Phase IIb, Randomized, Double-Blind, Placebo-Controlled Study of Naldemedine for the Treatment of Opioid-Induced Constipation in Patients With Cancer

Impacts of genetic polymorphisms and cancer cachexia on naldemedine pharmacokinetics and bowel movements in patients receiving opioid analgesics

BACKGROUND/OBJECTIVES

Clinical responses to naldemedine vary between individuals with advanced cancer. This is a prospective, single-center, observational study aimed to evaluate the influence of genetic polymorphisms and cachexia status on plasma naldemedine and clinical responses.

METHODS

Forty-eight patients being treated with naldemedine for opioid-induced constipation under treatment of cancer pain were enrolled. Plasma naldemedine concentrations were determined on the fourth day or later after administration of naldemedine, and the associations with genotypes, cachexia status, and clinical responses were assessed.

RESULTS

Cancer patients exhibited a large variation in the plasma naldemedine concentrations, and it was correlated with serum total protein level. Patients who were homozygous CYP3A5*3 had a higher plasma concentration of naldemedine than those with the *1 allele. ABCB1 genotypes tested in this study were not associated with plasma naldemedine. A negative correlation was observed between the plasma naldemedine concentration and 4β-hydroxycholesterol level. The plasma naldemedine concentration was lower in patients with refractory cachexia than in those with precachexia and cachexia. While serum levels of interleukin-6 (IL-6) and acute-phase proteins were higher in patients with refractory cachexia, they were not associated with plasma naldemedine. A higher plasma concentration of naldemedine, CYP3A5*3/*3, and an earlier naldemedine administration after starting opioid analgesics were related to improvement of bowel movements.

CONCLUSION

Plasma naldemedine increased under deficient activity of CYP3A5 in cancer patients. Cachectic patients with a higher serum IL-6 had a lower plasma naldemedine. Plasma naldemedine, related to CYP3A5 genotype, and the initiation timing of naldemedine were associated with improved bowel movements.

Opioid analgesics for nociceptive cancer pain: A comprehensive review

Pain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo-controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate-certainty to low-certainty evidence). Nonsteroidal anti-inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate-to-severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.

Efficacy and safety of naldemedine for opioid-induced constipation in older patients with cancer: a retrospective study

BACKGROUND

Opioids are pain relievers that are often associated with opioid-induced constipation (OIC) that worsens with age. We performed a multicenter, retrospective analysis on the efficacy and safety of naldemedine, an opioid receptor antagonist, in treating OIC in patients with cancer (age >75 years).

METHODS

The electronic medical records of cancer patients who received naldemedine at 10 Japanese institutions between 7 June 2017 and August 31, 2019, were retrieved. Patients aged ≥75 years who were treated with naldemedine for the first time and hospitalized for at least 7 days before and after initiating naldemedine therapy were included in this analysis.

RESULTS

Sixty patients were observed for at least 7 days before and after starting naldemedine. The response rate was 68.3%, and the frequency of bowel movements increased significantly after naldemedine administration in the overall population ( P  < 0.0001) and among those who defecated <3 times/week before naldemedine administration ( P  < 0.0001). Diarrhea was the most frequent adverse event in all grades, observed in 45% of patients, of which 92.6% were Grade 1 or 2. Grade 4 or higher adverse events, including death, were not observed.

CONCLUSION

Naldemedine exhibits significant efficacy and safety in OIC treatment in older patients with cancer.

The Management of Opioid-Induced Constipation in Cancer and Advanced Illness: A Meta-Analysis

CONTEXT

Constipation is a common problem among patients with cancer. By some accounts, about 60% of cancer patients experience constipation. There is limited empirical evidence of the clinical effectiveness of pharmacologic agents in opioid-induced constipation in advanced diseases.

OBJECTIVES

We sought to quantitatively summarize the therapeutic effectiveness of the pharmacologic means of managing opioid-induced constipation.

METHODS

Randomized control trials (RCTs) identified from medical literature databases that reported quantitative measures of the effect of pharmacotherapeutic agents to treat opioid induced constipation in patients with cancers and other advanced illnesses were included in this study. A conventional random effects meta-analysis was conducted including >3 trials with the same exposure and outcome assessed, and a network-meta-analysis was conducted for all placebo-controlled trials.

RESULTS

Eighteen studies that examined the effect of various pharmacotherapeutic agents were included. The medications were Methylnatrexone (N = 5), Naldemedine (N = 5), other conventional agents (N = 4) and herbal medicines (N = 4). In conventional meta-analysis, methylnaltrexone increased the proportion achieving rescue-free laxation by 2.68 fold (95% CI: 1.34, 5.37; P = 0.0054) within 4 hours of the administration compared to placebo. In network meta-analysis, the pooled RR of the pharmacotherapeutic agents on rescue-free bowel movements as 2.26 (95% CI: 1.52, 3.36) for methylnaltrexone, 1.58 (95% CI: 0.94, 2.66) for naldemedine, and 0.74 (95% CI: 0.45, 1.23) for polyethylene glycol, compared to placebo.

CONCLUSION

Methylnatrexone and Naldemedine have currently shown promise in randomized trials concerning opioid-induced constipation in cancer and advanced illness. It is imperative that future research ascertain not just the relative therapeutic efficacy but also the cost-benefit analyses of these newer regimens with more commonly used and accessible laxatives.

Pharmacological prevention and treatment of opioid-induced constipation in cancer patients: A systematic review and meta-analysis

BACKGROUND

Cancer-related pain often requires opioid treatment with opioid-induced constipation (OIC) as its most frequent gastrointestinal side-effect. Both for prevention and treatment of OIC osmotic (e.g. polyethylene glycol) and stimulant (e.g. bisacodyl) laxatives are widely used. Newer drugs such as the peripherally acting µ-opioid receptor antagonists (PAMORAs) and naloxone in a fixed combination with oxycodone have become available for the management of OIC. This systematic review and meta-analysis aims to give an overview of the scientific evidence on pharmacological strategies for the prevention and treatment of OIC in cancer patients.

METHODS

A systematic search in PubMed, Embase, Web of Science and the Cochrane Library was completed from inception up to 22 October 2022. Randomized and non-randomized studies were systematically selected. Bowel function and adverse drug events were assessed.

RESULTS

Twenty trials (prevention: five RCTs and three cohort studies; treatment: ten RCTs and two comparative cohort studies) were included in the review. Regarding the prevention of OIC, three RCTs compared laxatives with other laxatives, finding no clear differences in effectivity of the laxatives used. One cohort study showed a significant benefit of magnesium oxide compared with no laxative. One RCT found a significant benefit for the PAMORA naldemedine compared with magnesium oxide. Preventive use of oxycodone/naloxone did not show a significant difference in two out of three other studies compared to oxycodone or fentanyl. A meta-analysis was not possible. Regarding the treatment of OIC, two RCTs compared laxatives, of which one RCT found that polyethylene glycol was significantly more effective than sennosides. Seven studies compared an opioid antagonist (naloxone, methylnaltrexone or naldemedine) with placebo and three studies compared different dosages of opioid antagonists. These studies with opioid antagonists were used for the meta-analysis. Oxycodone/naloxone showed a significant improvement in Bowel Function Index compared to oxycodone with laxatives (MD -13.68; 95 % CI -18.38 to -8.98; I2 = 58 %). Adverse drug event rates were similar amongst both groups, except for nausea in favour of oxycodone/naloxone (RR 0.51; 95 % CI 0.31-0.83; I2 = 0 %). Naldemedine (NAL) and methylnaltrexone (MNTX) demonstrated significantly higher response rates compared to placebo (NAL: RR 2.07, 95 % CI 1.64-2.61, I2 = 0 %; MNTX: RR 3.83, 95 % CI 2.81-5.22, I2 = 0 %). With regard to adverse events, abdominal pain was more present in treatment with methylnaltrexone and diarrhea was significantly more present in treatment with naldemedine. Different dosages of methylnaltrexone were not significantly different with regard to both efficacy and adverse drug event rates.

