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

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.

Consensus Recommendations on Initiating Prescription Therapies for Opioid-Induced Constipation

Objective

Aims of this consensus panel were to determine (1) an optimal symptom‐based method for assessing opioid‐induced constipation in clinical practice and (2) a threshold of symptom severity to prompt consideration of prescription therapy.

Methods

A multidisciplinary panel of 10 experts with extensive knowledge/experience with opioid‐associated adverse events convened to discuss the literature on assessment methods used for opioid‐induced constipation and reach consensus on each objective using the nominal group technique.

Results

Five validated assessment tools were evaluated: the Patient Assessment of Constipation–Symptoms (PAC‐SYM), Patient Assessment of Constipation–Quality of Life (PAC‐QOL), Stool Symptom Screener (SSS), Bowel Function Index (BFI), and Bowel Function Diary (BF‐Diary). The 3‐item BFI and 4‐item SSS, both clinician administered, are the shortest tools. In published trials, the BFI and 12‐item PAC‐SYM are most commonly used. The 11‐item BF‐Diary is highly relevant in opioid‐induced constipation and was developed and validated in accordance with US Food and Drug Administration guidelines. However, the panel believes that the complex scoring for this tool and the SSS, PAC‐SYM, and 28‐item PAC‐QOL may be unfeasible for clinical practice. The BFI is psychometrically validated and responsive to changes in symptom severity; scores range from 0 to 100, with higher scores indicating greater severity and scores >28.8 points indicating constipation.

Conclusions

The BFI is a simple assessment tool with a validated threshold of clinically significant constipation. Prescription treatments for opioid‐induced constipation should be considered for patients who have a BFI score of ≥30 points and an inadequate response to first‐line interventions.

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.

Evolving paradigms in the treatment of opioid-induced bowel dysfunction

In recent years prescription of opioids has increased significantly. Although effective in pain management, bothersome gastrointestinal adverse effects are experienced by a substantial proportion of opioid-treated patients. This can lead to difficulties with therapy and subsequently inadequate pain relief. Collectively referred to as opioid-induced bowel dysfunction, these adverse effects are the result of binding of exogenous opioids to opioid receptors in the gastrointestinal tract. This leads to disturbance of three important gastrointestinal functions: motility, coordination of sphincter function and secretion. In the clinic this manifests in a wide range of symptoms such as reflux, bloating, abdominal cramping, hard, dry stools, and incomplete evacuation, although the most known adverse effect is opioid-induced constipation. Traditional treatment with laxatives is often insufficient, but in recent years a number of novel pharmacological approaches have been introduced. In this review the pathophysiology, symptomatology and prevalence of opioid-induced bowel dysfunction is presented along with the benefits and caveats of a suggested consensus definition for opioid-induced constipation. Finally, traditional treatment is appraised and compared with the latest pharmacological developments. In conclusion, opioid antagonists restricted to the periphery show promising results, but use of different definitions and outcome measures complicate comparison. However, an international working group has recently suggested a consensus definition for opioid-induced constipation and relevant outcome measures have also been proposed. If investigators within this field adapt the suggested consensus and include symptoms related to dysfunction of the upper gut, it will ease comparison and be a step forward in future research.

Prolonged-release oxycodone-naloxone for treatment of severe pain in patients with Parkinson's disease (PANDA): a double-blind, randomised, placebo-controlled trial

BACKGROUND

Pain is a common non-motor symptom of Parkinson's disease. We investigated the analgesic efficacy of prolonged-release oxycodone-naloxone (OXN PR) in patients with Parkinson's disease and chronic, severe pain.

METHODS

We did this phase 2 study in 47 secondary care centres in the Czech Republic, Germany, Hungary, Poland, Romania, Spain, and the UK. We enrolled patients with Hoehn and Yahr Stage II-IV Parkinson's disease, at least one type of severe pain, and an average 24-h pain score of at least 6 (assessed on an 11-point rating scale from 0=no pain to 10=pain as bad as you can imagine). Participants were randomly assigned (1:1) with a validated automated system (block size four) to either oral OXN PR or placebo for 16 weeks (starting dose oxycodone 5 mg, naloxone 2·5 mg, twice daily). Patients and investigators were masked to treatment assignment. The primary endpoint was average 24-h pain score at 16 weeks in the full analysis population. This study is registered with EudraCT (2011-002901-31) and ClinicalTrials.gov (NCT01439100).

FINDINGS

We enrolled 202 patients; 93 were assigned to OXN PR and 109 to placebo; the full analysis population consisted of 88 patients versus 106 patients. Least squares mean average 24-h pain score at 16 weeks in the full analysis population was 5·0 (95% CI 4·5 to 5·5) in the OXN PR group versus 5·6 (5·1 to 6·0) in the placebo group (difference -0·6, 95% CI -1·3 to 0·0; p=0·058). Similar proportions of patients in each group had adverse events (60/92 [65%] vs 76/109 [70%]), treatment-related adverse events (52/92 [57%] vs 62/109 [57%]), and serious adverse events (5/92 [5%] vs 7/109 [6%]). Treatment-related nausea was more common in the OXN PR group than in the placebo group (16/92 [17%] vs 10/109 [9%]), as was treatment-related constipation (16/92 [17%] vs 6/109 [6%]).

INTERPRETATION

The primary endpoint, based on the full analysis population at week 16, was not significant. Nonetheless, the results of this study highlight the potential efficacy of OXN PR for patients with Parkinson's disease-related pain and might warrant further research on OXN PR in this setting.

FUNDING

Mundipharma Research.

Quality of life and healthcare resource in patients receiving opioids for chronic pain: a review of the place of oxycodone/naloxone

In patients managed with opioids for chronic pain, opioid-induced bowel dysfunction—specifically, opioid-induced constipation (OIC)—is a common side effect, which has a significant impact on quality of life (QoL). The most recent developments for management of OIC are opioid antagonists, including naloxone, a competitive antagonist of peripheral opioid receptors that reverses opioid-induced peripheral gastrointestinal (GI) effects. A prolonged-release formulation of naloxone is available in combination with oxycodone (OXN PR). To review the specific role of OXN PR in the management of chronic pain and OIC and its impact on QoL and healthcare costs, a review of available relevant literature was conducted. Healthcare costs can be up to ten times higher for patients with GI events than for those without. Assessment of QoL in patients with OIC is essential, and multiple tools for its evaluation are available. The Bowel Function Index (BFI), a tool that was specifically developed and validated to measure bowel function in patients with OIC, can be an indication of QoL. In patients with moderate-to-severe chronic pain, randomized trials have demonstrated that OXN PR has equal analgesic efficacy and safety, but results in improved bowel function, compared with prolonged-release oxycodone (Oxy PR) alone. In conclusion, randomized studies using the BFI, as well as real-world clinical practice observations, have demonstrated improved QoL for patients taking OXN PR. This combination should allow more patients to benefit from the analgesic efficacy of opioid therapy and should minimize the side effects of constipation that correspond to improvements in QoL and healthcare offsets.

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.

Is oxycodone/naloxone effective and safe in managing chronic pain of a fragile elderly patient with multiple skin ulcers of the lower limbs? A case report

Skin ulcers are a common issue in the elderly, as physiological loss of skin elasticity, alterations in microcirculation, and concomitant chronic diseases typically occur in advanced age, thereby predisposing to these painful lesions. Wound-related pain is often associated with skin ulcers and negatively impacts both the patient's quality of life and, indirectly, wound healing. Pain management is an ongoing issue in the elderly, and remains underestimated and under-treated in this fragile population. Recent guidelines suggest the use of opioids as the frontline treatment of moderate and severe pain in nononcological pain in the elderly. However, due to the concerns of adverse reactions, drug interactions, and addiction, clinicians frequently hesitate to prescribe opioids. This case report describes an elderly diabetic patient with multiple ulcers of the lower limbs suffering wound-related pain. In our report, oxycodone/naloxone has proved to be an effective and safe drug, providing pain relief as well as increased compliance when redressing wounds and faster healing compared to that in similar patients. Our case provides anecdotal evidence, supported by other studies, to justify future, larger studies on chronic pain using this therapy.

