Evolving paradigms in the treatment of opioid-induced bowel dysfunction

Evolution, adaptation, and new applications of the FODMAP diet

The FODMAP diet has been a treatment of irritable bowel syndrome (IBS) for many years. Rigorous scientific evaluation and clinical application of the FODMAP diet have generated deep understanding regarding clinical efficacy, mechanisms of action, and potential adverse effects of this dietary approach. In turn, this knowledge has allowed fine-tuning of the diet to optimize treatment benefits and minimize risks, in the form of the traditional three-phase diet; the FODMAP-gentle approach, which is a less restrictive iteration; and a proposed FODMAP-modified, Mediterranean-style diet which endeavours to optimise both gastrointestinal symptoms and other health parameters. Furthermore, recognition that IBS-like symptoms feature in other conditions has seen the FODMAP diet tested in non-IBS populations, including in older adults with diarrhea and women with endometriosis. These areas represent new frontiers for the FODMAP diet and a space to watch as future research evaluates the validity of these novel clinical applications.

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.

Risk Factors for Postoperative Ileus in Patients Undergoing Spine Surgery

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

Postoperative ileus (POI) is a common complication following elective spinal surgeries. The aim of this study was to determine the incidence of POI and identify demographic and surgical risk factors for developing POI after elective instrumented fusion of the thoracolumbar spine.

METHODS

The University of Utah Institutional Review Board (IRB) approved this retrospective study. The study does not require informed consent given the data reviewed was deidentified and collected in accordance with the institution's standard of care. A designated IRB committee determined that study is exempt under exemption category 7. IRB approval number 00069703. Patients undergoing instrumented thoracolumbar fusion for one or more levels were retrospectively identified from an internal spine surgery database. Cases performed for trauma, infection, or tumors were excluded. Demographics, medical comorbidities, surgical variables, and opioid medication administration (morphine milligram equivalents, MME) were abstracted from the electronic medical record. Univariate analysis was used to identify variables associated with POI. These variables were then tested for independent association with POI using multivariate logistic regression.

RESULTS

418 patients were included in the current study. The incidence of POI was 9.3% in this cohort. There was no significant relationship between development of POI and patient age, gender, BMI, diabetes mellitus, thyroid dysfunction, lung disease, CKD, GERD, smoking status, alcohol abuse, anemia, or prior abdominal surgery. Univariate analysis demonstrated significant association between POI and fusion ≥7 levels compared to fusions of fewer levels (P = .001), as well as intraoperative sufentanil compared to other opioids (35.9% vs 20.1%, P = .02). POI was not significantly associated with total intraoperative MME, approach, use of interbody cage, or osteotomy. Multivariate logistic regression confirmed total 24-hour postoperative MME as an independent risk factor for POI (OR 1.004, P = .04), however, intraoperative sufentanil administration was not an independent risk factor for POI when controlling for other variables.

CONCLUSIONS

This retrospective cohort study demonstrates that greater postoperative MME is an independent risk factor for POI after thoracolumbar spine fusion when accounting for demographic, medical, and surgical variables with multiple logistic regression. Prospective studies are warranted to evaluate clinical measures to decrease the risk of POI among patients undergoing instrumented thoracolumbar spinal fusions.

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.

Opioids in the Treatment of Chronic Idiopathic Diarrhea in Humans—A Systematic Review and Treatment Guideline

In patients with chronic idiopathic diarrhea resistant to standard treatment, opioids are often used as rescue therapy. This systematic review investigated opioid effects on gut function in chronic diarrhea. PubMed and Embase were searched regarding effects of opioid agonists on the gastrointestinal tract in humans with chronic or experimentally induced diarrhea. A total of 1472 relevant articles were identified and, after thorough evaluation, 11 clinical trials were included. Generally, studies reported a reduction in stool frequency and an increase in transit time during treatment with the opioid receptor agonists loperamide, asimadoline, casokefamide, and codeine compared with placebo. Loperamide and diphenoxylate significantly improved stool consistency compared with placebo, whereas asimadoline showed no such effects. Compared with placebo, loperamide treatment caused less abdominal pain and urgency. Asimadoline showed no significant subjective improvements, but fedotozine was superior to placebo in reducing abdominal pain and bloating in selected patients. Only two relevant studies were published within the last 20 years, and standardized endpoint measures are lacking. Most trials included few participants, and further evidence is needed from larger, prospective studies. Likewise, consensus is needed to standardize endpoints for stool frequency, transit time, and consistency to conduct future meta-analyses on opioids in management of chronic idiopathic diarrhea.

A Retrospective Observational Study of Factors Affecting the Efficacy of Concurrent Prescription of Naldemedine for Opioid-Induced Constipation Caused by Oxycodone Tablets

Naldemedine is indicated for the treatment of opioid-induced constipation (OIC), but reports on its efficacy in preventing OIC are few. Therefore, we retrospectively investigated factors affecting the efficacy of concurrent prescription of naldemedine on OIC. Outpatients with cancer who were started on oxycodone 10 mg/d were included in the study. The eligible patients were classified by their physicians into the following three groups: Group A used regular laxatives before the introduction of oxycodone and initiated naldemedine treatment simultaneously with oxycodone administration, Group B did not take laxatives before the introduction of oxycodone and started naldemedine simultaneously with oxycodone administration, and Group C had been administering regular laxatives before the introduction of oxycodone and were not prescribed naldemedine simultaneously with oxycodone treatment. The Support Team Assessment Schedule Japanese edition score for constipation, frequency of defecation, Bristol Stool Form Scale, sense of incomplete rectal evacuation, and development or worsening of straining to pass bowel movements were compared among the three groups before and after oxycodone administration. In Group B, there was significant worsening of the four parameters except for the sense of incomplete rectal evacuation, whereas Groups A and C did not present any changes. In logistic regression analysis, body weight ≥51.8 kg was a factor significantly decreasing the preventive effect of naldemedine on OIC, and regular use of laxatives was a factor significantly increasing the preventive effect of naldemedine on OIC. Thus, the initiation of naldemedine should be considered depending on the body weight and regular laxative use.

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

Background

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

Methods

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

Discussion

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

Clinical Trial Registration

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

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.

