Randomized Phase III and Extension Studies of Naldemedine in Patients With Opioid-Induced Constipation and Cancer

The safety and effectiveness of naldemedine for opioid-induced constipation in patients with advanced cancer in real-world palliative care settings: a multicenter prospective observational study

PURPOSE

In this study, we aimed to evaluate the safety and effectiveness of naldemedine for treating opioid-induced constipation (OIC) in patients with advanced cancer, who are receiving palliative care, and particularly explored its early effects.

METHODS

Palliative care teams and inpatient palliative care units across 14 institutions in Japan were included in this multicenter, prospective, observational study. Patients who were newly prescribed a daily oral dose of 0.2 mg naldemedine were enrolled. The spontaneous bowel movement (SBM) within 24 h after the first dose of naldemedine was considered the primary outcome, whereas, the secondary outcomes included weekly changes in SBM frequency and adverse events.

RESULTS

A total of 204 patients were enrolled and 184 completed the 7-day study. The average age of the participants (103 males, 101 females) was 63 ± 14 years. The primary cancer was detected in the lungs (23.5%), gastrointestinal tract (13.7%), and urological organs (9.3%). A considerable proportion of patients (34.8%) had ECOG performance status of 3-4. Most patients were undergoing active cancer treatment, however, 40.7% of the patients were receiving the best supportive care. Within 24 h of the first naldemedine dose, 146 patients (71.6%, 95% CI: 65.4-77.8%) experienced SBMs. The weekly SBM counts increased in 62.7% of the participants. The major adverse events included diarrhea and abdominal pain, detected in 17.6% and 5.4% of the patients, respectively. However, no serious adverse events were observed.

CONCLUSION

Conclusively, naldemedine is effective and safe for OIC treatments in real-world palliative care settings.

TRIAL REGISTRATION NUMBER

UMIN000031381, registered 20/02/2018.

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.

Opioid-induced Constipation: Old and New Concepts in Diagnosis and Treatment

Daily use of opioid analgesics has significantly increased in recent years due to an increasing prevalence of conditions associated with chronic pain. Opioid-induced constipation (OIC) is one of the most common, under-recognized, and under-treated side effects of opioid analgesics. OIC significantly reduces the quality of life by causing psychological distress, lowering work productivity, and increasing access to healthcare facilities. The economic and social burden of OIC led to the development of precise strategies for daily clinical practice. Key aspects are the prevention of constipation through adequate water intake and fiber support, avoidance of sedentariness, and early recognition and treatment of cofactors that could worsen constipation. Recommended first-line therapy includes osmotic (preferably polyethylene glycol) and stimulant laxatives. Peripherally acting μ-opioid receptor antagonists, such as methylnaltrexone, naloxegol, or naldemedine, should be used in patients that have not responded to the first-line treatments. The bowel functional index is the main tool for assessing the severity of OIC and for monitoring the response. The paper discusses the recent literature on the pathophysiology, clinical evaluation, and management of OIC and provides a pragmatic approach for its assessment and treatment.

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.

Naldemedine and Magnesium Oxide as First-Line Medications for Opioid-Induced Constipation: A Comparative Database Study in Japanese Patients With Cancer Pain

Introduction Naldemedine and magnesium oxide are common first-line early laxative medications used in the real-world scenario in Japan, for patients with cancer pain who receive opioid prescriptions, as per a nationwide hospital claims database study. However, the real-world prescription patterns and associated outcomes are unknown. Methods In this retrospective, cohort study using the Medical Data Vision (MDV) database (January 2018 to December 2020), data were collected from eligible patients (who had a long-term prescription of strong opioids, for >30 days) in Japan with naldemedine or magnesium oxide as the first-line laxative prescription, for a long-term opioid prescription for cancer pain with ≥6 months post-opioid observation period. A laxative prescription within three days after the opioid prescription date was termed an "early" prescription. The composite incidence of dose increase or addition/change of laxatives at three months after the start of the opioid prescription was the primary endpoint after adjusting baseline characteristics between the treatment arms by propensity score matching. Results After propensity score matching, 1717 and 544 patients who were prescribed naldemedine and magnesium oxide each were included in the early prescription and non-early prescription groups, respectively. Even after matching, the incidence of death was not adjusted enough and was significantly higher in the naldemedine arm than in the magnesium oxide arm in the non-early group but comparable in the early group. The incidence of addition, change, or dose increase was significantly higher in the naldemedine arm than in the magnesium oxide arm of the early prescription group (hazard ratio (95% confidence interval), 1.08 (1.00, 1.17); p=0.0402); the incidence was comparable between the arms of the non-early group. Conclusion These findings may provide valuable insights into real-world clinical treatment patterns and preliminary evidence for the selection of first-line medications to mitigate opioid-induced constipation in Japanese patients with cancer pain.