Developments in managing severe chronic pain: role of oxycodone-naloxone extended release

Chronic pain is a highly disabling condition, which can significantly reduce patients’ quality of life. Prevalence of moderate and severe chronic pain is high in the general population, and it increases significantly in patients with advanced cancer and older than 65 years. Guidelines for the management of chronic pain recommend opioids for the treatment of moderate-to-severe pain in patients whose pain is not responsive to initial therapies with paracetamol and/or nonsteroidal anti-inflammatory drugs. Despite their analgesic efficacy being well recognized, adverse events can affect daily functioning and patient quality of life. Opioid-induced constipation (OIC) occurs in 40% of opioid-treated patients. Laxatives are the most common drugs used to prevent and treat OIC. Laxatives do not address the underlying mechanisms of OIC; for this reason, they are not really effective in OIC treatment. Naloxone is an opioid receptor antagonist with low systemic bioavailability. When administered orally, naloxone antagonizes the opioid receptors in the gut wall, while its extensive first-pass hepatic metabolism ensures the lack of antagonist influence on the central-mediated analgesic effect of the opioids. A prolonged-release formulation consisting of oxycodone and naloxone in a 2:1 ratio was developed trying to reduce the incidence of OIC maintaining the analgesic effect compared with use of the sole oxycodone. This review includes evidence related to use of oxycodone and naloxone in the long-term management of chronic non-cancer pain and OIC.

Chronic opioid induced constipation in patients with nonmalignant pain: challenges and opportunities

With the recent introduction and approval of medications directed at the treatment of opioid induced constipation (OIC) in patients with nonmalignant pain, there is increased interest and understanding of the unmet need and opportunities to enhance patient management. The high incidence of OIC is associated with rapid increase of narcotic analgesic prescriptions for nonmalignant chronic pain. This review addresses briefly the mechanisms of action of opioids that lead to OIC, the differential tolerance of gastrointestinal organs to the effects of opioids, the size and scope of the problem, the definition and outcome measures for OIC, current differential diagnosis and management algorithms, and the pharmacology and efficacy of treatments for OIC in patients with nonmalignant pain.

Treatment of failed back surgery syndrome in a forty-three-year-old man with high-dose oxycodone/naloxone

Introduction:

Failed back surgery syndrome (FBSS) is an increasing cause of chronic pain in most countries. This poses high costs to both patients and National Health Organizations.

Case Presentation:

In this report, multimodal pain management based on daily high-dose oxycodone/naloxone (OXN 180/90 mg) led to reduced patient's pain score and improved quality of life.

Conclusions:

Oxycodone/naloxone can be a good alternative for the management of FBSS when other interventional or pharmacologic strategies have failed. In this case report, higher doses than those recommended as a maximum daily ceiling (80/40 mg) were safely used in one selected patient with noncancer severe pain.

Emerging therapies for patients with symptoms of opioid-induced bowel dysfunction

Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal (GI) symptoms, including dry mouth, nausea, vomiting, gastric stasis, bloating, abdominal pain, and opioid-induced constipation, which significantly impair patients’ quality of life and may lead to undertreatment of pain. Traditional laxatives are often prescribed for OIBD symptoms, although they display limited efficacy and exert adverse effects. Other strategies include prokinetics and change of opioids or their administration route. However, these approaches do not address underlying causes of OIBD associated with opioid effects on mostly peripheral opioid receptors located in the GI tract. Targeted management of OIBD comprises purely peripherally acting opioid receptor antagonists and a combination of opioid receptor agonist and antagonist. Methylnaltrexone induces laxation in 50%–60% of patients with advanced diseases and OIBD who do not respond to traditional oral laxatives without inducing opioid withdrawal symptoms with similar response (45%–50%) after an oral administration of naloxegol. A combination of prolonged-release oxycodone with prolonged-release naloxone (OXN) in one tablet (a ratio of 2:1) provides analgesia with limited negative effect on the bowel function, as oxycodone displays high oral bioavailability and naloxone demonstrates local antagonist effect on opioid receptors in the GI tract and is totally inactivated in the liver. OXN in daily doses of up to 80 mg/40 mg provides equally effective analgesia with improved bowel function compared to oxycodone administered alone in patients with chronic non-malignant and cancer-related pain. OIBD is a common complication of long-term opioid therapy and may lead to quality of life deterioration and undertreatment of pain. Thus, a complex assessment and management that addresses underlying causes and patomechanisms of OIBD is recommended. Newer strategies comprise methylnaltrexone or OXN administration in the management of OIBD, and OXN may be also considered as a preventive measure of OIBD development in patients who require opioid administration.

Treatment with prolonged-release oxycodone/naloxone improves pain relief and opioid-induced constipation compared with prolonged-release oxycodone in patients with chronic severe pain and laxative-refractory constipation

PURPOSE

Laxative-refractory opioid-induced constipation (OIC) is defined as OIC despite using 2 laxatives with a different mechanism of action (based on the Anatomical Therapeutic Chemical Classification System level 4 term [contact laxatives, osmotically acting laxatives, softeners/emollients, enemas, and others]). OIC has a significant impact on the treatment and quality of life of patients with severe chronic pain. This noninterventional, observational, real-life study in Belgium investigated the efficacy of prolonged-release oxycodone/naloxone combination (PR OXN) treatment regarding pain relief and OIC compared with previous prolonged-release oxycodone (PR OXY) treatment for laxative-refractory OIC in daily clinical practice.

METHODS

Laxative-refractory OIC patients with severe chronic pain were treated with PR OXN for 12 weeks (3 visits). Pain relief (assessed on a numerical rating scale) and OIC (assessed by using the Bowel Function Index [BFI]) were evaluated at each visit. A responder was defined as a patient who had: (1) no worsening of pain at the last visit compared with visit 1 or a numerical rating scale ≤4 at visit 3/last visit; and (2) a reduction in BFI ≥12 units at visit 3/last visit compared with visit 1; or (3) a BFI ≤28.8 at visit 3/last visit.

FINDINGS

Sixty-eight laxative-refractory OIC patients with severe chronic pain (mean (sd) age 59.8 (13.3) years, 67.6% female and 91.2% non-malignant pain) were treated for 91 days with PR OXN (median daily dose, 20 mg). Treatment with PR OXN resulted in a significant and clinically relevant decrease of pain of 2.1 units (P < 0.001; 95% CI, 1.66-2.54) and of BFI by 48.5 units (P < 0.001; 95% CI, 44.4-52.7) compared with PR OXY treatment; use of laxatives was also significantly reduced (P < 0.001). Approximately 95% of patients were responders, and quality of life (as measured by using the EQ-5D) improved significantly. Adverse events were opioid related, and PR OXN treatment was well tolerated.

IMPLICATIONS

Treatment with PR OXN resulted in a significant and clinically relevant reduction in OIC compared with previous PR OXY treatment for these patients with severe chronic pain and laxative-refractory OIC. Treatment with PR OXN also resulted in a significant improvement in pain relief and quality of life. ClinicalTrials.gov identifier: NCT01710917.

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

BACKGROUND

Opioid-induced constipation (OIC) is the most prevalent patient complaint associated with opioid use and interferes with analgesic efficacy.

OBJECTIVES

This PROBE trial compares the overall safety and tolerability of oxycodone/naloxone (OXN) with those of traditional opioid therapy with oxycodone (OXY) or morphine (MOR) in the setting of the German healthcare system.

RESEARCH DESIGN AND METHODS

This was a prospective, randomized, open-label, blinded endpoint (PROBE) streamlined study (German pain study registry: 2012-0012-05; EudraCT: 2012-001317-16), carried out in 88 centers in Germany, where a total of 453 patients, requiring WHO step III opioids to treat low back pain, were randomized to OXN, OXY or MOR (1:1:1) for 3 months. The primary outcome was the percentage of patients without adverse event-related study discontinuations who presented with a combination of a ≥50% improvement of pain intensity, disability and quality-of-life and a ≤50% worsening of bowel function at study end.

RESULTS

Significantly more OXN patients met the primary endpoint (22.2%) vs. OXY (9.3%; OR: 2.80; p < 0.001) vs. MOR (6.3%; OR: 4.23; p < 0.001), with insignificant differences between OXY vs. MOR (p = 0.155). A ≥50% improvement of pain intensity, functional disability and quality-of-life has been found for OXN in 75.0/61.1/66.0% of patients and thus for all parameters significantly more than with OXY (58.9/49.0/48.3; p < 0.001 for each) or MOR (52.5/46.2/37.3; p < 0.001 for each). A total of 86.8% of OXN patients kept normal BFI scores during treatment, vs. 63.6% for OXY (p < 0.001) vs. 53.8% for MOR (p < 0.001). Overall 189 TEAEs (OXN: 45, OXY: 69, MOR: 75) in 92 patients (OXN: 21, OXY: 44, MOR: 37) occurred, most gastrointestinal (50.8%). One limitation is the open-label design, which presents the possibility of interpretive bias.