CONCLUSIONS

Magnesium oxide and naldemedine are most likely effective for prevention of OIC in cancer patients. Naloxone in a fixed combination with oxycodone, naldemedine and methylnaltrexone effectively treat OIC in cancer patients with acceptable adverse events. However, their effect has not been compared to standard (osmotic and stimulant) laxatives. More studies comparing standard laxatives with each other and with opioid antagonists are necessary before recommendations for clinical practice can be made.

A Systematic Review of Naldemedine and Naloxegol for the Treatment of Opioid-Induced Constipation in Cancer Patients

BACKGROUND

Opioid-induced constipation (OIC) is a pervasive and distressing side effect of chronic opioid therapy in patients with cancer pain, significantly impacting their quality of life. Peripherally acting μ-opioid receptor antagonists (PAMORAS) were developed for treatment-resistant OIC but most studies were conducted with non-cancer patients.

OBJECTIVE

to discuss two oral formulations of PAMORAs, naldemedine and naloxegol, and to review available evidence of the effectiveness of these drugs for OIC in cancer patients.

METHODS

a comprehensive search to identify primary literature for either naldemedine or naloxegol for OIC in cancer patients.

RESULTS

Only three prospective randomized, double-blind, placebo-controlled clinical trials for naldemedine enrolling cancer patients were identified; the results of a subgroup analysis of two of those studies and two non-interventional post marketing surveillance studies of these trials are also reported here. For naloxegol, only two randomized controlled trials were identified; both were unsuccessful in enrolling sufficient patients. An additional four prospective non-interventional observational studies with naloxegol were found that enrolled cancer patients. There were significantly higher rates of responders in the PAMORA groups than in the placebo groups. The most common side effect for both PAMORAs was diarrhea.

LIMITATIONS

All studies were industry-funded, and given that only three trials were randomized controlled studies, the overall quality of the studies was lacking.

CONCLUSION

Naldemedine or naloxegol appeared safe and useful in the treatment of OIC in cancer patients and may improve their quality of life. Larger-scale randomized placebo-controlled studies of PAMORAs in cancer patients would strengthen existing evidence.

Abdominal massage for chronic constipation in the elderly: a systematic review and meta-analysis protocol

INTRODUCTION

Chronic constipation (CC) is a highly prevalent health challenge that is particularly challenging to treat in elderly patients. Although lifestyle guidance and laxative therapy often yield positive outcomes, patients occasionally struggle with maintaining dietary control. Therefore, identifying an economical and safe alternative therapy to the existing treatment methods documented in the international literature is necessary. This systematic review and meta-analysis aims to evaluate the efficacy and safety of abdominal massage in elderly patients with CC to provide a basis for future mechanistic research.

METHODS AND ANALYSIS

Electronic searches will be conducted to identify clinical randomised controlled trials in various databases, including Web of Science, PubMed, Cumulated Index to Nursing and Allied Health Literature, Cochrane Library, Embase, Airiti Library, Chinese National Knowledge Infrastructure Databases, Chinese Science and Technology Periodical Database (VIP), Chinese Biomedical Literature Database and Wan Fang Database. Relevant data will be extracted, and a meta-analysis will be conducted using Reviewer Manager V.5.4. Quality and risk assessments of the included studies will be performed, and the outcome indicators of the trials will be observed. This review will evaluate abdominal massage as a treatment option for relieving symptoms and improving quality of life in elderly patients with CC. Moreover, it will provide additional insights for clinical treatment and mechanistic studies. The search will be performed following the publication of this protocol (estimated to occur on 30 December 2023).

ETHICS AND DISSEMINATION

As this is a literature review, ethics approval will not be required. We will disseminate the findings of this study to publications in peer-reviewed journals as well as presentations at relevant national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42023408629.

Naldemedine versus placebo in opioid-induced constipation: a meta-analysis

OBJECTIVE

Opioid-induced constipation (OIC) is a frequent adverse event among patients receiving chronic pain therapy that is requiring opioids. Naldemedine was approved by the Food and Drug Administration to treat OIC and appears to be more efficient than any other peripherally acting µ-opioid receptor antagonist. This meta-analysis aimed at assessing the available data on naldemedine in terms of efficacy.

METHODS

We searched the Cochrane Library, PubMed and ClinicalTrials on 24 May 2022 to identify randomised controlled trials (RCTs) comparing naldemedine to placebo among patients reporting OIC.

RESULTS

Evaluation of 6 RCTs enrolling 2769 participants showed significantly greater respondence to treatment (OR=2.48; 95% CI: 2.02 to 3.06; p<0.00001), change in weekly spontaneous bowel movements (SBMs) (mean difference=1.45; 95% CI: 1.14 to 1.76; p<0.00001), complete SBMs (mean difference=0.89; 95% CI: 0.62 to 1.17; p<0.00001) and SBMs without straining (mean difference=0.89; 95% CI: 0.61 to 1.17; p<0.00001) for patients treated with naldemedine. We found no difference in numeric pain rating scales after one (mean difference=0.05; 95% CI: -0.22 to 0.31; p=0.73) and two weeks of treatment (mean difference= -0.04; 95% CI: -0.31 to 0.22; p=0.75). Funding and clinical diversity were possible risks of bias.

CONCLUSIONS

Naldemedine improves a variety of bowel function parameters while preserving analgesia, confirming its efficacy for patients with OIC. However, head-to-head trials are needed to establish naldemedine as treatment of first choice for laxative-refractory OIC.

PROSPERO REGISTRATION NUMBER

CRD42022281353.

Current Management of Chronic Constipation in Japan

Constipation is a complicated condition. Chronic constipation is diagnosed when constipation occurs for more than 3 months. Chronic constipation is classified using patient symptoms and the pathophysiology. New therapeutic agents to treat chronic constipation have recently been approved in Japan. However, treatments for constipation that is refractory to traditional laxatives have been approved, an algorithm for the treatment of chronic constipation has not yet been developed. The accumulation of knowledge and data is necessary to develop a new algorithm.

Efficacy and Safety of Naldemedine Administration for Opioid-Induced Constipation in Cancer Patients with Poor Performance Status

Background: Constipation is a concern among patients with Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 3 and 4. Objectives: To assess naldemedine's efficacy and safety in cancer patients on opioids with poor PS. Design: Multicenter, retrospective study. Setting/Subjects: Japanese cancer patients with ECOG performance status 3 or 4 who received naldemedine. Measurements: Frequency of defecations before/after naldemedine use. Responders were patients whose defecation frequency increased to ≥3 times/week, from baseline ≥1 defecations/week over seven days after naldemedine administration. Results: Seventy-one patients were analyzed; 66.1% were responders (95% confidence interval: 54.5%-76.1%). Defecation frequency increased significantly after naldemedine in the overall population (6 vs. 2, p < 0.0001) and among those who defecated <3 times/week before naldemedine (4.5 vs. 1, p < 0.0001). Diarrhea (38.0%) of all grades was the most common adverse event; 23 (85.2%) events were classified as Grade 1 or 2. Conclusion: Naldemedine is effective and safe among cancer patients with poor PS.