Review document of the Spanish Association of Neurogastroenterology and Motility on the management of opioid-induced constipation

Opioid induced constipation is a rising problem due to the progressive increment in the prescription of opioids. By contrast to functional constipation, opioid-induced constipation is not a functional gut disorder, but a side effect of the use of opioids. Opioids produce constipation due to a decrease in gastrointestinal motility and a reduction in the gastrointestinal secretions. The treatment of OIC focuses on three basic pillars: optimizing opioid drug indication, preventing constipation onset, and treating it if it occurs. As with any other cause of constipation, lifestyle adjustments and laxatives should be the first-line treatment in the pharmacological management of OIC. Osmotic laxatives such as polyethylene glycol (PEG) are the agents of choice. PEG is inert and is neither fermented nor absorbed in the gastrointestinal tract. Furthermore, it has broad clinical applicability due to its favourable safety profile. If first-line treatments fail, peripheral mu receptor antagonists (PAMORA) are the drugs of choice. They reduce the peripheral effects of OIC with minimal potential to diminish analgesia or induce centrally mediated withdrawal syndrome. Different PAMORA are available in the market, both for oral and subcutaneous administration, with demonstrated efficacy for management of OIC in different clinical trials.

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.

Naldemedine is associated with earlier defecation in critically ill patients with opioid-induced constipation: A retrospective, single-center cohort study

INTRODUCTION

There are few reports describing the association of naldemedine with defecation in critically ill patients with opioid-induced constipation. The purpose of this study was to determine whether naldemedine is associated with earlier defecation in critically ill patients with opioid-induced constipation.

METHODS

In this retrospective cohort study, patients admitted to the Intensive Care Unit (ICU) without defecation for 48 hours while receiving opioids were eligible for enrollment. The primary endpoint was the time of the first defecation within 96 hours after inclusion. Secondary endpoints included presence of diarrhea, duration of mechanical ventilation, ICU length of stay, ICU mortality, and in-hospital mortality. The Cox proportional hazard regression analysis with time-dependent covariates was used to evaluate the association naldemedine with earlier defecation.

RESULTS

A total of 875 patients were enrolled and were divided into 63 patients treated with naldemedine and 812 patients not treated. Defecation was observed in 58.7% of the naldemedine group and 48.8% of the no-naldemedine group during the study (p = 0.150). The naldemedine group had statistically significantly prolonged duration of mechanical ventilation (8.7 days vs 5.5 days, p < 0.001) and ICU length of stay (11.8 days vs 9.2 days, p = 0.001) compared to the no-naldemedine group. However, the administration of naldemedine was significantly associated with earlier defecation [hazard ratio:2.53; 95% confidence interval: 1.71-3.75, p < 0.001].

CONCLUSION

The present study shows that naldemedine is associated with earlier defecation in critically ill patients with opioid-induced constipation.

Extreme opioid-induced constipation in advanced cancer: successful management

Unrecognised and untreated constipation may be a serious risk for complications, including definitive obstruction due to faecal impact or perforation due to the hypertensive intraluminal state. An intensive approach in an acute supportive palliative care unit may resolve the clinical picture allowing the resumption of intestinal transit in a short period of time.

Insights into the Current and Possible Future Use of Opioid Antagonists in Relation to Opioid-Induced Constipation and Dysbiosis

Opioid receptor agonists, particularly those that activate µ-opioid receptors (MORs), are essential analgesic agents for acute or chronic mild to severe pain treatment. However, their use has raised concerns including, among others, intestinal dysbiosis. In addition, growing data on constipation-evoked intestinal dysbiosis have been reported. Opioid-induced constipation (OIC) creates an obstacle to continuing treatment with opioid analgesics. When non-opioid therapies fail to overcome the OIC, opioid antagonists with peripheral, fast first-pass metabolism, and gastrointestinal localized effects remain the drug of choice for OIC, which are discussed here. At first glance, their use seems to only be restricted to constipation, however, recent data on OIC-related dysbiosis and its contribution to the appearance of several opioid side effects has garnered a great of attention from researchers. Peripheral MORs have also been considered as a future target for opioid analgesics with limited central side effects. The properties of MOR antagonists counteracting OIC, and with limited influence on central and possibly peripheral MOR-mediated antinociception, will be highlighted. A new concept is also proposed for developing gut-selective MOR antagonists to treat or restore OIC while keeping peripheral antinociception unaffected. The impact of opioid antagonists on OIC in relation to changes in the gut microbiome is included.

Influence of Brain Metastasis on Analgesia-Related Outcomes in Patients with Lung and Breast Cancers Treated with Naldemedine: A Propensity Score-Matched Analysis

Naldemedine is structurally designed to prevent passage across the blood-brain barrier (BBB), resulting in the attenuation of opioid-induced constipation without interfering with the analgesic effects of opioids. However, the influence of brain metastasis (BM), as one indicator of BBB disruption, on the analgesic effects of opioids in patients treated with naldemedine remains unclear. To examine whether the analgesic effects of opioids following naldemedine treatment are lower in patients with BM than in those without BM, we surveyed inpatients with lung and breast cancers treated with naldemedine at Fujita Health University Hospital between April 2017 and March 2022. Changes in the numeric rating scale (NRS) scores, morphine milligram equivalents (MMEs), and the number of rescues were assessed as analgesia-related outcomes during the first 7 days of naldemedine treatment in patients with or without BM, matched by the propensity score. In total, 172 patients were enrolled. After propensity-score matching, 30 patients with BM and 60 patients without BM were included in the analysis. Changes in NRS scores, MMEs, and the number of rescues did not differ between patients with and without BM. In the linear mixed-effects model, the coefficient of interaction between patients with or without BM and the days for each outcome was not statistically significant. BM does not influence the analgesic effect of opioids in patients with lung and breast cancers treated with naldemedine. Naldemedine may be useful for treating BM.