CONCLUSION

Under the conditions of this PROBE design, OXN was associated with a significantly better tolerability, a lower risk of OIC and a significantly better analgesic efficacy than OXY or MOR.

Advances in pharmacotherapy for opioid-induced constipation - a systematic review

INTRODUCTION

Opioid-induced constipation (OIC) is one of the most frequent and burdening adverse events (AE) of opioid therapy. This systematic review aimed to evaluate efficacy and safety of drugs in randomized controlled trials (RCTs) with adult OIC patients.

AREAS COVERED

Efficacy assessment focused on objective outcome measures (OOMs): bowel movement (BM) frequency, BM within 4 h and time to first BM. Twenty-one studies examining seven drugs were identified. Methylnaltrexone showed improvements in all three OOMs. RCTs in naloxone and alvimopan tended to be effective for BM frequency measures. Naloxegol (≥ 12.5 mg) improved all OOMs. Though effectiveness of lubiprostone was demonstrated for all OOMs, group differences were small to moderate. CB-5945 and prucalopride tended to increase BM frequency, especially for 0.1 mg twice daily and 4 mg daily, respectively. Besides nausea and diarrhea, abdominal pain was the most frequent AE for all drugs (risk ratio, range: 1.52 - 5.06) except for alvimopan. Treatment-related serious AEs were slightly higher for alvimopan (cardiac events) and prucalopride (severe abdominal pain, headache). Pain scores for placebo and intervention groups were similar for all drugs.

EXPERT OPINION

Finding a consensus definition and inclusion criteria for OIC plus a rational balance between efficacy and AEs of drugs remain future challenges.

Efficacy and tolerability of low-dose oral prolonged-release oxycodone/naloxone for chronic nononcological pain in older patients

Purpose

Chronic pain is highly prevalent in older adults. Increasing evidence indicates strong opioids as a valid option for chronic pain management in geriatrics. The aim of this study was to evaluate efficacy and safety of low-dose oral prolonged-release oxycodone–naloxone (OXN-PR) in patients aged ≥70 years.

Methods

This open-label prospective study assessed older patients naïve to strong opioids presenting with moderate-to-severe chronic pain. Patients were prescribed OXN-PR at an initial dose of 10/5 mg/day for 28 days. In case of insufficient analgesia, the initial daily dose could be increased gradually. The primary efficacy measure was change in pain intensity from baseline, assessed by a ten-point Numeric Rating Scale (NRS) at day 28 (T28). Changes in cognitive state, daily functioning, quality of life, constipation, and other adverse events were assessed.

Results

Of 53 patients enrolled (mean 81.7±6.2 years [range 70–92 years]), 52 (98.1%) completed the 28-day observation. At T28, the primary end point (≥30% reduction in mean pain from baseline in the absence of bowel function deterioration) was achieved in 38 patients (71.7%). OXN-PR significantly relieved pain (NRS score –3.26; P<0.0001), as well as daily need for rescue paracetamol (from 86.8% at baseline to 40.4% at T28; P<0.001), and reduced impact of pain on daily activities (Brief Pain Inventory Short Form from 6.2±1.5 to 3.4±2.1; P<0.0001). OXN-PR was also associated with significant improvement in daily functioning (Barthel Index from 53.3±14.1 to 61.3±14.3; P<0.01). No changes were observed in cognitive status and bowel function. OXN-PR was well tolerated; only one patient (1.9%) prematurely withdrew from treatment, due to drowsiness.

Conclusion

Findings from this open-label prospective study suggest that low-dose OXN-PR may be effective and well tolerated for treatment of moderate-to-severe chronic pain in older patients. Besides its effectiveness, these data indicate that low-dose OXN-PR may be considered a safe analgesic option in this fragile population and warrants further investigation in randomized controlled studies.

Long-term evaluation of combined prolonged-release oxycodone and naloxone in patients with moderate-to-severe chronic pain: pooled analysis of extension phases of two Phase III trials

BACKGROUND

While opioids provide effective analgesia, opioid-induced constipation (OIC) can severely impact quality of life and treatment compliance. This pooled analysis evaluated the maintenance of efficacy and safety during long-term treatment with combined oxycodone/naloxone prolonged-release tablets (OXN PR) in adults with moderate-to-severe chronic pain.

METHODS

Patients (N = 474) received open-label OXN PR during 52-week extension phases of two studies, having completed 12-week, double-blind, randomized treatment with oxycodone prolonged-release tablets (Oxy PR) or OXN PR. Analgesia and bowel function were assessed at each study visit using 'Average pain over last 24 h scale and Bowel Function Index (BFI), respectively. Treatment Satisfaction Questionnaire for Medication was assessed at study end only.

KEY RESULTS

Improvement in bowel function was particularly marked in patients who switched from Oxy PR in the double-blind phase to OXN PR during the extension phase, resulting in a clinically meaningful reduction (≥12 points) in BFI score: at the start of the extension phases, mean (SD) BFI score was 44.3 (28.13), and was 29.8 (26.36) for patients who had received OXN PR in the double-blind phase. One week later, BFI scores were similar for the two groups (26.5 [24.40] and 27.5 [25.60], respectively), as was observed throughout the following months. Fewer than 10% of patients received laxatives regularly. Mean 24-h pain scores were low and stable throughout the extension phases. No unexpected adverse events were observed.

CONCLUSIONS & INFERENCES

Pooled data demonstrate OXN PR is an effective long-term therapy for patients with chronic non-cancer pain, and can address symptoms of OIC. No new safety issues were observed which were attributable to the long-term administration of OXN PR.

Patient preference with respect to QoL and reduction in opioid-induced constipation (OIC) after treatment with prolonged-release (PR) oxycodone/naloxone compared with previous analgesic therapy [PREFER study]

OBJECTIVE

The aim of this study was to assess patient preference in terms of quality of life (QoL), analgesia and bowel function for patients with moderate to severe chronic non-malignant pain, when treated with oxycodone PR/naloxone PR compared with the previous WHO-step I and/or WHO-step II analgesic treatment .

STUDY DESIGN

This was a 3-week open-label phase 3b study conducted in Belgium and the Netherlands, after 3 weeks patients could enter an extension phase. Patient preference with respect to QoL for oxycodone PR/naloxone PR treatment compared with previous WHO-step I and/or WHO-step II analgesics was assessed. A patient was considered a responder with respect to QoL if this assessment was 'better' or 'much better' compared with previous WHO-step I or II analgesics at any time point.

RESULTS

Response rate with respect to QoL was 59.2% (95% CI: 51.7-66.8%) for the Full Analysis (FA)-population, for the Per Protocol-population response rate was 71.7% (95% CI: 63.1-80.3%). Explorative analysis showed that response rate with respect to QoL was highest in constipated patients pretreated with WHO-step II analgesics (73.8%). Mean ± SD pain score in the FA-population at start was 74.7 ± 16.6 decreasing to 53.9 ± 24.3 after a median (range) treatment period of 173.5 (31-771) days. For constipated subjects the significant reduction in constipation [improvement of the Bowel Function Index (BFI)], was -24.8 points (95% CI: -17.1 to -32.5). BFI for non-constipated subjects remained well below 28.8. Adverse events with oxycodone PR/naloxone PR treatment were well-known opioid-related adverse events.

CONCLUSION

This study shows that the studied patients previously treated with WHO-step I and/or WHO-step II analgesics prefer treatment with oxycodone PR/naloxone PR with respect to QoL. Moreover, the study shows that treatment with oxycodone PR/naloxone PR significantly reduces OIC in constipated patients and that non-constipated patients do not develop OIC during treatment with oxycodone PR/naloxone PR.

