Combined prolonged-release oxycodone and naloxone improves bowel function in patients receiving opioids for moderate-to-severe non-malignant chronic pain: a randomised controlled trial

To what extent are we confident that tapentadol induces less constipation and other side effects than the other opioids in chronic pain patients? a confidence evaluation in network meta-analysis

Background

A confidence evaluation helps to make informed decisions about the results of meta-analyses. The goal of this work is to perform a confidence evaluation of results of a network meta-analysis (NMA) on the digestive side effects of tapentadol in patients with chronic pain.

Methods

An updated search in PubMed/Medline and Web of Science search until March 2020 was done to perform pairwise meta-analyses with NMA using random-effect models and confidence in network meta-analysis (CiNeMA) for the confidence analysis.

Results

Twenty-five studies were included in the final analyses. Pairwise and indirect comparisons showed a reduced risk of constipation with tapentadol compared to oxycodone. The confidence evaluation did not raise any concerns in terms of confidence for the oxycodone versus tapentadol comparisons. The oxycodone-naloxone versus tapentadol comparisons showed some concerns, particularly in terms of imprecision and incoherence. Regarding the overall risk of any side effects, the confidence evaluation showed a major concern regarding imprecision, but not for the comparison between tapentadol and oxycodone. However, this comparison showed a major heterogeneity.

Discussion and conclusions

A confidence evaluation in meta-analysis on the effect of tapentadol compared to other opioids in chronic pain showed possible imprecision, heterogeneity and/or incoherence. However, with a high level of confidence, tapentadol was associated with a lower incidence of constipation than oxycodone. Confidence analyses can help to get more information from meta-analyses.

Cost-Effectiveness Analysis of Tapentadol Versus Oxycodone/Naloxone in both Branded and Generic Formulations in Patients with Musculoskeletal Pain

BACKGROUND AND OBJECTIVES

Current evidence shows that tapentadol hydrochloride prolonged-release is more cost effective than other opioids. However, the introduction into the market of generic formulations of traditional comparators, leading to potential savings due to their lower price, creates space for further research. The objective of this study is to evaluate and compare the efficacy of tapentadol versus oxycodone/naloxone and the economic impact of the two alternatives in both branded and generic formulations.

METHODS

A cost-effectiveness analysis was performed using the third-payer perspective (TPP), with specific reference to the Italian National Health Service. A Markov model was implemented to simulate transitions between states, comparing two arms: The first arm simulated the administration of tapentadol, while the second simulated the administration of oxycodone/naloxone, both branded and generic. The results were reported in terms of net monetary benefit (NMB). The willingness to pay (WPT) was estimated at €35,000/quality-adjusted life year.

RESULTS

Tapentadol was dominant in all scenarios, assuming a population of 1000 individuals over a 1-year time horizon. In all cases, although the prices of oxycodone/naloxone generic formulations were lower, the costs associated with treatment discontinuation were always higher than those associated with tapentadol. The comparison with the branded formulation of oxycodone/naloxone was associated with the highest savings of €431.77 per patient, and with the highest NMB of €1943.77 per patient.

CONCLUSION

The results of this pharmacoeconomic evaluation promote the use of tapentadol in comparison with oxycodone/naloxone, confirming the results obtained in previous studies with reference to the generic formulations.

Experimental considerations for the assessment of in vivo and in vitro opioid pharmacology

Morphine and other mu-opioid receptor (MOR) agonists remain the mainstay treatment of acute and prolonged pain states worldwide. The major limiting factor for continued use of these current opioids is the high incidence of side effects that result in loss of life and loss of quality of life. The development of novel opioids bereft, or much less potent, at inducing these side effects remains an intensive area of research, with multiple pharmacological strategies being explored. However, as with many G protein-coupled receptors (GPCRs), translation of promising candidates from in vitro characterisation to successful clinical candidates still represents a major challenge and attrition point. This review summarises the preclinical animal models used to evaluate the key opioid-induced behaviours of antinociception, respiratory depression, constipation and opioid-induced hyperalgesia and tolerance. We highlight the influence of distinct variables in the experimental protocols, as well as the potential implications for differences in receptor reserve in each system. Finally, we discuss how methods to assess opioid action in vivo and in vitro relate to each other in the context of bridging the translational gap in opioid drug discovery.

Efficacy and Safety of Peripherally Acting Mu-Opioid Receptor Antagonists for the Treatment of Opioid-Induced Constipation: A Bayesian Network Meta-analysis

OBJECTIVE

To assess the efficacy and safety of peripherally acting mu-opioid receptor antagonists (PAMORAs) for the treatment of opioid-induced constipation (OIC).

METHODS

Randomized controlled trials (RCTs) were searched for OIC therapy comparing PAMORAs with placebo. Both a pairwise and network meta-analysis were performed. The surface under the cumulative ranking area (SUCRA) was used to determine the efficacy and safety of OIC treatment using different PAMORAs.

RESULTS

The primary target outcome was a response that achieves an average of three or more bowel movements (BMs) per week. In the network meta-analysis, four PAMORAs (naldemedine, naloxone, methylnaltrexone, and alvimopan) showed a better BM response than the placebo. Naldemedine was ranked first (odds ratio [OR] = 2.8, 95% credible interval [CrI] = 2-4.5, SUCRA = 89.42%), followed by naloxone (OR = 2.9, 95% CrI = 1.6-5.3, SUCRA = 87.44%), alvimopan (OR = 2.2, 95% CrI = 1.3-3.5, SUCRA = 68.02%), and methylnaltrexone (OR = 1.7, 95% CrI = 1.0-2.8, SUCRA = 46.09%). There were no significant differences in safety found between the PAMORAs and the placebo.

CONCLUSIONS

We found that PAMORAs are effective and can be safely used for the treatment of OIC. In network meta-analysis, naldemedine and naloxone appear to be the most effective PAMORAs for the treatment of OIC.

Systematic review with meta-analysis: efficacy and safety of treatments for opioid-induced constipation

BACKGROUND

When opioid-induced constipation is treated with centrally acting opioid antagonists, there may be opioid withdrawal or aggravation of pain due to inhibition of μ-opioid analgesia. This led to the development of peripherally acting μ-opioid receptor antagonists (PAMORAs).

AIM

To evaluate the efficacy of available PAMORAs and other approved or experimental treatments for relieving constipation in patients with opioid-induced constipation, based on a systematic review and meta-analysis of published studies.

METHODS

A search of MEDLINE, EMBASE and EBM Reviews Cochrane Central Register of Controlled Trials was completed in July 2019 for randomised trials compared to placebo. FDA approved doses or highest studied dose was evaluated. Efficacy was based on diverse endpoints, including continuous variables (the bowel function index, number of spontaneous bowel movements and stool consistency based on Bristol Stool Form Scale), or responder analysis (combination of >3 spontaneous bowel movements or complete spontaneous bowel movements plus 1 spontaneous bowel movement or complete spontaneous bowel movements, respectively, over baseline [so-called FDA endpoints]). Adverse effects evaluated included central opioid withdrawal, serious adverse events, abdominal pain and diarrhoea.

RESULTS

We included 35 trials at low risk of bias enrolling 13 566 patients. All PAMORAs demonstrated efficacy on diverse patient response endpoints. There was greater efficacy with approved doses of the PAMORAs (methylnaltrexone, naloxegol and naldemidine), with lower efficacy or lower efficacy and greater adverse effects with combination oxycodone with naloxone, lubiprostone and linaclotide.

CONCLUSIONS

Therapeutic response in opioid-induced constipation is best achieved with the PAMORAs, methylnaltrexone, naloxegol and naldemidine, which are associated with low risk of serious adverse events.