Prevalence of opioid-induced adverse events across opioids commonly used for analgesic treatment in Japan: a multicenter prospective longitudinal study

PURPOSE

Although opioids have been shown to be effective for cancer pain, opioid-induced adverse events (AEs) are common. To date, little is known about the differences in risks of AEs by opioid type. This study was performed to compare the prevalence of AEs across opioids commonly used for analgesic treatment in Japan.

METHODS

This study was conducted as a preplanned secondary analysis of a multicenter prospective longitudinal study of inpatients with cancer pain who received specialized palliative care for cancer pain relief. We assessed daily AEs until termination of follow-up. We rated the severity of AEs based on the Common Terminology Criteria for Adverse Events version 5.0. We computed adjusted odds ratios for each AE (constipation, nausea and vomiting, delirium, and drowsiness) with the following variables: opioid, age, sex, renal dysfunction, and primary cancer site.

RESULTS

In total, 465 patients were analyzed. Based on the descriptive analysis, the top four most commonly used opioids were included in the analysis: oxycodone, hydromorphone, fentanyl, and tramadol. With respect to the prevalence of AEs among all analyzed patients, delirium (n = 25, 6.3%) was the most frequent, followed by drowsiness (n = 21, 5.3%), nausea and vomiting (n = 19, 4.8%), and constipation (n = 28, 4.6%). The multivariate logistic analysis showed that no single opioid was identified as a statistically significant independent predictor of any AE.

CONCLUSION

There was no significant difference in the prevalence of AEs among oxycodone, fentanyl, hydromorphone, and tramadol, which are commonly used for analgesic treatment in Japan.

Naldemedine-induced opioid withdrawal with restlessness as the predominant symptom in a palliative care setting

OBJECTIVES

Opioid analgesics play a central role in cancer pain treatment; however, it has been reported that opioid-induced constipation (OIC) develops in 80% of patients using opioid analgesics and leads to a decrease in quality of life. Naldemedine improves constipation without affecting the analgesic action of opioid analgesics via peripheral μ-opioid receptors.

METHODS

We report a terminally ill cancer patient who was diagnosed with opioid withdrawal syndrome (OWS) based on symptoms centered around restlessness and sweating that developed 43 days after administration of naldemedine for OIC.

RESULTS

The patient was a 78-year-old woman who was diagnosed with stage IVB uterine sarcoma in October, 1 year prior to her visit to our clinic,  and underwent chemotherapy after surgery, but the disease became progressive. Thereafter, metastasis to the fourth thoracic vertebrae (Th4) was identified, and loxoprofen and acetaminophen were started for pain at the metastatic site. Oxycodone hydrochloride hydrate 10 mg/day was additionally administered on postoperative day 11, followed by naldemedine 0.2 mg/day for OIC. On the 43rd day after administration, the patient began to wander the hospital ward in a wheelchair and became noticeably restless. OWS due to naldemedine administration was suspected, and naldemedine was discontinued. The symptoms improved 7 days later, and no similar symptoms were observed thereafter.

SIGNIFICANCE OF RESULTS

Patients receiving palliative care often exhibit psychiatric symptoms such as anxiety and depression, but OWS due to naldemedine should also be considered as a potential cause.

Current Treatment Practices for Adult Patients with Constipation in Japan

BACKGROUND

The prevalence of constipation in Japan is estimated to be 2-5%. Constipation is a disease found in older adults. In particular, Japan is an aging society, with 65% of men and 80.5% of women aged 65 years or older accounting for the majority of its population. Chronic constipation may be associated with survival, cardiovascular events, decreased quality of life, and death. This study summarizes the recent findings regarding constipation treatment practice in Japan.

SUMMARY

Until recently, the diagnosis of constipation was mainly based on medical interviews; however, with the recent development of handheld ultrasound devices, both physicians and nurses can easily and objectively diagnose fecal retention. Magnesium oxide and stimulant laxatives have been the mainstay treatments; however, since 2012, more than five new drugs for treating constipation have become available in Japan.

KEY MESSAGES

Magnesium oxide is less effective in patients who use acid-secretion inhibitors and patients who have undergone total gastrectomy and should be cared for hypermagnesemia. In addition, regular use of stimulant laxatives may lead to colonic inertia and decreased bowel movements; therefore, they should be used only occasionally. The following is an overview of the different uses of conventional and newer laxatives for treating constipation.

Real-World Evidence for the Safety and Effectiveness of Naldemedine in the Management of Opioid-Induced Constipation in Patients With Cancer Pain: Post-hoc Subgroup Analysis of Post-marketing Surveillance in Japan

BACKGROUND

Opioid-induced constipation is common and greatly affects the quality of life but is often under-recognised and undertreated. This study aimed to investigate the safety and effectiveness of naldemedine for opioid-induced constipation with cancer pain according to specific subgroups of clinical interest.