Opioid-Induced Constipation in Patients with Cancer Pain in Japan (OIC-J Study): A Post Hoc Analysis

Opioid-induced constipation (OIC) can limit the clinical benefit of opioid treatment. This post-hoc analysis evaluated the association between the Rome IV diagnostic criteria and other measures for OIC, including the Bowel Function Index (BFI), correlation between demographics and OIC onset, impact of OIC on pain treatment, and impact of patient–healthcare professional (HCP) communication on patient satisfaction. Patients recorded bowel habits in paper diaries for 14 days following opioid initiation. Study-specific questionnaires were used to evaluate patient awareness of OIC and satisfaction. Patients were ≥20 years old, initiating strong opioid therapy for cancer pain, had an ECOG PS ≤ 2, and had no constipation (≥3 bowel movements within 7 days of enrollment). A total of 220 patients were enrolled. The sensitivity and specificity of BFI for identifying OIC were 81.2% and 54.7%, respectively. Age <65 versus ≥65 years (odds ratio (OR) = 0.510, 95% confidence interval (CI): 0.267–0.977) and the presence or absence of comorbidities (OR = 0.443, 95% CI: 0.221–0.885) were correlated with OIC onset. The proportion of inpatients with sustainable pain control at week 2 was similar in patients with or without OIC (60.0% vs. 67.2%, respectively). By patient assessment, there was a significant correlation between an adequate level of patient–HCP communication and satisfaction with OIC treatment (OR = 9.538 (95% CI: 1.577–57.681)). Using BFI to screen for OIC represents a valid approach in patients with cancer pain. Patient–HCP communication is essential for effective management of OIC in patients with cancer pain.

Acupuncture for Cancer-Related Constipation: A Protocol for Systematic Review and Meta-Analysis

Objective: By evaluating the clinical effectiveness and safety, we can better understand the role of acupuncture for cancer-related constipation treatment and provide guidance for clinicians. Methods: We searched some academic databases (PubMed, MEDLINE, EMBASE, the Cochrane Library, Elsevier SD journal, Springer journal, Chinese Biomedicine, China National Knowledge Infrastructure, Chinese Wanfang Data, Chinese VIP Data, etc.). All documents were loaded into Endnote X8 for classification management. After extracting the data, two reviewers assessed the risk bias of each original study using the tool Cochrane manual v.5.1.0. Cochrane Review Manager 5.3 will be used to conduct this meta-analysis. Results: With the data, we can better evaluate the clinical effectiveness and safety of acupuncture for cancer-related constipation treatment. Conclusion: This study aimed to identify the best acupuncture therapy for cancer-related constipation to guide clinicians and patients.

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].

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.

Gastrointestinal dysmotility in a patient with advanced lung cancer: paraneoplastic or drug-induced?

A 75-year-old man was hospitalised for bronchoscopy with biopsy due to a suspicious pulmonary mass at chest tomography. He had significant dyspnoea, constipation, nausea, vomiting, anorexia and a 33% loss of weight in the past 3 months. Biopsy revealed a pulmonary squamous cell carcinoma, which was inoperable. Tramadol used at home for 3 months was replaced by morphine on admission. The patient remained constipated despite prokinetics and laxatives, leading to the diagnostic hypothesis of paraneoplastic motility disorder and opioid-induced constipation. Abdominal tomography ruled out the possibility of mechanical obstruction. As complications, the patient presented superior vena cava syndrome and opioid (morphine) intoxication. The patient died a few days later. The management of this case highlights the importance of multidisciplinary care and the challenges of palliative oncology care. Paraneoplastic motility disorder must always be considered among the mechanisms of intestinal dysfunction in patients with advanced oncological disease.

The Effect of Chronic Preoperative Opioid Use on Surgical Site Infections, Length of Stay, and Readmissions

BACKGROUND

Chronic opioid use in the United States is a well-recognized public health concern with many negative downstream consequences. Few data exist regarding the use of preoperative opioids in relation to outcomes after elective colorectal surgery.

OBJECTIVE

The purpose of this study was to determine if chronic opioid use before colorectal surgery is associated with a detriment in postoperative outcomes.

DESIGN

This is a retrospective review of administrative data supplemented by individual chart review.

SETTING

This study was conducted in a single-institution, multisurgeon, community colorectal training practice.

PATIENTS

All patients undergoing elective colorectal surgery over a 3-year time frame (2011-2014) were selected.

MAIN OUTCOME MEASURES

Opioid use was stratified based on total dose of morphine milligram equivalents (naive, sporadic use (>0-15 mg/day), regular use (>15-45 mg/day), and frequent use (>45 mg/day)). Primary outcomes were surgical site infections, length of hospital stay, and readmissions.

RESULTS

Of the 923 patients, 23% (n = 213) were using opioids preoperatively. The preoperative opioid group contained more women (p = 0.047), underwent more open surgery (p = 0.003), had more nonmalignant indications (p = 0.013), and had a higher ASA classification (p = 0.003). Although median hospital stay was longer (4.7 days vs 4.0, p < 0.001), there was no difference in any surgical site infections (10.3% vs 7.1%, p = 0.123) or readmissions (14.2% vs 14.1%, p=0.954). Multivariable analysis identified preoperative opioid use (17.0% longer length of stay; 95% CI, 6.8%-28.2%) and ASA 3 or 4 (27.2% longer length of stay; 95% CI, 17.1-38.3) to be associated with an increase in length of stay.

LIMITATIONS

Retrospectively abstracted opioid use and small numbers limit the conclusions regarding any dose-related responses on outcomes.

CONCLUSIONS

Although preoperative opioid use was not associated with an increased rate of surgical site infections or readmissions, it was independently associated with an increased hospital length of stay. Innovative perioperative strategies will be necessary to eliminate these differences for patients on chronic opioids. See Video Abstract at http://links.lww.com/DCR/B280. EFECTOS DEL CONSUMO CRÓNICO DE OPIOIDES EN EL PREOPERATORIO CON RELACIÓN A LAS INFECCIONES DE LA HERIDA QUIRÚRGICA, LA DURACIÓN DE LA ESTADÍA Y LA READMISIÓN: El consumo crónico de opioides en los Estados Unidos es un problema de salud pública bien reconocido a causa de sus multiples consecuencias negativas ulteriores. Existen pocos datos sobre el consumo de opioides en el preoperatorio relacionado con los resultados consecuentes a una cirugía colorrectal electiva.El propósito es determinar si el consumo crónico de opioides antes de la cirugía colorrectal se asocia con un detrimento en los resultados postoperatorios.Revisión retrospectiva de datos administrativos complementada por la revisión de un gráfico individual.Ejercicio durante la formación de multiples residentes en cirugía colorrectal enTodos los pacientes de cirugía colorrectal electiva durante un período de 3 años (2011-2014).El uso de opioides se estratificó en función de la dosis total de equivalentes de miligramos de morfínicos (uso previo, uso esporádico [> 0-15 mg / día], uso regular (> 15-45 mg / día) y uso frecuente (> 45 mg / día)). Los resultados primarios fueron las infecciones de la herida quirúrgica, la duración de la estadía hospitalaria y la readmisión.De los 923 pacientes, el 23% (n = 213) consumían opioides antes de la operación. El grupo con opioides preoperatorios tenía más mujeres (p = 0.047), se sometió a una cirugía abierta (p = 0.003), tenía mas indicaciones no malignas (p = 0.013) y tenía una clasificación ASA más alta (p = 0.003). Aunque la mediana de la estadía hospitalaria fue más larga (4,7 días frente a 4,0; p <0,001), no hubo diferencia en ninguna infección de la herida quirúrgica (10,3% frente a 7,1%, p = 0,123) o las readmisiones (14,2% frente a 14,1%, p = 0,954). El análisis multivariable identificó que el uso de opioides preoperatorios (17.0% más larga LOS; IC 95%: 6.8%, 28.2%) y ASA 3 o 4 (27.2% más larga LOS; IC 95%: 17.1, 38.3) se asocia con un aumento en LOS.La evaluación retrospectiva poco precisa del consumo de opioides y el pequeño número de casos limitan las conclusiones sobre cualquier respuesta relacionada con la dosis - resultado.Si bien el consumo de opioides preoperatorios no se asoció con un aumento en la tasa de infecciones de la herida quirúrgica o las readmisiones, ella se asoció de forma independiente con un aumento de la LOS hospitalaria. Serán necesarias estrategias perioperatorias innovadoras para eliminar estas diferencias en los pacientes consumidores cronicos de opioides. Consulte Video Resumen en http://links.lww.com/DCR/B280.