Fixed ratio (2:1) prolonged-release oxycodone/naloxone combination improves bowel function in patients with moderate-to-severe pain and opioid-induced constipation refractory to at least two classes of laxatives

OBJECTIVE

The effects of combined oxycodone/naloxone prolonged release tablets (OXN PR) were investigated in patients with moderate-to-severe chronic cancer-related or non-cancer pain. All patients had opioid-induced constipation (OIC) which persisted despite substantial laxative therapy.

RESEARCH DESIGN AND METHODS

This pooled analysis included 75 patients with OIC at study entry that was refractory to at least two laxatives with different modes of action. Patients completed randomized, double-blind treatment with OXN PR 20-120 mg/day for either 12 weeks (OXN 9001: non-cancer pain study) or 4 weeks (OXN 2001: cancer-related pain study). Analgesia and bowel function were assessed using the Brief Pain Inventory Short Form and Bowel Function Index (BFI), respectively. Use of laxative medication and safety were assessed throughout the studies.

CLINICAL TRIAL REGISTRATION

NCT00513656, EudraCT 2005-002398-57, EudraCT 2005-003510-15.

RESULTS

Statistically and clinically significant improvements in bowel function were observed following double-blind treatment with OXN PR. Mean (SD) reduction in BFI score was 21.2 (28.8) and comparable in patients with cancer-related (19.0 [28.9]) and non-cancer pain (23.3.[29.0]; P ≤ 0.0002). Furthermore, the proportion of patients with a BFI score within normal range (≤28.8) increased from 9.5% at screening to 43.1% at Day 15 of OXN PR. While all patients used ≥2 laxatives of different classes at screening, during study treatment 36% stopped using laxatives (P < 0.001). OXN PR provided effective analgesia, evidenced by stable pain scores during study treatment, and there were no unanticipated adverse events.

CONCLUSIONS

OXN PR significantly improved bowel function and reduced the use of laxatives in patients with OIC, previously unresponsive to at least two different classes of laxatives. OXN also provided effective analgesia for patients with moderate-to-severe cancer-related pain and non-cancer-related pain.

Narcotic bowel syndrome and opioid-induced constipation

Prescription opioid use for chronic non-cancer pain has reached epidemic levels in the USA. With this increased use is the recognition of serious opioid-related gastrointestinal complications such as narcotic bowel syndrome (NBS) and opioid-induced constipation (OIC). NBS consists of a paradoxical worsening of abdominal pain with escalating doses of opioids and is likely mediated by the central nervous system. Therapy requires an intensive multidisciplinary approach to detoxification. OIC is the most common gastrointestinal side effect of opioids. Several novel therapeutics are available to treat OIC that fails to respond to laxative therapy. This review will summarize recent findings on the pathophysiology and treatment approaches to NBS and OIC with a focus on controversies about diagnosis and intervention.

Long-term safety and efficacy of oxycodone/naloxone prolonged-release tablets in patients with moderate-to-severe chronic cancer pain

Aim

To evaluate the long-term safety and efficacy of prolonged-release oxycodone/naloxone (OXN PR) and its impact on quality of life (QoL), in patients with moderate-to-severe cancer pain.

Methods

This was an open-label extension (OLE) of a 4 week, randomized, double-blind (DB) study in which patients with moderate-to-severe cancer pain had been randomized to OXN PR or oxycodone PR (OxyPR). During the OLE phase, patients were treated with OXN PR capsules (≤20/60 mg/day) for ≤24 weeks. Outcome measures included safety, efficacy and QoL.

Results

One hundred and twenty-eight patients entered the OLE, average pain scores based on the modified Brief Pain Inventory—Short Form were low and stable over the 24-week period. The improvement in bowel function and constipation symptoms as measured by the Bowel Function Index and patient assessment of constipation in patients treated with OXN PR during the 4-week DB study was maintained. In patients treated with OxyPR during the DB phase, bowel function and constipation symptoms were improved during the OLE. In the DB and in the OLE, health status and QoL were similar for patients treated with OXN PR and OxyPR. There were no unexpected safety or tolerability issues.

Conclusions

In patients with moderate-to-severe cancer pain, long-term use of OXN PR is well tolerated and effective, resulting in sustained analgesia, improved bowel function and improved symptoms of constipation.

Oxycodone for neuropathic pain and fibromyalgia in adults

BACKGROUND

This review is one of a series on drugs used to treat neuropathic pain and fibromyalgia. These conditions are estimated to affect 3 to 10% of adults, and are difficult to treat. Although they probably have different aetiologies, neuropathic pain and fibromyalgia can respond to the same therapies. There have been substantial changes in the standards of evidence considered necessary for assessment of interventions to treat chronic pain, to provide data that are more robust and clinically relevant. Oxycodone is a strong opioid agonist widely used to manage severe pain; this review assesses evidence for oxycodone using current standards of evidence designed to reduce bias.

OBJECTIVES

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

SEARCH METHODS

On 6 November 2013, we searched CENTRAL, MEDLINE and EMBASE databases. We reviewed the bibliographies of all included studies and of reviews, and also searched two clinical trial databases, ClinicalTrials.gov and the World Health Organisation (WHO) International Clinical Trials Registry Platform, to identify additional published or unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with double-blind assessment of participant outcomes following two weeks of treatment or longer (although the emphasis of the review was on studies of eight weeks or longer) that used a placebo or active comparator.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted efficacy and adverse event data, examined issues of study quality, and assessed risk of bias. We performed analysis using three tiers of evidence. First tier evidence was derived from data meeting current best standards and subject to minimal risk of bias (outcome equivalent to substantial pain intensity reduction, intention-to-treat analysis without imputation for dropouts; at least 200 participants in the comparison, eight to 12 weeks duration, parallel design), second tier from data that failed to meet one or more of these criteria and were considered at some risk of bias but with adequate numbers in the comparison, and third tier from data involving small numbers of participants that was considered very likely to be biased or used outcomes of limited clinical utility, or both.

MAIN RESULTS

We included three studies with 254 participants; 204 had painful diabetic neuropathy and 50 postherpetic neuralgia. Study size ranged from 45 to 159 participants. Two studies used a cross-over design and one a parallel group design; study duration was four or six weeks. Controlled release oxycodone (oxycodone CR) was used in all three studies, with doses titrated up to a maximum of between 60 and 120 mg daily; mean doses achieved ranged between 37 and 45 mg daily. All studies used a placebo comparator, although in one study, an active placebo (benztropine) was used. All studies had one or more sources of potential major bias.No study reported the proportion of participants experiencing at least 50% pain relief or who were very much improved, while one reported the proportion with at least 30% pain relief, two reported at least moderate pain relief, and one reported the number of participants who considered treatment to be moderately effective. No study provided first or second tier evidence for an efficacy outcome. Third tier evidence indicated greater pain intensity reduction and better patient satisfaction with oxycodone than with placebo in all three studies, but such evidence was derived mainly from group mean data, with last observation carried forward (LOCF) imputation or completer analysis, in small studies lasting less than eight weeks (very low quality evidence).Adverse events were more common with oxycodone CR than with placebo. At least one adverse event was experienced by 86% of participants taking oxycodone CR and 63% taking placebo, and the number needed to treat for an additional harmful effect (NNH) was 4.3. The effect of oxycodone on serious adverse events reported was uncertain in comparison with placebo (oxycodone 3.4% versus placebo: 7.0%; RR 0.48 (95% confidence interval (CI) 0.18 to 1.23; very low quality evidence); one death was reported with oxycodone CR, but was not attributed to treatment. Adverse event withdrawals did not differ significantly between groups, occurring in 11% of participants with oxycodone CR and 6.4% with placebo (RR 1.69 (0.83 to 3.43); very low quality evidence). Withdrawals due to lack of efficacy were less frequent with oxycodone CR (1.1%) than placebo (11%), with an NNT to prevent one withdrawal of 10 (RR 0.12 (0.03 to 0.45); very low quality evidence).We found no relevant studies in chronic neuropathic pain conditions other than painful diabetic neuropathy or postherpetic neuralgia, or in fibromyalgia.

AUTHORS' CONCLUSIONS

No convincing, unbiased evidence suggests that oxycodone (as oxycodone CR) is of value in treating people with painful diabetic neuropathy or postherpetic neuralgia. There is no evidence at all for other neuropathic pain conditions, or for fibromyalgia. Adverse events typical of opioids appear to be common.

