Long-term use of naldemedine in the treatment of opioid-induced constipation in patients with chronic noncancer pain: a randomized, double-blind, placebo-controlled phase 3 study

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.

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.

Peripherally-active mu-opioid receptor antagonists for constipation in critically ill patients receiving opioids: A case-series and a systematic review and meta-analysis of the literature

BACKGROUND

Constipation is frequent in critically ill patients, and potentially related to adverse outcomes. Peripherally-active mu-opioid receptor antagonists (PAMORAs) are approved for opioid-induced constipation, but information on their efficacy and safety in critically ill patients is limited. We present a single-center, retrospective, case-series of the use of naldemedine for opioid-associated constipation, and we systematically reviewed the use of PAMORAs in critically ill patients.

METHODS

Case-series included consecutive mechanically-ventilated patients; constipation was defined as absence of bowel movements for >3 days. Naldemedine was administered after failure of the local laxation protocol. Systematic review: PubMed was searched for studies of PAMORAs to treat opioid-induced constipation in adult critically ill patients.

PRIMARY OUTCOMES

time to laxation, and number of patients laxating at the shortest follow-up.

SECONDARY OUTCOMES

gastric residual volumes and adverse events.

KEY RESULTS

A total of 13 patients were included in the case-series; the most common diagnosis was COVID-19 ARDS. Patients had their first bowel movement 1 [0;2] day after naldemedine. Daily gastric residual volume was 725 [405;1805] before vs. 250 [45;1090] mL after naldemedine, p = 0.0078. Systematic review identified nine studies (two RCTs, one prospective case-series, three retrospective case-series and three case-reports). Outcomes were similar between groups, with a trend toward a lower gastric residual volume in PAMORAs group.

CONCLUSIONS & INFERENCES

In a highly-selected case-series of patients with refractory, opioid-associated constipation, naldemedine was safe and associated to reduced gastric residuals and promoting laxation. In the systematic review and meta-analysis, the use of PAMORAs (mainly methylnaltrexone) was safe and associated with a reduced intolerance to enteral feeding but no difference in the time to laxation.

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.

Effects and Limitations of Naldemedine for Opioid-Induced Urinary Retention: A Case Report

A 78-year-old man with postoperative recurrence of esophageal cancer was admitted to the hospital due to chest pain and dyspnea. Oral short-acting opioids provided some relief, but chest pain persisted and worsened, leading to the initiation of a transdermal fentanyl patch. However, the patient developed opioid-induced urinary retention, which was treated with a naldemedine, a medication used for opioid-induced constipation and urinary retention. Opioid switching led to recurrent urinary retention, requiring placement of a urinary catheter. The patient ultimately required continuous deep sedation for refractory symptoms and died several days later.

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.

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.

Effects of a peripherally acting µ-opioid receptor antagonist for the prevention of recurrent acute pancreatitis: study protocol for an investigator-initiated, randomized, placebo-controlled, double-blind clinical trial (PAMORA-RAP trial)

BACKGROUND

Acute and chronic pancreatitis constitute a continuum of inflammatory disease of the pancreas with an increasing incidence in most high-income countries. A subset of patients with a history of pancreatitis suffer from recurrence of acute pancreatitis attacks, which accelerate disease progression towards end-stage chronic pancreatitis with loss of exocrine and endocrine function. There is currently no available prophylactic treatment for recurrent acute pancreatitis apart from removing risk factors, which is not always possible. Pain is the primary symptom of acute pancreatitis, which induces the endogenous release of opioids. This may further be potentiated by opioid administration for pain management. Increased exposure to opioids leads to potentially harmful effects on the gastrointestinal tract, including, e.g. increased sphincter tones and decreased fluid secretion, which may impair pancreatic ductal clearance and elevate the risk for new pancreatitis attacks and accelerate disease progression. Peripherally acting µ-opioid receptor antagonists (PAMORAs) have been developed to counteract the adverse effects of opioids on the gastrointestinal tract. We hypothesize that the PAMORA naldemedine will reduce the risk of new pancreatitis attacks in patients with recurrent acute pancreatitis and hence decelerate disease progression.