Association between opioid usage and rectal dysfunction in constipation: A cross-sectional study of 2754 patients

BACKGROUND

Opioid use has reached epidemic proportions. In contrast to the known effect of opioids on gut transit, the effect on rectal sensorimotor function has not been comprehensively investigated.

METHODS

Cross-sectional (hypothesis-generating) study of anorectal physiology studies in 2754 adult patients referred to a tertiary unit (2004-2016) for investigation of functional constipation (defined by "derived" Rome IV core criteria). Statistical associations between opioid usage, symptoms, and anorectal physiological variables were investigated. Opioids were sub-classified as prescriptions for mild-moderate or moderate-severe pain.

KEY RESULTS

A total of 2354 patients (85.5%) were classified as non-opioid users, 162 (5.9%) as opioid users for mild-moderate pain, and 238 (8.6%) for moderate-severe pain. Opioids for moderate-severe pain were associated with increased symptomatic severity (Cleveland Clinic constipation score 18.5 vs 15.1; mean difference 2.9 [95%-CI 2.3-3.6]; P < .001), rectal hyposensitivity (odds ratio 1.74 [95%-CI 1.23-2.46]; P = .002), functional evacuation disorders (odds ratio 1.73 [95%-CI 1.28-2.34]; P < .001), and delayed whole-gut transit (odds ratio 1.68 [95%-CI 1.19-2.37]; P = .003). Differences in anorectal variables between opioid users for mild-moderate pain and non-opioid users were not statistically significant. Hierarchical opioid use (non vs mild-moderate vs moderate-severe) was associated with decreasing proportions of patients with no physiological abnormality on testing (40.2% vs 38.1% vs 29.2%) and increasing proportions with both delayed whole-gut transit and rectal sensorimotor dysfunction (16.6% vs 17.5% vs 28.5%).

CONCLUSIONS AND INFERENCES

Opioid use is over-represented in patients referred for investigation of constipation. Opioids for moderate-severe pain are associated with rectal sensorimotor abnormalities. Further studies are required to determine whether this association indicates causation.

Comparing the effectiveness of magnesium oxide and naldemedine in preventing opioid-induced constipation: a proof of concept, single institutional, two arm, open-label, phase II, randomized controlled trial: the MAGNET study

Background

Patients taking opioids are known to develop opioid-induced constipation (OIC), which reduces their quality of life. The aim of this study is to compare magnesium oxide with naldemedine and determine which is more effective in preventing OIC.

Methods

This proof-of-concept, prospective, randomized controlled trial commenced in Japan in March 2018. Initially, a questionnaire-based survey will be conducted targeting adult patients with cancer who concomitantly commenced opioid treatment and OIC prevention treatment. Patients will then be randomly allocated to a magnesium oxide group (500 mg thrice daily) or a naldemedine group (0.2 mg once daily). Each drug will be orally administered for 12 weeks. The primary endpoint is defined as any improvement in scores on the Japanese version of Patient Assessment of Constipation Quality of Life questionnaire (JPAC-QOL) from baseline to 2 weeks of treatment.

Discussion

The primary endpoint is change in JPAC-QOL score from baseline to 2 weeks of intervention. The key secondary endpoint will be change in spontaneous bowel movements at 2 and 12 weeks of intervention. This study will determine whether magnesium oxide or naldemedine is more effective for the prevention of OIC.

Trial registration

University Hospital Medical Information Network (UMIN) Clinical Trials Registry, UMIN000031891. Registered March 25, 2018.

A prospective randomized controlled study of auricular point acupressure to manage chronic low back pain in older adults: study protocol

BACKGROUND

Chronic low back pain (cLBP) is a major health problem and the most common pain condition among those aged 60 years or older in the US. Despite the development of pharmacological and nonpharmacological interventions, cLBP outcomes have not improved and disability rates continue to rise. This study aims to test auricular point acupressure (APA) as a non-invasive, nonpharmacological self-management strategy to manage cLBP and to address current shortcomings of cLBP treatment.

METHODS/DESIGN

For this prospective randomized controlled study, participants will be randomly assigned to three groups: (1) APA group (active points related to cLBP), (2) Comparison group-1 (non-active points, unrelated to cLBP), and (3) Comparison group-2 (enhanced educational control, an educational booklet on cLBP will be given and the treatment used by participants for their cLBP will be recorded). The ecological momentary assessment smartphone app will be used to collect real-time cLBP outcomes and adherence to APA practice. Treatment and nonspecific psychological placebo effects will be measured via questionnaires for all participants. This proposed trial will evaluate the APA sustained effects for cLBP at 12-month follow-up. Monthly telephone follow-up will be used to collect study outcomes. Blood will be collected during study visits at baseline, post APA treatment, and follow-up study visits at 1, 3, 6, 9 and 12 months post completion of treatment for a total of seven assessments. Appointments will start between 9 and 11 am to control for circadian variation in cytokine levels.

DISCUSSION

This study is expected to provide vital information on the efficacy, sustainability, and underlying mechanism of APA on cLBP necessary for APA to gain acceptance from both healthcare providers and patients, which would provide a strong impetus for including APA as part of cLBP management in clinical and home settings.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03589703. Registered on 22 May 2018.