Clinical and economic evaluation of tapentadol extended release and oxycodone/naloxone extended release in comparison with controlled release oxycodone in musculoskeletal pain

OBJECTIVE

Chronic pain is a leading cause of disability and represents a relevant societal burden. Opioids are widely used for managing chronic non-cancer pain; however, the high incidence of side effects is often the main reason for discontinuation. Two formulations have recently been studied to improve the tolerability of opioids (tapentadol extended release [ER] and oxycodone/naloxone ER), but a direct comparison between these drugs is not available in the literature. The comparative cost effectiveness of these two drugs has not previously been assessed. The objective of this meta-analysis is a clinical and economic evaluation of tapentadol ER and oxycodone/naloxone ER for the treatment of musculoskeletal pain, by indirect comparison with controlled release (CR) oxycodone.

METHODS

A structured literature review was conducted to identify published data for the health-economic model. The authors performed a meta-analysis on three selected randomized controlled trials (RCTs) for each treatment (tapentadol ER and oxycodone/naloxone ER). As measure of treatment effect, risk ratio was calculated, compared to the control active treatment (CR oxycodone), for the following outcomes: discontinuation rate due to adverse events, due to gastrointestinal (GE) side effects and central nervous system (CNS) side effects. A Markov model was developed to compare the cost effectiveness of tapentadol ER and oxycodone/naloxone ER. Four health states were defined: (1) patients still on treatment; (2) occurrence of adverse events (gastroenterology, central nervous system); (3) treatment discontinuation as consequence of ineffectiveness of treatment; and (4) treatment discontinuation as consequence of adverse events.

RESULTS

Both drugs showed a significant clinical advantage over the active control, CR oxycodone; however, tapentadol ER resulted in a better risk ratio reduction for the primary outcome of discontinuation rate due to adverse events and for the secondary outcome nausea and vomiting. The two drugs gave equivalent results in the capacity of reduction of constipation risk. In the economic evaluation both interventions were cost effective compared with CR oxycodone. However, tapentadol ER showed the most favorable results as in 65% of cases it was less costly and produced a considerable quality adjusted life years (QALY) gain. The higher impact of tapentadol ER on the cost effectiveness results was probably due to the price and the lower incidence of adverse events and related discontinuation rate, resulting in a further economic advantage.

CONCLUSION

Both tapentadol ER and oxycodone/naloxone ER are cost effective interventions compared with CR oxycodone; however, tapentadol ER was shown to provide better clinical outcomes at lower costs.

Opioid-induced constipation in patients with chronic noncancer pain in the USA, Canada, Germany, and the UK: descriptive analysis of baseline patient-reported outcomes and retrospective chart review

BACKGROUND

The characteristics of patients who suffer from noncancer pain and opioid-induced constipation are not well understood.

METHODS

Cross-sectional patient survey and chart review data from the baseline assessment of an ongoing longitudinal study in the USA, Canada, Germany, and the UK were evaluated via descriptive statistics. Participants had confirmation of daily opioid therapy ≥30 mg for ≥4 weeks and self-reported opioid-induced constipation. Response to laxatives was defined by classifying participants into categories of laxative use and evaluating the prevalence of inadequate response to one laxative agent and two or more agents from at least two different laxative classes. Outcomes included the Patient Assessment of Constipation-Symptoms, Work Productivity and Activity Impairment Questionnaire-Specific Health Problem, EuroQOL 5 Dimensions, and Global Assessment of Treatment Benefit, Satisfaction, and Willingness to Continue.

RESULTS

Patients reported a mean of 1.4 bowel movements not preceded by laxatives and 3.7 bowel movements with laxative use per week; 83% wanted at least one bowel movement per day. Most commonly reported on Patient Assessment of Constipation-Symptoms were straining/squeezing to pass bowel movements (83%), bowel movements too hard (75%), flatulence (69%), and bloating (69%). Eighty-four percent were taking natural or behavioral therapies; 60% were taking at least one over-the-counter laxative; and 19% were taking at least one prescription laxative. Prevalence of inadequate response to one laxative agent was 94%; inadequate response to two or more agents from at least two different laxative classes was 27%. Mean Work Productivity and Activity Impairment Questionnaire-Specific Health Problem values for percent work time missed, percent impairment while working, and percent activity impairment were 9%, 32% (equivalent of 14 hours of lost productivity per week), and 38%. Mean EuroQOL 5 Dimensions index and visual analog scale scores were 0.49 and 50.6, respectively. Forty-four percent reported being satisfied with their treatment for constipation.

CONCLUSION

Patients treated with opioids for noncancer pain commonly endure constipation symptoms that limit their work productivity and overall health-related quality of life while adhering to treatments that provide little relief. Further research is needed to identify more efficacious constipation therapies for this patient population.

Oxycodone/Naloxone: role in chronic pain management, opioid-induced constipation, and abuse deterrence

The use of opioids in the treatment of chronic pain is widespread; the prevalence of specific opioids varies from country to country and depends on product availability, national formulary systems, and provider preferences. Patients often receive opioids for legitimate treatment of pain conditions, but on the opposite side of the spectrum, nonmedical use of opioids is a significant public health concern. Opioids are associated with several side effects, and constipation is the most commonly reported and persistent symptom. Unlike some adverse effects associated with opioid use, tolerance does not develop to constipation. Opioid-induced constipation (OIC) is the most prevalent patient complaint associated with opioid use and has been associated with declines in various quality of life measures. OIC can be extremely difficult for patients to tolerate and may prompt patients to decrease or discontinue opioid treatment. Current management strategies for OIC are often insufficient. A prolonged-release formulation of oxycodone/naloxone (OXN) has been investigated for the treatment of nonmalignant and cancer pain and mitigation of OIC, and evidence is largely favorable. Studies have demonstrated the capability of OXN to alleviate OIC while maintaining pain control comparable to oxycodone-only regimens. There is insufficient evidence for OXN efficacy for patients with mild OIC or patients maintained on high doses of opioids, and use in these populations is controversial. The reduction of costs associated with OIC may provide overall cost effectiveness with OXN. Additionally, the presence of naloxone may deter abuse/misuse by those seeking to misuse the formulation by modes of administration other than oral ingestion. Most studies to date have occurred in European countries, and phase 3 trials continue in the United States. This review will include current therapeutic options for pain and constipation, unique characteristics of OXN, evidence related to use of OXN and its place in therapy, discussion of opioid abuse/misuse, and various abuse-deterrent mechanisms, and areas of continuing research.

Opioid-induced constipation: pathophysiology, clinical consequences, and management

Although opioids offer potent analgesia for severe acute and chronic noncancer pain, adverse gastrointestinal effects potentially undermine their clinical utility. In particular, between 40% and 95% of patients develop opioid-induced constipation (OIC). Therefore, there is a consensus that patients should commence laxatives at the start of opioid therapy and continue throughout treatment. Nevertheless, laxatives are not routinely coprescribed with opioids. Even when concurrent laxatives are prescribed, approximately half the patients treated for OIC do not achieve the desired improvement. Moreover, laxatives do not target the underlying cause of OIC (opioid binding to the μ-receptors in the enteric system) and as such are not very effective at managing OIC. The failure of lifestyle modification and laxatives to treat adequately many cases of OIC led to the concurrent use of peripherally acting opioid antagonists (such as methylnaltrexone bromide and naloxone) to reduce the incidence of gastrointestinal adverse events without compromising analgesia. Judicious use of the various options to manage OIC should allow more patients to benefit from opioid analgesia. Therefore, this paper reviews the causes, consequences, and management of OIC to help clinicians optimise opioid analgesia.

Effects of prolonged-release oxycodone/naloxone on pain control, bowel function and quality of life: A prospective observational study

Background and aim

Strong opioids including oxycodone are amongst the most effective analgesics to combat moderate to severe pain of various aetiologies, but opioid-induced bowel dysfunction (OIBD) represents a relevant problem. The rationale for development of a prolonged-release (PR) fixed combination of oxycodone and naloxone was to counteract OIBD. Due to its negligible oral bioavailability, the μ-opioid receptor antagonist naloxone is able to selectively displace opioids from local μ-receptors in the gastrointestinal tract without affecting central opioid binding sites. Pivotal trials of PR oxycodone/naloxone not only demonstrated improved bowel function but also equivalent analgesic efficacy compared to PR oxycodone alone. Controlled clinical trials comparing PR oxycodone/naloxone with strong opioids other than oxycodone are not available. The present study is the first data set aimed at comparing pain control, bowel function, and quality of life (QoL) in patients newly treated with or switched to PR oxycodone/naloxone or other strong opioids during routine clinical practice.