METHODS

In this exploratory post-hoc subgroup analysis of post-marketing surveillance from Japan (UMIN: 000042851), data were investigated by the subgroups: age (≥75, <75 years), Eastern Cooperative Oncology Group performance status (PS 0-2, 3-4), constipation severity (mild, moderate, severe), brain metastasis (yes, no), anticancer drug treatment (yes, no), opioid at naldemedine initiation (fentanyl only, only strong opioids other than fentanyl, weak opioids only, other), and prior or concomitant use of laxative (only osmotic/saline laxatives, only stimulant laxatives, other, none). Enrolled patients (n = 1184) received naldemedine (0.2 mg once daily) orally for up to 12 weeks. Regarding safety endpoints, the incidence of adverse drug reactions, including diarrhoea, was determined within each subgroup. Regarding effectiveness endpoints, improvement rates in the frequency and condition of bowel movements were investigated by subgroups.

RESULTS

The incidence of adverse drug reactions, including diarrhoea, among subgroups ranged from 7.74% to 16.08% (diarrhoea: 5.95% to 13.19%), compared to 11.30% (diarrhoea: 9.09%) in the total population. Through week two to week 12, improvement rates in the frequency and condition of bowel movement among subgroups ranged from 63.6% to 89.7% and 67.6% to 94.9%, compared to 75.0% to 83.2% and 80.0% to 88.0% in the total population, respectively.

CONCLUSIONS

Naldemedine was well tolerated and effective in patients with opioid-induced constipation and cancer pain regardless of the subgroups investigated.

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.

Factors associated with non-response to naldemedine for opioid-induced constipation in cancer patients: A subgroup analysis

BACKGROUND

Opioid-induced constipation (OIC) is one of the most common adverse events of opioid therapy and can severely reduce quality of life (QOL). Naldemedine is the orally available peripheral-acting μ-opioid receptor antagonist approved for OIC treatment. However in daily clinical practice, some cancer patients show insufficient control of OIC even while receiving naldemedine.

OBJECTIVE

To identify factors associated with non-response to naldemedine in cancer patients.

METHODS

This study retrospectively analyzed 127 cancer patients prescribed naldemedine at Seirei Hamamatsu General Hospital in Japan between November 2016 and June 2021. For the regression analysis of factors associated with OIC, variables were extracted manually from electronic medical records. Naldemedine had been prescribed by the attending physician after the presence of OIC had been defined with reference to Rome IV diagnostic criteria. Naldemedine was evaluated as "effective" in cases where the number of defecations increased at least once in the first 3 days after starting naldemedine. Multivariate logistic regression analysis was performed to identify factors associated with non-response to naldemedine. The data used were from the group of patients who received naldemedine in our previous study.

RESULTS

Factors significantly associated with non-response to naldemedine included chemotherapy with taxanes within 1 month of evaluation of naldemedine effect (odds ratio [OR] = 0.063; 95% confidence interval [CI] = 0.007-0.568), and addition of or switching to naldemedine due to insufficient efficacy of prior laxatives (OR = 0.352, 95% CI = 0.129-0.966).

CONCLUSION

The identification of factors associated with non-response to naldemedine prescribed for OIC may help improve QOL among cancer patients.

Opioid withdrawal syndrome developing after long-term administration of naldemedine

OBJECTIVE

One of the side effects of opioid administration is opioid-induced constipation (OIC). To address this side effect, the oral peripheral μ opioid receptor antagonist naldemedine was developed. As this drug does not cross the blood-brain barrier, it is thought that it does not lead to opioid withdrawal syndrome (OWS) with central nervous system symptoms.

METHODS

Here, we report a cancer patient who presented with symptoms centered round anxiety and irritation 4 months after administration of naldemedine for OIC and who was diagnosed with OWS after close investigation.

RESULTS

The patient was a 65-year-old female who had surgery for stage IB endometrial cancer 4 years previously, but experienced recurrence involving the pelvis 2 years later. Medical narcotics were used to control pain, but naldemedine was started to control subsequent constipation. When naldemedine-related OWS was suspected and the administration of naldemedine discontinued, the above symptoms disappeared within two days, and no recurrence was observed thereafter.

SIGNIFICANCE OF THE RESULTS

For patients receiving naldemedine, it is necessary to consider the possibility of OWS regardless of the period of administration in order to maintain patient quality of life.

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.

In Silico Repurposed Drugs against Monkeypox Virus

Monkeypox is an emerging epidemic of concern. The disease is caused by the monkeypox virus and an increasing global incidence with a 2022 outbreak that has spread to Europe amid the COVID-19 pandemic. The new outbreak is associated with novel, previously undiscovered mutations and variants. Currently, the US Food and Drug Administration (FDA) approved poxvirus treatment involves the use of tecovirimat. However, there is otherwise limited pharmacopoeia and research interest in monkeypox. In this study, virtual screening and molecular dynamics were employed to explore the potential repurposing of multiple drugs previously approved by the FDA or other jurisdictions for other applications. Several drugs are predicted to tightly bind to viral proteins, which are crucial in viral replication, including molecules which show high potential for binding the monkeypox D13L capsid protein, whose inhibition has previously been demonstrated to suppress viral replication.