Gastrointestinal pain

Gastrointestinal (GI) pain - a form of visceral pain - is common in some disorders, such as irritable bowel syndrome, Crohn's disease and pancreatitis. However, identifying the cause of GI pain frequently represents a diagnostic challenge as the clinical presentation is often blurred by concomitant autonomic and somatic symptoms. In addition, GI pain can be nociceptive, neuropathic and associated with cancer, but in many cases multiple aetiologies coexist in an individual patient. Mechanisms of GI pain are complex and include both peripheral and central sensitization and the involvement of the autonomic nervous system, which has a role in generating the symptoms that frequently accompany pain. Treatment of GI pain depends on the precise type of pain and the primary disorder in the patient but can include, for example, pharmacological therapy, cognitive behavioural therapies, invasive surgical procedures, endoscopic procedures and lifestyle alterations. Owing to the major differences between organ involvement, disease mechanisms and individual factors, treatment always needs to be personalized and some data suggest that phenotyping and subsequent individual management of GI pain might be options in the future.

Pathophysiology and management of diabetic gastroenteropathy

Polyneuropathy is a common complication to diabetes. Neuropathies within the enteric nervous system are associated with gastroenteropathy and marked symptoms that severely reduce quality of life. Symptoms are pleomorphic but include nausea, vomiting, dysphagia, dyspepsia, pain, bloating, diarrhoea, constipation and faecal incontinence. The aims of this review are fourfold. First, to provide a summary of the pathophysiology underlying diabetic gastroenteropathy. Secondly to give an overview of the diagnostic methods. Thirdly, to provide clinicians with a focussed overview of current and future methods for pharmacological and nonpharmacological treatment modalities. Pharmacological management is categorised according to symptoms arising from the upper or lower gut as well as sensory dysfunctions. Dietary management is central to improvement of symptoms and is discussed in detail, and neuromodulatory treatment modalities and other emerging management strategies for diabetic gastroenteropathy are discussed. Finally, we propose a diagnostic/investigation algorithm that can be used to support multidisciplinary management.

Preliminary Effectiveness of Auricular Point Acupressure on Chemotherapy-Induced Neuropathy: Part 1 Self-Reported Outcomes

PURPOSE

To reduce chemotherapy-induced neuropathy (CIN)-a significant challenge among cancer patients following chemotherapy-we explored the effects of auricular point acupressure (APA), which involves needleless, acupuncture-like stimulation on specific ear points.

DESIGN/METHOD

This pilot study examined the effects of a 4-week APA intervention in the management of CIN. Descriptive analysis was used to examine the changes in study outcomes.

RESULTS

Fifteen participants were enrolled. Two participants dropped out because they developed new medical conditions. Thirteen participants completed the study (87% retention rate). Study participants had more severe symptoms in their lower extremities (i.e., toes, feet, soles) than in their upper extremities (i.e., fingers, wrists, elbows). After the 4-week APA intervention, the mean percentage change scores ranged from 38% (tingling) to 49% (numbness); compared to pre-intervention, the therapeutic effects of APA were sustained at the 1-month follow-up. Function in both upper and lower extremities improved after the APA intervention (≥28%) and continued to improve at the 1-month follow-up (≥36%).

CONCLUSIONS

Preliminary results from this small sample provide initial evidence of the effectiveness of APA on CIN. Future studies should confirm these results using a larger sample, a comparative sham control, and an examination of the underlying physiological mechanisms of the anti-CIN effects of APA.

CLINICAL IMPLICATIONS

APA may provide an inexpensive and effective complementary approach for the self-management of CIN. Once the seeds have been taped to the patient's ear by the provider, patients are empowered to self-manage their CIN in their own environment.

Pharmacologic effects of naldemedine, a peripherally acting μ-opioid receptor antagonist, in in vitro and in vivo models of opioid-induced constipation

BACKGROUND

Naldemedine (S-297995) is a peripherally acting μ-opioid receptor antagonist developed as a once-daily oral drug for opioid-induced constipation (OIC) in adults with chronic noncancer or cancer pain. This study characterized the pharmacological effects of naldemedine in vitro and in vivo.

METHODS

The binding affinity and antagonist activity of naldemedine against recombinant human μ-, δ-, and κ-opioid receptors were assayed in vitro. Pharmacologic effects of naldemedine were investigated using animal models of morphine-induced inhibition of small and large intestinal transit, castor oil-induced diarrhea, antinociception, and morphine withdrawal.

KEY RESULTS

Naldemedine showed potent binding affinity and antagonist activities for recombinant human μ-, δ-, and κ-opioid receptors. Naldemedine significantly reduced opioid-induced inhibition of small intestinal transit (0.03-10 mg kg^-1 ; P < 0.05) and large intestinal transit (0.3-1 μmol L^-1 ; P < 0.05). Naldemedine (0.03-1 mg kg^-1 ) pretreatment significantly reversed the inhibition of castor oil-induced diarrhea by subcutaneous morphine (P < 0.01). Naldemedine (1-30 mg kg^-1 ) pretreatment (1 or 2 hours) did not alter the analgesic effects of morphine in a model measuring the latency of a rat to flick its tail following thermal stimulation. However, a significant delayed reduction of the analgesic effect of morphine was seen with higher doses of naldemedine (10-30 mg kg^-1 ). Some centrally mediated and peripherally mediated withdrawal signs in morphine-dependent rats were seen with naldemedine doses ≥3 and ≥0.3 mg kg^-1 , respectively.

CONCLUSIONS & INFERENCES

Naldemedine displayed potent binding affinity to, and antagonistic activity against, μ-, δ-, and κ-opioid receptors. Naldemedine tempered OIC in vivo without compromising opioid analgesia.

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

INTRODUCTION

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

Randomized phase III and extension studies: efficacy and impacts on quality of life of naldemedine in subjects with opioid-induced constipation and cancer

BACKGROUND

The efficacy and safety of naldemedine (a peripherally acting µ-opioid receptor antagonist) for opioid-induced constipation (OIC) in subjects with cancer was demonstrated in the primary report of a phase III, double-blind study (COMPOSE-4) and its open-label extension (COMPOSE-5). The primary end point, the proportion of spontaneous bowel movement (SBM) responders, was met. Here, we report results from secondary end points, including quality of life (QOL) assessments from these studies.