Methods

In this three-arm, prospective observational study, 588 patients with moderate to severe pain of varying aetiologies received either PR oxycodone/naloxone (OXN group and OXN 40/20 group with indicated use of the 40 mg/20 mg dose strength at baseline) or other strong opioids (control group), dosed according to pain severity, for 4–6 weeks. Data documented include pain intensity (NRS), bowel function (Bowel Function Index, BFI), pain-related functional impairment (BPI-SF), QoL (EuroQol EQ-5D-3L), and a global assessment of treatment.

Results

Patients receiving PR oxycodone/naloxone experienced a clinically important reduction in pain intensity and pain-related functional impairment of approximately 40%. The reductions of pain intensity (−2.9 ± 2.3) and pain-related functional impairment (−2.4 ± 2.3) in the OXN group were significantly more pronounced than in the control group (−2.1 ± 2.1 and −1.8 ± 1.7). In the control group, mean reductions in pain intensity did not reach the threshold of ≥30% for at least moderate clinically important differences, although patients were prescribed higher doses of morphine equivalents than OXN group patients. Improvements in bowel function (OXN: −16.0 ± 27.6; control: 3.1 ± 24.4) and QoL (OXN: 20.8 ± 24.2; control: 13.2 ± 23.1) were also significantly more pronounced in the OXN group, with BFI scores reduced to a level that reflects normal bowel function. Results for the OXN 40/20 group receiving higher doses of PR oxycodone/naloxone were in line with those for the OXN group. In the control group, more frequent gastrointestinal adverse events and less favourable ratings of tolerability resulted in a higher rate of treatment discontinuations due to adverse events.

Conclusions

In patients receiving PR oxycodone/naloxone, more favourable outcomes compared with other strong opioids regarding pain control, bowel function, and QoL were observed.

Implications

The present findings underline the value of PR oxycodone/naloxone in the management of patients with moderate to severe chronic pain. The data set further adds to our understanding of the benefits and risks of opioid treatment in routine clinical practice.

End-of-dose pain in chronic pain: does it vary with the use of different long-acting opioids?

A large percentage of patients with chronic pain on around-the-clock (ATC) opioids may experience increased pain occurring at the end of a scheduled dose, also known as end-of-dose pain. Despite the significant prevalence and impact of end-of-dose pain in patients using extended-release (ER) opioids, there are no detailed analyses examining how the frequency of end-of-dose pain is linked to the formulations of long-acting opioids. Consequently, we performed a systematic review to evaluate how many published studies on patients with chronic cancer or noncancer pain identified end-of-dose pain. As only a few studies mentioned end-of-dose pain explicitly, we used breakthrough pain (BTP) as a surrogate parameter. We determined if any opioid formulation had a greater association with the frequency of BTP, the use of rescue medication for BTP, and the frequency of end-of-dose pain. Of the 39 studies entered in the final analysis, 14 studies across different formulations showed that ER opioids were effective in the prevention of BTP. The opioids most frequently studied were hydromorphone (26%), followed by morphine (23%), and transdermal buprenorphine (23%). Only 5% of the studies used immediate-release preparations. Overall, most studies showed that patients using ER preparations experienced fewer episodes of BTP compared with patients on placebo or an active comparator. This could reflect the favorable duration of action of these opioids compared with short-acting formulations. Future studies should examine the incidence of end-of-dose pain and use of rescue medicine in a longitudinal manner in patients with chronic pain taking short- vs. long-acting ATC opioids.

Cancer pain therapy with a fixed combination of prolonged-release oxycodone/naloxone: results from a non-interventional study

BACKGROUND

Strong opioids, including oxycodone, are the most effective analgesics used to combat moderate to severe cancer pain, but opioid-induced bowel dysfunction is a relevant problem associated with the therapy. Clinical studies have demonstrated equivalent analgesic efficacy and improved bowel function in treatment with a fixed combination of prolonged-release (PR) oxycodone and PR naloxone compared to oxycodone alone in patients with nonmalignant pain. Here, we report of a prospective, non-interventional study evaluating the effectiveness and safety of PR oxycodone/PR naloxone in a subgroup of patients with severe cancer pain.

PATIENTS AND METHODS

Within the non-interventional multicenter study, 1,178 cancer patients with severe chronic pain received PR oxycodone/PR naloxone, dosed according to pain intensity, for 4 weeks. Recorded variables included pain intensity, patient-reported bowel function (Bowel Function Index), and pain-related functional impairment as a measure of quality of life (QoL).

RESULTS

During treatment with PR oxycodone/PR naloxone, clinically relevant improvements in pain intensity were observed in opioid-naïve patients and in patients pretreated with weak or strong opioids, as reflected by reductions in pain scores of 51%, 53%, and 33%, respectively. Improvement in analgesia was paralleled by a significant reduction of opioid-induced bowel dysfunction in opioid-pretreated patients. The reductions in the mean Bowel Function Index of -20.5 and -36.5 in patients pretreated with weak and strong opioids, respectively, represent clinically relevant improvements in bowel function. Pain-related functional impairment decreased consistently across all seven domains, which is equivalent to a substantial improvement in QoL.

CONCLUSION

This subgroup analysis of cancer patients within a large non-interventional study demonstrates that treatment with PR oxycodone/PR naloxone provides effective analgesia with minimization of bowel dysfunction and improved QoL. These data extend our knowledge of the effectiveness and tolerability of PR oxycodone/PR naloxone to the population of patients with cancer under real-life conditions.

[Prescription of high-potency opioids in 2011]

BACKGROUND

The aim of this study was to analyze the prescription of high-potency (WHO step III) opioids with respect to regional differences and to assess the proportion of opioid-naïve new users of transdermal fentanyl.

METHODS

Prescription claims data of the largest single German health fund (BARMER GEK) with 9.1 million insured persons from the year 2011 were used. For new users of transdermal fentanyl who had had no prescription in the preceding 6 months it was studied whether they had received other high-potency or low-potency opioids before.

RESULTS

A total of 18.9 million defined daily doses (DDD) of high-potency opioids were included corresponding to a mean of 208.6 DDD per 100 persons. Significant regional differences were found with lower values in the south, ranging from 145.9 DDD in Baden-Württemberg to 259.5 DDD per 100 persons in Lower Saxony. Fentanyl was the most frequently used step III opioid (40.8% of DDDs) which is nearly only given transdermally. Of the 11,184 patients with new use of transdermal fentanyl 80.7% had received no other high-potency opioid before and 52.9% had received neither low-potency nor high-potency opioids before. The first prescription exceeded the smallest available dose of 12.5 μg/h for over half of the patients starting treatment.

CONCLUSIONS

Although oral morphine, oxycodone and hydromorphone are recommended as first-line step III opioids, transdermal fentanyl seems to be prescribed too often as the first choice and might not be appropriate.

Efficacy and gastrointestinal tolerability of oral oxycodone/naloxone combination for chronic pain in outpatients with cancer: an observational study

Combination opioid agonist/antagonist therapy has been shown to preserve bowel function in patients with chronic cancer pain. This retrospective study evaluated the efficacy and tolerability of prolonged-released fixed-dose oxycodone-naloxone (PR OXN) in consecutive outpatients with chronic cancer pain. Of 206 patients prescribed PR OXN (mean age 61.3 ± 12.9 years; 52.9% female), 31.5% were opioid naïve. PR OXN was associated with a significant decrease in pain score measured on a visual analogue scale over 28 days (P < .0001), without adverse effects on bowel function, nor change in laxative use. PR OXN efficacy and tolerability were similar in opioid-naïve and -experienced patients, and among age-stratified subgroups. No severe side effects occurred. In a real-life outpatient setting, PR OXN provided analgesia without bowel dysfunction in patients with chronic cancer pain.

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

OBJECTIVES

There has been no definitive synthesis of the evidence for any benefit of available pharmacological therapies in opioid-induced constipation (OIC). We conducted a systematic review and meta-analysis to address this deficit.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials through to December 2012 to identify placebo-controlled trials of μ-opioid receptor antagonists, prucalopride, lubiprostone, and linaclotide in the treatment of adults with OIC. No minimum duration of therapy was required. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Effect of pharmacological therapies was reported as relative risk (RR) of failure to respond to therapy, with 95% confidence intervals (CIs).