[Efficacy Survey of Naldemedine in the Poor-performance Status Group]

Naldemedine (Nal) is widely used as a therapeutic drug against opioid-induced constipation. However, patients in phase III trials are limited to those with good performance status (PS). Cancer patients may have inferior PS owing to progression of symptoms and adverse events from chemotherapy. Therefore, it is important to survey the efficacy of Nal in patients with poor PS. This study aimed to evaluate Nal efficacy in patients with poor PS. We retrospectively investigated patients from July 2017 to June 2019 and compared Nal efficacy between patients with good and poor PS. The efficacy of Nal was evaluated using changes in the number of spontaneous bowel movements 7 days before and after the introduction of Nal with reference to previous reports. Multivariate analysis was performed to reveal whether poor PS affects Nal efficacy. In total, 141 patients at the Hokkaido University Hospital were analyzed. The effective rate of Nal from day 1 to day 7 of administration was 71.7% and 71.4% in the patients with good and poor PS, respectively, that from day 1 to day 2 of administration was 61.1% and 57.1%, respectively, and that from day 3 to day 7 of administration was 60.2% and 71.4%, respectively, suggesting an absence of significant differences. Furthermore, results of multivariate analysis showed that "best supportive care" and "body weight (55 kg and above)" reduced Nal efficacy. In conclusion, Nal showed similar effectiveness in patients with poor PS as that in those with good PS.

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.

Constipation in Cancer Patients - an Update of Clinical Evidence

OPINION STATEMENT

Constipation is one of the most frequent problems in cancer patients, and its etiology is multifactorial. It leads to decreased quality of life and impedes optimal pain treatment. Despite the high prevalence, constipation is frequently underdiagnosed mainly because of lack of validated diagnostic criteria or widely accepted definition of constipation in cancer patients. All cancer patients should be evaluated regularly for constipation, and concomitant causes and risk factors were assessed. Opioids are responsible for a much of the secondary constipation in cancer patients. The management of constipation in cancer patients should be multifaceted, addressing dietary and behavioral issues and optimizing pharmacological interventions. Prevention of opioid-induced constipation (OIC) is pivotal, as treatment is often unsatisfactory or inefficient. Dietary and behavioral interventions should be considered. Non-pharmacological measures include hydration and nutrition, ensuring privacy during defecation, using a commode or footstool, and the availability of a caregiver. Abdominal massage may be of value. Traditional laxatives are recommended in prevention but not in the treatment of OIC. Peripherally acting mu-opioid receptor antagonists (PAMORA) appear the first choice in the treatment and an alternative to laxatives in some recent clinical practice guidelines in preventing OIC. Naldemedine, naloxegol, and methylnaltrexone are supported by quality evidence for OIC management. Naloxone or naltrexone, taken orally in combined formulations with opioids, may be valuable in preventing or reducing OIC symptoms.

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 (▼).

ADRB2 is a potential protective gene in breast cancer by regulating tumor immune microenvironment

Background

Breast cancer (BRCA) is the leading cause of cancer death among females. Studies suggested that β-adrenoceptors involved in tumor progression by regulating immune system. However, how ADRB2 affects the immune infiltration in BRCA is still being unraveled.

Methods

Expressions of ADRB2 in multiple tissues, cancers and blood cells were analyzed by using the Human Protein Atlas and UALCAN database. Expression differentiation of ADRB2 in tumor microenvironment (TME) of BRCA was detected in TISCH database. Correlations between ADRB2 and immune cell infiltration were analyzed by TIMER 2.0, and co-expression genes of ADRB2 were obtained from the cBioPortal website. Functional enrichment analyses and protein-protein interactions were constructed as well. Finally, the potential mechanisms of ADRB2 and candidate drugs targeting BRCA were discussed by using the Metascape, STITCH and Cmap tools.

Results

ADRB2 was significantly down-regulated in BRCA, and lower ADRB2 expression often resulted in worse prognosis in BRCA patients. ADRB2 was mainly expressed in breast tissue and blood. Among blood cell subtypes and TME of BRCA, ADRB2 was specifically expressed in T cell subtypes. Also, ADRB2 expression level was positively correlated with the infiltration levels of immune cells such as CD4+ T cell, CD8+ T cell, Tγδ and myeloid DC while negatively correlated with Treg, Tfh and myeloid-derived suppressor cell. Furthermore, functional enrichment analyses revealed that most enriched pathways were immune-related, especially in T cell-related pathways. Also, transcription factors (TFs) analyses showed that most downstream TFs regulated by ADRB2 were immune-related, and most candidate drugs had promising anti-tumor effects.

Conclusions

In conclusion, ADRB2 was a potential protective gene in BRCA, and it might play a vital role in regulating immune responses. The expression level of ADRB2 was positively correlated with immune cells infiltration in BRCA, especially for T cells. Therefore, ADRB2 would be a target for boosting immunotherapy effects in BRCA.

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.

Use of naldemedine is associated with reduced incidence of hyperactive delirium in cancer patients with opioid-induced constipation: a nationwide retrospective cohort study in Japan

BACKGROUND

Medical benefits of peripherally-acting mu-opioid receptor antagonists other than improving opioid-induced constipation remain unclear. Our aim was to evaluate the association between the use of naldemedine and incidence of hyperactive delirium in cancer patients receiving chemotherapy and opioid therapy.