A Retrospective Study of the Efficacy and Safety of Naldemedine for Treatment of Opioid-Induced Constipation in Patients with Hepatobiliary Pancreatic Cancer

Background and Objectives: Opioid analgesics, which are used for cancer-related pain management, cause opioid-induced constipation (OIC). Naldemedine, a peripheral opioid receptor antagonist, is an OIC-modifying agent, but no focused efficacy and safety analysis has been conducted for its use in hepatobiliary pancreatic cancers. We performed a multi-institutional study on the efficacy and safety of naldemedine in patients with hepatobiliary pancreatic cancer using opioids in clinical practice. Materials and Methods: We retrospectively evaluated patients with hepatobiliary pancreatic cancer (including liver, biliary tract, and pancreatic cancers) treated with opioids and naldemedine during hospitalization at ten institutions in Japan from June 2017 to August 2019. We assessed the frequency of bowel movements before and after the initiation of naldemedine therapy. Responders were defined as patients who defecated ≥3 times/week, with an increase from a baseline of ≥1 defecations/week over seven days after the initiation of naldemedine administration. Results: Thirty-four patients were observed for one week before and one week after starting naldemedine. The frequency of bowel movements increased by one over the baseline frequency or to at least thrice per week in 21 patients. The response rate was 61.7% (95% confidence interval: 45.4–78.0%). The median number of weekly bowel movements before and after naldemedine treatment was 2 (range: 0–9) and 6 (range: 1–17), respectively, in the overall population (n = 34); the increase in the number of bowel movements following naldemedine administration was statistically significant (Wilcoxon signed-rank test, p < 0.0001). Diarrhea was the predominant gastrointestinal symptom, and 10 (29.4%) patients experienced grade 1, grade 2, or grade 3 adverse events. The only other adverse event included fatigue in one patient; grade 2–4 adverse events were absent. Conclusions: Naldemedine is effective, and its use may be safe in clinical practice for patients with hepatobiliary pancreatic cancer receiving opioid analgesics.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

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

Mu-opioid antagonists for opioid-induced bowel dysfunction in people with cancer and people receiving palliative care

BACKGROUND

Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events (AEs) of treatment for pain in cancer and palliative care, resulting in increased morbidity and reduced quality of life. This review is a partial update of a 2008 review, and critiques as previous update (2018) trials only for people with cancer and people receiving palliative care.

OBJECTIVES

To assess for OIBD in people with cancer and people receiving palliative care the effectiveness and safety of mu-opioid antagonists (MOAs) versus different doses of MOAs, alternative pharmacological/non-pharmacological interventions, placebo, or no treatment.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science (December 2021), clinical trial registries and regulatory websites. We sought contact with MOA manufacturers for further data.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the effectiveness and safety of MOAs for OIBD in people with cancer and people at a palliative stage irrespective of the type of terminal disease.

DATA COLLECTION AND ANALYSIS

Two review authors assessed risk of bias and extracted data. The appropriateness of combining data from the trials depended upon sufficient homogeneity across trials. Our primary outcomes were laxation response, effect on analgesia, and AEs. We assessed the certainty of evidence using GRADE and created summary of findings tables.

MAIN RESULTS

We included 10 studies (two new trials) randomising in-total 1343 adults with cancer irrespective of stage, or at palliative care stage of any disease. The MOAs were oral naldemedine and naloxone (alone or in combination with oxycodone), and subcutaneous methylnaltrexone. The trials compared MOAs with placebo, MOAs at different doses, or in combination with other drugs. Two trials of naldemedine and three of naloxone with oxycodone were in people with cancer irrespective of disease stage. The trial on naloxone alone was in people with advanced cancer. Four trials on methylnaltrexone were in palliative care where most participants had advanced cancer. All trials were vulnerable to biases; most commonly, blinding of the outcome assessor was not reported.  Oral naldemedine versus placebo Risk (i.e. chance) of spontaneous laxations in the medium term (over two weeks) for naldemedine was over threefold greater risk ratio (RR) 2.00, 95% confidence interval (CI) 1.59 to 2.52, 2 trials, 418 participants, I² = 0%. Number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 3 to 4; moderate-certainty evidence). Earlier risk of spontaneous laxations and patient assessment of bowel change was not reported. Very low-certainty evidence showed naldemedine had little to no effect on opioid withdrawal symptoms. There was little to no difference in the risk of serious (non-fatal) AEs (RR 3.34, 95% CI 0.85 to 13.15: low-certainty evidence). Over double the risk of AEs (non-serious) reported with naldemedine (moderate-certainty evidence). Low-dose oral naldemedine versus higher dose Risk of spontaneous laxations was lower for the lower dose (medium term, 0.1 mg versus 0.4 mg: RR 0.69, 95% CI 0.53 to 0.89, 1 trial, 111 participants (low-certainty evidence)). Earlier risk of spontaneous laxations and patient assessment of bowel change not reported. Low-certainty evidence showed little to no difference on opioid withdrawal symptoms (0.1 mg versus 0.4 mg mean difference (MD) -0.30, 95% CI -0.85 to 0.25), and occurrences of serious AEs (0.1 mg versus 0.4 mg RR 0.25, 95% CI 0.03 to 2.17). Low-certainty evidence showed little to no difference on non-serious AEs. Oral naloxone versus placebo Risk of spontaneous laxations and AEs not reported. Little to no difference in pain intensity (very low-certainty evidence). Full data not given. The trial reported that no serious AEs occurred. Oral naloxone + oxycodone versus oxycodone Risk of spontaneous laxations within 24 hours and in the medium term not reported. Low-certainty evidence showed naloxone with oxycodone reduced the risk of opioid withdrawal symptoms. There was little to no difference in the risk of serious (non-fatal) AEs (RR 0.68, 95% CI 0.44 to 1.06), 3 trials, 362 participants, I² = 55%: very low-certainty evidence). There was little to no difference in risk of AEs (low-certainty evidence).  Subcutaneous methylnaltrexone versus placebo Risk of spontaneous laxations within 24 hours with methylnaltrexone was fourfold greater than placebo (RR 2.97, 95% CI 2.13 to 4.13. 2 trials, 287 participants, I² = 31%. NNTB 3, 95% CI 2 to 3; low-certainty evidence). Risk of spontaneous laxations in the medium term was over tenfold greater with methylnaltrexone (RR 8.15, 95% CI 4.76 to 13.95, 2 trials, 305 participants, I² = 47%. NNTB 2, 95% CI 2 to 2; moderate-certainty evidence). Low-certainty evidence showed methylnaltrexone reduced the risk of opioid withdrawal symptoms, and did not increase risk of a serious AE (RR 0.59, 95% CI 0.38 to 0.93. I² = 0%; 2 trials, 364 participants). The risk of AEs was higher for methylnaltrexone (low-certainty evidence). Lower-dose subcutaneous methylnaltrexone versus higher dose There was little to no difference in risk of spontaneous laxations in the medium-term (1 mg versus 5 mg or greater: RR 2.91, 95% CI 0.82 to 10.39; 1 trial, 26 participants very low-certainty evidence), or in patient assessment of improvement in bowel status (RR 0.98, 95% CI 0.71 to 1.35, 1 trial, 102 participants; low-certainty evidence). Medium-term assessment of spontaneous laxations and serious AEs not reported. There was little to no difference in symptoms of opioid withdrawal (MD -0.25, 95% CI -0.84 to 0.34, 1 trial, 102 participants) or occurrence of AEs (low-certainty evidence).

AUTHORS' CONCLUSIONS

This update's findings for naldemedine and naloxone with oxycodone have been strengthened with two new trials, but conclusions have not changed. Moderate-certainty evidence for oral naldemedine on risk of spontaneous laxations and non-serious AEs suggests in people with cancer that naldemedine may improve bowel function over two weeks and increase the risk of AEs. There was low-certainty evidence on serious AEs. Moderate-certainty evidence for methylnaltrexone on spontaneous laxations over two weeks suggests subcutaneous methylnaltrexone may improve bowel function in people receiving palliative care, but certainty of evidence for AEs was low. More trials are needed, more evaluation of AEs, outcomes patients rate as important, and in children.

A retrospective study of the efficacy and safety of naldemedine for opioid-induced constipation in thoracic cancer patients

Background

We conducted a multicenter, retrospective study on the efficacy and safety of naldemedine in thoracic cancer patients using opioids in clinical practice.