Prolonged-Release (PR) Oxycodone/Naloxone Improves Bowel Function Compared with Oxycodone PR and Provides Effective Analgesia in Chinese Patients with Non-malignant Pain: A Randomized, Double-Blind Trial

Introduction

Prolonged-release oxycodone/naloxone (OXN PR), combining an opioid analgesic with selective blockade of enteric µ-opioid receptors, provided effective analgesia and improved bowel function in patients with moderate-to-severe pain and opioid-induced constipation in clinical trials predominantly conducted in Western countries. This double-blind randomized controlled trial investigated OXN PR (N = 116) versus prolonged-release oxycodone (OXY PR, N = 115) for 8 weeks at doses up to 50 mg/day in patients with moderate-to-severe, chronic, non-malignant musculoskeletal pain and opioid-induced constipation recruited in China.

Methods

A total of 234 patients at least 18 years of age with non-malignant musculoskeletal pain for more than 4 weeks that was moderate-to-severe in intensity and required round-the-clock opioid therapy were randomized (1:1) to OXN PR or OXY PR. The primary endpoint was bowel function using the Bowel Function Index (BFI). Secondary endpoints included safety, Brief Pain Inventory-Short Form (BPI-SF), use of analgesic and laxative rescue medication, and health-related quality of life (EQ-5D).

Results

While BFI scores were comparable at baseline, at week 8 improvements were greater with OXN PR vs OXY PR (least squares mean [LSM] difference (95% CI) − 9.1 (− 14.0, − 4.2); P < 0.001. From weeks 2 to 8, mean BFI scores were in the range of normal bowel function (≤ 28.8) with OXN PR but were in the range of constipation (> 28.8) at all timepoints with OXY PR. Analgesia with OXN PR was similar and non-inferior to OXY PR on the basis of modified BPI-SF average 24-h pain scores at week 8: LSM difference (95% CI) − 0.3 (− 0.5, − 0.1); P < 0.001. The most frequent treatment-related AEs were nausea (OXN PR 5% vs OXY PR 6%) and dizziness (4% vs 4%).

Conclusion

OXN PR provided clinically meaningful improvements in bowel function and effective analgesia in Chinese patients with moderate-to-severe musculoskeletal pain and pre-existing opioid-induced constipation.

Trial Registration

ClinicalTrials.gov, identifier NCT01918098.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01244-x) contains supplementary material, which is available to authorized users.

Peripheral Opioid Receptor Antagonists for Opioid-Induced Constipation: A Primer on Pharmacokinetic Variabilities with a Focus on Drug Interactions

Opioid analgesics remain a treatment option for refractory acute and chronic pain, despite their potential risk for abuse and adverse events (AEs). Opioids are associated with several common AEs, but the most bothersome is opioid-induced constipation (OIC). OIC is often overlooked but has the potential to affect patient quality of life, increase associated symptom burden, and impede long-term opioid compliance. The peripherally acting µ-receptor antagonists (PAMORAs) are a class of drugs that include methylnaltrexone, naloxegol, and naldemedine. Collectively, each is approved for the treatment of OIC. PAMORAs work peripherally in the gastrointestinal tract, without impacting the central analgesic effects of opioids. However, each has unique pharmacokinetic properties that may be impacted by coadministered drugs or food. This review focuses on important metabolic and pharmacokinetic principals that are pertinent to drug interactions involving µ-opioid receptor antagonists prescribed for OIC. It highlights subtle differences among the PAMORAs that may have clinical significance. For example, unlike naloxegol or naldemedine, methylnaltrexone is not a substrate for CYP3A4 or p-glycoprotein; therefore, its plasma concentration is not altered when coadministered with concomitant medications that are CYP3A4 or p-glycoprotein inducers or inhibitors. With a better understanding of pharmacokinetic nuances of each PAMORA, clinicians will be better equipped to identify potential safety and efficacy considerations that may arise when PAMORAs are coadministered with other medications.

Pharmacovigilance in Hospice/Palliative Care: De-Prescribing Combination Controlled Release Oxycodone-Naloxone

Background: Pharmacovigilance studies in hospice/palliative care provide extra information to improve medication safety. Combination controlled release oxycodone-naloxone offers an alternative opioid with less risk of opioid-induced constipation. Objective: To examine why palliative care clinicians chose to cease oxycodone-naloxone and to explore immediate and short-term benefits and harms of this medication change. Design: A consecutive cohort study. Setting: 112 adults from 13 palliative care centers. Measurements: Reasons for ceasing medication and the harms and benefits that followed this 24 and 72 hours later. Symptom burdens were summarised by the National Cancer Institute Common Terminology Criteria for Adverse Events Toxicity Gradings. Results: Combination medication was most commonly ceased because of poor pain control or impaired hepatic function. The last median oral morphine equivalent oxycodone dose before the switch was 45 mg (range 7.5-240 mg) with 76 switched to an alternative long-acting opioid (initial median oral morphine equivalent dose being 45 mg [range 5-210 mg]). Subgroup analysis of those switched because of clinicians' concerns about hepatic dysfunction demonstrated this group were receiving significantly lower opioid doses pre-cessation compared to those switched because of other reasons( p = 0.007). Regardless of why the medication was changed, improvements in pain and constipation scores were seen, the latter associated with an attendant increase in laxatives. Conclusions: This preliminary work suggests that despite theoretical concerns regarding the effect of the naloxone on opioid doses, most people were switched safely to very similar opioid doses with attendant improvements in pain control.

Implications of the Opioid Epidemic for the Clinical Gastroenterology Practice

PURPOSE OF REVIEW

The opioid epidemic in the USA has led to a rise in opioid-related gastrointestinal (GI) side effects that are often difficult to diagnose and treat. The aim of this report is to discuss opioid pathophysiology, opioid-related GI side effects, clinical presentation, and diagnostic criteria and to review the current pharmacotherapy available.

RECENT FINDINGS

Opioid-related GI disorders are increasingly recognized and include, but are not limited to, opioid-induced esophageal dysfunction (OIED), gastroparesis, opioid-induced constipation (OIC), narcotic bowel syndrome (NBS), acute post-operative ileus, and anal sphincter dysfunction. Treatment of these conditions is challenging. OIC has the most available pharmacotherapy for treatment, including classical laxatives, peripherally acting μ-receptor antagonists (PAMORAs), novel therapies (lubiprostone, prucalopride- 5-HT agonist), and preventative therapies (PR oxycodone/naloxone). The gastrointestinal effects of opioid therapy are variable and often debilitating. While medical management for some opioid-related GI side effects exists, limiting or completely avoiding opioid use for chronic non-cancer pain will mitigate these effects most effectively.

Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: systematic review and network meta-analysis

OBJECTIVE

Opioids are increasingly prescribed in the West and have deleterious GI consequences. Pharmacological therapies to treat opioid-induced constipation (OIC) are available, but their relative efficacy is unclear. We performed a systematic review and network meta-analysis to address this deficit in current knowledge.

DESIGN

We searched MEDLINE, EMBASE, EMBASE Classic and the Cochrane central register of controlled trials through to December 2017 to identify randomised controlled trials (RCTs) of pharmacological therapies in the treatment of adults with OIC. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Efficacy and safety of pharmacological therapies was reported as a pooled relative risk (RR) with 95% CIs to summarise the effect of each comparison tested and ranked treatments according to their P-score.

