Emerging treatments in neurogastroenterology: a multidisciplinary working group consensus statement on opioid-induced constipation

Efficacy and Safety of Naldemedine for Opioid-Induced Constipation in Children

Background: Naldemedine, a peripherally acting opioid μ receptor antagonist, is effective for prevention of opioid-induced constipation (OIC); however, evidence on its use in children is limited. Objective: To evaluate the efficacy and safety of naldemedine in pediatric patients with OIC. Design, Setting/Subjects: Retrospective analysis of 32 pediatric patients with OIC treated with naldemedine in a single institution in Japan from June 2017 to March 2021. Measurements: Efficacy was evaluated in 13 evaluable patients with bowel movement (BM) response, defined as those with at least three BMs in the first 7 days after naldemedine initiation and an increase of at least one BM from baseline. Safety was evaluated by examining adverse events (AEs) based on the Common Terminology Criteria for AEs (v5.0). Results: BM response was recorded in 11 of the 13 patients (85%), and the number BMs per day significantly increased from 0.43 before naldemedine to 1.00 after naldemedine (p = 0.025). The most common AE was diarrhea, observed in 16 of the 32 patients (50%), and all instances were grade 1 or 2. In three of the 16 patients, naldemedine was discontinued owing to worsening diarrhea. Conclusions: In pediatric patients, naldemedine resulted in a high rate of BM response and increased the BM frequency, indicating its efficacy. In some patients, grade 2 diarrhea required naldemedine discontinuation, suggesting that it should be used with caution in pediatric patients. Further studies are warranted to determine the optimal naldemedine dose in pediatric patients.

Online Educational Module Improves Knowledge of Nurses on Bowel Preparation for Colonoscopy

The effectiveness of colonoscopy is limited by the adequacy of bowel preparation. Nurses are essential in providing bowel cleansing agents and instructions for hospitalized patients before colonoscopy. This study aims to assess and improve the knowledge of nurses on bowel preparation for inpatient colonoscopy. Participants were asked to complete the survey before and after completing an educational module. The module and survey questions were placed in the NetLearning environment of the hospital intranet. A minimum post-test score of 80% was required to pass the course. A total of 1,107 nurses participated in the survey. Overall, the average score improved from 87% to 93% after the module (p < .0495). Knowledge of the different ways of consuming bowel cleansing agents improved from 54.3% to 83.6% (p = .0001). Only 56.2% of nurses knew how to carry out a split-dose bowel preparation regimen, which increased to 80.1% after the educational module (p = .0001). Nurses' knowledge about the different ways of consuming bowel cleansing agents before colonoscopy and the split-dose regimen is inadequate. A simple online educational module significantly improved the knowledge of nurses on bowel preparation for colonoscopy.

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.

Incidence of opioid-induced constipation in the pediatric intensive care unit: A descriptive cohort study

BACKGROUND

Opioid-induced constipation (OIC) is a well-known phenomenon, although there is limited literature evaluating the incidence of OIC in children admitted to the pediatric intensive care unit (PICU). The primary aim of this study was to determine the incidence of OIC in the PICU and to determine if it is associated with a higher rate of morbidities or prolonged length of stay (LOS).

METHODS

We conducted a single-center retrospective chart review from July 1, 2014, to June 30, 2015, in our PICU. We included all patients aged ≤18 years with a PICU stay of ≥96 h who received opioids during their admission. Data were collected on the frequency of bowel movements and characteristics of opioid administration. Demographic and clinical data were obtained from Virtual Pediatric Systems, LLC.

RESULTS

Of the 94 patients who met the study criteria, 39.4% developed constipation. These patients tended to be older (P = 0.06) and were noted to weigh more (P = 0.03). There was no significant difference in the total or median daily doses, duration of opioid treatment, or mode of administration. Constipation rates did not differ by the severity of illness. There was a higher incidence of constipation in the patients who were admitted for neurological issues or after trauma or abdominal surgery (P = 0.002). Patients with constipation had a longer LOS than patients without constipation, but the difference was not statistically significant.

CONCLUSION

These results indicate that opioid use is not the sole risk factor for constipation in the PICU setting.

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.

Opioid-induced constipation: a stepwise treatment algorithm feasibility study

BACKGROUND

Opioid-induced constipation (OIC) is frequently undertreated in patients with advanced cancer. Our hypothesis is that the use of a stepwise treatment algorithm, supported by regular patient-reported outcome measures, should improve the management of OIC. The aim of this feasibility study was to determine whether a definitive study could be successfully completed.

METHODS

Patients with OIC (Rome Foundation diagnostic criteria positive), and a Bowel Function Index (BFI) score of ≥30, were recruited to the study. The study involved weekly assessments, and decisions about management were based on the current BFI score (and the tolerability of the current treatment). Management was based on a four-step treatment algorithm, developed from recent international guidelines.

RESULTS

One hundred patients entered the study, and 79 patients completed the study. Fifty-seven (72%) participants responded to treatment, with 34 (43%) participants having a 'complete' response (ie, final BFI<30) and 23 (29%) participants having a 'partial' response (ie, change in BFI≥12). In participants with a complete response, 73.5% were prescribed conventional laxatives, 12% were prescribed a peripherally acting mu-opioid receptor antagonist (PAMORA) and 14.5% were prescribed a PAMORA and conventional laxative.

DISCUSSION

The feasibility study suggests that a definitive study can be successfully completed. However, we will amend the methodology to try to improve participant recruitment, participant retention and adherence to the treatment algorithm. The feasibility study also suggests that the use of the BFI to monitor OIC, and the use of a treatment algorithm to manage OIC, can result in clinically important improvements in OIC.Trial registration number NCT04404933.

Pupillary monitoring decreases remifentanil consumption during laparoscopic uterine surgery and improves postoperative recovery

BACKGROUND

The aim of this paper was to explore pupillary monitoring for determining remifentanil consumption during general anesthesia and evaluating postoperative recovery quality.

METHODS

Eighty patients undergoing elective laparoscopic uterine surgery were randomly divided into pupillary monitoring group (Group P) and control group (Group C). In Group P, remifentanil dosage during general anesthesia was determined according to pupil dilation reflex; in Group C, it was adjusted according to hemodynamic changes. Intraoperative remifentanil consumption and endotracheal tube extraction time were recorded. The Numerical Rating Scale (NRS) Score, hemodynamic changes, and opioid-related adverse reactions in the post-anesthesia care unit were also recorded. The parameters of pupil light reflex from extubation to 30 min after extubation were analyzed in Group P, and the responsiveness of these parameters and hemodynamic changes to NRS was determined by ROC curve analyses.

RESULTS

Compared with Group C, in Group P, intraoperative remifentanil consumption, the NRS Score at 20 minutes after extubation, extubation time, and the incidence of nausea, vomiting, and respiratory amnesia were all significantly decreased (all, P<0.05). In Group P, ∆HR and ∆MAP had no value in judging the change of NRS. The ROC values and diagnostic cutoff values of ΔInit, ΔACV, and ΔMCV responding to NRS variation were 0.775 (95% CI: 0.582-0.968), 0.734(95% CI: 0.537-0.930), and 0.822 (95% CI: 0.648-0.997) and 0.21 (sensitivity, 92.3%; specificity, 23.1%), -1.3 (sensitivity, 92.3%; specificity, 18.3%), and -1.0 (sensitivity, 84.6%; specificity, 17.7%), respectively.