Methods

We retrospectively evaluated thoracic cancer patients treated with naldemedine at 10 institutions in Japan. Clinical data of patients administered naldemedine between June 2017 and August 2019 were extracted from electronic medical records. Inclusion criteria were as follows: (i) patients hospitalized for at least seven days before and after naldemedine administration, and (ii) those whose frequency of defecation was entered in the medical records.

Results

Forty patients were analyzed, and defecation frequency was observed for at least seven days before and after naldemedine administration. The response rate was 65.0% (95% CI: 50.2%–79.7%). The number of defecations increased significantly after naldemedine administration in the overall population, as well as among only those who defecated <3 times/week before naldemedine administration, and those that were administered ≥30 mg/day of morphine equivalent. Diarrhea was the most common adverse event in all grades, occurring in 11 patients (27.5%), of which 9 (81.8%) were grade 1 or 2. None of the patients experienced grade 4 or higher adverse events.

Conclusion

The efficacy and safety of naldemedine for thoracic cancer patients in clinical practice were comparable with those of prospective studies, which suggest that naldemedine may be effective and feasible for most thoracic cancer patients.

Efficacy and Safety of Naldemedine for Patients with Cancer with Opioid-Induced Constipation in Clinical Practice: A Real-World Retrospective Study

The efficacy and safety of naldemedine for opioid-induced constipation in patients with cancer has not been investigated in clinical practice. We conducted a multicenter, retrospective study to assess the effects of naldemedine among 10 Japanese institutions between June 2017 and August 2019. We evaluated the number of defecations 7 days before and after naldemedine administration. A total of 149 patients (89 male) with a median age of 72 years (range, 38−96) were included. The performance status was 0−1, 2, and ≥3 in 40, 38, and 71 patients, respectively. The median opioid dose in oral morphine equivalents was 30 mg/day (range: 7.5−800 mg). We observed 98 responders and 51 non-responders. The median number of defecations increased significantly in the 7 days following naldemedine administration from three to six (p < 0.0001). Multivariate analysis revealed that an opioid dose <30 mg/day [odds ratio, 2.08; 95% confidence interval, 1.01−4.32; p = 0.042] was significantly correlated with the effect of naldemedine. Diarrhea was the most common adverse event (38.2%) among all grades. The efficacy and safety of naldemedine in clinical practice are comparable to those of prospective studies, suggesting that it is effective in most patients.

Effects of Electroacupuncture on Opioid-Induced Constipation in Patients With Cancer: Study Protocol for a Multicenter Randomized Controlled Trial

Background

Opioid-induced constipation (OIC) is one of the most prevalent adverse events associated with cancer patients who receive opioid analgesics for moderate to severe pain. Acupuncture may be an effective treatment for OIC. We designed this trial to assess the efficacy and safety of electroacupuncture for OIC in cancer patients.

Methods

This is a multicenter, sham-controlled, parallel-group, subject- and assessor-blinded randomized trial. A total of 100 cancer patients with OIC will be randomly assigned to either the electroacupuncture group or the sham electroacupuncture group at a ratio of 1:1. Patients in each group will receive a total of 24-session treatment over 8 weeks, three sessions a week and 30 min each session. Thereafter, patients will be followed up for another 8 weeks. The primary outcome will be the proportion of responders, defined as a patient who has ≥3 spontaneous bowel movements (SBMs)/wk and ≥ increase of 1 SBM from baseline simultaneously for at least 6 out of 8 weeks of the treatment period. The secondary outcomes will include the mean weekly SBMs and complete spontaneous bowel movements, the mean Bristol Stool Form Scale score for stool consistency, the mean score for straining of SBM, the total and subscale scores of Patient Assessment of Constipation-Symptom questionnaires, and the total and subscale scores of Patient Assessment of Constipation-Quality of Life questionnaire. Patients' global assessment of treatment effectiveness, patients' expectation toward the effectiveness of acupuncture and safety of acupuncture will also be assessed. All efficacy analyses will be performed in the intention-to-treat population.

Discussion

To improve the adherence to intervention protocols, the majority of the participants will be recruited from an inpatient setting. The results will help to determine the clinical effects and safety of electroacupuncture for the treatment of OIC among patients with cancer.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT03797586, registered on 4 January 2019, https://clinicaltrials.gov/ct2/show/NCT03797586.

Revision of Pharmacological Treatment Recommendations for Cancer Pain: Clinical Guidelines from the Japanese Society of Palliative Medicine

Background: Pain is one of the most common symptoms in cancer patients. The Japanese Society for Palliative Medicine (JSPM) first published its clinical guidelines for the management of cancer pain in 2010. Since then, more research on cancer pain management has been reported, and new drugs have become available in Japan. Thus, the JSPM has now revised the clinical guidelines using a validated methodology. Methods: This guideline was developed through a systematic review, discussion, and the Delphi method, following a formal guideline development process. Results: Thirty-five recommendations were created: 19 for the pharmacological management of cancer pain, 6 for the management of opioid-induced adverse effects, and 10 for pharmacological treatment procedures. Due to the lack of evidence that directly addressed our clinical questions, most of the recommendations had to be based on consensus among committee members and other guidelines. Discussion: It is critical to continue to build high-quality evidence in cancer pain management, and revise these guidelines accordingly.

Naldemedine for opioid-induced constipation

Generic name: Naldemedine tosylate Brand name: Rizmoic Formulation: 200 mcg film-coated tablets Market Authorisation holder: Shionogi B.V Indication: Treatment of opioid-induced constipation in adult patients who have previously been treated with a laxative Dose: 200 mcg/day, taken at the same time every day. Naldemedine may be used with or without a laxative. It must be discontinued if treatment with the opioid is discontinued. Cost: £41.72 for 28 tablets Classification: Prescription only medicine subject to additional monitoring (▼).

Post-marketing surveillance of the safety and effectiveness of naldemedine in the management of opioid-induced constipation in patients with cancer pain in Japan

Purpose

This prospective post-marketing surveillance (PMS) was designed to collect data on the safety and effectiveness of naldemedine in routine clinical practice in patients with opioid-induced constipation (OIC) and cancer pain in Japan and explore the characteristics of patients prone to diarrhea.

Methods

The enrolled patients received naldemedine (0.2 mg, once a day) orally for up to 12 weeks. In the safety analysis, adverse drug reactions (ADRs), including diarrhea as a special interest, were assessed. Effectiveness was evaluated, especially regarding the frequency and condition of bowel movement.

Results

In the safety analysis set (n = 1177), 145 ADRs occurred in 133 (11.30%) patients, and diarrhea was the most frequent event (n = 107, 9.09%). Most cases of diarrhea were non-serious (98.1%). Most ADRs were non-serious (93.8%), and they resolved within 2 weeks (75.9%). No patient characteristics influenced the risk of diarrhea development or aggravation. Both the frequency (75.0% and 83.2%) and condition of bowel movement (80.0% and 88.0%) were improved at 2 and 12 weeks, respectively in the effectiveness analysis set (n = 953). Frequency and condition of bowel movement were also improved in patients excluded (e.g., Eastern Cooperative Oncology Group performance status was ≥ 3) or with very small numbers (e.g., received weak opioid) in the clinical trials.

Conclusions

This PMS indicates that naldemedine is well tolerated and effective in patients of various backgrounds in routine clinical practice who have OIC and cancer pain.

Trial registration

UMIN000042851.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-022-06807-y.