RESULTS

Twenty-seven eligible RCTs of pharmacological therapies, containing 9149 patients, were identified. In our primary analysis, using failure to achieve an average of ≥3 bowel movements (BMs) per week with an increase of ≥1 BM per week over baseline or an average of ≥3 BMs per week, to define non-response, the network meta-analysis ranked naloxone first in terms of efficacy (RR=0.65; 95% CI 0.52 to 0.80, P-score=0.84), and it was also the safest drug. When non-response to therapy was defined using failure to achieve an average of ≥3 BMs per week, with an increase of ≥1 BM per week over baseline, naldemedinewas ranked first (RR=0.66; 95% CI 0.56 to 0.77, P score=0.91) and alvimopan second (RR=0.74; 95% CI 0.57 to 0.94, P-score=0.71).

CONCLUSION

In network meta-analysis, naloxone and naldemedine appear to be the most efficacious treatments for OIC. Naloxone was the safest of these agents.

Pathophysiology and management of opioid-induced constipation: European expert consensus statement

Background

Opioid-induced bowel dysfunction is a complication of opioid therapy, in which constipation is the most common and problematic symptom. However, it is frequently under-recognised and thus effective management is often not instituted despite a number of treatment options.

Objective

The central objective of this study is to provide a summary of the pathophysiology and clinical evaluation of opioid-induced constipation and to provide a pragmatic management algorithm for day-to-day clinical practice.

Methods

This summary and the treatment algorithm is based on the opinion of a European expert panel evaluating current evidence in the literature.

Results

The pathophysiology of opioid-induced constipation is multi-faceted. The key aspect of managing opioid-induced constipation is early recognition. Specific management includes increasing fluid intake, exercise and standard laxatives as well as addressing exacerbating factors. The Bowel Function Index is a useful way of objectively evaluating severity of opioid-induced constipation and monitoring response. Second-line treatments can be considered in those with recalcitrant symptoms, which include gut-restricted or peripherally acting mu-opioid receptor antagonists. However, a combination of interventions may be needed.

Conclusion

Opioid-induced constipation is a common, yet under-recognised and undertreated, complication of opioid therapy. We provide a pragmatic step-wise approach to opioid-induced constipation, which should simplify management for clinicians.

The role of oxycodone/naloxone in the management of patients with pain and opioid-induced constipation

INTRODUCTION

Common opioid adverse effects (AE) of the gastrointestinal tract include opioid-induced constipation (OIC) and opioid-induced bowel dysfunction (OIBD) with traditional laxatives being of limited efficacy, having AEs and not addressing the pathophysiology of OIC or OIBD. Targeted treatment comprises of PAMORA (peripherally acting mu-opioid receptor antagonists) and a combination of an opioid receptor agonist with its antagonist, namely prolonged-release oxycodone with prolonged-release naloxone (OXN) tablets at a fixed ratio of 2:1. Oxycodone provides analgesia, whereas naloxone prevents binding or displaces it from opioid receptors located in the gut wall. Areas covered: The authors review the role of OXN in the management of patients with pain and OIC. A literature search was performed using the search terms 'oxycodone/naloxone' and 'opioid-induced constipation' using the PubMed database up to October 2018. Expert opinion: OXN delivers analgesia comparable (or superior versus placebo and in observational studies) to oxycodone alone and other opioids with a limited or decreased disturbing effect on bowel function. OXN in daily doses of up to 160 mg/80 mg provides effective analgesia with little negative impact on bowel function. OXN may be successfully used in patients with chronic pain, to prevent or treat symptoms of OIC and OIBD.

Pharmacological Treatment of Opioid-Induced Constipation Is Effective but Choice of Endpoints Affects the Therapeutic Gain

BACKGROUND

Widespread opioid use has led to increase in opioid-related adverse effects like constipation. We examined the impact of study endpoints on reported treatment benefits.

METHODS

Using MEDLINE, EMBASE, and ClinicalTrials.gov, we searched for randomized control trials targeting chronic opioid-induced constipation (OIC) and subjected them to meta-analysis. Data are given with 95% confidence intervals.

RESULTS

Thirty trials met our inclusion criteria. Combining all dichotomous definitions of responders, active drugs were consistently more effective than placebo, with an odds ratio (OR): 2.30 [2.01-2.63; 15 studies], independent of the underlying drug mechanism. The choice of endpoints significantly affected the therapeutic gain. When time from drug administration to defecation was used, the OR decreased from 4.74 [2.71-4.74] at 6 h or less to 2.46 [1.80-3.30] at 24 h (P < 0.05). Using other response definitions, the relative benefit over placebo was 2.10 [1.77-2.50; 12 studies] for weekly bowel frequency, 2.03 [1.39-2.95; 9 studies] for symptom scores, 2.21 [1.25-3.90; 4 studies] for global assessment scales, and 1.27 [0.79-2.03; 7 studies] for rescue laxative use.

CONCLUSION

While treatment of OIC with active drugs is more effective than placebo, the relative gain depends on the choice of endpoints. The commonly used time-dependent response definition is associated with the highest response rate but is of questionable relevance in a chronic disorder. The limited data do not clearly demonstrate a unique advantage of the peripherally restricted opioid antagonists, suggesting that treatment with often cheaper agents should be optimized before shifting to these novel expensive agents.

Efficacy of Treatments for Opioid-Induced Constipation: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Opioid-induced constipation (OIC) is a common problem in patients on chronic opioid therapy for cancer-related and non-cancer-related pain. Approved treatments for OIC are methylnaltrexone, naloxone, naloxegol, alvimopan, naldemedine, and lubiprostone. Since a meta-analysis performed in 2014, 2 new agents have been approved by the Food and Drug Administration for treatment of OIC (naloxegol and naldemedine).

METHODS

We conducted a search of the medical literature following the protocol outlined in the Cochrane Handbook for systematic review. We searched MEDLINE, EMBASE, EMBASE Classic, Web of Science, and the Cochrane Central Register of Controlled Trials until March 2017 to identify randomized controlled trials of peripheral μ-opioid-receptor antagonists (methylnaltrexone, naloxone, naloxegol, alvimopan, axelopran, or naldemedine), lubiprostone, or prucalopride. Response to therapy was extracted in a dichotomous assessment as an overall response to therapy. The effect of pharmacologic therapies was pooled and reported as a relative risk (RR) of failure to respond to the treatment drug, with 95% CIs.

RESULTS

We included 27 placebo-controlled trials in our meta-analysis (23 trials evaluated μ-opioid-receptor antagonists, 3 trials evaluated lubiprostone, and 1 trial evaluated prucalopride). In these trials, 5390 patients received a drug and 3491 received a placebo. Overall, μ-opioid-receptor antagonists, lubiprostone, and prucalopride were superior to placebo for the treatment of OIC, with a RR of failure to respond to therapy of 0.70 (95% CI, 0.64-0.75) and an overall number needed to treat of 5 (95% CI, 4-7). When restricted to only Food and Drug Administration-approved medications for OIC, the RR of failure to respond to therapy was 0.69 (95% CI, 0.62-0.77), with a number needed to treat of 5 (95% CI, 4-7). Sensitivity analyses and meta-regression performed to account for heterogeneity showed that treatment was more likely to be effective in study populations taking higher doses of opiates at baseline or refractory to laxatives. Study duration and prespecified primary outcome did not affect the RR of failure. Participants who received μ-opioid-receptor antagonists were significantly more likely to have diarrhea, abdominal pain, nausea, or vomiting than patients who received placebo.

CONCLUSIONS

In a systematic review and meta-analysis, we found μ-opioid-receptor antagonists to be safe and effective for the treatment of OIC. Prescription-strength laxatives (prucalopride, lubiprostone) are slightly better than placebo in reducing OIC.