CONCLUSIONS

Intraoperative pupil dilation reflex monitoring can reduce remifentanil consumption and improve postoperative recovery quality. Furthermore, postoperative pupil light reflex monitoring can help evaluate pain degree with high sensitivity.

Management of Constipation in Hospitalized Patients

Constipation is frequently encountered in hospital settings and can have potentially serious consequences yet is often underrecognized and undertreated. Opioid-induced constipation is a common cause of constipation in hospitalized patients. Opioids induce constipation through agonistic effects on enteric µ-opioid receptors. This review aims to provide insight on the identification and management of constipation in inpatient settings, with a particular focus on opioid-induced constipation. Constipation assessment should be routinely initiated at hospital admission and can be facilitated by thorough symptom assessments; relevant patient history, including recent medication use; physical examination; and patient assessment tools developed to evaluate the impact of constipation. Management of opioid-induced constipation should begin with ensuring adequate hydration and electrolyte balance and encouraging patient mobilization. Other treatments may include laxatives, enemas, intestinal secretagogues, peripherally acting µ-opioid receptor antagonists, and manual disimpaction. Surgical intervention may be required for some patients as a salvage therapy in severe, refractory cases.

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.

Efficacy and Safety of Naloxegol in Patients with Chronic Non-Cancer Pain Who Experience Opioid-Induced Constipation: A Pooled Analysis of Two Global, Randomized Controlled Studies

Objective

This study evaluates the onset, magnitude, and consistency of improvement of opioid-induced constipation (OIC) symptoms with naloxegol treatment.

Methods

This was a pooled analysis of two Phase 3, double-blind, randomized, placebo-controlled studies (KODIAC-04/05, NCT01309841/NCT01323790) in patients with chronic non-cancer pain and OIC treated with naloxegol 25mg or 12.5mg daily. This analysis assessed improvements in response rates, frequency of spontaneous bowel movement (SBM) and complete SBMs (CSBM), OIC constipation symptoms (straining, stool consistency), time to first post-dose SBM and CSBM, and onset of adverse events over the 12-week period.

Subjects

The population of 1337 subjects had a mean age of 52 years and mean duration of opioid use of 3.6 years at baseline. Mean SBM frequency was 1.4/week.

Results

Naloxegol 25mg and 12.5mg demonstrated significantly higher response rates vs placebo (PBO) [41.9% (P < 0.001), 37.8% (P = 0.008), 29.4% respectively]. Rapid (within 1 week) and sustained (over 12 weeks) symptom improvement was significantly greater for naloxegol vs PBO (P < 0.05). Both doses showed statistically significant and clinically meaningful improvements in straining, stool consistency, number of SBMs and CSBMs/wk. Significantly shorter times to first post-dose SBM and CSBM were observed with naloxegol vs PBO (SBM HR: 25mg = 1.90, 12.5mg= 1.60; CSBM HR: 25mg = 1.42, 12.5mg = 1.36; P < 0.001 for each regimen). Adverse events occurred more frequently in the naloxegol 25mg group and were most frequently reported during the first week.

Conclusion

In patients with chronic non-cancer pain, naloxegol 25mg and 12.5mg demonstrated significantly higher response rates and rapid and sustained improvements in OIC symptoms compared with PBO.

New insight on the enteric cholinergic innervation of the pig colon by central and peripheral nervous systems: reduction by repeated loperamide administration

Introduction

The central and peripheral nervous systems provide cholinergic innervation in the colon. The ability to assess their neuroanatomical distinctions is still a challenge. The pig is regarded as a relevant translational model due to the close similarity of its enteric nervous system (ENS) with that of human. Opioid-induced constipation is one of the most common side effects of opioid therapy.

Methods

We developed an approach to differentiate the central and peripheral cholinergic innervation of the pig colon using double immunolabeling with a novel mouse anti-human peripheral type of choline acetyltransferase (hpChAT) antibody combined with a rabbit anti-common type of ChAT (cChAT) antibody, a reliable marker of cholinergic neurons in the central nervous system. We examined their spatial configurations in 3D images of the ENS generated from CLARITY-cleared colonic segments. The density was quantitated computationally using Imaris 9.7. We assessed changes in the distal colon induced by daily oral treatment for 4  weeks with the μ opioid receptor agonist, loperamide (0.4 or 3  mg/kg).

Results

The double labeling showed strong cChAT immunoreactive (ir) fibers in the cervical vagus nerve and neuronal somata and fibers in the ventral horn of the sacral (S2) cord while hpChAT immunoreactivity was visualized only in the ENS but not in the vagus or sacral neural structures indicating the selectivity of these two antibodies. In the colonic myenteric plexus, dense hpChAT-ir neurons and fibers and varicose cChAT-ir fibers surrounding hpChAT-ir neurons were simultaneously visualized in 3D. The density of cChAT-ir varicose fibers in the outer submucosal plexus of both males and females were higher in the transverse and distal colon than in the proximal colon and in the myenteric plexus compared to the outer submucosal plexus and there was no cChAT innervation in the inner submucosal plexus. The density of hpChAT in the ENS showed no segmental or plexus differences in both sexes. Loperamide at the highest dose significantly decreased the density hpChAT-ir fibers + somata in the myenteric plexus of the distal colon.

Discussion

These data showed the distinct density of central cholinergic innervation between myenteric and submucosal plexuses among colonic segments and the localization of cChAT-ir fibers around peripheral hpChAT neurons in 3D. The reduction of cholinergic myenteric innervation by chronic opiate treatment points to target altered prokinetic cholinergic pathway to counteract opiate constipation.

Methylnaltrexone Treatment for Opioid-Induced Constipation in Patients with and without Cancer: Effect of Initial Dose

Purpose

Opioid-induced constipation (OIC) is a common side effect of opioid therapy. Methylnaltrexone (MNTX) is a selective, peripherally acting μ-opioid receptor antagonist, with demonstrated efficacy in treating OIC. We pooled results from MNTX clinical trials to compare responses to an initial dose in patients with chronic cancer and noncancer pain.

Patients and Methods

This post hoc analysis used pooled data from 3 randomized, placebo-controlled studies of MNTX in patients with advanced illness with OIC. Assessments included the proportions of patients achieving rescue-free laxation (RFL) within 4 and 24 hours of the first study drug dose, time to RFL, current and worst pain intensity, and adverse events, stratified by the presence/absence of cancer.