Real-World Patient Characteristics and Treatment Patterns of Naldemedine for the Treatment of Opioid-Induced Constipation in Patients with Cancer: A Multicenter Retrospective Chart Review Study

Background and Objectives: Naldemedine is a peripherally acting μ-opioid receptor antagonist that improves opioid-induced constipation. Although clinical trials have excluded patients with poor performance status (PS) and those started on naldemedine early after opioid initiation, clinical practice has used naldemedine for the same patients. Therefore, we investigated the treatment patterns of naldemedine in a real-world setting. Materials and Methods: This was a multicenter, retrospective chart review study of opioid-treated patients with cancer receiving naldemedine. Adverse events that occurred within 7 days of naldemedine initiation were evaluated in those who received one or more doses of the same. Effectiveness was assessed in patients who used naldemedine for more than 7 days. Results: A total of 296 patients satisfied the eligibility criteria, among whom 129 (43.6%) had a PS of ≥3 and 176 (59.5%) started naldemedine within 2 weeks of opioid initiation. Moreover, 203 (79.6%) patients had ≥3 bowel movements per week. Incidences of all grades of diarrhea and abdominal pain were 87 (29.4%) and 12 (4.1%), respectively. No patient had grade 4 or higher adverse events. Conclusions: Although nearly half of the patients receiving naldemedine in clinical practice belonged to populations that were not included in the clinical trials, our results suggested that naldemedine in clinical practice had the same efficacy and safety as that in clinical trials.

Analysis of Predictive Factors for Diarrhea after the Administration of Naldemedine

Naldemedine (NAL), a peripherally acting μ-opioid receptor antagonist, is effective for opioid-induced constipation (OIC). However, diarrhea is the most common adverse event. We investigated the incidence of NAL-induced diarrhea in patients who started NAL at Nagasaki University Hospital between June 2017 and March 2019. Predictors of NAL-induced diarrhea were analyzed using a multivariate logistic regression model. Two hundred and forty-two patients were included in the present study, and NAL-induced diarrhea was observed in 17.8% (43 patients). The results of multiple logistic regression analyses identified the administration of opioid analgesics for 8 d or longer before the initiation of NAL (odds ratio (OR): 2.20, 95% confidence interval (95% CI): 1.04-4.64, p = 0.039), the combination of a laxative (OR: 2.22, 95%CI: 1.03-4.81, p = 0.042), and the combination of CYP3A4 inhibitors (strong/moderate) (OR: 2.80, 95%CI: 1.02-7.67, p = 0.045) as risk factors. Therefore, the development of diarrhea needs to be considered in patients with these risk factors. Furthermore, diarrhea may be controlled by the initiation of NAL within 7 d of opioid analgesics and, where possible, the discontinuation of or change in the combination of moderate or strong CYP3A4 inhibitors.

Efficacy and Safety of Peripherally Acting μ-Opioid Receptor Antagonist (PAMORAs) for the Management of Patients With Opioid-Induced Constipation: A Systematic Review

In treating chronic and acute pain, opioids are widely used. Although they do provide analgesia, their usage does come with adverse events (AEs). One of the most burdensome is opioid-induced bowel dysfunction, and more specifically opioid-induced constipation (OIC). The pathogenesis of these AEs is well known as the consequence of the action of opioids on m-receptors in the enteric nervous system. In recent years, medicines counteracting this specific action at the receptors have been registered for clinical use: the peripherally acting μ-opioid receptor antagonists (PAMORAs). The knowledge of their comparative efficacy and tolerability is very important for physicians and patients in opioid therapy. This systematic review of the existing literature on PAMORAs aimed to study the relative clinical advantages and disadvantages. The most important data banks, including "PubMed," "Embase," "CT.gov," "ICTRP" and "CINAHL" were used to find the published material on PAMORAs. The selected publications were examined to systematically analyze the efficacy and safety of the four existing PAMORAs. All of the medications are superior to placebo in reducing OIC. There are few published data on alvimopan used to treat OIC, and it is only indicated for the treatment of post-abdominal surgery ileus. Methylnaltrexone is studied mainly in its subcutaneous (SC) formulation. When used in its oral formulation, it seems more rapid than naloxegol and placebo in the reduction of OIC. Naldemedine is able to produce more spontaneous bowel movements (SBMs) when compared to alvimopan and naloxegol. Tolerability was found to be similar for all of them. In particular, they affect the gastrointestinal tract (GI), with flatulence and diarrhea, especially at high dosages. For some of them, nasopharyngitis and abdominal pain were observed as treatment adverse effects (TEAs). Several cardiovascular TEAs were reported after methylnaltrexone use, but it is not clear whether they were consequences of the drug or related to the general conditions of the patients. Considering the existing data, naloxegol and naldemedine seem to be the best choices, with a higher number of spontaneous bowel movements following naldemedine administration.

Insights into the Use of Peripherally Acting μ-Opioid Receptor Antagonists (PAMORAs) in Oncologic Patients: from Scientific Evidence to Real Clinical Practice

OPINION STATEMENT

Management of chronic pain is crucial to improve the quality of life of cancer and palliative care patients. Opioid-based treatments used to control pain can be prolonged over time. Unfortunately, constipation is one of the most disturbing adverse effects of long-term use of opioids. Opioid-induced constipation (OIC) occurs when opioids bind to the specific receptors present in the gastrointestinal (GI) tract, and can affect any patients receiving chronic opioid therapy, including cancer patients. The limited efficacy of laxatives to treat OIC symptoms prompted the search for new therapeutic strategies. Peripherally acting μ-opioid receptor antagonists (PAMORAs) have recently emerged as new effective drugs for OIC management due to their specific binding to enteric μ-receptors. Little information is available on the use of PAMORAs in real-life practice for OIC treatment in cancer patients. In this paper, a panel of experts specializing in cancer and palliative care pools their clinical experience with PAMORAs in cancer patients presenting OIC and highlights the importance of timing and choice of therapy in achieving prompt OIC management and benefitting patients.

Management of Opioid-Induced and Non-Opioid-Related Constipation in Patients With Cancer: Systematic Review and Meta-Analysis

PROBLEM IDENTIFICATION

A systematic review and meta-analysis was conducted to inform the development of national clinical practice guidelines on the management of cancer constipation.

LITERATURE SEARCH

PubMed®, Wiley Cochrane Library, and CINAHL® were searched for studies published from May 2009 to May 2019.

DATA EVALUATION

Two investigators independently reviewed and extracted data from eligible studies. The Cochrane Collaboration risk-of-bias tool was used, and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to assess the certainty of the evidence.

SYNTHESIS

For patients with cancer and opioid-induced constipation, moderate benefit was found for osmotic or stimulant laxatives; small benefit was found for methylnaltrexone, naldemedine, and electroacupuncture. For patients with cancer and non-opioid-related constipation, moderate benefit was found for naloxegol, prucalopride, lubiprostone, and linaclotide; trivial benefit was found for acupuncture.

IMPLICATIONS FOR PRACTICE

Effective strategies for managing opioid-induced and non-opioid-related constipation in patients with cancer include lifestyle, pharmacologic, and complementary approaches.

SUPPLEMENTAL MATERIAL CAN BE FOUND AT&NBSP;HTTPS

//bit.ly/3c4yewT.

ONS Guidelines™ for Opioid-Induced and Non-Opioid-Related Cancer Constipation

PURPOSE

This evidence-based guideline intends to support clinicians, patients, and others in decisions regarding the treatment of constipation in patients with cancer.

METHODOLOGIC APPROACH

An interprofessional panel of healthcare professionals with patient representation prioritized clinical questions and patient outcomes for the management of cancer-related constipation. Systematic reviews of the literature were conducted. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to assess the evidence and make recommendations.

FINDINGS

The panel agreed on 13 recommendations for the management of opioid-induced and non-opioid-related constipation in patients with cancer.

IMPLICATIONS FOR NURSING

The panel conditionally recommended a bowel regimen in addition to lifestyle education as first-line treatment for constipation. For patients starting opioids, the panel suggests a bowel regimen as prophylaxis. Pharmaceutical interventions are available and recommended if a bowel regimen has failed. Acupuncture and electroacupuncture for non-opioid-related constipation are recommended in the context of a clinical trial.