New developments in the treatment of opioid-induced gastrointestinal symptoms

Chronic pain affects a large part of the global population, leading to an increase of opioid use. Opioid-induced constipation (OIC), a highly prevalent adverse effect of opioid use, has a major impact on patients' quality of life. Thanks to the introduction of new drugs for chronic constipation, which can also be used in OIC, and the development of peripherally acting mu-opioid receptor blockers, specifically for use in OIC, therapeutic options have seen major development. This review summarises current and emerging treatment options for OIC based on an extensive bibliographical search. Efficacy data for laxatives, lubiprostone, prucalopride, linaclotide, oxycodone/naloxone combinations, methylnaltrexone, alvimopan, naloxegol, naldemedine, axelopran, and bevenopran in OIC are summarised.

Management of Paediatric Ulcerative Colitis, Part 2: Acute Severe Colitis-An Evidence-based Consensus Guideline From the European Crohn's and Colitis Organization and the European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND AND AIM

Acute severe colitis (ASC) is one of the few emergencies in pediatric gastroenterology. Tight monitoring and timely medical and surgical interventions may improve outcomes and minimize morbidity and mortality. We aimed to standardize daily treatment of ASC in children through detailed recommendations and practice points which are based on a systematic review of the literature and consensus of experts.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). Fifteen predefined questions were addressed by working subgroups. An iterative consensus process, including 2 face-to-face meetings, was followed by voting of the national representatives of ECCO and all members of the Paediatric Inflammatory Bowel Disease (IBD) Porto group of ESPGHAN (43 voting experts).

RESULTS

A total of 24 recommendations and 43 practice points were endorsed with a consensus rate of at least 91% regarding diagnosis, monitoring, and management of ASC in children. A summary flowchart is presented based on daily scoring of the Paediatric Ulcerative Colitis Activity Index. Several topics have been altered since the previous 2011 guidelines and from those published in adults.

DISCUSSION

These guidelines standardize the management of ASC in children in an attempt to optimize outcomes of this intensive clinical scenario.

Reduction in pain: Is it worth the gain? The effect of opioids on the GI tract

The use of opioid medications for acute and chronic pain has increased significantly in the past 20 years in the United States. Given the high density of opioid receptors in the gastrointestinal tract, side effects are common in these patients including constipation, dysphagia, bloating, nausea, and vomiting. These side effects, which are experienced by most patients who take opioids, can lead to significant impairment in quality of life. Unlike other side effects from opioids, gastrointestinal side effects do not diminish with continued use, often leading patients to reduce or discontinue their opioid treatment to relieve these side effects. Therefore, physicians must be aware and anticipate potential side effects in patients receiving opioids to ensure appropriate pain management.

Analgesic Efficacy and Safety of Prolonged-Release Oxycodone/Naloxone in Korean Patients with Chronic Pain from Spinal Disorders

Background

A prolonged-release formulation of oxycodone/naloxone has been shown to be effective in European populations for the management of chronic moderate to severe pain. However, no clinical data exist for its use in Korean patients. The objective of this study was to assess efficacy and safety of prolonged-release oxycodone/naloxone in Korean patients for management of chronic moderate-to-severe pain.

Methods

In this multicenter, single-arm, open-label, phase IV study, Korean adults with moderate-to-severe spinal disorder-related pain that was not satisfactorily controlled with weak opioids and nonsteroidal anti-inflammatory drugs received prolonged-release oral oxycodone/naloxone at a starting dose of 10/5 mg/day (maximum 80/40 mg/day) for 8 weeks. Changes in pain intensity and quality of life (QoL) were measured using a numeric rating scale (NRS, 0–10) and the Korean-language EuroQol-five dimensions questionnaire, respectively.

Results

Among 209 patients assessed for efficacy, the mean NRS pain score was reduced by 25.9% between baseline and week 8 of treatment (p < 0.0001). There was also a significant improvement in QoL from baseline to week 8 (p < 0.0001). The incidence of adverse drug reactions was 27.7%, the most common being nausea, constipation, and dizziness; 77.9% of these adverse drug reactions had resolved or were resolving at the end of the study.

Conclusions

Prolonged-release oxycodone/naloxone provided significant and clinically relevant reductions in pain intensity and improved QoL in Korean patients with chronic spinal disorders. (ClinicalTrials.gov identifier: NCT01811238)

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.

European Pain Federation position paper on appropriate opioid use in chronic pain management

Poorly controlled pain is a global public health issue. The personal, familial and societal costs are immeasurable. Only a minority of European patients have access to a comprehensive specialist pain clinic. More commonly the responsibility for chronic pain management and initiating opioid therapy rests with the primary care physician and other non‐specialist opioid prescribers. There is much confusing and conflicting information available to non‐specialist prescribers regarding opioid therapy and a great deal of unjustified fear is generated. Opioid therapy should only be initiated by competent clinicians as part of a multi‐faceted treatment programme in circumstances where more simple measures have failed. Throughout, all patients must be kept under close clinical surveillance. As with any other medical therapy, if the treatment fails to yield the desired results and/or the patient is additionally burdened by an unacceptable level of adverse effects, the overall management strategy must be reviewed and revised. No responsible clinician will wish to pursue a failed treatment strategy or persist with an ineffective and burdensome treatment. In a considered attempt to empower and inform non‐specialist opioid prescribers, EFIC convened a European group of experts, drawn from a diverse range of basic science and relevant clinical disciplines, to prepare a position paper on appropriate opioid use in chronic pain. The expert panel reviewed the available literature and harnessed the experience of many years of clinical practice to produce these series of recommendations. Its success will be judged on the extent to which it contributes to an improved pain management experience for chronic pain patients across Europe.

Significance

This position paper provides expert recommendations for primary care physicians and other non‐ specialist healthcare professionals in Europe, particularly those who do not have ready access to specialists in pain medicine, on the safe and appropriate use of opioid medications as part of a multi‐faceted approach to pain management, in properly selected and supervised patients.

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.

Opioid-Induced Constipation and Bowel Dysfunction: A Clinical Guideline

OBJECTIVE

To formulate timely evidence-based guidelines for the management of opioid-induced bowel dysfunction.

SETTING

Constipation is a major untoward effect of opioids. Increasing prescription of opioids has correlated to increased incidence of opioid-induced constipation. However, the inhibitory effects of opioids are not confined to the colon, but also affect higher segments of the gastrointestinal tract, leading to the coining of the term "opioid-induced bowel dysfunction."

METHODS

A literature search was conducted using Medline, EMBASE, and EMBASE Classic, and the Cochrane Central Register of Controlled Trials. Predefined search terms and inclusion/exclusion criteria were used to identify and categorize relevant papers. A series of statements were formulated and justified by a comment, then labeled with the degree of agreement and their level of evidence as judged by the Strength of Recommendation Taxonomy (SORT) system.

RESULTS

From a list of 10,832 potentially relevant studies, 33 citations were identified for review. Screening the reference lists of the pertinent papers identified additional publications. Current definitions, prevalence, and mechanism of opioid-induced bowel dysfunction were reviewed, and a treatment algorithm and statements regarding patient management were developed to provide guidance on clinical best practice in the management of patients with opioid-induced constipation and opioid-induced bowel dysfunction.

CONCLUSIONS

In recent years, more insight has been gained in the pathophysiology of this "entity"; new treatment approaches have been developed, but guidelines on clinical best practice are still lacking. Current knowledge is insufficient regarding management of the opioid side effects on the upper gastrointestinal tract, but recommendations can be derived from what we know at present.