Results

A total of 355 patients with cancer (MNTX n = 198, placebo n = 157) and 163 without active cancer (MNTX n = 83; placebo n = 80) were included. More patients treated with MNTX compared with those who received placebo achieved an RFL within 4 (cancer: MNTX, 61.1% vs placebo,15.3%, p<0.0001; noncancer: MNTX, 62.2% vs placebo, 17.5%, p<0.0001) and 24 hours (cancer: MNTX, 71.2% vs placebo, 41.4%, p<0.0001; noncancer: MNTX, 74.4% vs placebo, 37.5%, p<0.0001) of the initial dose. Cumulative RFL response rates within 4 hours of the first, second, or third dose of study drug were also higher in MNTX-treated patients. The estimated time to RFL was shorter among those who received MNTX and similar in cancer and noncancer patients. Mean pain scores declined similarly in all groups. The most common adverse events in both cancer and noncancer patients were abdominal pain, flatulence, and nausea.

Conclusion

After the first dose, MNTX rapidly induced a laxation response in the majority of both cancer and noncancer patients with advanced illness. Opioid-induced analgesia was not compromised, and adverse events were primarily gastrointestinal in nature. Methylnaltrexone is a well-tolerated and effective treatment for OIC in both cancer and noncancer patients.

Regulation of enteric nervous system via sacral nerve stimulation in opioid-induced constipated rats

Objectives

Sacral nerve stimulation (SNS) has been employed for treating constipation. However, its mechanisms involving enteric nervous system (ENS) and motility are largely unknown. In this study, we investigated the possible ENS involvement of SNS in treating Loperamide-induced constipation in rats.

Methods

Experiment-1 was designed to study the effects of acute SNS on whole colon transit time (CTT). In experiment-2, we induced constipation by Loperamide and then applied daily SNS or sham-SNS for 1 week. Choline acetyltransferase (ChAT), nitric oxide synthase (nNOS), and PGP9.5 in colon tissue were examined at the end of the study. Moreover, survival factors such as phosphorylated AKT (p-AKT) and Glial cell-derived neurotrophic factor (GDNF) were measures by immunohistochemistry (IHC) and western blot (WB).

Key results

(1) SNS with one set of parameters shortened CTT starting at 90 min after phenol red administration (p < 0.05). (2) While Loperamide induced slow transit constipation with a significant reduction in fecal pellet number and feces wet weight, daily SNS for a week resolved constipation. (3) Moreover, SNS was able to shorten whole gut transit time comparing to sham-SNS (p = 0.01). (4) Loperamide reduced the number of PGP9.5 and ChAT positive cells, and downregulated ChAT protein expression and upregulated nNOS protein expression, whereas these detrimental effects were significantly reversed by SNS. (5) Furthermore, SNS increased expressions of both GDNF and p-AKT in colon tissue. (6) Vagal activity was reduced following Loperamide (p < 0.01); yet SNS normalized vagal activity.

Conclusion

SNS with appropriate parameters improves opioid-induced constipation and reversed the detrimental effects of Loperamide on enteric neurons possibly via the GDNF-PI3K/Akt pathway.GRAPHICAL ABSTRACT.

A Nationwide Hospital Claims Database Analysis of Real-World Patterns of Laxative Use for Opioid-Induced Constipation in Japanese Patients with Cancer

INTRODUCTION

Opioid-induced constipation (OIC) is one of the most common side effects in patients with cancer treated with opioid analgesics. The actual use of laxatives for OIC in Japan remains unelucidated. This study aimed to investigate the real-world patterns of laxative use for patients with cancer who newly initiated opioid analgesic therapy.

METHODS

We used a Japanese nationwide hospital claims database (January 2018-December 2019). Patients with cancer newly receiving opioid analgesic therapy were included and classified on the basis of opioid classes (weak or strong) and route of administration (oral or transdermal) at initiation. The patients were divided into two groups on the basis of whether they received early medication (starting laxatives within 3 days after initiating opioid analgesic therapy), and patterns of laxative use were analyzed.

RESULTS

There were 26,939 eligible patients, with 50.7% of them initiated with strong opioids. The proportion of patients who received early medication was 25.0% for weak opioids and 57.3% for strong opioids. Osmotic laxatives were most frequently used as first-line therapy in the early medication group (oral weak opioids: 12.3%, oral strong opioids: 29.4%, transdermal strong opioids: 12.8%). Stimulant laxatives were frequently used as first-line therapy, to the same extent or more than osmotic laxatives in the non-early medication group (oral weak opioids: 13.7%, oral strong opioids: 7.7%, transdermal strong opioids: 15.1%). Peripherally acting μ-opioid receptor antagonists were the second most frequently used in the early medication group for those on oral strong opioids (9.4%).

CONCLUSION

This study demonstrated for the first time that the patterns of laxative use for OIC in Japanese patients with cancer were different, depending on the opioid types at initiation and the timing of laxative medication.

Management of Opioid-induced Constipation in Older Adults

Opioid-induced constipation (OIC) is a common condition in older adults who may not be responsive to traditional laxative therapy. OIC is defined as new or worsening constipation symptoms that occur with initiation of or altering the dose of opioid analgesia. For adult patients with OIC and noncancer pain, we recommend considering nonpharmacologic interventions (eg, dietary measures, increased physical activity, and biofeedback training) and over-the-counter laxatives, followed by prescription opioid receptor antagonists (methylnaltrexone, naloxegol, and naldemedine) if traditional over-the-counter laxatives fail. Other options may include lubiprostone, linaclotide, plecanatide, and prucalopride; however, these are not indicated for OIC specifically or studied in older adults. Because of the complex nature of absorption, distribution, metabolism, and excretion in the aging population, all agents used to treat OIC must be evaluated individually and reevaluated as patients continue to age. This review will serve as a guide to managing OIC in older adults.

Cumulative Laxation Response with Methylnaltrexone: Implications for Hospitalized Patients with Advanced Illness and Opioid-Induced Constipation

Background

Opioid-induced constipation (OIC) may increase the risk of fecal impaction and mortality in patients with advanced illness. Methylnaltrexone (MNTX) is efficacious for OIC.

Objective

The purpose of this analysis was to evaluate cumulative rescue-free laxation response with repeat MNTX dosing in patients with advanced illness who were refractory to current laxative regimens and to assess the influence, if any, of poor functional status on response to MNTX treatment.

Methods

This analysis included pooled data from patients with advanced illness and established OIC who were on a stable opioid regimen in a pivotal, randomized, placebo (PBO)-controlled clinical trial (study 302 [NCT00402038]) or a randomized, PBO-controlled Food and Drug Administration-required postmarketing study (study 4000 [NCT00672477]). Patients in study 302 received subcutaneous MNTX 0.15 mg/kg or PBO every other day, whereas those in study 4000 received MNTX 8 mg (body weight ≥38 to <62 kg), MNTX 12 mg (body weight ≥62 kg), or PBO every other day. Outcomes included cumulative rescue-free laxation rates at 4- and 24-hours postdose for the first 3 doses of study drug and time to rescue-free laxation. To assess if functional status influenced treatment outcomes, we performed a secondary analysis on the outcomes stratified by baseline World Health Organization/Eastern Cooperative Oncology Group performance status, pain scores, and safety.