SUPPLEMENTARY MATERIAL CAN BE FOUND AT&NBSP;HTTPS

//bit.ly/30y29sI.

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.

Naldemedine: A New Option for OIBD

Opioid-induced bowel dysfunction (OIBD) is a common complication in long-term opioid users and abusers. It is a burdensome condition, which significantly limits quality of life and is associated with increasing health costs. OIBD affects up to 60% of patients with chronic non-cancer pain and over 80% of patients suffering from cancer pain and is one of the conditions of the most common symptoms associated with opioid maintenance. Given the continued use of opioids for chronic pain management in appropriate patients, OIBD is likely to persist in clinical practice in the coming years. We will herein review its underlying pathophysiological mechanisms and the available treatments. In the last years, pharmaceutical research has focused on the opportunity of targeting peripheral mu-opioid receptors without affecting their analgesic activity in the central nervous system, and several peripherally acting mu-opioid receptors antagonists (PAMORAs) drugs have been approved. We will mainly focus on naldemedine, discussing its pharmacological properties, its clinical efficacy and side effects. Head-to-head comparisons between naldemedine and the other PAMORAs are not available yet, but some considerations will be discussed based on the pharmacological and clinical data. As a whole, the available data suggest that naldemedine is a valid treatment option for OIBD, as it is a well-tolerated drug that alleviates constipation without affecting analgesia or causing symptoms of opioid withdrawal.

The Use of Peripheral μ-Opioid Receptor Antagonists (PAMORA) in the Management of Opioid-Induced Constipation: An Update on Their Efficacy and Safety

Peripherally acting μ-opioid receptor antagonists (PAMORAs) constitute a class of drugs which reverse opioid-induced constipation (OIC) with similar opioid analgesic effects. OIC differs from other forms of constipation in that it is an iatrogenic condition that occurs when an opioid acts on the dense network of μ-opioid receptors in the enteric system, which affect a variety of functions including gastrointestinal motility, secretion, and other factors that can cause bowel dysfunction. Unfortunately, laxative products, bowel regimens, dietary changes, and lifestyle modifications have limited effectiveness in preventing OIC, Opioid-associated adverse effect which occurs in 40% to 80% of opioid patients and may led to cessation of the treatment. PAMORAs are μ-receptor opioid antagonists specifically developed so that they have very limited ability to cross the blood-brain barrier and thus they are able to antagonize peripheral but not central μ-opioid receptors. PAMORAs are designed to have no effect on the analgesic benefits of opioid pain relievers but to relieve but antagonizing the effects of the opioid in the gastrointestinal system. The three main PAMORAS are methyltrexone (oral or parenteral), naldemedine (oral only), and naloxegol (oral only). Clinical studies demonstrate the safety and efficacy of these agents for alleviating constipation without diminishing the analgesic effect of opioid therapy. The aim of this narrative review to update the current status of PAMORAs for treating OIC in terms of safety and efficacy.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Prevention and management of diarrhea associated with naldemedine among patients receiving opioids: a retrospective cohort study

BACKGROUND

Naldemedine, a novel peripherally-acting mu-opioid receptor antagonist, has improved opioid-induced constipation in randomized controlled trials. The most frequent adverse event of naldemedine is diarrhea, which can cause abdominal pain and often leads to treatment discontinuation. We aimed to identify risk factors and appropriate management strategies for key adverse events including diarrhea associated with naldemedine, since those have not been extensively studied.

METHODS

We conducted a multi-center retrospective cohort study. Eligible patients had cancer, had undergone palliative care at participating centers, had been prescribed regular opioids, and had taken at least one dose of naldemedine between June 2017 and March 2018. The primary endpoint was the incidence of diarrhea according to baseline characteristics. Secondary endpoints included the duration of naldemedine administration, daily defecation counts before and after starting naldemedine, duration and severity of diarrhea as an adverse event of naldemedine, other adverse events, and the incidence of constipation within 7 days after recovery from diarrhea. We defined patients who started naldemedine within three days of starting a regularly prescribed opioid as the early group, and the remainder as the late group.

RESULTS

Among 103 patients who received naldemedine, 98 fulfilled the eligibility criteria. The median age was 68 years and 48% of the patients were female. Median performance status was 3, and the median oral intake was 50%. The median duration of naldemedine administration and overall survival were 25 and 64 days, respectively. The incidence of diarrhea in the early group (n = 26) was significantly lower than in the late group (n = 72) (3.9% vs. 22.2%, p = 0.02). Daily defecation counts increased after late (median 0.43 to 0.88, p < 0.001), but remained stable after early naldemedine administration (median 1.00 to 1.00, p = 0.34). Constipation after the diarrhea was resolved was common (53%), especially among patients who stopped naldemedine (78%). The diarrhea was improved within three days in 92% of patients who stopped other laxatives.

CONCLUSIONS

The early administration of naldemedine is beneficial because it reduces adverse events including diarrhea. Diarrhea caused by naldemedine can be effectively managed by stopping other laxatives while continuing naldemedine.

Naldemedine: A Review in Opioid-Induced Constipation

Naldemedine [Symproic^® (Japan; USA); Rizmoic^® (EU)], an orally available peripherally acting μ-opioid receptor antagonist (PAMORA), is approved in several countries for the treatment of opioid-induced constipation. In phase III trials, naldemedine was more effective than placebo at increasing the frequency of bowel movements in patients with constipation induced by opioid treatment for cancer pain or chronic non-cancer pain. Naldemedine was also associated with improvements in patient-rated constipation-related symptoms and quality of life. Naldemedine was generally well tolerated, including over the longer term. Because naldemedine specifically targets opioid receptors in the gastrointestinal (GI) tract and does not cross the blood-brain barrier, it does not cause opioid withdrawal symptoms or interfere with centrally mediated opioid analgesia. Consistent with its mechanism of action, the most commonly reported adverse events were GI in nature. In conclusion, current data indicate that naldemedine is an effective and generally well-tolerated treatment option for opioid-induced constipation in patients with cancer pain or chronic non-cancer pain, with the convenience of once-daily oral dosing.

Safety and efficacy of naldemedine in cancer patients with opioid-induced constipation: a pooled, subgroup analysis of two randomised controlled studies

Objective

This post hoc, pooled, subgroup analysis of two randomised studies evaluated baseline characteristics that may influence the efficacy and safety of naldemedine in patients with opioid-induced constipation (OIC) and cancer.

Methods

Data for patients who received 0.2 mg naldemedine or placebo were pooled from randomised, placebo-controlled, phase IIb and phase III studies. Proportions of spontaneous bowel movement (SBM) responders and patients with diarrhoea were assessed for each treatment group. For the patient subgroups with or without possible blood–brain barrier (BBB) disruptions, changes in Numerical Rating Scale (NRS) and Clinical Opioid Withdrawal Scale (COWS) scores were assessed.

Results

A total of 307 patients were included in this analysis (naldemedine: n=155; placebo: n=152). The pooled proportion of SBM responders was 73.5% with naldemedine versus 35.5% with placebo. There was a significant increase in the proportion of SBM responders with naldemedine versus placebo (38.0% (95% CI 27.6% to 48.4%); p<0.0001). Greater proportions of SBM responders and patients who experienced diarrhoea were observed with naldemedine versus placebo in all subgroups. Changes from baseline in NRS and COWS scores were similar with naldemedine or placebo in patients with or without brain metastases.

Conclusions

Although not powered to detect statistically significant differences in treatment effect among subgroups, this study demonstrated that naldemedine appeared to benefit patients with OIC and cancer, irrespective of baseline characteristics, and did not seem to affect analgesia or withdrawal–even in patients with potential BBB disruptions. Baseline characteristics did not appear to affect the incidence of diarrhoea in patients who received naldemedine.