PATIENTS AND METHODS

In COMPOSE-4, eligible adults with OIC and cancer were randomly assigned 1:1 to receive once-daily oral naldemedine 0.2 mg (n = 97) or placebo (n = 96) for 2 weeks, and those who continued on to COMPOSE-5 received naldemedine for 12 weeks (n = 131). Secondary assessments in COMPOSE-4 included the proportion of complete SBM (CSBM) responders, SBM or CSBM responders by week, and subjects with ≥1 SBM or CSBM within 24 h postinitial dose. Changes from baseline in the frequency of SBMs or CSBMs per week were assessed at weeks 1 and 2. Time to the first SBM or CSBM postinitial dose was also evaluated. In both studies, QOL impact was evaluated by Patient Assessment of Constipation-Symptoms (PAC-SYM) and PAC-QOL questionnaires.

RESULTS

Naldemedine improved bowel function for all secondary efficacy assessments versus placebo (all P ≤ 0.0002). The timely onset of naldemedine activity versus placebo was evidenced by median time to the first SBM (4.7 h versus 26.6 h) and CSBM (24.0 h versus 218.5 h) postinitial dose (all P < 0.0001). In COMPOSE-4, significant differences between groups were observed with the PAC-SYM stool domain (P = 0.045) and PAC-QOL dissatisfaction domain (P = 0.015). In COMPOSE-5, significant improvements from baseline were observed for overall and individual domain scores of PAC-SYM and PAC-QOL.

CONCLUSIONS

Naldemedine provided effective and timely symptomatic relief from OIC and improved the QOL of subjects with OIC and cancer. TRIAL REGISTRATION ID: www.ClinicalTrials.jp: JAPIC-CTI-132340 (COMPOSE-4) and JAPIC-CTI-132342 (COMPOSE-5).

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

The long-term safety of naldemedine, a peripherally acting µ-opioid receptor antagonist, was evaluated in patients with opioid-induced constipation and chronic noncancer pain in a 52-week, randomized, double-blind, phase 3 study. Eligible adults who could be on a routine laxative regimen were randomized 1:1 to receive once-daily oral naldemedine 0.2 mg (n = 623) or placebo (n = 623). The primary endpoint was summary measures of treatment-emergent adverse events (AEs). Additional endpoints included opioid withdrawal on the Clinical Opiate Withdrawal Scale and the Subjective Opiate Withdrawal Scale, pain intensity on Numeric Rating Scale, frequency of bowel movements, and constipation-related symptoms and quality of life on the Patient Assessment of Constipation Symptoms and Patient Assessment of Constipation Quality of Life scales, respectively. Treatment-emergent AEs (naldemedine, 68.4% vs placebo, 72.1%; difference: -3.6% [95% confidence interval: -8.7 to 1.5]) and treatment-emergent AEs leading to study discontinuation (6.3% vs 5.8%; difference: 0.5% [-2.2 to 3.1)] were reported for similar proportions of patients. Diarrhea was reported more frequently with naldemedine (11.0%) vs placebo (5.3%; difference: 5.6% [2.6-8.6]). There were no meaningful differences between groups in opioid withdrawal or pain intensity. Sustained significant improvements in bowel movement frequency and overall constipation-related symptoms and quality of life were observed with naldemedine (P ≤ 0.0001 vs placebo at all time points). Naldemedine was generally well tolerated for 52 weeks and did not interfere with opioid-mediated analgesia or precipitate opioid withdrawal. Naldemedine significantly increased bowel movement frequency, improved symptomatic burden of opioid-induced constipation, and increased patients' quality of life vs placebo.

Small Fiber Neuropathy: Disease Classification Beyond Pain and Burning

Small fiber neuropathy (SFN) has a poorly understood pathology, but patients would benefit from determination of clinical phenotypes that allows for better diagnosis and treatment planning. I propose that patients should be classified dependent on whether there is sodium channel dysfunction, classic neurologic symptoms only, widespread neuropathic pain, or autonomic symptoms. Patients with SFN can then be considered in light of their clinical phenotype, allowing for focus on subsets of patients who might have diagnosable conditions or be more prone to responding to a particular type of therapy that may not be efficacious in the broader patient population with SFN. There are several therapies currently available that can address the symptoms of SFN; however, to develop novel therapeutic strategies, it will be imperative to classify patients to understand and target the underlying pathology.

Opioid misuse in gastroenterology and non-opioid management of abdominal pain

Opioids were one of the earliest classes of medications used for pain across a variety of conditions, but morbidity and mortality have been increasingly associated with their chronic use. Despite these negative consequences, chronic opioid use is increasing worldwide, with the USA and Canada having the highest rates. Chronic opioid use for noncancer pain can have particularly negative effects in the gastrointestinal and central nervous systems, including opioid-induced constipation, narcotic bowel syndrome, worsening psychopathology and addiction. This Review summarizes the evidence of opioid misuse in gastroenterology, including the lack of evidence of a benefit from these drugs, as well as the risk of harm and negative consequences of opioid use relative to the brain-gut axis. Guidelines for opioid management and alternative pharmacological and nonpharmacological strategies for pain management in patients with gastrointestinal disorders are also discussed. As chronic pain is complex and involves emotional and social factors, a multimodal approach targeting both pain intensity and quality of life is best.

Colorectal Transit and Volume During Treatment With Prolonged-release Oxycodone/Naloxone Versus Oxycodone Plus Macrogol 3350

BACKGROUND/AIMS

Opioid-induced constipation (OIC) is the most common gastrointestinal (GI) side effect to opioid treatment. Opioid receptor antagonists against OIC have been introduced, but their efficacy has not been directly compared to conventional laxatives. Our aim was to compare symptoms and objective parameters of gut function in an experimental model of OIC during treatment with the opioid antagonist naloxone and oxycodone in prolonged-release (PR) formulation versus oxycodone plus macrogol 3350.

METHODS

In this randomized, double-blind, crossover trial 20 healthy men received a 5-day treatment of combined PR oxycodone/naloxone or PR oxycodone plus macrogol 3350. Regional GI transit times and segmental colorectal transit were assessed with the Motilis 3D-Transit electromagnetic capsule system. Colorectal volumes were determined by MRI. OIC symptoms were assessed with validated questionnaires, along with stool frequency and consistency.

RESULTS

Total colorectal volume did not change after 5 days' treatment with PR oxycodone/naloxone (941 vs 1036 mL; P = 0.091), but increased significantly after PR oxycodone plus macrogol treatment (912 vs 1123 mL; P < 0.001). Neither regional GI transit times nor segmental colorectal transit differed between the treatments (all P > 0.05). The Patient Assessment of Constipation Symptom Questionnaire abdominal symptoms score was lower during PR oxycodone/naloxone compared to PR oxycodone plus macrogol (0.2 vs 3.2; P = 0.002). Stool frequency was lower during PR oxycodone/naloxone compared to PR oxycodone plus macrogol (4.2 vs 5.4; P = 0.035).