Results

One hundred eighty-five patients received PBO and 179 patients received MNTX. The median age was 66.0 years, 51.5% were women, 56.5% had a baseline World Health Organization/Eastern Cooperative Oncology Group performance status score >2, and 63.4% had a primary diagnosis of cancer. Cumulative rescue-free laxation rates were significantly higher with MNTX than PBO 4- and 24-hours after doses 1, 2, and 3 (P < 0.0001), and between-treatment comparisons remained significant (P < 0.0001) regardless of performance status. The estimated time to first rescue-free laxation was shorter for patients receiving MNTX versus PBO. No new safety signals were identified.

Conclusions

Repeated use of MNTX represents a safe and effective treatment for OIC in patients with advanced illness regardless of baseline performance status. ClinicalTrials.gov identifier: NCT00672477. (Curr Ther Res Clin Exp. 2023; 84:XXX-XXX)© 2023 Elsevier HS Journals, Inc.

P2Y1 receptor in the colonic submucosa of rats and its association with opioid‑induced constipation

The aim of the present study was to explore the expression changes of P2Y purinergic receptor 1 (P2Y1) in the distal colonic submucosa of opioid-induced constipation (OIC) rats and its association with the occurrence of OIC, an OIC rat model was generated by intraperitoneal injection of loperamide hydrochloride, a selective agonist of µ-opioid receptors (MORs). At 7 days post-treatment, the model was assessed by analyzing stool scores and calculating the gastrointestinal (GI) transit ratio of rats. The distribution of P2Y1-expressing neurons in the colonic submucosal plexus was demonstrated by immunofluorescence (IF). Western blotting was performed to evaluate the expression changes of MOR, P2Y1 and ATP synthase subunit β (ATPB) proteins in the colonic submucosa, while reverse transcription-quantitative PCR (RT-qPCR) analysis was performed to determine the relative mRNA expression of MOR and P2Y1. After 7 days, the feces of OIC rats exhibited an appearance of sausage-shaped pieces and both the stool weight and GI transit ratio of OIC rats were significantly decreased. IF revealed co-expression of P2Y1 and calbindin and MOR and ATPB in the nerve cells of the distal colonic submucosal plexus. Moreover, RT-qPCR analysis showed that the MOR mRNA levels were significantly increased in the distal colonic submucosa of OIC rats, while mRNA levels of P2Y1 were decreased. WB showed that in the distal colonic submucosa of OIC rats, MOR protein expression was increased, whereas that of P2Y1 was significantly decreased. GI transit ratio analysis suggested that the P2Y agonist ATP significantly relieved constipation symptoms in rats, while the P2Y inhibitor MRS2179 aggravated these symptoms. Finally, P2Y1 expression change was shown to be associated with the occurrence of OIC, while expression of MOR and P2Y1 was associated with OIC development in rats.

Possible mechanism for improving the endogenous immune system through the blockade of peripheral μ-opioid receptors by treatment with naldemedine

BACKGROUND

It has been considered that activation of peripheral μ-opioid receptors (MORs) induces side effects of opioids. In this study, we investigated the possible improvement of the immune system in tumour-bearing mice by systemic administration of the peripheral MOR antagonist naldemedine.

METHODS

The inhibitory effect of naldemedine on MOR-mediated signalling was tested by cAMP inhibition and β-arrestin recruitment assays using cultured cells. We assessed possible changes in tumour progression and the number of splenic lymphocytes in tumour-bearing mice under the repeated oral administration of naldemedine.

RESULTS

Treatment with naldemedine produced a dose-dependent inhibition of both the decrease in the cAMP level and the increase in β-arrestin recruitment induced by the MOR agonists. Repeated treatment with naldemedine at a dose that reversed the morphine-induced inhibition of gastrointestinal transport, but not antinociception, significantly decreased tumour volume and prolonged survival in tumour-transplanted mice. Naldemedine administration significantly decreased the increased expression of immune checkpoint-related genes and recovered the decreased level of toll-like receptor 4 in splenic lymphocytes in tumour-bearing mice.

CONCLUSIONS

The blockade of peripheral MOR may induce an anti-tumour effect through the recovery of T-cell exhaustion and promotion of the tumour-killing system.

Recognizing and Defining Occasional Constipation: Expert Consensus Recommendations

Constipation is a common problem, affects 15% of the population, and is often self-diagnosed and self-managed. Over the past 3 decades, there have been significant advances in our understanding and management of chronic constipation, with the emerging recognition that occasional constipation (OC) is another subtype that falls outside current classifications. The purpose of this review was to describe the process of developing and proposing a new definition for OC based on expert consensus and taking into consideration the multifactorial nature of the problem such as alterations in bowel habit that include stool frequency and difficulty with stool passage, perception of the sufferer, duration of symptoms, and potential responsiveness to treatment. Leading gastroenterologists from 5 countries met virtually on multiple occasions through an online digital platform to discuss the problem of OC and recommended a practical, user-friendly definition: "OC can be defined as intermittent or occasional symptomatic alteration(s) in bowel habit. This includes a bothersome reduction in the frequency of bowel movements and/or difficulty with passage of stools but without alarming features. Bowel symptoms may last for a few days or a few weeks, and episodes may require modification of lifestyle, dietary habits and/or use of over-the-counter laxatives or bulking agents to restore a satisfactory bowel habit." Prospective studies are required to validate this definition and determine OC prevalence in the community. This review highlights current knowledge gaps and could provide impetus for future research to facilitate an improved understanding of OC and development of evidence-based management guidelines.

Naloxone Versus Methylnaltrexone for Opioid-Induced Constipation in Critically Ill Patients

Background:

Opioid-induced constipation (OIC) may occur in up to 81% of critically ill patients and can lead to many complications. Opioid antagonists are a reasonable approach and may be used for managing OIC.

Objective:

The purpose of this study was to assess the efficacy of enteral naloxone (NLX) versus subcutaneous methylnaltrexone (MNTX) for the management of OIC in critically ill patients.

Methods:

A retrospective analysis was conducted on adult patients who received NLX or MNTX and a continuous opioid infusion for at least 48 hours. The primary end point was time to resolution of constipation, defined as hours to first bowel movement (BM) after the first dose of an opioid antagonist. Reversal of analgesia was assessed by comparing the total number of morphine milligram equivalents (MME) 24 hours preopioid and postopioid antagonist administration. Univariate and multivariate analyses were conducted to assess treatment response within 48 hours.

Results:

Baseline characteristics were similar between patients receiving NTX (n = 89) and MNTX (n = 71). However, the time to the first BM with NLX was 18 hours compared with 41 hours with MNTX ( P = 0.004). There was no difference in MME requirements 24 hours pre/post NLX or MNTX administration. Naloxone administration was identified as a statistically significant predictor of BM within 48 hours (odds ratio [OR] = 2.68 [1.33-5.38]).

Conclusion and Relevance:

The time to first BM was shorter with enteral NLX. Both NLX and MNTX appear to be effective for the management of OIC without causing reversal of analgesia. Future controlled, prospective trials comparing these agents are warranted.

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.