METHODS

The study is a double-blind, randomized controlled trial with allocation of patients to either 0.2 mg naldemedine daily or matching placebo for 12 months. A total of 120 outpatients will be enrolled from five specialist centres in Denmark and Sweden. The main inclusion criteria is a history of recurrent acute pancreatitis (minimum of two confirmed pancreatitis attacks). The primary endpoint is time to acute pancreatitis recurrence after randomization. Secondary outcomes include changes in quality of life, gastrointestinal symptom scores, new-onset diabetes, exocrine pancreatic insufficiency, disease severity, health care utilization, adherence to treatment, and frequency of adverse events. Exploratory outcomes are included for mechanistic linkage and include the progression of chronic pancreatitis-related findings on magnetic resonance imaging (MRI) and changes in circulating blood markers of inflammation and fibrosis.

DISCUSSION

This study investigates if naldemedine can change the natural course of pancreatitis in patients with recurrent acute pancreatitis and improve patient outcomes.

TRIAL REGISTRATION

EudraCT no. 2021-000069-34.

CLINICALTRIALS

gov NCT04966559. Registered on July 8, 2021.

Targeting human thymidylate synthase: Ensemble-based virtual screening for drug repositioning and the role of water

A drug repositioning computational approach was carried to search inhibitors for human thymidylate synthase. An ensemble-based virtual screening of FDA-approved drugs showed the drugs Imatinib, Lumacaftor and Naldemedine to be likely candidates for repurposing. The role of water in the drug-receptor interactions was revealed by the application of an extended AutoDock scoring function that included the water forcefield. The binding affinity scores when hydrated ligands were docked were improved in the drugs considered. Further binding free energy calculations based on the Molecular Mechanics Poisson-Boltzmann Surface Area method revealed that Imatinib, Lumacaftor and Naldemedine scored -130.7 ± 28.1, -210.6 ± 29.9 and -238.0 ± 25.4 kJ/mol, respectively, showing good binding affinity for the candidates considered. Overall, the analysis of the molecular dynamics trajectory of the receptor-drug complexes revealed stable structures for Imatinib, Lumacaftor and Naldemedine, for the entire simulation time.

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.

Update on the role of naldemedine in opioid-induced constipation in patients with chronic noncancer pain

Chronic noncancer pain (CNCP) affects up to 20% of adults and can interfere with activities of daily living. Up to 4% of adults in the United States receive chronic opioid therapy and up to 57% of patients on long-term opioids for CNCP report opioid-induced constipation (OIC). OIC is essentially constipation occurring after starting opioid treatment. While laxatives are traditionally the first-line therapy for OIC, 81% of patients taking daily laxatives and opioids still reported OIC and considered that it negatively affected their quality of life. Naldemedine is a peripherally acting µ-opioid receptor antagonists (PAMORA) approved for the treatment of OIC in patients with CNCP. This article reviews the mechanism of action, efficacy, and safety of naldemedine in CNCP patients. Naldemedine improves OIC in patients with CNCP by acting as an opioid receptor antagonist in the gastrointestinal tract. It does not interfere with the analgesic properties of opioids or cause withdrawal symptoms since these effects are centrally mediated, and naldemedine does not cross the blood brain barrier. Naldemedine showed significant and sustained improvement in frequency of bowel movements, quality of life, and constipation-related symptoms. It is generally well tolerated with a higher incidence of gastrointestinal adverse events of mild or moderate severity such as diarrhea, abdominal pain, or vomiting compared to placebo. While there are no randomized, controlled trials that compare head-to-head pharmacological therapies used for treatment of OIC, network meta-analysis shows that naldemedine has an overall good benefit-risk profile compared to the other approved medications.

Establishing Minimal Clinically Important Differences in Quality of Life Measures in Opioid-Induced Constipation

BACKGROUND & AIMS

Opioids have a role in chronic pain management. However, opioid-induced constipation may cause patients to skip or reduce opioid doses, leading to inadequate pain relief and negatively impacting quality of life. We sought to establish a minimal clinically important difference to understand whether changes in quality of life scores are of value to patients.