Trial registration numbers

JapicCTI-111510 and JapicCTI-132340.

Risk Factors and Prevention Strategies for Postoperative Opioid Abuse

Worldwide, 80% of patients who undergo surgery receive opioid analgesics as the fundamental agent for pain relief. However, the irrational use of opioids leads to excessive drug dependence and drug abuse, resulting in an increased mortality rate and huge economic loss. The crisis of opioid overuse remains a great challenge. In this review, we summarize several key factors in opioid abuse, including race, region, income, genetic factors, age and gender, smoking and alcohol abuse, history of chronic pain and analgesic drug abuse, surgery, neuropsychiatric illness, depression and antidepressant use, human factors, national policies, hospital regulations, and health insurance under treatment of pain. Furthermore, we present several prevention strategies, such as perioperative measures, opioid substitutes, treatment of the primary illness, emotional regulation, use of opioid antagonists, efforts of the state, hospitals, doctors and pharmacy benefit managers, gene therapy, and vaccines. Greater understanding and better assessment are required of the risks associated with opioid abuse to ensure the safety and analgesic effects of pain treatment after surgery.

Peripherally acting μ-opioid antagonist for the treatment of opioid-induced constipation: Systematic review and meta-analysis

BACKGROUND AND AIM

Opioid-induced constipation (OIC) is a frequent adverse event (AE) that impairs patients' quality of life (QOL). Peripherally acting μ-opioid receptor antagonists (PAMORAs) have been recognized as a treatment option for OIC, but the effect consistent across the studies has not been evaluated.

METHODS

We conducted a quantitative meta-analysis to explore the efficacy of PAMORA for OIC (registered with PROSPERO: CRD42018085298). We systematically searched randomized controlled trials (RCTs) in Medline, Embase, and Central databases. Change from baseline in spontaneous bowel movements, pooled proportion of responders, QOL, and AEs were calculated and compared with results in placebo cases.

RESULTS

We included 31 RCTs with 7849 patients. A meta-analysis revealed that patients under PAMORA therapy had considerably improved spontaneous bowel movement from baseline compared with those given placebo (20 RCTs; mean difference, 1.43; 95% confidence interval [CI], 1.18-1.68; n = 5622) and more responded (21 RCTs; risk ratio [RR], 1.81; 95% CI, 1.55-2.12; n = 4821). Moreover, QOL of patients receiving PAMORA was significantly better (8 RCTs; mean difference, -0.22; 95% CI, -0.28 to -0.17; n = 2884). AEs were increased significantly in the PAMORA group (26 RCTs; RR, 1.10; 95% CI, 1.06-1.15; n = 7715), especially in gastrointestinal disorders, whereas serious AEs were not significant (17 RCTs; RR, 1.04; 95% CI, 0.85-1.28; n = 5890).

CONCLUSION

Peripherally acting μ-opioid receptor antagonist has been shown to be effective and durable for patients with OIC and is the only drug with confirmed evidence in meta-analysis. The possibility of publication bias was the limitation of this study.

Opioid-induced constipation: a narrative review of therapeutic options in clinical management

Pain therapy often entails gastrointestinal adverse events. While opioids are effective drugs for pain relief, the incidence of opioid-induced constipation (OIC) varies greatly from 15% to as high as 81%. This can lead to a significant impairment in quality of life, often resulting in discontinuation of opioid therapy. In this regard, a good doctor-patient relationship is especially pivotal when initiating opioid therapy. In addition to a detailed history of bowel habits, patient education regarding the possible gastrointestinal side effects of the drugs is crucial. In addition, the bowel function must be regularly evaluated for the entire duration of treatment with opioids. Furthermore, if the patient has preexisting constipation that is well under control, continuation of that treatment is important. In the absence of such history, general recommendations should include sufficient fluid intake, physical activity, and regular intake of dietary fiber. In patients of OIC with ongoing opioid therapy, the necessity of opioid use should be critically reevaluated in terms of an with acceptable quality of life, particularly in cases of non-cancer pain. If opioids must be continued, lowering the dose may help, as well as changing the type of opioid. If these measures do not suffice, the next step for persistent OIC is the administration of laxatives. If these are ineffective as well, treatment with peripherally active μ-opioid receptor antagonists should be considered. Enemas and irrigation are emergency measures, often used as a last resort.

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.

A meta-analysis of naldemedine for the treatment of opioid-induced constipation

INTRODUCTION

Opioid-induced constipation (OIC) is a common adverse effect in patients under long-term opioid therapy. Naldemedine is a novel peripherally acting μ-opioid receptor antagonists being developed for the treatment of OIC without affecting central analgesia. This meta-analysis is to assess the current evidence for efficacy and safety of naldemedine for the treatment of OIC. Areas covered: We searched through MEDLINE, EMBASE, Web of Science and Cochrane Library, 'ISRCTN Register' and'ClinicalTrials.gov' (up to Aug 2018). Our final review included five randomized clinical trials (1751 participants in total), three trials observed naldemedine for the treatment of OIC in non-cancer patients and two trials in cancer patients. A Random Effects model was used for all comparisons. Subgroup analyses for the following subgroups were carried out: naldemedine 0.1 mg; 0.2 mg; 0.4 mg; cancer patients; non-cancer patients. Expert opinion: Naldemedine improved the proportion of responders and spontaneous bowel movements frequency. The incidence of serious adverse effects (AEs) in naldemedine group was higher than placebo, especially in cancer patient subgroup. The AEs occurred in participants with naldemedine were mild to moderate and well tolerated during treatment. The results of this network meta-analysis will guide the future researchers in evaluating naldemedine for the treatment of OIC.

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.

Population Pharmacokinetics and Exposure-Response Relationships of Naldemedine

Purpose

To characterize population pharmacokinetic (PK) of naldemedine, to identify factors which influence naldemedine PK, and to evaluate their clinical relevancy based on exposure-response relationships.

Methods

A population PK model was developed with pooled naldemedine concentrations from healthy subjects, patients with chronic non-cancer pain and opioid-induced constipation (OIC), and cancer patients with OIC. Exposure-response analyses were performed with efficacy (responder or non-responder) and safety (occurrence of gastrointestinal disorders or not) data in phase 2b and phase 3 studies.

Results

Naldemedine plasma concentrations were adequately described by a 2-compartment model with first-order absorption and absorption lag time. The final model included the effects of age, creatinine clearance, race, and gender on apparent total clearance; the effects of body weight, health status, and food condition on apparent volume of central compartment; and the effect of age on first-order rate of absorption. When subjects took 0.2 mg of naldemedine once daily, the probability of spontaneous bowel movement (SBM) responders was predicted to be approximately 50%, while that of severe gastrointestinal disorders was predicted to be less than 3%. The influence of the covariates on PK was not considered clinically significant because similar efficacy and safety were expected based on the exposure-response analysis.

Conclusions

The covariates are identified in the population PK analysis; however, no dose-adjustment is required for them based on the exposure-response analysis.

Electronic supplementary material

The online version of this article (10.1007/s11095-018-2501-7) contains supplementary material, which is available to authorized users.

Mu-opioid antagonists for opioid-induced bowel dysfunction in people with cancer and people receiving palliative care

BACKGROUND

Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events of treatment for pain in cancer and in palliative care, resulting in increased morbidity and reduced quality of life.This is an update of two Cochrane reviews. One was published in 2011, Issue 1 on laxatives and methylnaltrexone for the management of constipation in people receiving palliative care; this was updated in 2015 and excluded methylnaltrexone. The other was published in 2008, Issue 4 on mu-opioid antagonists (MOA) for OIBD. In this updated review, we only included trials on MOA (including methylnaltrexone) for OIBD in people with cancer and people receiving palliative care.