Opioids in Gastroenterology: Treating Adverse Effects and Creating Therapeutic Benefits

The use of opioid medications on both an acute and chronic basis is ubiquitous in the United States. As opioid receptors densely populate the gastrointestinal tract, symptoms and side effects can be expected in these patients. In the esophagus, dysmotility may result, manifesting with dysphagia and a syndrome indistinguishable from primary achalasia. In the stomach, a marked delay in gastric emptying may occur with postprandial nausea and early satiety. Postoperatively, particularly with abdominal surgery, opioid-induced ileus may ensue. In the colon, opioid-induced constipation is common. A unique syndrome termed narcotic bowel syndrome is characterized by chronic abdominal pain often accompanied by nausea and vomiting in the absence of other identifiable causes. With the recognition of the important role of opioids on gastrointestinal function, novel drugs have been developed that use this physiology. These medications include peripheral acting opioid agonists to treat opioid-induced constipation and combination agonist and antagonists used for diarrhea-predominant irritable bowel syndrome. This review summarizes the most recent data in these areas.

A phase III randomized controlled study on the efficacy and improved bowel function of prolonged-release (PR) oxycodone-naloxone (up to 160/80 mg daily) vs oxycodone PR

BACKGROUND

Oxycodone/naloxone (OXN PR) is a prolonged-release formulation containing oxycodone and naloxone in a 2:1 ratio. This study aimed to evaluate the tolerability and efficacy of doses up to OXN160/80 mg PR compared with oxycodone prolonged-release formulation (OxyPR) in a randomised controlled trial.

METHODS

Two hundred and forty-three patients were randomised to treatment with OXN PR (n = 123) or OxyPR (n = 120) during the 5-week double-blind study. Measured were: opioid-induced constipation [bowel function index score (BFI)]; analgesic efficacy (NRS 0-10); daily laxative rescue medication use; rescue medication use, and the number of complete spontaneous bowel movements (CSBMs) per week. A subanalysis was conducted in cancer patients.

RESULTS

Greater reductions in mean BFI scores were reported for the OXN PR group compared with OxyPR from Week 1 onwards; at Week 5 the mean change from baseline was -32.5 versus -14.2. Average 24-h pain scores were low and remained stable in the range 3-4 in both treatment groups. Analgesic rescue medication use was similar between the groups. Patients receiving OXN PR used significantly lower mean daily doses of laxative rescue medication than those receiving OxyPR (P = 0.006). The number of CSBM in the OXN PR group approximately doubled compared with a 25% decrease in the OxyPR group. Comparable results to the total study population were reported in the cancer patient subgroup.

CONCLUSIONS

OXN PR in daily doses of up to 160/80 mg significantly improves bowel function compared with equivalent doses of OxyPR while still providing comparable analgesic efficacy.

SIGNIFICANCE

Effective analgesia can be achieved using oxycodone/naloxone PR up to 160/80 mg daily without compromising bowel function. A similar outcome was reported in cancer and non-cancer patients.

Long-term efficacy and safety of oxycodone-naloxone prolonged-release formulation (up to 180/90 mg daily) - results of the open-label extension phase of a phase III multicenter, multiple-dose, randomized, controlled study

Background

The inclusion of naloxone with oxycodone in a fixed combination prolonged‐release formulation (OXN PR) improves bowel function compared with oxycodone (Oxy) alone without compromising analgesic efficacy. In a recent 5‐week, randomized, double‐blind comparative trial of OXN PR and OxyPR, it could be shown that the beneficial properties of OXN PR extend to doses up to 160/80 mg.

Methods

Bowel function, pain, quality of life (QoL) and safety of OXN PR up to 180/90 mg daily were evaluated in a 24‐week open‐label extension phase of the 5‐week randomized comparative study in patients with non‐malignant or malignant pain requiring opioids and suffering from opioid‐induced constipation.

Results

During treatment with a mean (SD) daily dose OXN PR of 130.7 (26.56) mg (median, maximum: 120 and 180 mg), the Bowel Function Index (BFI) decreased from 45.3 (26.37) to 26.7 (21.37) with the largest decrease seen in the first week. The average pain over the last 24 h remained stable (median Pain Intensity Scale score 4.0) and QoL was maintained throughout the study. Adverse events were consistent with the known effects of OXN PR and no new safety concerns emerged. Equivalent efficacy and safety benefits were observed in cancer patients.

Conclusions

The OXN PR in doses up to 180/90 mg provides effective analgesia with maintenance of bowel function during long‐term treatment. The beneficial effects of such dose levels of OXN PR contribute to stable patient‐reported QoL and health status despite serious underlying pain conditions, such as cancer.

Significance

In patients with pain requiring continuous opioid therapy at doses above 80 mg of oxycodone, stable and effective long‐term analgesia can be achieved using OXN PR up to 180/90 mg daily without compromising bowel function and may be preferential to supplemental oxycodone.

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.

The efficacy of standard laxative use for the prevention and treatment of opioid induced constipation during oxycodone use: a small Dutch observational pilot study

BACKGROUND

Dutch clinical guidelines recommend that a standard laxative treatment (SLT) should be prescribed concomitantly when starting opioid treatment to prevent opioid-induced constipation (OIC).

METHODS

Clinical evidence for SLT in the treatment of OIC is lacking, therefore an observational pilot study was performed to explore the efficacy and tolerability of SLT on OIC in patients treated with the opioid oxycodone.

RESULTS

Twenty-four patients (58% female, median (range) age 65 (39-92)) were included in this pilot study. The analysis showed that 9 out of 21 patients (43%) were non-responders to SLT. When also taking into consideration patients tending to develop diarrhea 75% of patients are non-responsive to SLT.

CONCLUSION

This pilot study indicates that optimal laxative therapy (SLT) might not be effective and feasible for the prevention and treatment of OIC.

Treatment of Severe Pain and Opioid-induced Constipation: An Observational Study of Quality of Life, Resource Use, and Costs in Sweden

INTRODUCTION

Opioid-induced constipation (OIC) is a common and costly side effect of opioid treatment affecting patients' quality of life (QoL). The combination oxycodone/naloxone reduces OIC while providing effective analgesia in patients with moderate to severe pain. The objective of this observational study was to compare health-related quality of life (HRQoL), healthcare resource use, and costs in patients with severe pain who were initially treated with oxycodone and laxatives and then subsequently switched to treatment with oxycodone/naloxone.

METHODS

Data were collected by means of questionnaires completed by patients with OIC before and after the initiation of oxycodone/naloxone treatment at different clinical centers in Sweden. The questionnaires included questions on healthcare resource use and absence from work and also consisted of the Patient Assessment of Constipation-QoL (PAC-QoL) instrument, the EuroQol five dimensions questionnaire (EQ-5D), the Patient Assessment of Constipation Symptoms (PAC-SYM) instrument, and the Bowel Function Index (BFI).

RESULTS

The analysis included 37 patients. Resource utilization was lower after treatment with oxycodone/naloxone, in terms of both the number of healthcare contacts and the purchases of medicine for the treatment of constipation. According to the BFI score, patients had fewer problems with OIC after the initiation of oxycodone/naloxone. The PAC-QoL score showed a positive change for patients in both the 96-point dissatisfaction index and the 16-point satisfaction index. PAC-SYM scores was lower after the initiation of oxycodone/naloxone treatment, indicating fewer constipation-related problems.

CONCLUSION

Treatment with oxycodone/naloxone had an overall positive effect on patients, consisting mainly of decreasing the severity of the constipation problems, increasing HRQoL, and decreasing the use of healthcare resources.

FUNDING

Mundipharma AB, Gothenburg, Sweden.