METHODS

We conducted a propensity score-matched analysis using a nationwide inpatient database in Japan. Cancer patients receiving both inpatient chemotherapy and opioid therapy from June 1, 2017 to March 31, 2018 were included. Patients receiving naldemedine were matched to control patients by propensity score. Our primary outcome was the incidence of hyperactive delirium during hospitalization, and secondary outcomes were the length of hospital stay, hospital costs, in-hospital mortality, and incidence of ileus.

RESULTS

Of 34,031 patients receiving inpatient chemotherapy and opioid therapy, 1905 (5.6%) were included in the naldemedine group. After one-to-four propensity score matching, 1904 patients were included in the naldemedine group and 7616 in the control group. Naldemedine users had significantly reduced incidence of hyperactive delirium compared with the control patients (19.4% vs 23.3%; risk difference, -3.9 [95% confidence interval, -5.9 - -1.9]; risk ratio, 0.83 [0.75-0.92]; P<0.001; subdistribution hazard ratio, 0.85 [0.75-0.97]; P=0.015). The median length of hospital stay was significantly shorter in the naldemedine group compared with the control group (12 days [interquartile range, 6-23] vs 14 days [6-26]; P=0.001). The median hospital costs were also significantly lower in the naldemedine group compared with the control group (US $6179 [3351-10,026] vs US $6576 [3436-11,107]; P<0.001). No significant differences were found for in-hospital mortality or incidence of ileus between the groups.

CONCLUSIONS

Our findings suggest that the use of naldemedine may have benefits in preventing hyperactive delirium, shortening hospital stay, and decreasing hospital costs in cancer patients receiving chemotherapy and opioid therapy.

Naldemedine-induced opioid withdrawal syndrome with severe psychiatric symptoms in an advanced cervical cancer patient without brain metastasis

OBJECTIVE

Naldemedine, an oral peripheral μ-opioid receptor antagonist, was developed for the treatment of constipation, a side effect of opioid use. Naldemedine is not generally recognized as causing opioid withdrawal in which associated symptoms affecting the central nervous system.

METHOD

From the series of cancer patients undergoing symptom management, we report a case treated with naldemedine for constipation in relation to the use of opioids for cancer pain and who displayed severe psychological symptoms associated with withdrawal immediately after the use of naldemedine.

RESULTS

The patient was a 36-year-old woman diagnosed with cervical cancer Stage IIB, PS3. When the patient, who was using oxycodone hydrochloride hydrate (80 mg/day) for ileal pain, was started on naldemedine for constipation, she complained of sweating after just 5 min and hallucinations after 1 h. The patient also displayed physical/behavioral abnormalities such as diarrhea and hyperactivity, and psychological abnormalities such as aggression toward staff.Despite the psychiatric symptoms worsening over time, there were no abnormalities in terms of blood biochemical data, and no brain metastasis was observed on MRI. Based on the Clinical Opiate Withdrawal Scale, these symptoms were judged to indicate opioid withdrawal. Naldemedine was discontinued due to naldemedine-related opioid withdrawal syndrome and, thereafter, the psychiatric symptoms diminished, with no recurrence of similar symptoms observed to date.

SIGNIFICANCE OF RESULTS

If mental and behavioral abnormalities occur in patients receiving naldemedine, it is necessary to consider the possibility of opioid withdrawal syndrome as a differential diagnosis.

Tapentadol Safety and Patient Characteristics Associated with Treatment Discontinuation in Cancer Therapy: A Retrospective Multicentre Study in Japan

INTRODUCTION

Tapentadol has analgesic effects comparable to those of conventional opioids and is associated with fewer side effects, including gastrointestinal symptoms, drowsiness, and dizziness, than other opioids. However, the safety of tapentadol in the Japanese population remains unclear; the present multicentre study aimed to examine the safety of tapentadol and the characteristics of patients likely to discontinue this treatment owing to adverse events.

METHODS

The safety of tapentadol was assessed retrospectively in patients with any type of cancer treated between August 18, 2014 and October 31, 2019 across nine institutions in Japan. Patients were examined at baseline and at the time of opioid discontinuation. Multivariate analysis was performed to identify factors associated with tapentadol discontinuation owing to adverse events.

RESULTS

A total of 906 patients were included in this study, and 685 (75.6%) cases were followed up until tapentadol cessation for any reason. Among patients who discontinued treatment, 119 (17.4%) did so because of adverse events. Among adverse events associated with difficulty in taking medication, nausea was the most common cause of treatment discontinuation (4.7%), followed by drowsiness (1.8%). Multivariate analysis showed that those who were prescribed tapentadol by a palliative care physician (odds ratio [OR] 2.60, 95% confidence interval [CI] 1.36-4.99, p = 0.004), patients switching to tapentadol due to side effects from previous opioids (OR 2.19, 95% CI 1.05-4.56, p = 0.037), and patients who did not use naldemedine (OR 5.06, 95% CI 2.47-10.37, p < 0.0001) had an increased risk of treatment discontinuation owing to adverse events.

CONCLUSIONS

This study presents the safety profile of tapentadol and the characteristics of patients likely to discontinue this treatment owing to adverse events in the Japanese population. Prospective controlled trials are required to evaluate the safety of tapentadol and validate the present findings.