OBJECTIVES

To assess the effectiveness and safety of MOA for OIBD in people with cancer and people receiving palliative care.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, and Web of Science to August 2017. We also searched clinical trial registries and regulatory websites. We contacted manufacturers of MOA to identify further data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that assessed the effectiveness and safety of MOA for OIBD in people with cancer and people at a palliative stage irrespective of the type of terminal disease they experienced.

DATA COLLECTION AND ANALYSIS

Two review authors assessed risk of bias and extracted data. The appropriateness of combining data from the trials depended upon sufficient homogeneity across the trials. Our primary outcomes were laxation, impact on pain relief, and adverse events. Impact on pain relief was a primary outcome because a possible adverse effect of MOAs is a reduction in pain relief from opioids. We assessed the evidence on these outcomes using GRADE.

MAIN RESULTS

We identified four new trials for this update, bringing the total number included in this review to eight. In total, 1022 men and women with cancer irrespective of stage or at a palliative care stage of any disease were randomised across the trials. The MOAs evaluated were oral naldemedine and naloxone (alone or in combination with oxycodone), and subcutaneous methylnaltrexone. The trials compared with MOA with a placebo or with the active intervention administered at different doses or in combination with other drugs. The trial of naldemedine and the two of naloxone in combination with oxycodone were in people with cancer irrespective of disease stage. The trial on naloxone alone was in people with advanced cancer. The four trials on methylnaltrexone were undertaken in palliative care where most participants had cancer. All trials were vulnerable to biases; four were at a high risk as they involved a sample of fewer than 50 participants per arm.In the trial of naldemedine compared to placebo in 225 participants, there were more spontaneous laxations over the two-week treatment for the intervention group (risk ratio (RR) 1.93, 95% confidence intervals (CI) 1.36 to 2.74; moderate-quality evidence). In comparison with higher doses, lower doses resulted in fewer spontaneous laxations (0.1 mg versus 0.2 mg: RR 0.73, 95% CI 0.55 to 0.95; 0.1 mg versus 0.4 mg: RR 0.69, 95% CI 0.53 to 0.89; moderate-quality evidence). There was moderate-quality evidence that naldemedine had no effect on opiate withdrawal. There were five serious adverse events. All were in people taking naldemedine (low-quality evidence). There was an increase in the occurrence of other (non-serious) adverse events in the naldemedine groups (RR 1.36, 95% CI 1.04 to 1.79, moderate-quality evidence). The most common adverse event was diarrhoea.The trials on naloxone taken either on its own, or in combination with oxycodone (an opioid) compared to oxycodone only did not evaluate laxation response over the first two weeks of administration. There was very low-quality evidence that naloxone alone, and moderate-quality evidence that oxycodone/naloxone, had no effect on analgesia. There was low-quality evidence that oxycodone/naloxone did not increase the risk of serious adverse events and moderate-quality evidence that it did not increase risk of adverse events.In combined analysis of two trials of 287 participants, we found methylnaltrexone compared to placebo induced more laxations within 24 hours (RR 2.77, 95% CI 1.91 to 4.04. I² = 0%; moderate-quality evidence). In combined analysis, we found methylnaltrexone induced more laxation responses over two weeks (RR 9.98, 95% CI 4.96 to 20.09. I² = 0%; moderate-quality evidence). The proportion of participants who had a rescue-free laxation response within 24 hours of the first dose was 59.1% in the methylnaltrexone arms and 19.1% in the placebo arm. There was moderate-quality evidence that the rate of opioid withdrawal was not affected. Methylnaltrexone did not increase the likelihood of a serious adverse event; there were fewer in the intervention arm (RR 0.59, 95% CI 0.38 to 0.93; I² = 0%; moderate-quality evidence). There was no difference in the proportion of participants experiencing an adverse event (RR 1.17, 95% CI 0.94 to 1.45; I² = 74%; low-quality evidence). Methylnaltrexone increased the likelihood of abdominal pain and flatulence.Two trials compared differing methylnaltrexone schedules of higher doses with lower doses. For early laxation, there was low-quality evidence of no clear difference between doses on analgesia and adverse events. Both trials measured laxation response within 24 hours of first dose (trial one: RR 0.82, 95% CI 0.41 to 1.66; trial two: RR 1.07, 95% CI 0.81 to 1.42).

AUTHORS' CONCLUSIONS

In this update, the conclusions for naldemedine are new. There is moderate-quality evidence to suggest that, taken orally, naldemedine improves bowel function over two weeks in people with cancer and OIBD but increases the risk of adverse events. The conclusions on naloxone and methylnaltrexone have not changed. The trials on naloxone did not assess laxation at 24 hours or over two weeks. There is moderate-quality evidence that methylnaltrexone improves bowel function in people receiving palliative care in the short term and over two weeks, and low-quality evidence that it does not increase adverse events. There is a need for more trials including more evaluation of adverse events. None of the current trials evaluated effects in children.

Drugs for Treating Opioid-Induced Constipation: A Mixed Treatment Comparison Network Meta-analysis of Randomized Controlled Clinical Trials

CONTEXT

Opioid-induced constipation is a common problem associated with chronic use of opioid analgesics.

OBJECTIVES

The objective of this study was to compare available interventions for the treatment of opioid-induced constipation, using principles of network meta-analysis.

METHODS

Electronic databases were searched for randomized controlled clinical trials evaluating drugs used in opioid-induced constipation. Number of patients with rescue-free bowel movements (RFBM) was the primary outcome, and time for achieving RFBM, adverse events, and changes in the analgesic activity of the opioid analgesics were the secondary outcomes. Inverse variance heterogeneity model was used for direct and mixed treatment comparison analysis. Odds ratio for categorical outcomes and weighted mean difference for numerical outcomes were the effect estimates.

RESULTS

We included a total of 23 studies in the systematic review and 21 in the network meta-analysis. Lubriprostone, prucalopride, naldemedine, naloxegol, alvimopan, subcutaneous, and oral methyl naltrexone were observed to perform better than placebo in terms of RFBM. Additionally, subcutaneous methyl naltrexone was significantly better than lubiprostone, naloxegol, oral methyl naltrexone, and prucalopride. Lubiprostone and naldemedine were associated with increased risks of adverse events. Subcutaneous methyl naltrexone did not significantly affect the analgesia due to background opioid use. Quality of evidence for the comparisons is either low or very low.

CONCLUSION

Subcutaneous methyl naltrexone was found to perform better than other interventions for managing opioid-induced constipation.

Phase 1, Randomized, Double-Blind, Placebo-Controlled Studies on the Safety, Tolerability, and Pharmacokinetics of Naldemedine in Healthy Volunteers

Naldemedine (S-297995) is a peripherally acting μ-opioid receptor antagonist for the treatment of opioid-induced constipation, a common side effect of opioid therapy. We determined the safety, tolerability, and pharmacokinetic profiles of oral naldemedine in healthy volunteers in 2 randomized, double-blind, placebo-controlled, phase 1 studies. In the single ascending dose study, subjects received a single dose of naldemedine (0.1-100 mg; n = 42) or placebo (n = 14). In the multiple ascending dose study, subjects received once-daily naldemedine (3-30 mg; n = 27) or placebo (n = 9) for 10 days. On day 1 of the single ascending dose studies and day 10 of the multiple ascending dose studies, respectively, the maximum plasma concentration levels of naldemedine were 1.98 to 2510 ng/mL and 73.8 to 700 ng/mL, peaked at 0.5 hours and 0.5 to 0.75 hours, and the fraction excreted in urine was 15.9% to 20.5% and 19.7% to 19.1%. There were no major safety or tolerability concerns even at naldemedine doses 150 to 500 times the therapeutic dose of 0.2 mg. The incidence of adverse events was not dose dependent. Gastrointestinal adverse events occurred more frequently with naldemedine vs placebo, and all of these were considered treatment related. Overall, naldemedine was rapidly absorbed, and no safety or tolerability issues were noted at the doses evaluated.