Oxycodone for neuropathic pain in adults

BACKGROUND

This is an update of an earlier review that considered both neuropathic pain and fibromyalgia (Issue 6, 2014), which has now been split into separate reviews for the two conditions. This review considers neuropathic pain only.Opioid drugs, including oxycodone, are commonly used to treat neuropathic pain, and are considered effective by some professionals. Most reviews have examined all opioids together. This review sought evidence specifically for oxycodone, at any dose, and by any route of administration. Separate reviews consider other opioids.

OBJECTIVES

To assess the analgesic efficacy and adverse events of oxycodone for chronic neuropathic pain in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE from inception to 6 November 2013 for the original review and from January 2013 to 21 December 2015 for this update. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries. This update differs from the earlier review in that we have included studies using oxycodone in combination with naloxone, and oxycodone used as add-on treatment to stable, but inadequate, treatment with another class of drug.

SELECTION CRITERIA

We included randomised, double-blind studies of two weeks' duration or longer, comparing any dose or formulation of oxycodone with placebo or another active treatment in chronic neuropathic pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. Where pooled analysis was possible, we used dichotomous data to calculate risk ratio and numbers needed to treat for one additional event, using standard methods.We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table.

MAIN RESULTS

The updated searches identified one additional published study, and one clinical trial registry report. We included five studies reporting on 687 participants; 637 had painful diabetic neuropathy and 50 had postherpetic neuralgia. Two studies used a cross-over design and three used a parallel group design; all studies used a placebo comparator, although one study used an active placebo (benztropine). Modified-release oxycodone (oxycodone MR) was titrated to effect and tolerability. One study used a fixed dose combination of oxycodone MR and naloxone. Two studies added oxycodone therapy to ongoing, stable treatment with either pregabalin or gabapentin. All studies had one or more sources of potential major bias.No study reported the proportion of participants experiencing 'substantial benefit' (at least 50% pain relief or who were very much improved). Three studies (537 participants) in painful diabetic neuropathy reported outcomes equivalent to 'moderate benefit' (at least 30% pain relief or who were much or very much improved), which was experienced by 44% of participants with oxycodone and 27% with placebo (number needed to treat for one additional beneficial outcome (NNT) 5.7).All studies reported group mean pain scores at the end of treatment. Three studies reported a greater pain intensity reduction and better patient satisfaction with oxycodone MR alone than with placebo. There was a similar result in the study adding oxycodone MR to stable, ongoing gabapentin, but adding oxycodone MR plus naloxone to stable, ongoing pregabalin did not show any additional effect.More participants experienced adverse events with oxycodone MR alone (86%) than with placebo (63%); the number needed to treat for an additional harmful outcome (NNH) was 4.3. Serious adverse events (oxycodone 3.4%, placebo 7.0%) and adverse event withdrawals (oxycodone 11%, placebo 6.4%) were not significantly different between groups. Withdrawals due to lack of efficacy were less frequent with oxycodone MR (1.1%) than placebo (11%), with a number needed to treat to prevent one withdrawal of 10. The add-on studies reported similar results.We downgraded the quality of the evidence to very low for all outcomes, due to limitations in the study methods, heterogeneity in the pain condition and study methods, and sparse data.

AUTHORS' CONCLUSIONS

There was only very low quality evidence that oxycodone (as oxycodone MR) is of value in the treatment of painful diabetic neuropathy or postherpetic neuralgia. There was no evidence for other neuropathic pain conditions. Adverse events typical of opioids appeared to be common.

New Options in Constipation Management

Constipation is common in the general population and for those on opioids and/or who are suffering from advanced cancer. Self-management consists of dietary changes, exercise, and laxatives. However, responses to self-management efforts are often inadequate to relieve the subjective and objective experience of constipation. Multiple new anti-constipating medications have recently been tested in randomized trials and the following are available commercially: probiotics, prucalopride, lubiprostone, linaclotide, elobixibat, antidepressants, methylnaltrexone, alvimopan, and naloxegol. This review will discuss the evidence-based benefits of these medications and outline an approach to managing constipation.

The Clinical Applications of Extended-Release Abuse-Deterrent Opioids

Opioids are the mainstay for treatment of acute pain and cancer pain, and also have a role in the treatment of chronic non-malignant pain. There has been, however, a growing public health problem stemming from the misuse of opioid analgesics leading to serious consequences. To deter abuse, new formulations of extended-release opioid analgesics and tamper-resistant opioids have recently been developed. The concept of abuse-deterrent extended-release opioids is relatively new and, although abuse may not be completely prevented, the utilization of such abuse-deterrent extended-release opioids could reduce this risk. Extended-release abuse-deterrent opioids have been found to have important clinical applications in cancer, acute pain, and chronic non-malignant pain for analgesia control with decreased incidence of tampering and abuse. In this review, different extended-release formulations of opioids available for clinical applications are presented with descriptions of the formulations, their physical properties, and the clinical studies performed to provide physicians with a better understanding of their uses.

Opioid-Induced Constipation among a Convenience Sample of Patients with Cancer Pain

BACKGROUND

Little is known regarding the burden of opioid-induced constipation (OIC) among patients who suffer from cancer-related pain.

METHODS

A prospective longitudinal study was conducted among cancer patients in the United Kingdom (UK), Canada, and Germany, which included medical record data abstraction, Internet-based patient surveys, and physician surveys. Patients on daily opioid therapy (≥30 mg for ≥4 weeks) for treatment of cancer pain with self-reported OIC were recruited. Response to laxatives was defined by classifying participants into categories of laxative use and evaluating the prevalence of inadequate response. Descriptive statistics were used to evaluate outcomes, including the patient assessment of constipation-symptom (PAC-SYM), patient assessment of constipation-quality of life, EuroQOL-5 dimensions, and global assessment of treatment benefit, satisfaction, and willingness to continue.

RESULTS

Recruitment was difficult for this study with only 31 participants completing the baseline survey and meeting criteria for opioid use and OIC (26 UK, 1 Canada, and 4 Germany). Fifty-two percent (n = 16) of participants were male, and all were White. Breast (23%, n = 7), pancreatic (13%, n = 4), and multiple myeloma (13%, n = 4) were the most common cancers. Mean duration of chronic pain and opioid use were 2.3 and 1.3 years, respectively. Participants reported having a mean of 4.4 bowel movements/week in the 2 weeks prior to baseline, of which a mean of 0.9 were spontaneous. Most participants (90%, n = 28) were using at least 1 lifestyle approach to manage their constipation; 65% (n = 20) were taking ≥1 over-the-counter laxative; 19% (n = 6) were taking ≥1 prescription laxative; 23% (n = 7) reported no laxative use in the prior 2 weeks. Moderate-to-severe constipation symptoms on the PAC-SYM were common, and mean scores on health-related quality of life outcomes were comparable to chronic pain populations.

CONCLUSION

In this primarily UK sample, there appears to be considerable unmet OIC treatment needs among cancer patients.

Switching to low-dose oral prolonged-release oxycodone/naloxone from WHO-Step I drugs in elderly patients with chronic pain at high risk of early opioid discontinuation

PURPOSE

Chronic pain has a high prevalence in the aging population. Strong opioids also should be considered in older people for the treatment of moderate to severe pain or for pain that impairs functioning and the quality of life. This study aimed to assess the efficacy and safety of the direct switch to low-dose strong opioids (World Health Organization-Step III drugs) in elderly, opioid-naive patients.