TRIAL REGISTRATION NUMBER

UMIN 000044282 (University Hospital Medical Information Network).

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.

Elobixibat Effectively Relieves Chronic Constipation in Patients with Cancer Regardless of the Amount of Food Intake

BACKGROUND

Constipation is a common, distressing complication in patients with cancer receiving palliative care. Elobixibat is a novel inhibitor of the ileal bile acid transporter that is used to treat chronic constipation by stimulating bowel function. However, its efficacy in patients with cancer has not been examined. This study investigated the drug's effectiveness in patients with cancer with chronic constipation.

PATIENTS AND METHODS

This prospective-sampling, single-center, observational study included hospitalized patients with cancer diagnosed, using the Rome IV criteria, with chronic constipation. Within 2 weeks of hospitalization, each participant was administered elobixibat (5-15 mg) daily until discharge. Spontaneous bowel movements (SBMs), complete spontaneous bowel movements (CSBMs), Bristol stool form scale (BSFS) scores, and the Patient Assessment of Constipation Quality of Life questionnaire (PAC-QOL) scores were assessed before and after elobixibat administration. We also evaluated the relationship between the amount of food consumed and the SBM frequency.

RESULTS

Among the 83 participants, the mean pre- and post-treatment frequencies of daily SBMs were 0.3 and 1.2 (p < .0001) and those of CSBMs were 0.1 and 0.6 (p < .0001), respectively. The mean pretreatment BSFS score was 1.6, whereas the post-treatment value was 3.5 (p < .0001); the mean PAC-QOL score (overall) improved from 1.01 to 0.74 (p = .01). There was no significant change in the daily SBM frequency between fasting and feeding states (1.2 vs. 1.3; p = .8), and there was no correlation between the amount of food intake and the SBM frequency after elobixibat administration (r = .03). Serious adverse events were not observed.

CONCLUSION

This study showed that elobixibat is safe and effective for patients with cancer with chronic constipation, regardless of the food intake amount.

IMPLICATIONS FOR PRACTICE

Elobixibat was effective at relieving chronic constipation in patients with various cancers. Serious adverse events were not observed, and the relief of constipation was independent of variation in food intake.

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.

Common Clinical Practice for Opioid-Induced Constipation: A Physician Survey

Background

Opioid-induced constipation (OIC) remains an important clinical obstacle despite the availability of several guidelines and pharmacological options for its management. Here, we surveyed common practices and perceptions about OIC among physicians who prescribe opioids in Italy.

Methods

The online survey included 26 questions about OIC. Responses were analyzed descriptively and aggregated by physician specialty.

Results

A total of 501 physicians completed the survey. Most respondents (67%) did not feel adequately educated about OIC despite general consensus regarding interest in the topic. Overall, 62–75% of physicians regularly evaluated intestinal function or OIC symptoms in patients receiving opioid therapy. The most common method for assessment was patient diary; few physicians used a validated instrument such as the Rome IV criteria. Psychiatrists and addiction specialists showed the lowest interest and poorest practices. Most respondents (78%) preferred macrogol prophylaxis followed by macrogol plus another laxative for first-line treatment of OIC symptoms. Peripheral-acting mu opioid receptor antagonists (PAMORAs) were not widely used among physicians; 61% had never prescribed a PAMORA for OIC.

Conclusion

Our findings reveal important differences in clinical practice for OIC across physician specialties. Additional formative efforts are necessary to improve awareness about best practices in OIC.

Management of Opioid-Induced Constipation and Bowel Dysfunction: Expert Opinion of an Italian Multidisciplinary Panel

The prescribing and use of opioid analgesics is increasing in Italy owing to a profusion in the number and types of opioid analgesic products available, and the increasing prevalence of conditions associated with severe pain, the latter being related to population aging. Herein we provide the expert opinion of an Italian multidisciplinary panel on the management of opioid-induced constipation (OIC) and bowel dysfunction. OIC and opioid-induced bowel dysfunction are well-recognised unwanted effects of treatment with opioid analgesics that can profoundly affect quality of life. OIC can be due to additional factors such as reduced mobility, a low-fibre diet, comorbidities, and concomitant medications. Fixed-dose combinations of opioids with mu (μ) opioid receptor antagonists, such as oxycodone/naloxone, have become available, but have limited utility in clinical practice because the individual components cannot be independently titrated, creating a risk of breakthrough pain as the dose is increased. A comprehensive prevention and management strategy for OIC should include interventions that aim to improve fibre and fluid intake, increase mobility or exercise, and restore bowel function without compromising pain control. Recommended first-line pharmacological treatment of OIC is with an osmotic laxative (preferably polyethylene glycol [macrogol]), or a stimulant laxative such as an anthraquinone. A second laxative with a complementary mechanism of action should be added in the event of an inadequate response. Second-line treatment with a peripherally acting μ opioid receptor antagonist (PAMORA), such as methylnaltrexone, naloxegol or naldemedine, should be considered in patients with OIC that has not responded to combination laxative treatment. Prokinetics or intestinal secretagogues, such as lubiprostone, may be appropriate in the third-line setting, but their use in OIC is off-label in Italy, and should therefore be restricted to settings such as specialist centres and clinical trials.