METHODS

Integrated data from the double-blind, controlled, phase 3 COMPOSE-1 and COMPOSE-2 trials of naldemedine in chronic noncancer pain and opioid-induced constipation were used to determine minimal clinically important differences using Patient Assessment of Constipation Symptoms (PAC-SYM) and Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaires. Patients completed the questionnaires (5-point Likert scale; predose, Weeks 2, 4, and 12), kept a daily log of Bowel Movement and Constipation Assessment, and rated satisfaction at end of study. Minimal clinically important differences were computed using an anchor-based method with 6 anchors: 5 from the Bowel Movement and Constipation Assessment and 1 from patient satisfaction. Threshold values for each anchor were set to define responders versus nonresponders based on score definitions. Clinically meaningful cutoff values for changes in PAC-SYM and PAC-QOL scores were determined using receiver operating characteristic curves.

RESULTS

Data from 1095 patients (549, naldemedine; 546, placebo) were analyzed. The area under the curve for the receiver operating characteristic curves (ranges, 0.719 to 0.798 for PAC-SYM and 0.734 to 0.833 for PAC-QOL) indicated that both instruments can discriminate responders and nonresponders for each anchor. PAC-SYM cutoff values ranged from -1.04 to -0.83; PAC-QOL cutoff values ranged from -0.93 to -0.82.

CONCLUSIONS

Based on data derived from the anchor method, reductions in PAC-SYM and PAC-QOL scores of >1.0 in patients with chronic noncancer pain and opioid-induced constipation are clinically meaningful.

CLINICALTRIALS

gov Registration: NCT01965158; NCT01993940.

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.

Rational Design, Chemical Syntheses, and Biological Evaluations of Peripherally Selective Mu Opioid Receptor Ligands as Potential Opioid Induced Constipation Treatment

Opioid-induced constipation (OIC) is a common adverse effect of opioid analgesics. Peripherally acting μ opioid receptor antagonists (PAMORAs) can be applied in the treatment of OIC without compromising the analgesic effects. NAP, a 6β-N-4-pyridyl-substituted naltrexamine derivative, was previously identified as a potent and selective MOR antagonist mainly acting peripherally but with some CNS effects. Herein, we introduced a highly polar aromatic moiety, for example, a pyrazolyl or imidazolyl ring to decrease CNS MPO scores in order to reduce passive BBB permeability. Four compounds 2, 5, 17, and 19, when administered orally, were able to increase intestinal motility during morphine-induced constipation in the carmine red dye assays. Among them, compound 19 (p.o.) improved GI tract motility by 75% while orally administered NAP and methylnaltrexone showed no significant effects at the same dose. Thus, this compound seemed a promising agent to be further developed as an oral treatment for OIC.

Opioid-Related Constipation

Opioid-related constipation encompasses constipation directly caused by opioid use (opioid-induced constipation [OIC]) as well as pre-existing constipation worsened by opioid use (opioid-exacerbated constipation [OEC]). Over-the-counter laxatives should be used as first-line agents for both OIC and OEC, given their efficacy, low cost, and high safety profiles. Symptoms of OIC and responses to therapy can be assessed with the Bowel Function Index. Individuals with OIC refractory to laxatives may be responsive to peripherally acting μ-opioid receptor antagonists. Although data supporting the superiority of one prescription agent over another is lacking, all have proven effective for the treatment of OIC.

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.

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.

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.

Naldemedine is effective in the treatment of opioid-induced constipation in patients with chronic non-cancer pain who had a poor response to laxatives

BACKGROUND

Two studies demonstrated the efficacy and safety of naldemedine in adult patients with chronic non-cancer pain and opioid-induced constipation (OIC). However, no studies have compared the efficacy of peripherally acting µ-opioid receptor antagonists in patients with adequate and inadequate responses to prior OIC therapy with laxatives. This post hoc analysis of integrated data from the two previous studies compared the efficacy of naldemedine in patients who were unsuccessfully treated with laxatives [poor laxative responders (PLRs)] with those who either did not receive laxatives >30 days prior to screening or those who only received rescue laxative at or after screening (non-PLRs).

