seen with OXY (32.8% [98/300]) (odds ratio [OR]: 2.47, 95% confidence interval [CI]: 1.77-3.44; P<0.001) or MOR (29.7% [89/300]) (OR: 2.84, 95% CI: 2.03-3.97; P<0.001). Absolute BFI changes of ≥12mm 100 mm horizontal visual analog scale (VAS100) vs. baseline were seen for OXN in 41.4%, for OXY in 68.7%, and for MOR in 72.3%. Complete spontaneous bowel movements decreased at least by one per week in 10.3% with OXN vs 42.3% for OXY (OR: 6.39, 95% CI 4.13-9.89; P<0.001) and 42.0% for MOR (OR: 6.31, 95% CI: 4.08-9.76; P<0.001). Overall, 359 treatment emergent adverse events (78 [OXN], 134 [OXY], and 147 [MOR]) in 204 patients (41 [OXN], 80 [OXY], and 83 [MOR]) occurred, most affecting the gastrointestinal (49.3%) and the nervous system (39.3%). Treatment contrasts between randomized vs nonrandomized patients were insignificant.

CONCLUSION

In this post hoc analysis of data from a real-life 12-week study, OXN treatment was associated with a significantly lower risk of opioid-induced constipation, superior tolerability, and significantly better analgesic efficacy compared with OXY and MOR.