Reductions in All-Cause Mortality Associated with the Use of Methylnaltrexone for Opioid-Induced Bowel Disorders: A Pooled Analysis

OBJECTIVE

Preclinical and clinical studies suggest that activation of the µ-opioid receptor may reduce overall survival and increase the risk for all-cause mortality in patients with cancer and noncancer pain. Methylnaltrexone, a selective, peripherally acting µ-opioid receptor antagonist, has demonstrated efficacy for the treatment of opioid-induced constipation. This retrospective analysis of 12 randomized, double-blind, placebo-controlled studies of methylnaltrexone evaluated the treatment of opioid-induced bowel disorders in patients with advanced illness or noncancer pain.

METHODS

The risk of all-cause mortality within 30 days after the last dose of study medication during the double-blind phase was compared between methylnaltrexone and placebo groups. The data were further stratified by cancer vs noncancer, age, gender, and acute vs chronic diagnoses.

RESULTS

Pooled data included 2,526 methylnaltrexone-treated patients of which 33 died, and 1,192 placebo-treated patients of which 35 died. The mortality rate was 17.8 deaths/100 person-years of exposure in the methylnaltrexone group and 49.5 deaths/100 person-years of exposure for the placebo group. The all-cause mortality risk was significantly lower among patients receiving methylnaltrexone compared with placebo (hazard ratio: 0.399, 95% confidence interval: 0.25, 0.64; P = .0002), corresponding to a 60% risk reduction. Significant risk reductions were observed for those receiving methylnaltrexone who had cancer or chronic diagnoses. Methylnaltrexone-treated patients had a significantly reduced mortality risk compared with placebo regardless of age or gender.

CONCLUSIONS

Methylnaltrexone reduced all-cause mortality vs placebo treatment across multiple trials, suggesting methylnaltrexone may confer survival benefits in patients with opioid-induced bowel disorders taking opioids for cancer-related or chronic noncancer pain.

Opioid-Induced Constipation in Real-World Practice: A Physician Survey, 1 Year Later

INTRODUCTION

Opioid-induced constipation (OIC) is the most common adverse effect of opioid therapy, but it is underdiagnosed and undertreated. Last year, a survey among Italian healthcare providers revealed important differences in the clinical management of OIC across physician specialties, the need of standardization of diagnosis and treatment, and the urgency of further education. Herein, we submitted an updated version of the survey to the same cohort of experts to evaluate potential progress.

METHODS

The online survey included 15 questions about OIC. Responses were analyzed descriptively and aggregated by physician specialty.

RESULTS

A total of 190 physicians completed the survey. Most respondents (65%) did not feel adequately educated about OIC despite general consensus regarding interest in the topic and acknowledgement of OIC impact on patients' QoL and adherence to opioid therapy. Overall, 55-77% of physicians regularly evaluated intestinal function or OIC symptoms in patients receiving opioid therapy, with one-third of respondents implementing it in the past year. Even though the most common method for assessment was still patient diary, the use of specific scales underwent a small but significant increase compared to the previous year, with major implementation in the use of Rome IV criteria. As regards first-line treatment, most respondents (49%) preferred macrogol prophylaxis followed by macrogol plus another laxative. For second-line treatment, we revealed a growth in the prescription of peripherally acting mu-opioid receptor antagonists (PAMORAs), with 46% of all the respondents having increased their use during the past year.

CONCLUSIONS

Despite some limitations, our study demonstrated a slow but important step closer to standardization of diagnosis and treatment of OIC. Further educational and training efforts should be put in place to favor best evidence-based clinical practice.

Effectiveness of Naldemedine Compared with Magnesium Oxide in Preventing Opioid-Induced Constipation: A Randomized Controlled Trial

Simple Summary

Opioids are used in cancer pain management, however, their continuous use may not be tolerable owing to adverse effects such as constipation, sleepiness, nausea, and respiratory depression. Opioid-induced constipation reduces the quality of life of patients, and osmotic laxatives are conventionally recommended for preventing opioid-induced constipation. Recently, naldemedine, a peripherally acting μ-opioid receptor antagonist, can be used to safely and effectively treat opioid-induced constipation based on its etiological mechanism, without affecting central analgesia. In this study, we compared the effectiveness of magnesium oxide with that of naldemedine in preventing opioid-induced constipation. Naldemedine significantly prevented deterioration in the quality of defecation (the Japanese Patient Assessment of Constipation Quality of Life and complete spontaneous bowel movement) and reduced gastrointestinal adverse effects, mainly nausea, compared with magnesium oxide during 12-week administration.

Abstract

Opioid-induced constipation (OIC) may occur in patients receiving opioid treatment, decreasing their quality of life (QOL). We compared the effectiveness of magnesium oxide (MgO) with that of naldemedine (NAL) in preventing OIC. This proof-of-concept, randomized controlled trial (registration number UMIN000031891) involved 120 patients with cancer scheduled to receive opioid therapy. The patients were randomly assigned and stratified by age and sex to receive MgO (500 mg, thrice daily) or NAL (0.2 mg, once daily) for 12 weeks. The change in the average Japanese version of Patient Assessment of Constipation QOL (JPAC-QOL) from baseline to 2 weeks was assessed as the primary endpoint. The other endpoints were spontaneous bowel movements (SBMs) and complete SBMs (CSBMs). Deterioration in the mean JPAC-QOL was significantly lower in the NAL group than in the MgO group after 2 weeks. There were fewer adverse events in the NAL group than in the MgO group. Neither significant differences in the change in SBMs between the groups nor serious adverse events/deaths were observed. The CSBM rate was higher in the NAL group than in the MgO group at 2 and 12 weeks. In conclusion, NAL significantly prevented deterioration in constipation-specific QOL and CSBM rate compared with MgO.

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.

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.

A Prospective, Real-World, Multinational Study of Naloxegol for Patients with Cancer Pain Diagnosed with Opioid-Induced Constipation-The NACASY Study

The Naloxegol Cancer Study (NACASY) was a multinational European study aimed to evaluate the 4-week safety and efficacy of naloxegol in a real-world setting in patients with cancer pain diagnosed with opioid-induced constipation. The primary safety endpoint was the incidence of adverse events leading to study discontinuation. We recruited 170 patients who received at least one dose of naloxegol (i.e., safety population). Out of 170 patients, 20 (11.8%, 95%CI 6.9-16.6) discontinued the study due to adverse events, and, of them, 12 (7.1%, 95%CI 3.2-10.9%) were study discontinuations due to naloxegol-related adverse events. From 76 patients subjects who had completed both 4 weeks of treatment and 28 days of the diary, 55 patients (72.4%, 95% CI 62.3-82.4%) were regarded as responders (i.e., showed ≥3 bowel-movements per week and an increase of ≥1 bowel-movement over baseline) to naloxegol treatment. The Patient Assessment of Constipation-Quality of Life Questionnaire total score and all its subscales improved from baseline to 4 weeks of follow up. Our findings support and provide new evidence about the beneficial effect of naloxegol in terms of improvement of constipation and quality-of-life in patients with cancer-related pain and opioid-induced constipation and show a safety profile consistent with previous pivotal and real-world studies.