METHODS

Patients with OIC were randomized to once-daily treatment with naldemedine 0.2 mg or placebo. The primary efficacy endpoint was the proportion of responders [⩾3 spontaneous bowel movements (SBMs)/week and an increase from baseline of ⩾1 SBM/week for ⩾9 weeks of the 12-week treatment period and ⩾3 weeks of the final 4 weeks of the 12-week treatment period]. Additional endpoints included change in SBM frequency, change in frequency of SBMs without straining, proportion of complete SBM (CSBM) responders, change in CSBM frequency, and time to first SBM. Treatment-emergent adverse events (TEAEs) were assessed.

RESULTS

The analysis included 538 (317 PLRs, 221 non-PLRs) and 537 (311 PLRs, 226 non-PLRs) patients in the naldemedine and placebo arms, respectively. There were significantly more responders in the naldemedine PLR (46.4%; p < 0.0001) and non-PLR (54.3%; p = 0.0009) subgroups versus the placebo groups (30.2% and 38.9%, respectively). In both the PLR and non-PLR subgroups, naldemedine treatment was superior to placebo on all additional endpoints. Overall incidence of TEAEs in the PLR subgroups treated with naldemedine or placebo was similar.

CONCLUSION

This integrated analysis further supports the efficacy and tolerability of naldemedine in the treatment of OIC and demonstrates a consistent effect in both PLR and non-PLR subgroups.[ClinicalTrials.gov identifier: NCT01965158 and NCT01993940].

Associated mood changes with naloxegol therapy for opioid-induced constipation in a patient with psychiatric disease

The objective of this clinical case report is to highlight unusual adverse effects brought on by Naloxegol therapy in a patient with underlying psychiatric illness. The patient is a 68-year-old female, with a psychiatric history of bipolar disorder, who presented for chronic pain management and opioid-induced constipation. After failing other therapies, she was trialed on Naloxegol on three separate occasions. She experienced mood lability with symptoms including agitation, confusion, irritability, hysteria and unprompted crying spells on each occasion. Notably, the drug manufacturer does not describe mood lability, nor the profound psychiatric manifestations outlined in our case report, as side effects of Naloxegol. Clinicians may consider judicious prescription of Naloxegol when treating opioid-induced constipation in patients with pre-existing psychiatric co-morbidities.

Naldemedine Improves Patient-Reported Outcomes of Opioid-Induced Constipation in Patients with Chronic Non-Cancer Pain in the COMPOSE Phase 3 Studies

Objective

Opioid-induced constipation is among the most common side effects associated with opioid use in patients with chronic non-cancer pain, and it can have a significant negative impact on health-related quality of life (QOL). This analysis evaluated the effect of naldemedine 0.2 mg on patient-reported outcomes in three phase 3 clinical studies.

Methods

COMPOSE-1 and COMPOSE-2 were identical randomized, double-blind, placebo-controlled, parallel-group studies of 12 weeks’ duration, allowing data to be integrated (n=1095). COMPOSE-3 was similar in design, but of 52 weeks’ duration (n=1241). Patients were adults with chronic non-cancer pain who had been treated with opioid analgesics for ≥3 months and experiencing opioid-induced constipation. Patient-reported outcomes included Patient Assessment of Constipation Symptoms (PAC-SYM; 12 questions assessed on a 5-point Likert scale), PAC-QOL (28 questions assessed on a 5-point Likert scale), and Subject Global Satisfaction (measured on a 7-point Likert scale). The proportion of patients achieving a ≥1.5 improvement in PAC-SYM and PAC-QOL was calculated. The correlation between change in PAC-SYM and PAC-QOL scores and frequency of bowel movements was also explored.

Results

The proportion of PAC-SYM and PAC-QOL responders was significantly higher for naldemedine than for placebo at all assessed time points in COMPOSE-1/COMPOSE-2 (p<0.005 for both) and COMPOSE-3 (p<0.005 and p<0.0001, respectively). There was a statistically significant correlation between improvement in PAC-SYM/PAC-QOL and frequency of bowel movements at all time points (p≤0.0002). The majority of patients treated with naldemedine reported markedly or moderately improved satisfaction with constipation and abdominal symptoms on the Subject Global Satisfaction questionnaire.

Discussion

Naldemedine treatment was associated with a rapid and sustained clinically relevant improvement in patient-reported outcomes, indicating improvement in opioid-induced constipation-related symptoms and QOL.