CONCLUSIONS

PR oxycodone plus macrogol increases colorectal volume, but does not improve GI transit compared to PR oxycodone/naloxone. However, PR oxycodone/naloxone results in a lower abdominal symptom burden, despite higher stool frequency during macrogol treatment.

European Pain Federation position paper on appropriate opioid use in chronic pain management

Poorly controlled pain is a global public health issue. The personal, familial and societal costs are immeasurable. Only a minority of European patients have access to a comprehensive specialist pain clinic. More commonly the responsibility for chronic pain management and initiating opioid therapy rests with the primary care physician and other non‐specialist opioid prescribers. There is much confusing and conflicting information available to non‐specialist prescribers regarding opioid therapy and a great deal of unjustified fear is generated. Opioid therapy should only be initiated by competent clinicians as part of a multi‐faceted treatment programme in circumstances where more simple measures have failed. Throughout, all patients must be kept under close clinical surveillance. As with any other medical therapy, if the treatment fails to yield the desired results and/or the patient is additionally burdened by an unacceptable level of adverse effects, the overall management strategy must be reviewed and revised. No responsible clinician will wish to pursue a failed treatment strategy or persist with an ineffective and burdensome treatment. In a considered attempt to empower and inform non‐specialist opioid prescribers, EFIC convened a European group of experts, drawn from a diverse range of basic science and relevant clinical disciplines, to prepare a position paper on appropriate opioid use in chronic pain. The expert panel reviewed the available literature and harnessed the experience of many years of clinical practice to produce these series of recommendations. Its success will be judged on the extent to which it contributes to an improved pain management experience for chronic pain patients across Europe.

Significance

This position paper provides expert recommendations for primary care physicians and other non‐ specialist healthcare professionals in Europe, particularly those who do not have ready access to specialists in pain medicine, on the safe and appropriate use of opioid medications as part of a multi‐faceted approach to pain management, in properly selected and supervised patients.

Treatment with Naloxegol Versus Placebo: Pain Assessment in Patients with Noncancer Pain and Opioid-Induced Constipation

OBJECTIVE

To summarize results from pain and opioid use assessments with naloxegol in adults with opioid-induced constipation (OIC) and chronic noncancer pain.

METHODS

Two phase 3 randomized, double-blind, 12-week studies evaluated the efficacy and safety of oral naloxegol (12.5 or 25 mg daily) in adults (18 to < 85 years) with confirmed OIC and chronic noncancer pain: KODIAC-04 (NCT01309841) and KODIAC-05 (NCT01323790). Pain level was assessed daily (11-point numeric rating scale [NRS]; 0 = no pain, 10 = worst imaginable pain). Changes from baseline in mean weekly pain scores and opioid dose (weeks 1 through 12) were analyzed using mixed-model repeated measures.

RESULTS

At baseline, mean daily NRS average pain scores ranged from 4.5 to 4.8 for all groups in KODIAC-04 (N = 652) and were 4.6 for each group in KODIAC-05 (N = 700). Respective mean ± SD changes from baseline average pain for placebo, naloxegol 12.5 mg, and naloxegol 25 mg were -0.2 ± 1.07, -0.3 ± 1.05 (P = 0.773 vs. placebo), and 0.2 ± 0.95 (P = 0.837 vs. placebo; KODIAC-04) and -0.1 ± 0.94, -0.1 ± 0.87 (P = 0.744), and 0.0 ± 1.18 (P = 0.572; KODIAC-05). At baseline, mean daily opioid doses ranged from 135.6 to 143.2 morphine equivalent units (MEUs)/day in KODIAC-04, and from 119.9 to 151.7 MEUs/day in KODIAC-05. Respective mean ± SD changes from baseline dose were -1.8 ± 30.19, -2.3 ± 20.52 (P = 0.724 vs. placebo), and 0.4 ± 13.01 (P = 0.188 vs. placebo; KODIAC-04) and -0.3 ± 17.14, -1.3 ± 17.11 (P = 0.669 vs. placebo), and 0.1 ± 8.54 (P = 0.863 vs. placebo; KODIAC-05). Changes in maintenance opioid dose were few; reasons for such changes were similar across treatment groups.

CONCLUSION

Centrally mediated opioid analgesia was maintained during treatment with naloxegol in patients with noncancer pain and OIC.

The Current State of Perioperative Pain Management: Challenges and Potential Opportunities for Nurses

Achievement of adequate postoperative pain management is a critical challenge in health care, with an estimated three out of four adult surgical patients reporting moderate to extreme pain after surgery. Overreliance on opioids in acute care settings has persisted, despite well-known adverse side effects frequently associated with this class of drugs. Furthermore, patients with a history of chronic opioid use present additional challenges in terms of postsurgical pain management. Advances in the development of newer analgesic agents and anesthetic techniques may be useful in surgical patients with a history of chronic opioid use and in the overall surgical patient population. Systemic inefficiencies and problematic medical practice patterns can also have negative effects on perioperative pain management. As the surgical patient's primary advocate, perioperative nurses play an important role in overcoming these diverse challenges and addressing the problems associated with inadequately controlled postsurgical pain.

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

Purpose Opioid-induced constipation (OIC) is a frequent and debilitating adverse effect (AE) of opioids-common analgesics for cancer pain. We investigated the efficacy and safety of a peripherally acting μ-opioid receptor antagonist, naldemedine (S-297995), for OIC, specifically in patients with cancer. Patients and Methods This phase III trial consisted of a 2-week, randomized, double-blind, placebo-controlled study (COMPOSE-4) and an open-label, 12-week extension study (COMPOSE-5). In COMPOSE-4, eligible adults with OIC and cancer were randomly assigned on a 1:1 basis to receive once-daily oral naldemedine 0.2 mg or placebo. The primary end point was the proportion of spontaneous bowel movement (SBM) responders (≥ 3 SBMs/week and an increase of ≥ 1 SBM/week from baseline). The primary end point of COMPOSE-5 was safety. Results In COMPOSE-4, 193 eligible patients were randomly assigned to naldemedine (n = 97) or placebo (n = 96). The proportion of SBM responders in COMPOSE-4 was significantly greater with naldemedine than with placebo (71.1% [69 of 97 patients] v 34.4% [33 of 96 patients]; P < .0001). A greater change from baseline was observed with naldemedine than with placebo in the frequency of SBMs/week (5.16 v 1.54; P < .0001), SBMs with complete bowel evacuation/week (2.76 v 0.71; P < .0001), and SBMs without straining/week (3.85 v 1.17; P = .0005). In COMPOSE-4, more patients treated with naldemedine than with placebo reported treatment-emergent AEs (TEAEs) (44.3% [43 of 97 patients] v 26.0% [25 of 96 patients]; P = .01); in COMPOSE-5, 105 (80.2%) of 131 of patients reported TEAEs. Diarrhea was the most frequently reported TEAE in COMPOSE-4 (19.6% [19 of 97 patients] v 7.3% [seven of 96 patients] with naldemedine v placebo) and COMPOSE-5 (18.3% [24 of 131 patients] with naldemedine). Naldemedine was not associated with signs or symptoms of opioid withdrawal and had no notable impact on opioid-mediated analgesia. Conclusion Once-daily oral naldemedine 0.2 mg effectively treated OIC and was generally well tolerated in patients with OIC and cancer.