The efficacy of laparoscopic transversus abdominis plane block on reducing postoperative narcotic usage in patients undergoing minimally invasive adrenalectomy

BACKGROUND

Post-operative pain relief after abdominal operations is critical for patient satisfaction and rapid recovery. Narcotics have been a traditional part of postoperative analgesia, with transversus abdominis plane (TAP) block introduced recently. The aim of this study is to assess the efficacy of laparoscopic TAP block on postoperative pain control in patients undergoing minimally invasive adrenalectomy.

METHODS

This was an institutional review board-approved retrospective study. Parameters related to postoperative pain control were compared between patients who underwent robotic transabdominal lateral adrenalectomy with (after December 2018) or without laparoscopic TAP block (control group) (before December 2018) by one surgeon. Statistics were performed using Mann Whitney U and Chi-square tests.

RESULTS

There were 86 patients in the TAP and 83 patients in the control group. Groups were similar regarding demographic and clinical parameters. Despite the availability of intravenous acetaminophen to a higher percentage of patients in the control (31.3%) versus the TAP group (8.1%), 0-24 h lowest postoperative pain scores were significantly lower in the TAP group (P < 0.0001). In TAP versus control group, percentage of patients requiring narcotics and amount of narcotics used was lower (P = 0.04 vs P = 0.0004, respectively). Mainly due to less pain-related over-stay, percentage of patients requiring more than a day of hospital stay was less in the TAP (12%) versus control group (18%) (P = 0.01).

CONCLUSION

To our knowledge, the utility of TAP block in patients undergoing minimally invasive adrenalectomy has not been reported in the past. This study shows that there may be benefits of laparoscopic TAP block in reducing post-operative narcotic usage while improving pain control in these patients.

First-Dose Efficacy of Methylnaltrexone in Patients with Severe Medical Illness and Opioid-Induced Constipation: A Pooled Analysis

BACKGROUND

Opioid-induced constipation (OIC) is a frequent consequence of opioid analgesia that may increase patient risk for emergency department visits and hospitalization. Methylnaltrexone is a peripherally acting µ-opioid receptor antagonist indicated for the treatment of OIC.

OBJECTIVE

To assess the safety and efficacy of a single methylnaltrexone dose.

METHODS

Results were pooled from three randomized, placebo-controlled methylnaltrexone (MNTX) studies in opioid-treated patients with advanced illness and OIC, despite treatment with conventional laxatives. Baseline assessments included demographics, disease/treatment characteristics, and functional levels. Efficacy endpoints included rescue-free laxation (RFL) rates within 4 and 24 h, time to first RFL, pain score change, and adverse events (AEs) after a single MNTX dose or placebo.

RESULTS

The analysis included 281 patients receiving MNTX and 237 receiving placebo. Mean age was 66.2 years for MNTX and 65.8 for placebo; ∼50% were men. The most frequent primary diagnosis was cancer (MNTX = 70.5%; placebo = 66.2%) and most (∼98%) were receiving at least one laxative at baseline. RFL occurred in 61.4% vs. 16.0%, and 72.1% vs. 40.1% MNTX vs. placebo patients, within 4 and 24 h of the initial dose, respectively. Relative to placebo, MNTX use reduced the time to first RFL, with most MNTX-treated patients achieving RFL within 2 h. Baseline and posttreatment pain scores were similar (p = 0.9556 vs. placebo for current and worst pain change from baseline), demonstrating that MNTX did not negatively affect opioid analgesia. Most AEs were gastrointestinal related and dissipated by the second dose.

CONCLUSIONS

Methylnaltrexone provides early RFL without compromising analgesia in patients receiving chronic opioid therapy.

Impact and Consequences of Opioid-Induced Constipation: A Survey of Patients

INTRODUCTION

Opioids are a valuable tool to help achieve control of pain. However, opioid-induced constipation (OIC) is an important limitation of treatment with this class of drugs.

METHODS

To better understand the impact of OIC on patient-reported outcomes, we carried out a survey involving patients being treated with opioids. Both ad hoc questions and the PROMIS and PAC-SYM and PAC-QOL scores were used.

RESULTS

Of the 597 participants, 150 (25%) had cancer-related pain, and 447 (75%) had non-cancer pain; 66% experienced OIC. PROMIS pain interference questions indicated that pain is more likely to interfere with a patient's life when they have OIC. PAC-QOL and PAC-SYM revealed that 58% of patients with non-cancer pain and OIC reported at least one "severe" or "very severe" constipation symptom, compared to 83% with cancer-related pain. Younger age and less time on opioids were associated with greater impact of OIC on quality of life. Only 41% of patients were satisfied with how their constipation was managed. Over 50% of those with non-cancer pain said that they modified their opioid regimen due to constipation, vs. 6% of those with cancer pain. Constipation had been discussed with the healthcare provider (HCP) in 48% of non-cancer patients and in 73% of cancer patients. In those with chronic pain and OIC, 24% expressed varying degrees of dissatisfaction with the healthcare system, vs. 37% in those with cancer pain and OIC.

CONCLUSION

Our results provide additional evidence that management of OIC is inadequate in many cases. Moreover, they indicate that there is a definite need for better education about OIC among HCPs.

Impact of opioid-induced constipation on opioid substitution therapy management: the patient perspective

Background

Although opioid-induced bowel dysfunction is a well-known and frequent adverse event correlated with opioids, it is scarcely investigated in patients on opioid substitution treatment (OST) and no standard of care is currently available for this population. We aimed to explore the opinion of patients on the impact of constipation on the management of OST and quality of life (QoL).

Methods

We performed a survey that was directed to opioid-dependent patients treated with OST and followed-up in a Service for Addiction Treatment in Italy. The questionnaire included questions about sociodemographic characteristics, the experience of constipation, general QoL, OST management, interference of opioid-induced constipation (OIC) with opioid management, the experience of OIC treatment in the health system, and risk factors for constipation.

Results

Constipation at the moment of the survey (n=105) was reported by 81% of patients and was the most frequent adverse event of OST; 73% of respondents reported at least one severe or very severe symptom of constipation in the last 2 weeks. OIC was reported to hinder adherence to OST by 33% of respondents and 38% of them felt that control of craving had been more difficult since initiation of constipation. Overall, 34% of patients interfered with their OST by changing the schedule on their own in an attempt to improve constipation. Patients were proactive in looking for a solution for constipation but reported poor help from the healthcare system.

Conclusion

Our patient-based survey suggests that careful and efficient management of constipation could increase adherence to OST and improve patient satisfaction and QoL.

Diet and Chronic Non-Cancer Pain: The State of the Art and Future Directions

Nutrition plays an important role in pain management. Healthy eating patterns are associated with reduced systemic inflammation, as well as lower risk and severity of chronic non-cancer pain and associated comorbidities. The role of nutrition in chronic non-cancer pain management is an emerging field with increasing interest from clinicians and patients. Evidence from a number of recent systematic reviews shows that optimising diet quality and incorporating foods containing anti-inflammatory nutrients such as fruits, vegetables, long chain and monounsaturated fats, antioxidants, and fibre leads to reduction in pain severity and interference. This review describes the current state of the art and highlights why nutrition is critical within a person-centred approach to pain management. Recommendations are made to guide clinicians and highlight areas for future research.