ClinicalTrials.gov Registration

NCT01965158, NCT01993940, NCT01965652.

Opioid-induced Constipation: A Review of Health-related Quality of Life, Patient Burden, Practical Clinical Considerations, and the Impact of Peripherally Acting μ-Opioid Receptor Antagonists

Objective:

The objective of this study was to provide an overview of opioid-induced constipation (OIC) and its influence on disease burden and quality of life (QOL).

Methods:

This is a narrative review.

Results:

For many patients, opioid-related side effects, the most common being OIC, have the potential to significantly impair patients’ QOL. Patients with OIC often experience substantial overall burden (ie, increases in anxiety and depression, impairments in activities of daily living, low self-esteem, feelings of embarrassment) and economic burden (ie, higher health care costs, more frequent doctor visits, increased out-of-pocket medication costs), which often causes patients to modify or discontinue opioid treatment despite the analgesic benefits. OIC occurs when opioids bind to peripheral μ-opioid receptors in the gastrointestinal tract. Currently, 4 Food and Drug Administration (FDA)-approved medications are available for OIC, 3 of which are peripherally acting µ-opioid receptor antagonists (PAMORAs). PAMORAs block µ-opioid receptors in the gastrointestinal tract without affecting the central analgesic effects of the opioid and thus provide a targeted approach to OIC management. Two PAMORAs, naldemedine and methylnaltrexone, have shown significant improvements in QOL based on the Patient Assessment of Constipation Symptoms questionnaire relative to placebo. Along with pharmacologic management for OIC, health care providers should institute comprehensive communication strategies with patients to ensure OIC is effectively recognized and managed.

Discussion:

OIC has both physical and psychological impacts on patients. PAMORAs provide effective relief of OIC while also improving QOL. To augment the pharmacologic management of OIC, proactive counseling approaches between physicians and patients may help relieve some of the patient burden associated with OIC and lead to improved outcomes.

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.

Cardiovascular safety of naltrexone and bupropion therapy: Systematic review and meta-analyses

Despite being approved for clinical use, evidence of cardiovascular safety (CV) is lacking for treatment with bupropion, naltrexone, or their combination (B-N). The purpose of the study is to determine the relationship between these treatments and the risk of major cardiovascular adverse events (MACE). Phase 3 randomized clinical trials (RCT) evaluating bupropion, naltrexone, or B-N versus control with reported incidence of MACE. The meta-analysis included 12 RCTs, 69% for weight loss and 29% for smoking cessation, with 19,176 patients and 7354 patient-years who were randomized to an active treatment (bupropion [n = 2965] or B-N [n = 6980] or naltrexone [n = 249]) versus control (placebo [n = 6968] or nicotine patch [n = 2014]). The mean age was 54 ± 8 years (55% female), and the baseline BMI was 32 ± 5 kg/m² . The additive network meta-analysis model for random effects showed no association between bupropion, B-N, or naltrexone and MACE (odds ratio [OR] = 0.90 [95%CI 0.65-1.25], p = 0.52; OR = 0.97 [95%CI 0.75-1.24], p = 0.79; OR = 1.08 [95%CI 0.71-1.63], p = 0.73, respectively; I² = 0%, p = 0.86). Meta-regression analyses showed no significant association between MACE and potential confounders from RCT demographic disparities (p = 0.58). The statistical power (post hoc two-tailed) for non-inferiority was 91%, giving a strong probability of validity. Naltrexone, bupropion, or B-N is not associated with the incidence of MACE as compared with placebo.

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.

Senna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled Trial

INTRODUCTION

This is the first prospective, double-blinded, randomized, placebo-controlled trial to evaluate the safety and efficacy of a stimulant laxative compared with an osmotic agent for the treatment of chronic idiopathic constipation.

METHODS

Patients were randomly administered stimulant laxative (senna, 1.0 g), osmotic agent (magnesium oxide [MgO], 1.5 g), or placebo for 28 consecutive days. The primary endpoint was overall symptom improvement. Secondary endpoints were spontaneous bowel movement (SBM), complete SBM, and patient assessment of constipation quality of life (QOL).