PATIENTS AND METHODS

This was a single-center, retrospective, observational study in opioid-naive patients aged ≥75 years, with moderate to severe chronic pain (>6-month duration) and constipation, who initiated treatment with prolonged-release oxycodone/naloxone (OXN-PR). Patients were re-evaluated after 15, 30, and 60 days (T60, final observation). Response to treatment was defined as an improvement in pain of ≥30% after 30 days of therapy without worsening of constipation.

RESULTS

One-hundred and eighty-six patients (mean ± SD age 80.7±4.7 years; 64.5% women) with severe chronic pain (mean average pain intensity 7.1±1.0 on the 11-point numerical rating scale) and constipation (mean Bowel Function Index 64.1±24.4; 89.2% of patients on laxatives) were initiated treatment with OXN-PR (mean daily dose 11.3±3.5 mg). OXN-PR reduced pain intensity rapidly and was well tolerated; 63.4% of patients responded to treatment with OXN-PR. At T60 (mean daily OXN-PR dose, 21.5±9.7 mg), the pain intensity was reduced by 66.7%. In addition, bowel function improved (mean decrease of Bowel Function Index from baseline to T60, -28.2, P<0.0001) and the use of laxatives decreased. Already after 15 days and throughout treatment, ~70% of patients perceived their status as much/extremely improved. Only 1.6% of patients discontinued treatment due to adverse events.

CONCLUSION

Low-dose OXN-PR in elderly patients naive to opioids proved to be an effective option for the treatment of moderate to severe chronic pain. Large-scale trials are needed to improve clinical guidance in the assessment and treatment of pain in older people.

Oxycodone and Naloxone Combination: A 12-Week Follow-up in 20 Patients Shows Effective Analgesia Without Opioid-Induced Bowel Dysfunction

Introduction

Opioid analgesics are widely regarded to be highly effective but are equally known for their side effects on the bowel. A new combination of the opioid analgesic oxycodone and naloxone has been developed to combat opioid-induced bowel dysfunction (OIBD) whilst still being effective as an analgesic. The aim of this observational study was to assess the analgesic efficacy of this new combination and to analyze its effect on bowel function.

Methods

Twenty-six patients underwent a trial of this new combination, with 21 patients reaching week 8 and 18 reaching week 12.

Results

A significant reduction was seen in the pain severity score at weeks 4, 8, and 12 (P < 0.05), and a significant improvement in the bowel function index was again seen at these points (P < 0.001 at week 4 and 12, P < 0.05 at week 8). In the patients’ global impression of change, 83.3% of patients rated the new medication as an improvement compared to their previous regimen, and 87.5% rated it overall as “good” or “very good.”

Conclusion

This small single-center study suggests that the use of ONC in selected patients could lead to an improvement in pain severity and pain interference with a significant improvement in OIBD. Compliance with the combination is good, and it is generally well tolerated.

Long-term efficacy and safety of oxycodone-naloxone prolonged release in geriatric patients with moderate-to-severe chronic noncancer pain: a 52-week open-label extension phase study

BACKGROUND

Two-thirds of older people suffer from chronic pain and finding valid treatment options is essential. In this 1-yearlong investigation, we evaluated the efficacy and safety of prolonged-release oxycodone-naloxone (OXN-PR) in patients aged ≥70 (mean 81.7) years.

METHODS

In this open-label prospective study, patients with moderate-to-severe noncancer chronic pain were prescribed OXN-PR for 1 year. The primary endpoint was the proportion of patients who achieved ≥30% reduction in pain intensity after 52 weeks of treatment, without worsening bowel function. The scheduled visits were at baseline (T0), after 4 weeks (T4), and after 52 weeks (T52).

RESULTS

Fifty patients completed the study. The primary endpoint was achieved in 78% of patients at T4 and 96% at T52 (P<0.0001). Pain intensity, measured on a 0-10 numerical rating scale, decreased from 6.0 at T0 to 2.8 at T4 and to 1.7 at T52 (P<0.0001). Mean daily dose of oxycodone increased from 10 to 14.4 mg (T4) and finally to 17.4 mg (T52). Bowel Function Index from 35.1 to 28.7 at T52. No changes were observed in cognitive functions (Mini-Mental State Examination evaluation), while daily functioning improved (Barthel Index from 53.1 to 61.0, P<0.0001). The Screener and Opioid Assessment for Patients with Pain-Revised score at 52 weeks was 2.6 (standard deviation 1.6), indicating a low risk of aberrant medication-related behavior. In general, OXN-PR was well tolerated.

CONCLUSION

This study of the long-term treatment of chronic pain in a geriatric population with OXN-PR shows satisfying analgesic effects achieved with a stable low daily dose, coupled with a good safety profile and, in particular, with a reduction of constipation, often present during opioid therapy. Our findings support the indications of the American Geriatrics Society, suggesting the use of opioids to treat pain in older people not responsive to acetaminophen or nonsteroidal anti-inflammatory drugs.

Impact of prolonged-release oxycodone/naloxone on outcomes affecting patients' daily functioning in comparison with extended-release tapentadol: a systematic review

PURPOSE

The objective of this systematic review was to assess the clinical efficacy, safety, tolerability, and health-related quality of life outcomes associated with management of moderate-to-severe chronic pain with oxycodone/naloxone and tapentadol, focusing on the effect of these treatments on patients' daily functioning.

METHODS

Literature from a wide range of sources, including Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials, was searched to identify randomized controlled trials investigating tapentadol or oxycodone/naloxone for the treatment of patients with chronic pain. A network meta-analysis was conducted to determine the relative efficacy and safety profiles of these treatments.

FINDINGS

Oxycodone/naloxone was significantly better than tapentadol with respect to the Patient Assessment of Constipation Symptoms total score (risk ratio = -3.60; 95% credible interval, -5.36 to -2.11) and revealed a significantly lower risk of dizziness (risk ratio = 0.72; 95% credible interval, 0.42-0.98). Oxycodone/naloxone was directionally favored, although not significantly superior to tapentadol for headache, fatigue, dry mouth, dyspepsia, and withdrawals due to lack of efficacy. For the AE outcomes of constipation, nausea, and vomiting, as well as pain efficacy and all-cause withdrawals from studies, tapentadol was directionally favored without any statistical difference from oxycodone/naloxone. However, the two treatments were not wholly comparable for the evaluation of pain efficacy because of differences in on-study rescue medication and a higher baseline pain severity in the tapentadol studies.

IMPLICATIONS

Oxycodone/naloxone offers significant improvements in Patient Assessment of Constipation Symptoms total score and dizziness and was directionally favored for fatigue and headache compared with extended-release tapentadol, which may translate to improved patient daily functioning and health-related quality of life.

Definition, diagnosis and treatment strategies for opioid-induced bowel dysfunction–Recommendations of the Nordic Working Group

Background and aims

Opioid-induced bowel dysfunction (OIBD) is an increasing problem due to the common use of opioids for pain worldwide. It manifests with different symptoms, such as dry mouth, gastro-oesophageal reflux, vomiting, bloating, abdominal pain, anorexia, hard stools, constipation and incomplete evacuation. Opioid-induced constipation (OIC) is one of its many symptoms and probably the most prevalent. The current review describes the pathophysiology, clinical implications and treatment of OIBD.

Methods

The Nordic Working Group was formed to provide input for Scandinavian specialists in multiple, relevant areas. Seven main topics with associated statements were defined. The working plan provided a structured format for systematic reviews and included instructions on how to evaluate the level of evidence according to the GRADE guidelines. The quality of evidence supporting the different statements was rated as high, moderate or low. At a second meeting, the group discussed and voted on each section with recommendations (weak and strong) for the statements.