RESULTS

Fourteen eligible randomized controlled trials (RCTs) of μ-opioid receptor antagonists, containing 4,101 patients, were identified. These were superior to placebo for the treatment of OIC (RR of failure to respond to therapy=0.69; 95% CI 0.63-0.75). Methylnaltrexone (six RCTs, 1,610 patients, RR=0.66; 95% CI 0.54-0.84), naloxone (four trials, 798 patients, RR=0.64; 95% CI 0.56-0.72), and alvimopan (four RCTs, 1,693 patients, RR=0.71; 95% CI 0.65-0.78) were all superior to placebo. Total numbers of adverse events, diarrhea, and abdominal pain were significantly commoner when data from all RCTs were pooled. Reversal of analgesia did not occur more frequently with active therapy. Only one trial of prucalopride was identified, with a nonsignificant trend toward higher responder rates with active therapy. Two RCTs of lubiprostone were found, with significantly higher responder rates with lubiprostone in both, but reporting of data precluded meta-analysis.

CONCLUSIONS

μ-Opioid receptor antagonists are safe and effective for the treatment of OIC. More data are required before the role of prucalopride or lubiprostone in the treatment of OIC are clear.

The place of oxycodone/naloxone in chronic pain management

Opioid analgesics are usually effective in the management of severe chronic pain. However, symptoms of opioid-induced bowel dysfunction (OIBD) are common during opioid therapy. Opioid-induced bowel dysfunction is often unsuccessfully managed due to limited effectiveness and numerous adverse effects of traditional laxatives. Newer treatment possibilities directed at the pathomechanism of OIBD comprise combined prolonged-release oxycodone with prolonged-release naloxone (oxycodone/naloxone) tablets. Oxycodone/naloxone provides effective analgesia with limited impact on bowel function as oxycodone displays high oral bioavailability and naloxone act as local antagonist on opioid receptors in the gastrointestinal tract due to nearly complete inactivation in the liver. Oxycodone/naloxone is administered to opioid-naive patients with severe pain and those unsuccessfully treated with weak opioids. Oxycodone/naloxone may be also administered to patients treated with strong opioids who experience intense symptoms of OIBD. Studies conducted to date indicate that oxycodone/naloxone is an important drug in chronic pain management, prevention and treatment of OIBD.

A comparison of oxycodone prolonged-release vs. oxycodone + naloxone prolonged-release after laparoscopic hysterectomy

BACKGROUND

Targiniq®, an oxycodone prolonged-release (PR) formulation combined with the opioid antagonist naloxone PR, aims to prevent opioid-induced constipation without impairing the analgesic efficacy. This has been confirmed during prolonged use in chronic pain or cancer patients. The purpose of our study was to compare clinical effects of oxycodone PR with oxycodone PR + naloxone PR for short-term post-operative pain management.

METHODS

This randomised, double-blind, prospective study included 85 women undergoing laparoscopic hysterectomy. The two groups received either oxycodone PR 10 mg or oxycodone PR 10 mg + naloxone PR 5 mg as pre-medication and twice daily for 3 days. As rescue analgesic, the patients received oxycodone intravenous during the first 24 h post-operatively and oxycodone tablets in the 24-72-h period. Constipation, other side effects, pain and satisfaction were registered during the first 7 post-operative days.

RESULTS

Demographic, pre- and perioperative variables and the use of rescue analgesics were similar in the groups. There were no significant differences in variables related to constipation. In the oxycodone PR + naloxone PR group, 25% had no defecation during the first 72 h post-operatively, compared with 20% in the oxycodone PR group (mean 1.2 ± 1.1 vs. 2.1 ± 2.4 defecations). Other opioid-induced effects and side effects showed no significant differences. Only 7% were dissatisfied with their oral pain treatment.

CONCLUSION

Addition of naloxone to oxycodone PR tablets in a pain regimen administered twice daily the first three post-operative days had no significant clinical effects on constipation or other variables during the first week after hysterectomy.

Oxycodone combined with opioid receptor antagonists: efficacy and safety

INTRODUCTION

A mu receptor antagonist combined with oxycodone (OXY) may improve pain control, reduce physical tolerance and withdrawal, minimizing opioid-related bowel dysfunction and act as an abuse deterrent.

AREAS COVERED

The authors cover the use of OXY plus ultra-low-dose naltrexone for analgesia and the use of sustained-release OXY plus sustained-release naloxone to reduce the opioid bowel syndrome. The authors briefly describe the use of sustained-release OXY and naltrexone pellets as a drug abuse deterrent formulation. Combinations of ultra-low-dose naltrexone plus OXY have been in separate trials involved in patients with chronic pain from osteoarthritis and idiopathic low back pain. High attrition and marginal differences between ultra-low-dose naltrexone plus OXY and OXY led to discontinuation of development. Prolonged-release (PR) naloxone combined with PR OXY demonstrates a consistent reduction in opioid-related bowel dysfunction in multiple randomized controlled trials. However, gastrointestinal side effects, including diarrhea, were increased in several trials with the combination compared with PR OXY alone. Analgesia appeared to be maintained although non-inferiority to PR OXY is not formally established. There were flaws to trial design and safety monitoring. Naltrexone has been combined with OXY in individual pellets encased in a capsule. This combination has been reported in a Phase II trial and is presently undergoing Phase III studies.

EXPERT OPINION

Due to the lack of efficacy the combination of altered low-dose naltrexone with oxycodone should cease in development. The combination of sustained release oxycodone plus naloxone reduces constipation with a consistent benefit. Safety has been suboptimally evaluated which is a concern. Although the drug is commercially available in several countries, ongoing safety monitoring particularly high doses would be important.

Controlled-release oxycodone and naloxone in the treatment of chronic low back pain: a placebo-controlled, randomized study

BACKGROUND

For Canadian regulatory purposes, an analgesic study was required to complement previously completed, pivotal studies on bowel effects and analgesia associated with controlled-release (CR) oxycodone⁄CR naloxone.

OBJECTIVES

To compare the analgesic efficacy and safety of CR oxycodone⁄CR naloxone versus placebo in patients with chronic low back pain.

METHODS

Patients requiring opioid therapy underwent a two- to seven-day opioid washout before being randomly assigned to receive either 10 mg⁄5 mg CR oxycodone⁄CR naloxone or placebo every 12 h, titrated weekly according to efficacy and tolerability to 20 mg⁄10 mg, 30 mg⁄15 mg or 40 mg⁄20 mg every 12 h. After four weeks, patients crossed over to the alternative treatment for an additional four weeks. Acetaminophen⁄codeine (300 mg⁄30 mg every 4 h to 6 h as needed) was provided as rescue medication.

RESULTS

Of the 83 randomized patients, 54 (65%) comprised the per-protocol population. According to per-protocol analysis, CR oxycodone⁄CR naloxone resulted in significantly lower mean (± SD)pain scores measured on a visual analogue scale (48.6 ± 23.1 mm versus 55.9 ± 25.4 mm; P=0.0296) and five-point ordinal pain intensity scores (2.1 ± 0.8 versus 2.4 ± 0.9; P=0.0415) compared with placebo. After the double-blinded phase, patients and investigators both preferred CR oxycodone⁄CR naloxone over placebo. These outcomes continued in the 79% of patients who chose to continue receiving CR oxycodone⁄CR naloxone in a six-month, open-label evaluation.

CONCLUSIONS

In patients complying with treatment as per protocol, CR oxycodone⁄CR naloxone was effective for the management of chronic low back pain of moderate or severe intensity.

Methylnaltrexone for the treatment of opioid-induced constipation

Opioids are the drugs of choice for treating moderate-to-severe pain, especially for patients in the end stage of cancer or other advanced illnesses, and also in critical care or for the treatment of chronic pain. Side effects such as nausea, pruritus, dizziness and constipation have to be controlled in order to use these drugs to their full potential. Opioid-induced bowel syndrome and constipation caused by activation of μ-receptors in the gut can have such distressing effects that some patients prefer to forego adequate pain control. Methylnaltrexone is a μ-opioid receptor antagonist that, unlike naltrexone or naloxone, does not pass the blood-brain barrier, and therefore does not impair the centrally mediated analgesic effect of opioids. It is licensed for the treatment of opioid-induced constipation in palliative care in more than 50 countries. This article presents practically relevant pharmacological data, basic research results and evidence from clinical research about methylnaltrexone, and outlines potential future therapeutic options for this promising drug.