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.

Opioid-Induced Constipation in Advanced Cancer Patients

The present study discusses opioid-induced constipation (OIC) in advanced cancer patients, focusing on the OIC definition, pathophysiology, and treatment. OIC is any change from baseline defecation patterns and bowel habits that developed after starting opioid therapy. The condition is characterized by bowel frequency reduction, worsening or development of straining, a sensation of incomplete defecation, or distress associated with bowel habits. OIC is common in advanced cancer patients, with a prevalence of approximately 51%-87% in patients taking opioids for pain management. Patients are likely to experience severe distress, work productivity reduction, poor quality of life, and increased healthcare utilization. OIC has a complex pathophysiology that involves propulsive and peristalsis impairment, intestinal mucosal secretion inhibition, intestinal fluid absorption enhancement, and anal sphincters function impairment. The Rome III criteria are used to assess and diagnose clinical OIC and can also be diagnosed through the Patient Assessment of Constipation (PAC) measures, including the symptom survey (PAC-SYM) and quality of life survey (PAC-QOL). Non-pharmacological treatment of OIC involves lifestyle habits and dietary adjustments, although these interventions might be insufficient to manage the condition. Pharmacological treatments involve the use of traditional laxatives and newer agents like peripherally acting mu-opioid receptor agonists (PAMORAs), including naldemedine, naloxegol, and methylnaltrexone. More novel treatments for OIC that target the pathophysiology are still needed and should be studied carefully for safety and efficacy.

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.

Successive treatment with naltrexone induces epithelial-mesenchymal transition and facilitates the malignant biological behaviors of bladder cancer cells

Naltrexone is widely used for alleviating opioid-related side effects in cancer patients. However, the effects of naltrexone on cancer progression are controversial in the literature. The present study was carried out to investigate the effects of successive treatment with clinically relevant doses of naltrexone on the malignant biological behaviors of bladder cancer cells. The human bladder cancer T24 cells and mouse bladder cancer MB49 cells were treated with naltrexone. Cell proliferation, migration, and invasion abilities were analyzed. Morphological changes of the cells were confirmed by F-actin immunofluorescence staining. Epithelial-mesenchymal transition (EMT)-related markers and transcriptional factors, as well as activation of the phosphatidylinositol 3 kinase (PI3K)/AKT signaling pathway, were analyzed. Results showed that, compared with the control group, successive treatment with naltrexone significantly promoted the proliferation and decreased the apoptosis of bladder cancer cells, together with increase in cell migration and invasion ability. Continuous treatment with naltrexone also significantly reduced the expression of epithelial markers (E-cadherin and cytokeratin 19), increased the expression of mesenchymal markers (N-cadherin and vimentin) and EMT-inducing transcription factors (Snail and Slug), and further shifted the morphological phenotype of bladder cancer cells to a mesenchymal phenotype. The PI3K/AKT signaling pathway was activated by successive treatment with naltrexone. Notably, incubation with the specific PI3K inhibitor LY294002 together with naltrexone reversed the naltrexone-induced EMT progression. In conclusion, successive treatment with naltrexone may be favorable for the progression of bladder tumors by activating the PI3K/AKT signaling pathway and inducing EMT. Long-term exposure to naltrexone should be used cautiously in patients with bladder cancer.

Opioid therapy duration before naldemedine treatment is a significant independent risk of diarrhea: a retrospective cohort study

Background

The most common adverse event (AE) associated with opioid analgesics is opioid-induced constipation (OIC). Naldemedine (NAL) is widely used for the treatment of OIC. However, diarrhea has been reported as the most common treatment-emergent AE of NAL, and little is known about the risk factors associated with the development of diarrhea during NAL administration. This study examined the risk factors for NAL-induced diarrhea via a retrospective chart review of hospitalized patients.

Methods

The data of 101 hospitalized adult patients who received NAL for the first time for the treatment of OIC at Mie University Hospital between June 2017 and December 2018 were extracted from electronic medical records. According to the inclusion and exclusion criteria, 70 of the 101 patients were enrolled in this study. Diarrhea was defined as “diarrhea” on the medical record within 2 weeks of NAL administration. Univariate and multivariate analyses were performed to identify risk factors for the development of diarrhea in patients receiving NAL.

Results

Twenty-two of the 70 patients enrolled (31%) developed diarrhea within 2 weeks of NAL administration. The median duration (range) of NAL treatment before diarrhea onset was 3 (1–12) days. Patients with diarrhea had a significantly longer duration of opioid therapy before NAL administration than patients without diarrhea (P=0.002). Multivariate logistic regression analysis indicated that the independent risk factors for the development of NAL-induced diarrhea were NAL administration after more than 17 days of opioid therapy (odds ratio [OR]=7.539; P=0.016) and pancreatic cancer (OR=6.217; P=0.025). In fact, the incidence of diarrhea in patients who were administered NAL within a day of opioid therapy was significantly lower than that in patients who were administered NAL after more than 17 days of opioid therapy (13% vs. 54%, P=0.030).

Conclusions

These results suggested that a prolonged duration of opioid therapy prior to NAL initiation is associated with increased incidence of diarrhea.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40780-020-00187-3.

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

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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.