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 factors with constipation and health-related quality of life in lung cancer patients with platinum-based chemotherapy: A cross-sectional study

The main purpose of this study was to investigate current state of constipation for lung cancer (LC) patients receiving platinum-based chemotherapy. The relationships between social demography, clinical variables, psychological status, and constipation were analyzed. In addition, quality of life (QoL) in LC patients with constipation was also analyzed. One hundred LC patients participated in this cross-sectional study. Under the guidance of the researchers, Functional Living Index-Emesis, Piper Fatigue Scale, Patient Health Questionnaire, Generalized Anxiety Disorder-7, European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 (version 3.0), Pittsburgh Sleep Quality Index, General Well-being Scale, Social Support Rate Scale, General Self-Efficacy Scale, and other related questionnaires were completed. The result showed the symptom of constipation was observed in 41 (41%) LC patients. The occurrence and development of constipation were associated with gender, food intake, exercise, nausea, fatigue, anxiety, depression, sleep disorders, and happiness. The study also found patients with constipation had significant lower QoL scores, especially the score in the general state. Constipation was very common in LC patients undergoing platinum-based chemotherapy. Reduced food intake and fatigue were the independent factors. Constipation significantly affects the QoL of the patients. Therefore, more attention should be paid to the risk factors of constipation in LC patients undergoing platinum-based chemotherapy, the earlier intervention was done to these patients, the better to improve their QoL.

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.

An opioid receptor-independent mechanism underlies motility dysfunction and visceral hyperalgesia in opioid-induced bowel dysfunction

Constipation and abdominal pain are commonly encountered in opioid-induced bowel dysfunction (OBD). The underlying mechanisms are incompletely understood, and treatments are not satisfactory. As patients with OBD often have fecal retention, we aimed to determine whether fecal retention plays a pathogenic role in the development of constipation and abdominal pain in OBD, and if so to investigate the mechanisms. A rodent model of OBD was established by daily morphine treatment at 10 mg/kg for 7 days. Bowel movements, colonic muscle contractility, visceromotor response to colorectal distention, and cell excitability of colon-projecting dorsal root ganglion neurons were determined in rats fed with normal pellet food, or with clear liquid diet. Morphine treatment (Mor) reduced fecal outputs starting on day 1, and caused fecal retention afterward. Compared with controls, Mor rats demonstrated suppressed muscle contractility, increased neuronal excitability, and visceral hypersensitivity. Expression of cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) was upregulated in the smooth muscle of the distended colon in Mor rats. However, prevention of fecal retention by feeding rats with clear liquid diet blocked upregulation of COX-2 and NGF, restored muscle contractility, and attenuated visceral hypersensitivity in Mor rats. Moreover, inhibition of COX-2 improved smooth muscle function and fecal outputs, whereas anti-NGF antibody administration attenuated visceral hypersensitivity in Mor rats. Morphine-induced fecal retention is an independent pathogenic factor for motility dysfunction and visceral hypersensitivity in rats with OBD. Liquid diet may have therapeutic potential for OBD by preventing fecal retention-induced mechanotranscription of COX-2 and NGF.NEW & NOTEWORTHY Our preclinical study shows that fecal retention is a pathogenic factor in opioid-induced bowel dysfunction, as prevention of fecal retention with liquid diet improved motility and attenuated visceral hyperalgesia in morphine-treated animals by blocking expression of cyclooxygenase-2 and nerve growth factor in the colon.

Validity and Reliability of the Hindi Version of the Patient Assessment of Constipation Quality of Life Questionnaire in Cancer Patients on Opioids for Pain Management at Tertiary Care Center, India

Background:

Opioid-induced constipation (OIC) causes a significant worsening of quality of life (QOL). The patient assessment of constipation QOL questionnaire (PAC-QOL) is a validated scale in English language to assess the QOL in patients with chronic constipation and guide the management by measuring response to a targeted therapy.

Objective:

The objective of the study was to evaluate the validity and reliability of PAC-QOL questionnaire after translation in Hindi language for Indian cancer patients with OIC.

Materials and Methods:

This was a prospective observational cross-sectional study. Three hundred and thirteen adult cancer patients receiving opioid treatment for pain and experiencing self-reported symptoms of constipation were evaluated. The severity of constipation was assessed at baseline and at an interval of at least 2 weeks by the physician using constipation scoring system (CSS) and self-reported Hindi version of PAC-QOL questionnaire.

Results:

The data obtained from 313 patients were taken for analysis. The internal consistency of the tool was established with the favorable value of Cronbach's alfa coefficient (i.e., >0.70) obtained for all four subgroups and overall score. The intraclass correlation coefficient value of >0.70 also established good correlation between overall and subgroups scores of Hindi version of PAC-QOL, obtained at 1^st and 2^nd visit. It was observed from the result that a significant correlation existed between the overall and subgroups scores of Hindi version of PAC-QOL and CSS, thus establishing concurrent validity.

Conclusion:

It was concluded from the study results that Hindi version of PAC-QOL is both reliable and valid to assess the QOL in patients with OIC.

Opioid-induced constipation in patients with cancer: a "real-world," multicentre, observational study of diagnostic criteria and clinical features

The aim of this study was to investigate opioid-induced constipation (OIC) in a large cohort of "real-world" patients with cancer; the objectives were to determine the prevalence of OIC, the utility of a simple screening question, the accuracy of the Rome IV diagnostic criteria, the clinical features of OIC (physical and psychological), and the impact of OIC (quality of life). One thousand patients with cancer were enrolled in the study, which involved completion of the Rome IV diagnostic criteria for OIC, the Bowel Function Index, the Patient Assessment of Constipation Quality of Life questionnaire, and the Memorial Symptom Assessment Scale-Short Form. Participants also underwent a thorough clinical assessment by an experienced clinician (ie, "gold-standard" assessment of OIC). Fifty-nine percent of patients were clinically assessed as having OIC, 2.5% as having another cause of constipation, and 19% as not having constipation but were taking regular laxatives. The simple screening question produced a number of false-negative results (19% of patients), whereas the Rome IV diagnostic criteria had an accuracy of 81.9%. Patients with OIC had more symptoms overall, higher Memorial Symptom Assessment Scale-Short Form subscale scores (and total score), and higher Patient Assessment of Constipation Quality of Life questionnaire subscale scores (and the overall score). Opioid-induced constipation was not associated with demographic factors, cancer diagnosis, performance status, or opioid equivalent dosage: OIC was associated with opioid analgesic, with patients receiving tramadol and transdermal buprenorphine having less constipation. The study confirms that OIC is common among patients with cancer pain and is associated with a spectrum of physical symptoms, a range of psychological symptoms, and an overall deterioration in the quality of life.

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.