RESULTS

Ninety patients (mean age, 42 years; 93% women; mean duration of symptoms, 9.9 years) were enrolled; all completed the study. The response rate for overall improvement was 11.7% in the placebo group, 69.2% in the senna group, and 68.3% in the MgO group (P < 0.0001). Change in SBM was significantly greater in the senna and MgO groups than that in the placebo group (P < 0.001). Similarly, change in complete SBM was significantly greater in the senna and MgO groups than that in the placebo group (P < 0.01). On the patient assessment of constipation QOL, significant improvements were seen in the senna and MgO groups compared with those in the placebo group (senna, P < 0.05; MgO, P < 0.001). The frequency of severe treatment-related adverse events was 0%.

DISCUSSION

Senna and MgO significantly improved the frequency of bowel movements and QOL score and seem to be effective in the treatment of constipation.

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.

Safety and Efficacy of Naldemedine for the Treatment of Opioid-Induced Constipation in Patients with Chronic Non-Cancer Pain Receiving Opioid Therapy: A Subgroup Analysis of Patients ≥ 65 Years of Age

Background

Opioid-induced constipation (OIC), the most common side effect of opioid treatment, is under-recognized and undertreated in older patients. Naldemedine, an oral, peripherally acting μ-opioid receptor antagonist (PAMORA), is approved in Japan, the United States, and the European Union for treatment of OIC in adult patients.

Objective

This integrated analysis of three phase 3 trials (COMPOSE-1, COMPOSE-2, and COMPOSE-3) evaluated the safety and efficacy of naldemedine for up to 12 weeks in a subgroup of patients aged ≥ 65 years.

Methods

Patients aged 18–80 years with chronic non-cancer pain for ≥ 3 months (treated with opioids for ≥ 3 months in COMPOSE-1 and COMPOSE-2) and OIC received oral naldemedine 0.2 mg or placebo once daily. Safety assessments included overall incidence of treatment-emergent adverse events (TEAEs), TEAEs in the gastrointestinal disorders System Organ Class, and TEAEs of opioid withdrawal or possible opioid withdrawal. Efficacy was based on the proportion of responders in COMPOSE-1 and COMPOSE-2, defined as having ≥ 3 spontaneous bowel movements/week and a ≥ 1-spontaneous bowel movement/week increase from baseline for ≥ 9 of 12 weeks and ≥ 3 of the last 4 weeks.

Results

A total of 14.8% (344/2328) of patients were aged ≥ 65 years in all studies. The incidence of TEAEs in naldemedine-treated patients aged ≥ 65 years (45.9%) was comparable to that in patients aged ≥ 65 years receiving placebo (51.6%) and in the overall naldemedine group (47.1%). The incidence of gastrointestinal disorders System Organ Class TEAEs in naldemedine-treated patients aged ≥ 65 years (20.2%) was also comparable to that in patients aged ≥ 65 years receiving placebo (16.1%) and in the overall naldemedine group (21.8%). The incidence of TEAEs of opioid withdrawal with naldemedine was 1.1% in patients aged ≥ 65 years and 1.0% overall, and the incidence of TEAEs of possible opioid withdrawal was 1.1% in patients aged ≥ 65 years and 1.7% overall. The proportion of responders was higher in naldemedine-treated patients versus placebo, both overall (50.1% vs 34.1%; p < 0.0001) and in those aged ≥ 65 years (51.8% vs 37.6%).

Conclusions

This integrated analysis confirmed that OIC treatment with naldemedine 0.2 mg was generally well tolerated and effective in patients aged ≥ 65 years with chronic non-cancer pain. Safety and efficacy results were consistent with the overall patient population.

ClinicalTrials.gov registration

NCT01965158, NCT01993940, NCT01965652.

Electronic supplementary material

The online version of this article (10.1007/s40266-020-00753-2) contains supplementary material, which is available to authorized users.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 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 (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).