Naldemedine versus placebo for opioid-induced constipation (COMPOSE-1 and COMPOSE-2): two multicentre, phase 3, double-blind, randomised, parallel-group trials

BACKGROUND

Opioid-induced constipation is a frequent side-effect of opioid treatment, and standard interventions have limited or inconsistent efficacy. This study assessed the efficacy and safety of naldemedine, a peripherally acting μ-opioid receptor antagonist, for the treatment of opioid-induced constipation in patients with chronic non-cancer pain.

METHODS

We report two double-blind, randomised, placebo-controlled trials in adults with chronic non-cancer pain and opioid-induced constipation. The first (COMPOSE-1) was done in 68 outpatient sites in seven countries and the second (COMPOSE-2) at 69 outpatient sites in six countries; both studies were done in Europe and the USA. Eligible patients were aged 18-80 years, did not use laxatives, and had a stable opioid regimen for treatment of chronic non-cancer pain with a total daily dose averaging at least 30 mg (morphine equivalent) for at least 1 month before screening. Patients were randomly assigned (1:1) to receive either oral naldemedine 0·2 mg or matching placebo once a day for 12 weeks. Randomisation was stratified by average total daily opioid dose (30-100 mg and >100 mg equivalents of oral morphine sulphate). The primary endpoint was proportion of responders. A responder had at least three spontaneous bowel movements (SBMs) per week with an increase from baseline of at least one SBM per week for at least 9 weeks of the 12-week treatment period including at least three of the last 4 weeks. Efficacy endpoints were analysed by intention to treat and the safety population included all patients who received at least one dose of study drug. These trials have both been completed and are registered with ClinicalTrials.gov, numbers NCT01965158 and NCT01993940.

FINDINGS

In COMPOSE-1, 547 patients were recruited between Aug 29, 2013, and Jan 22, 2015, and were randomly assigned to receive naldemedine (n=274) or placebo (n=273). Patients for COMPOSE-2 were recruited between Nov 4, 2013, and June 9, 2015; 553 patients were randomly assigned to receive naldemedine (n=277) or placebo (n=276). Five patients were enrolled at more than one site, so were excluded from the intention-to-treat population (COMPOSE-1: one per group; COMPOSE-2: one in the naldemedine group, two from the placebo group), with intention-to-treat group sizes of 273 in the naldemedine group and 272 in the placebo group in COMPOSE-1, and 276 in the naldemedine group and 274 in the placebo group in COMPOSE-2. The proportion of responders in both trials was significantly higher with naldemedine than with placebo in COMPOSE-1 (130 responders [47·6%] of 273 in the naldemedine group vs 94 responders [34·6%] of 272 in the placebo group, difference 13·0% [95% CI 4·8-21·3]; p=0·002) and in COMPOSE-2 (145 [52·5%] of 276 vs 92 [33·6%] of 274, difference 18·9% [10·8-27·0]; p<0·0001). Incidence of adverse events with naldemedine was similar to placebo (COMPOSE-1: 132 [49%] of 271 in the naldemedine group vs 123 [45%] of 272 in the placebo group; COMPOSE-2: 136 [50%] of 271 vs 132 [48%] of 274). Treatment-related adverse events were noted in 59 (22%) of 271 patients in the naldemedine group and 45 (17%) of 272 in the placebo group in COMOPOSE-1, and in 54 (20%) of 271 patients in the naldemedine group and 31 (11%) of 274 in the placebo group of COMPOSE-2; the between-group differences were largely due to gastrointestinal disorders, which were more common with naldemedine than placebo (COMPOSE-1: 40 [15%] patients in the naldemedine group vs 18 [7%] in the placebo group; COMPOSE-2: 42 [16%] vs 20 [7%]).

INTERPRETATION

Naldemedine treatment led to a significantly higher responder rate than did placebo and was generally well tolerated. These results support that naldemedine could be a new option for the treatment of opioid-induced constipation in patients with chronic non-cancer pain.

FUNDING

Shionogi & Co, Ltd.

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

Purpose This randomized, double-blind, multicenter study aimed to determine the dose of naldemedine, a peripherally-acting μ-opioid receptor antagonist, for future trials by comparing the efficacy and safety of three doses of naldemedine versus placebo in patients with cancer and opioid-induced constipation. Methods Patients ≥ 18 years old with cancer, an Eastern Cooperative Oncology Group performance status ≤ 2, who had been receiving a stable regimen of opioid analgesics for ≥ 2 weeks, had at least one constipation symptom despite laxative use, and no more than five spontaneous bowel movements (SBMs) during the past 14 days, were randomly assigned (1:1:1:1) to oral, once-daily naldemedine 0.1, 0.2, or 0.4 mg, or placebo, for 14 days. The primary end point was change in SBM frequency per week from baseline during the treatment period. Secondary end points included SBM responder rates, change from baseline in the frequency of SBM without straining, and complete SBM. Safety was also assessed. Results Of 227 patients who were randomly assigned, 225 were assessed for efficacy (naldemedine 0.1 mg, n = 55; 0.2 mg, n = 58; 0.4 mg, n = 56; placebo, n = 56) and 226 for safety. Change in SBM frequency (primary end point) was higher with all naldemedine doses versus placebo ( P < .05 for all comparisons), as were SBM responder rates and change in complete SBM frequency. Change in SBM frequency without straining was significantly improved with naldemedine 0.2 and 0.4 (but not 0.1) mg versus placebo (at least P < .05). Treatment-emergent adverse events were more common with naldemedine (0.1 mg: 66.1%; 0.2 mg: 67.2%; 0.4 mg: 78.6%) than placebo (51.8%); the most common treatment-emergent adverse event was diarrhea. Conclusion Fourteen-day treatment with naldemedine significantly improved opioid-induced constipation in patients with cancer and was generally well tolerated. Naldemedine 0.2 mg was selected for phase III studies.

Efficacy and tolerability balance of oxycodone/naloxone and tapentadol in chronic low back pain with a neuropathic component: a blinded end point analysis of randomly selected routine data from 12-week prospective open-label observations

Objective

To evaluate the benefit–risk profile (BRP) of oxycodone/naloxone (OXN) and tapentadol (TAP) in patients with chronic low back pain (cLBP) with a neuropathic component (NC) in routine clinical practice.