Rethinking Docusate's Role in Opioid-Induced Constipation: A Critical Analysis of the Evidence

Opioid induced constipation (OIC) is a predictable and preventable adverse effect of opioid use. Docusate is often utilized for OIC prophylaxis and treatment because of its low cost, easy accessibility and tolerability. However, the costs of docusate use may not outweigh the benefits given limited reported efficacy. The authors seek to provide the first critical review of clinical evidence for docusate use in OIC management. PubMed, Google Scholar, OVID Medline, and EMBASE were queried for primary literature, guidelines, and consensus recommendations (CR) evaluating docusate use for OIC management. Thirteen guidelines or CR and four primary literature studies were evaluated. The primary literature studies had significant design limitations and collectively revealed non-compelling evidence for use. The majority of guidelines or CR that endorsed the use of docusate for OIC prophylaxis or treatment did not cite primary evidence to support their recommendations. The inclusion of docusate in major guidelines and CR for OIC management is weakly evidence based, though docusate use is still widely recommended. Institutions and health care providers should consider careful evaluation of OIC protocols and/or algorithms to ensure integration of evidence-based therapy and reduce unnecessary drug use and associated costs, which may include removal of docusate.

Medications Development for Treatment of Opioid Use Disorder

This review describes methods for preclinical evaluation of candidate medications to treat opioid use disorder (OUD). The review is founded on the propositions that (1) drug self-administration procedures provide the most direct method for assessment of medication effectiveness, (2) procedures that assess choice between opioid and nondrug reinforcers are especially useful, and (3) states of opioid dependence and withdrawal profoundly influence both opioid reinforcement and effects of candidate medications. Effects of opioid medications and vaccines on opioid choice in nondependent and opioid-dependent subjects are reviewed. Various nonopioid medications have also been examined, but none yet have been identified that safely and reliably reduce opioid choice. Future research will focus on (1) strategies for increasing safety and/or effectiveness of opioid medications (e.g., G-protein-biased μ-opioid agonists), and (2) continued development of nonopioid medications (e.g., clonidine) that might serve as adjunctive agents to current opioid medications.

Opioid-induced constipation in patients with cancer pain in Japan (OIC-J study): a post hoc subgroup analysis of patients with gastrointestinal cancer

BACKGROUND

Constipation is a common side effect of opioid therapy. An observational study of opioid-induced constipation (OIC) in Japanese patients with cancer (OIC-J) included 212 patients with various tumor types. This post hoc analysis of OIC-J evaluated a subgroup of patients with gastrointestinal (GI) cancer.

METHODS

Patients were aged ≥ 20 years, starting strong opioid therapy, had an ECOG PS of ≤ 2, and must have had ≥ 3 bowel movements during the week before enrollment. OIC was evaluated for 2 weeks after opioid initiation using the Rome IV diagnostic criteria for colorectal disorders, as well as physician's diagnosis, number of spontaneous bowel movements, Bowel Function Index score, and patient's self-assessment. Relationships between baseline characteristics and OIC incidence, and the effects of OIC on quality of life (QOL) were also explored.

RESULTS

Fifty patients from OIC-J who had GI cancer [colon (50%), stomach (28%), and esophageal (22%)] were included. OIC incidence varied by which diagnostic criteria were used (46.0-62.0%) and occurred rapidly after initiating opioid therapy. The use of prophylactic laxatives reduced the overall incidence rate of OIC from 71.0% to 47.4%. No baseline characteristics, except comorbidities, were associated with OIC incidence. Change from baseline to day 15 in PAC-SYM total score was significantly greater for patients with OIC versus those without OIC (0.188 versus -0.362; P = 0.0011).

CONCLUSIONS

This post hoc analysis suggests that OIC occurs rapidly in patients with GI cancer after initiating opioid therapy, and negatively impacts QOL. Early and effective intervention strategies may be particularly useful in this group.

ADDITIONAL INFORMATION

Coauthor Makio Gamoh is deceased.

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.

Microvascular reconstruction in head and neck cancer - basis for the development of an enhanced recovery protocol

Introduction

Microvascular reconstructions after head and neck cancer are among the most complicated procedures in plastic surgery. Postoperative complications are common, which often leads to prolonged hospital stay. Enhanced recovery after surgery (ERAS) is a peri- and postoperative care concept with the aim of achieving pain- and risk-free surgery. It has been previously established as superior to conventional care for a wide variety of procedures, including microsurgical procedures such as reconstructions of the breast. Several ERAS protocols for microvascular head and neck cancer reconstructions have been proposed, although most of these are based on extrapolated evidence from different surgical specialties. Results from the implementation of ERAS for these procedures are inconsistent.

Methods

The current study investigates our clinical experience of head and neck cancer reconstruction for the period of 2014-2016 with the aim of establishing a list of functional discharge criteria. By combining these with the current published knowledge on the subject, we developed an ERAS protocol.

Results

We performed 89 microvascular procedures in the study period, of which 58 were in the oral cavity/sinuses and 31 were laryngopharyngeal. Most cases were squamous cell carcinoma (89%). The average LOS was 20.3 days in both groups. Postoperative complications included infection (37%), 30-days re-operations (19%), and re-admissions (17%). Furthermore, we identified the following discharge criteria: adequate pain relief, ambulation, sufficient nutritional intake, normal infection-related blood parameter results and absence of fever, bowel function, and closure of tracheostomy.

Conclusion

Based on our retrospective analysis and identified discharge criteria, we present an approach to develop an ERAS protocol for microvascular reconstruction after head and neck cancer.

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.

Onset of action of naldemedine in the treatment of opioid-induced constipation in patients with chronic noncancer pain: results from 2 randomized, placebo-controlled, phase 3 trials

Naldemedine improves opioid-induced constipation in a timely manner in patients using opioids for noncancer pain; most experienced spontaneous bowel movement within 24 hours of treatment.

Opioid-induced constipation (OIC) is a common side effect of chronic opioid therapy. Previously, naldemedine, a peripherally acting μ-opioid receptor antagonist demonstrated efficacy in the treatment of OIC. In this exploratory analysis, the onset of action of naldemedine was evaluated in 2 identically designed phase 3, randomized, placebo-controlled trials. Proportion of patients experiencing a spontaneous bowel movement (SBM) within 24 hours of treatment initiation, time from initial dose to first SBM and weekly SBM frequency were assessed. Naldemedine was associated with significant increases in the proportion of patients experiencing an SBM at 4, 8, 12, and 24 hours after the initial dose compared with placebo (all P < 0.0001). Within 24 hours in both studies, statistically significantly (P < 0.0001) more patients treated with naldemedine compared with placebo experienced an SBM (61.2% vs 28.3% and 56.5% vs 33.6%, respectively). Median times to first SBM were significantly shorter in the naldemedine group vs placebo (COMPOSE-1, 16.1 vs 46.7 hours; COMPOSE-2, 18.3 vs 45.9 hours; P < 0.0001). Naldemedine was also associated with significant increases in weekly SBM frequency vs placebo within 1 week (P < 0.001). Most common treatment-emergent adverse events were gastrointestinal-related (abdominal pain, diarrhea, and nausea). Treatment-emergent adverse events were reported most frequently on day 1, followed by a decrease from days 2 to 7. Naldemedine had a timely onset of effect, and gastrointestinal adverse events largely resolved within the first week. These findings should assist clinicians counseling patients with chronic noncancer pain on expectations when initiating naldemedine for OIC.

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.