Blood-brain barrier: mechanisms governing permeability and interaction with peripherally acting μ-opioid receptor antagonists

The blood-brain barrier (BBB) describes the unique properties of endothelial cells (ECs) that line the central nervous system (CNS) microvasculature. The BBB supports CNS homeostasis via EC-associated transport of ions, nutrients, proteins and waste products between the brain and blood. These transport mechanisms also serve as physiological barriers to pathogens, toxins and xenobiotics to prevent them from contacting neural tissue. The mechanisms that govern BBB permeability pose a challenge to drug design for CNS disorders, including pain, but can be exploited to limit the effects of a drug to the periphery, as in the design of the peripherally acting μ-opioid receptor antagonists (PAMORAs) used to treat opioid-induced constipation. Here, we describe BBB physiology, drug properties that affect BBB penetrance and how data from randomized clinical trials of PAMORAs improve our understanding of BBB permeability.

Naldemedine for the Use of Management of Opioid Induced Constipation

PURPOSE OF REVIEW

Opioid medications are a pillar of acute and chronic analgesia, though their use is often accompanied by side-effects, such as opioid-induced constipation. Unfortunately, tolerance rarely develops to this untoward side effect. This review presents the background, evidence, and indications for the use of Naldemedine (Brand name Symproic 0.2 mg tablets) to treat opioid-induced constipation.

RECENT FINDINGS

Opioids are often used for the treatment of acute and chronic analgesia. Outside of the central effect they exert, they also interact with peripheral receptors, resulting in opioid-induced constipation, the commonest of side effects of chronic opioid usage. Complications include colonic distention, ileus, perforation, and can progress to other serious bowel complications, which can result in hospitalization and fatal events.For the most part, laxatives and other anti-constipation therapies are often inefficient and require intervention directed at the root cause, such as peripheral mu receptor agonists, including methylnaltrexone, naloxegol, and naldemedine. Naldemedine is the most recent to gain FDA approval of the group.An antagonist of Mu, Kappa, and Delta peripheral receptors, Naldemedine, is the only drug to counteract all three receptor classes. It was shown to be both safe and effective when compared with placebo. No data exists to compare its efficacy to that of other members of the group.

SUMMARY

Opioids are frequently used in the management of acute and chronic pain. The most common of the side effects is opioid-induced constipation, secondary to the peripheral activity of opioids. Naldemedine is an FDA-approved, once-daily oral tablet that counteracts this side effect by antagonizing mu, kappa, and delta-opioid receptors and has been shown to be safe and effective. Further investigation including head-to-head clinical trials are required to evaluate the relative efficacy of naldemedine compare with other peripheral opiate receptor antagonists.

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 for the treatment of opioid-induced constipation in adults with chronic noncancer pain

This review aims to summarize the efficacy data for naldemedine, a member of the novel peripherally acting μ-opioid receptor antagonists (PAMORAs), which gained US FDA approval for the treatment of opioid-induced constipation in adults with chronic noncancer pain-related syndromes in 2017. In Phase III trials, patients receiving naldemedine were significantly more likely to meet the primary end point ≥3 spontaneous bowel movements/week and an increase of ≥1 spontaneous bowel movement/week from baseline for at least 9/12 weeks compared to placebo (p < 0.0001). The most frequent adverse events were abdominal pain (8%) and diarrhea (7%). Based on available data, naldemedine appears to be an effective and safe first-line therapy for the treatment of opioid-induced constipation in adults with chronic noncancer pain.

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.

A Renal Impairment Subgroup Analysis of the Safety and Efficacy of Naldemedine for the Treatment of Opioid-Induced Constipation in Patients with Chronic Non-Cancer Pain Receiving Opioid Therapy

Purpose

Naldemedine, an oral, peripherally acting μ-opioid receptor antagonist approved for the treatment of opioid-induced constipation (OIC), is renally excreted. This subgroup analysis integrated data from 3 Phase 3 trials (COMPOSE-1, COMPOSE-2, COMPOSE-3) to evaluate the safety and efficacy of naldemedine in patients with renal impairment (RI).

Patients and Methods

Patients age 18–80 years with chronic non-cancer pain (CNCP) and OIC received oral naldemedine 0.2 mg or placebo once daily. RI subgroups consisted of patients with normal function (baseline glomerular filtration rate ≥90 mL/min/1.73 m²), mild (≥60 to <90 mL/min/1.73 m²), and moderate (≥30 to <60 mL/min/1.73 m²) RI. Safety assessments based on ≤12 weeks of treatment from all 3 studies included incidence of treatment-emergent adverse events (TEAEs). Efficacy was based on the proportion of responders in COMPOSE-1 and COMPOSE-2 only, defined as ≥3 spontaneous bowel movements (SBMs)/week and a ≥1-SBM/week increase from baseline for ≥9 of 12 weeks and ≥3 of the last 4 weeks.