Methods

This was a blinded end point analysis of randomly selected 12-week routine/open-label data of the German Pain Registry on adult patients with cLBP-NC who initiated an index treatment in compliance with the current German prescribing information between 1st January and 31st October 2015 (OXN/TAP, n=128/133). Primary end point was defined as a composite of three efficacy components (≥30% improvement of pain, pain-related disability, and quality of life each at the end of observation vs baseline) and three tolerability components (normal bowel function, absence of either central nervous system side effects, and treatment-emergent adverse event [TEAE]-related treatment discontinuation during the observation period) adopted to reflect BRP assessments under real-life conditions.

Results

Demographic as well as baseline and pretreatment characteristics were comparable for the randomly selected data sets of both index groups without any indicators for critical selection biases. Treatment with OXN resulted formally in a BRP noninferior to that of TAP and showed a significantly higher primary end point response vs TAP (39.8% vs 25.6%, odds ratio: 1.93; P=0.014), due to superior analgesic effects. Between-group differences increased with stricter response definitions for all three efficacy components in favor of OXN: ≥30%/≥50%/≥70% response rates for OXN vs TAP were seen for pain intensity in 85.2%/67.2%/39.1% vs 83.5%/54.1%/15.8% (P= ns/0.031/<0.001), for pain-related disability in 78.1%/64.8%/43.8% vs 66.9%/50.4%/24.8% (P=0.043/0.018/0.001), and for quality of life in 76.6%/68.0%/50.0% vs 63.9%/54.1%/34.6% (P=0.026/0.022/0.017). Overall, OXN vs TAP treatments were well tolerated, and proportions of patients who either maintained a normal bowel function (68.0% vs 72.2%), reported no central nervous system side effects (91.4% vs 89.5%), or completed the 12-week evaluation period without any TEAE-related treatment discontinuations (93.0% vs 92.5%) were similar for both index medications (P= ns for each comparison).

Conclusion

In daily practice, the BRP of OXN proved to be noninferior to that of TAP in patients with cLBP-NC, but showed a superior efficacy if stricter analgesic response definitions were evaluated.

The role of naloxegol in the management of opioid-induced bowel dysfunction

Opioid-induced constipation (OIC) and other gastrointestinal (GI) symptoms of opioid-induced bowel dysfunction (OIBD) significantly deteriorate patients' quality of life and may lead to noncompliance with opioid schedule and undertreatment of pain. Although traditional oral laxatives are the first-line treatment of OIC, they do not address OIBD pathophysiology, and display numerous adverse effects. OIC treatment includes prokinetics (lubiprostone), opioid switch, and changing route of opioid administration. Targeted management of OIBD comprises the use of purely peripherally acting μ-opioid receptor antagonists (PAMORA): naloxegol and methylnaltrexone. Naloxegol (NKTR-118) is a polymer conjugate of the opioid antagonist naloxone. The polyethylene glycol limits naloxegol capacity to cross the blood-brain barrier (BBB). Naloxegol is substrate for the P-glycoprotein (P-gp) transporter. The central nervous system penetration of naloxegol is negligible due to reduced permeability and its increased efflux across the BBB, related to P-gp transporter. Naloxegol antagonizes μ- and κ-opioid receptors and displays low affinity to δ-opioid receptors in the GI tract, thereby decreasing OIBD symptoms without reversing central analgesic effects. Naloxegol is metabolised through CYP3A4 to six metabolites, with the majority of the dose (68%) excreted with faeces and less (16%) with urine. The dose of naloxegol equals 25 mg administered orally once daily on a fasting condition. Mild or moderate hepatic impairment has no impact on naloxegol dosing; naloxegol was not studied and is not recommended in patients with hepatic failure. Dose reduction (12.5 mg once daily) and caution is recommended in patients with moderate-to-severe renal impairment. Efficacy (bowel movement in 42-49% of patients not responsive to laxatives) and safety of naloxegol were confirmed in studies conducted in patients with OIC and nonmalignant pain. Naloxegol may be useful for cancer patients with OIC, although studies in this population are lacking.

Definition, diagnosis and treatment strategies for opioid-induced bowel dysfunction–Recommendations of the Nordic Working Group

Background and aims

Opioid-induced bowel dysfunction (OIBD) is an increasing problem due to the common use of opioids for pain worldwide. It manifests with different symptoms, such as dry mouth, gastro-oesophageal reflux, vomiting, bloating, abdominal pain, anorexia, hard stools, constipation and incomplete evacuation. Opioid-induced constipation (OIC) is one of its many symptoms and probably the most prevalent. The current review describes the pathophysiology, clinical implications and treatment of OIBD.

Methods

The Nordic Working Group was formed to provide input for Scandinavian specialists in multiple, relevant areas. Seven main topics with associated statements were defined. The working plan provided a structured format for systematic reviews and included instructions on how to evaluate the level of evidence according to the GRADE guidelines. The quality of evidence supporting the different statements was rated as high, moderate or low. At a second meeting, the group discussed and voted on each section with recommendations (weak and strong) for the statements.

Results

The literature review supported the fact that opioid receptors are expressed throughout the gastrointestinal tract. When blocked by exogenous opioids, there are changes in motility, secretion and absorption of fluids, and sphincter function that are reflected in clinical symptoms. The group supported a recent consensus statement for OIC, which takes into account the change in bowel habits for at least one week rather than focusing on the frequency of bowel movements. Many patients with pain receive opioid therapy and concomitant constipation is associated with increased morbidity and utilization of healthcare resources. Opioid treatment for acute postoperative pain will prolong the postoperative ileus and should also be considered in this context. There are no available tools to assess OIBD, but many rating scales have been developed to assess constipation, and a few specifically address OIC. A clinical treatment strategy for OIBD/OIC was proposed and presented in a flowchart. First-line treatment of OIC is conventional laxatives, lifestyle changes, tapering the opioid dosage and alternative analgesics. Whilst opioid rotation may also improve symptoms, these remain unalleviated in a substantial proportion of patients. Should conventional treatment fail, mechanism-based treatment with opioid antagonists should be considered, and they show advantages over laxatives. It should not be overlooked that many reasons for constipation other than OIBD exist, which should be taken into consideration in the individual patient.

Conclusion and implications

It is the belief of this Nordic Working Group that increased awareness of adverse effects and OIBD, particularly OIC, will lead to better pain treatment in patients on opioid therapy. Subsequently, optimised therapy will improve quality of life and, from a socio-economic perspective, may also reduce costs associated with hospitalisation, sick leave and early retirement in these patients.