Results

The literature review supported the fact that opioid receptors are expressed throughout the gastrointestinal tract. When blocked by exogenous opioids, there are changes in motility, secretion and absorption of fluids, and sphincter function that are reflected in clinical symptoms. The group supported a recent consensus statement for OIC, which takes into account the change in bowel habits for at least one week rather than focusing on the frequency of bowel movements. Many patients with pain receive opioid therapy and concomitant constipation is associated with increased morbidity and utilization of healthcare resources. Opioid treatment for acute postoperative pain will prolong the postoperative ileus and should also be considered in this context. There are no available tools to assess OIBD, but many rating scales have been developed to assess constipation, and a few specifically address OIC. A clinical treatment strategy for OIBD/OIC was proposed and presented in a flowchart. First-line treatment of OIC is conventional laxatives, lifestyle changes, tapering the opioid dosage and alternative analgesics. Whilst opioid rotation may also improve symptoms, these remain unalleviated in a substantial proportion of patients. Should conventional treatment fail, mechanism-based treatment with opioid antagonists should be considered, and they show advantages over laxatives. It should not be overlooked that many reasons for constipation other than OIBD exist, which should be taken into consideration in the individual patient.

Conclusion and implications

It is the belief of this Nordic Working Group that increased awareness of adverse effects and OIBD, particularly OIC, will lead to better pain treatment in patients on opioid therapy. Subsequently, optimised therapy will improve quality of life and, from a socio-economic perspective, may also reduce costs associated with hospitalisation, sick leave and early retirement in these patients.

Opioid-induced constipation: advances and clinical guidance

Currently opioids are the most frequently used medications for chronic noncancer pain. Opioid-induced constipation is the most common adverse effect associated with prolonged use of opioids, having a major impact on quality of life. There is an increasing need to treat opioid-induced constipation. With the recent approval of medications for the treatment of opioid-induced constipation, there are several therapeutic approaches. This review addresses the clinical presentation and diagnosis of opioid-induced constipation, barriers to its diagnosis, effects of opioids in the gastrointestinal tract, differential tolerance to opiates in different gastrointestinal organs, medications approved and in development for the treatment of opioid-induced constipation, and a proposed clinical management algorithm for treating opioid-induced constipation in patients with noncancer pain.

Reproducible Research Practices and Transparency across the Biomedical Literature

There is a growing movement to encourage reproducibility and transparency practices in the scientific community, including public access to raw data and protocols, the conduct of replication studies, systematic integration of evidence in systematic reviews, and the documentation of funding and potential conflicts of interest. In this survey, we assessed the current status of reproducibility and transparency addressing these indicators in a random sample of 441 biomedical journal articles published in 2000–2014. Only one study provided a full protocol and none made all raw data directly available. Replication studies were rare (n = 4), and only 16 studies had their data included in a subsequent systematic review or meta-analysis. The majority of studies did not mention anything about funding or conflicts of interest. The percentage of articles with no statement of conflict decreased substantially between 2000 and 2014 (94.4% in 2000 to 34.6% in 2014); the percentage of articles reporting statements of conflicts (0% in 2000, 15.4% in 2014) or no conflicts (5.6% in 2000, 50.0% in 2014) increased. Articles published in journals in the clinical medicine category versus other fields were almost twice as likely to not include any information on funding and to have private funding. This study provides baseline data to compare future progress in improving these indicators in the scientific literature.

Examination of recent trends in reproducibility and transparency practices in biomedical research reveals an ongoing lack of access to full datasets and detailed protocols for both clinical and non-clinical studies.

There is increasing interest in the scientific community about whether published research is transparent and reproducible. Lack of replication and non-transparency decreases the value of research. Several biomedical journals have started to encourage or require authors to submit detailed protocols, full datasets, and disclose information on funding and potential conflicts of interest. In this study, we investigate the reproducibility and transparency practices across the full spectrum of published biomedical literature from 2000–2014. We identify an ongoing lack of access to full datasets and detailed protocols for both clinical and non-clinical biomedical investigation. We also map the availability of information on funding and conflicts of interest in this literature. The results from this study provide baseline data to compare future progress in improving these indicators in the scientific literature. We believe that this information may be essential to sensitize stakeholders in science about the need for improving reproducibility and transparency practices.

Cost-effectiveness analysis of oxycodone with naloxone versus oxycodone alone for the management of moderate-to-severe pain in patients with opioid-induced constipation in Canada

BACKGROUND

Approximately 20-30% of Canadians suffer from chronic pain. Guidelines for the management of chronic pain support the use of controlled-release (CR) opioids to treat chronic pain. Although effective in managing chronic pain, oxycodone is associated with high rates of opioid-induced constipation (OIC). The cost-effectiveness of a combination of oxycodone for the management of pain and naloxone for the relief of OIC has not previously been evaluated for Canada.

METHODS

A decision analytic model was developed to estimate the cost-utility of combination oxycodone/naloxone compared to oxycodone alone in four populations. Drug costs for managing pain and healthcare costs related to managing OIC were included in the analysis and the primary measure of effectiveness was quality adjusted life years (QALYs) derived from OIC rates observed in clinical trials. The analysis was conducted from a healthcare system perspective, used a 1-year time horizon, and results were expressed in 2015 Canadian dollars.

RESULTS

In all four patient populations, there was a trade-off between slightly higher total expected costs for Targin treated patients compared to oxycodone treated patients, but also improved clinical benefits in terms of reduced OIC, which resulted in higher QALYs for patients. Although analgesic costs were found to be slightly higher for Targin treated patients, Targin also resulted in cost offsets to the healthcare system in terms of less rescue laxative drug use and other resources required for the management of OIC. The resulting 1-year cost-utility of Targin compared to oxycodone ranged from $2178-$7732 per QALY gained in the base case analysis, and it was found that these cost-utility results remained robust and at low values throughout a series of one-way deterministic analyses of uncertainty.

CONCLUSION

The clinical effectiveness of oxycodone/naloxone in managing pain and OIC compared to CR oxycodone alone resulted in low cost-utility estimates.

Intractable restless legs syndrome: role of prolonged-release oxycodone-naloxone

Restless legs syndrome (RLS) is a common neurological disorder characterized by an irresistible urge to move the legs accompanied by uncomfortable sensations that occur at night or at time of rest. Pharmacological therapy should be limited to patients who suffer from clinically relevant symptoms. Chronic RLS is usually treated with either a dopamine agonist (pramipexole, ropinirole, rotigotine) or an α2δ calcium-channel ligand (gabapentin, gabapentin enacarbil, pregabalin). Augmentation is the main complication of long-term dopaminergic treatment, and frequently requires a reduction of current dopaminergic dose or a switch to non-dopaminergic medications. Opioids as monotherapy or add-on treatment should be considered when alternative satisfactory regimens are unavailable and the severity of symptoms warrants it. In a recent Phase III trial, oxycodone-naloxone prolonged release (PR) demonstrated a significant and sustained effect on patients with severe RLS inadequately controlled by previous treatments. The adverse-event profile was consistent with the safety profile of opioids. The most frequent adverse events were fatigue, constipation, nausea, headache, hyperhidrosis, somnolence, dry mouth, and pruritus. Adverse events were usually mild or moderate in intensity. No cases of augmentation were reported. Oxycodone-naloxone PR is approved for the second-line symptomatic treatment of adults with severe to very severe idiopathic RLS after failure of dopaminergic treatment. Further studies are needed to evaluate if oxycodone-naloxone PR is equally efficacious as a first-line treatment. Moreover, long-term comparative studies between opioids, dopaminergic drugs and α2δ ligands are needed.