Results

In total, 2328 patients were included in this analysis. The incidence of TEAEs was similar in the naldemedine and placebo groups (overall, 47.1% vs 45.6%; normal, 44.6% vs 43.6%; mild RI, 49.0% vs 44.7%; moderate RI, 46.6% vs 55.9%). GI-related TEAEs occurred more frequently in the naldemedine group versus placebo (overall, 21.8% vs 13.8%; normal, 21.6% vs 12.5%; mild RI, 22.6% vs 14.7%; moderate RI, 18.0% vs 14.2%). A significantly greater proportion of patients in the naldemedine 0.2 mg group were responders versus the placebo group (overall, 50.1% vs 34.1%, P<0.0001; normal, 52.0% vs 39.3%; mild RI, 48.3% vs 30.3%; moderate RI, 52.5% vs 31.7%).

Conclusion

This integrated analysis confirmed that OIC treatment with naldemedine 0.2 mg was generally well tolerated and effective in patients with CNCP and mild or moderate RI. Safety and efficacy results were consistent with the overall population.

Clinicaltrials.gov Registration

COMPOSE-1: NCT01965158; COMPOSE-2: NCT01993940; COMPOSE-3: NCT01965652.

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.

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.

Implications of the Opioid Epidemic for the Clinical Gastroenterology Practice

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

The Influence of Renal or Hepatic Impairment on the Pharmacokinetics, Safety, and Tolerability of Naldemedine

Naldemedine is a peripherally acting μ‐opioid‐receptor antagonist for the treatment of opioid‐induced constipation. Two phase 1 single‐dose studies investigated the pharmacokinetics and safety of a 0.2‐mg oral dose of naldemedine in subjects with renal impairment (mild, n = 9; moderate, n = 9; severe, n = 6; and end‐stage renal disease, n = 8) or hepatic impairment (mild or moderate, n = 8 each) and demographically matched healthy subjects with normal renal and hepatic function (n = 8, both studies). Pharmacokinetic assessments indicate that dose adjustments for naldemedine are not necessary for subjects with any degree of renal impairment or for subjects with mild or moderate hepatic impairment. In subjects with renal impairment compared with healthy subjects with normal renal function, the geometric mean ratios of naldemedine area under the concentration‐time curve (AUC_0‐inf) ranged from 82.8% (90%CI 69.5% to 98.6%) to 137.8% (90%CI 114.0% to 166.5%). Renal clearance decreased with reduced renal function (normal function 1.3 L/h; mild impairment 1.1 L/h; moderate impairment 1.0 L/h; severe impairment 0.5 L/h), and only 2.7% of naldemedine was removed by hemodialysis. In subjects with hepatic impairment compared with healthy subjects with normal hepatic function, the geometric mean ratio of AUC_0‐inf ranged from 82.8% (90%CI 65.7% to 104.5%) to 105.2% (90%CI 83.4% to 132.6%). Naldemedine was well tolerated in both healthy subjects and subjects with renal or hepatic impairment, and reported adverse events were generally consistent with the known safety profile.

Targeting mu opioid receptors to modulate gastrointestinal function: what have we learnt so far from the studies in functional bowel disorders?

Opioids have recently received much attention because of the epidemic in their use in some countries such as the USA and the UK. Concerns have been raised about the possibility that they can increase mortality in patients when used on a long-term basis. Moreover, they are known to induce paradoxical hyperalgesia as well as alterations of gut function. The analgesic properties of opioids are mediated by receptors located in the brain, but as opioid receptors are also expressed in the gastrointestinal tract, new drugs acting on these receptors have recently been developed to treat two functional disorders, namely irritable bowel syndrome with diarrhoea and opioid-induced constipation. The aim of this article is to highlight some interesting observations resulting from the development of these drugs in the field of functional gastrointestinal disorders.