Prolonged-release oxycodone/naloxone in nonmalignant pain: single-center study in patients with constipation

INTRODUCTION

Opioid treatment for chronic malignant and nonmalignant pain of moderateto-severe intensity is associated with bowel dysfunction leading to constipation; this often requires opioid dose reduction or interruption. Combination opioid agonist/antagonist therapy can restore normal bowel function. A prolonged-released (PR) fixed-dose combination of oxycodone and naloxone has been developed and efficacy has been demonstrated in phase 3 clinical trials.

METHODS

This 2-month, retrospective, singlecenter, observational study assessed the effectiveness and safety of PR oxycodone/naloxone in consecutive nononcological patients with constipation and chronic pain despite analgesic treatment; specific subgroup analyses were performed in opioid-experienced or opioid-naïve patients and in age subgroups. Efficacy was assessed by: intensity of pain; bowel function; effective oxycodone/naloxone dose; Patients' Global Impression of Change (PGIC) scale; rescue paracetamol; and laxative use. Safety evaluations were also performed.

RESULTS

Of 1,051 patients starting on the oxycodone/naloxone combination (32.0% male; mean age 67 ± 13 years, 53.9% opioid naïve), 1,012 completed 2 months of treatment. Overall, PR oxycodone/naloxone was associated with a significant decrease in pain intensity (P < 0.001), a reduced need for rescue paracetamol (P < 0.001), and PGIC score of "very much improved" or "much improved" in 84.0% of patients. Constipation markedly decreased (P < 0.001) despite reduced laxative use (P < 0.001 vs. baseline). The most frequent treatment-emergent adverse events were somnolence (2.0%), dizziness (1.1%), and confusion (1.0%). Clinical differences in endpoints were seen between opioid-naïve and opioid-experienced patients, and among agestratified groups, but efficacy was similar to the overall population.

CONCLUSIONS

Fixed combination PR oxycodone/naloxone was effective and well tolerated in moderate-to-severe chronic pain in patients with constipation, providing analgesia and relief from bowel dysfunction. Consistent efficacy across patient subgroups provides guidance for daily management of chronic pain when therapy options are limited due to bowel dysfunction, regardless of age or previous medication. Supplementary material belonging to this paper is available on SpringerLink.

Combined oral prolonged-release oxycodone and naloxone in chronic pain management

INTRODUCTION

The use of opioids is associated with unwanted adverse effects, particularly opioid-induced constipation (OIC). The adverse effects of opioids on gastrointestinal function are mediated by the interaction with opioid receptors in the gastrointestinal tract. The most common drugs used for relieving OIC are laxatives, which do not address the opioid receptor-mediated bowel dysfunction and do not provide sufficient relief.

AREAS COVERED

This paper discusses the role of a combination of prolonged-release formulation of oxycodone (OX) and naloxone (N) in the prevention and management of OIC, reporting efficacy and safety outcome of controlled studies. In a therapeutic area of great unmet need, the combination tablet of prolonged release of OX and N (PR OXN) could offer patients effective analgesia, while improving opioid-induced bowel dysfunction.

EXPERT OPINION

PR OXN offers a unique and specific mechanism to control OIC in patients receiving chronic opioid therapy. This combination has the potential advantage of preventing OIC, particularly in subgroups of population, like elderly or advanced cancer patients. This approach can decrease the use of laxatives and additional medications, which represent a burden for patients presenting comorbidities requiring multiple medications.

Prolonged-release Oxycodone/Naloxone in Postoperative Pain Management: From a Randomized Clinical Trial to Usual Clinical Practice

Objective:

These studies evaluated the feasibility of using oral prolonged-release oxycodone/naloxone (OXN PR) for the management of acute postoperative pain.

Methods:

Three studies were undertaken: (i) the analgesic efficacy of OXN PR was compared with prolonged-release oxycodone (OXY PR) in patients with knee arthroplasty in an immediate postoperative period (IPOP) study; (ii) OXN PR treatment was compared with other opioids during rehabilitation after knee arthroplasty in a noninterventional study (NIS); and (iii) surgical patients on other opioids were switched to OXN PR postoperatively during a quality improvement programme (QIP).

Results:

In the IPOP study, the pain intensity at rest score decreased by a similar amount in the OXN PR and OXY PR groups, indicating similar analgesic efficacies. In the NIS, patient assessments indicated enhanced efficacy and tolerability for OXN PR compared with other opioids. The QIP indicated significant improvements in bowel function and less difficulty passing urine at the end of OXN PR treatment compared with baseline. No safety concerns were raised.

Conclusions:

The analgesic efficacies of OXN PR and OXY PR were similar in postoperative pain settings. OXN PR reduced the degree of restriction in relation to patients carrying out physio - therapy compared with other opioids, and improved bowel and bladder function.

Opioid/naloxone prolonged release combinations for opioid induced constipation

I read with great interest the recent article by Chen et al in a recent issue of your esteemed journal. The article is highly thought provoking. One emerging therapeutic alternative for opioid induced constipation is the emergence of opioid/naloxone prolonged release combinations. For instance, naloxone when administered in a 1:2 ratio with oxycodone reverses the inhibitory effect of oxycodone on the gastrointestinal tract. The advantage of oxycodone/naloxone prolonged release (OXN) is that while its anti-nociceptive efficacy is equivalent to that of oxycodone prolonged release (OXC), it significantly decreases the “Bowel Function Index” thereby ameliorating symptoms of opioid induced constipation to a large extent. Schutter et al in a recent study have reported a decrease in the bowel function index from 38.2 to 15.1. Similarly, Löwenstein et al in another recent study have reported that following a month of therapy, complete spontaneous bowel movements per week is increased from one in OXC therapy to three in OXN therapy.

The impact of opioid analgesics on the gastrointestinal tract function and the current management possibilities

Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal symptoms such as constipation, anorexia, nausea, vomiting, gastro-oesophageal reflux, delayed digestion, abdominal pain, bloating, hard stool and incomplete evacuation that significantly deteriorate patients' quality of life and compliance. Approximately one third of patients treated with opioids do not adhere to the opioid regimen or simply quit the treatment due to OIBD. Several strategies are undertaken to prevent or treat OIBD. Traditional oral laxatives are used but their effectiveness is limited and they display adverse effects. Other possibilities comprise opioid switch or changing the administration route. New therapies target opioid receptors in the gut that seem to be the main source of OIBD. One is a combination of an opioid and opioid antagonist (oxycodone/naloxone) in prolonged-release tablets, and another is a purely peripherally acting opioid receptor antagonist (methylnaltrexone) available in subcutaneous injections. The aim of this article is to review the pathomechanism and possible treatment strategies of OIBD.

Prolonged-release oxycodone/naloxone in the treatment of neuropathic pain - results from a large observational study

OBJECTIVES

Opioids have shown consistent efficacy in neuropathic pain, but opioid-induced bowel dysfunction is a relevant problem. In controlled clinical trials, a fixed-dose combination of prolonged-release (PR) oxycodone/PR naloxone was superior to oxycodone alone in bowel function, while providing effective analgesia. The present report is an analysis of its efficacy and safety in a subgroup of patients with severe chronic neuropathic pain who were treated in a large observational study under real-life conditions.

RESEARCH DESIGN AND METHODS

Dosed according to pain severity, 1488 patients with chronic severe neuropathic pain received PR oxycodone/PR naloxone for up to 4 weeks. Variables included pain severity, patient-reported bowel function (Bowel Function Index; BFI) and quality of life.

RESULTS

During treatment with PR oxycodone/PR naloxone, mean pain intensity decreased in opioid-naive and opioid-pretreated patients. After 4 weeks on treatment, mean BFI scores were reduced from 41.6 ± 31.6 at the initiation visit to 16.5 ± 19.6 (p < 0.001), reflecting normal bowel function. Quality of life was improved by 47%.

CONCLUSIONS

Treatment of severe neuropathic pain with PR oxycodone/PR naloxone provided effective analgesia with the added benefit of favorable effects on bowel function and quality of life.