Optimal treatment of opioid induced constipation in daily clinical practice - an observational study

The P2Y1 receptor in the colonic myenteric plexus of rats and its correlation with opioid-induced constipation

This study was designed to explore the expression changes of P2Y1 receptors in the distal colonic myenteric layer of rats. An opioid induced constipation(OIC) rat model was generated by intraperitoneal (i.p) injection of loperamide. At 7 days post-treatment, the model rats were assessed by calculating the fecal water content and the gastrointestinal transit ratio. The immunofluorescence (IF)-based histochemical study was used to observe the distribution of P2Y1 receptors in the distal colonic myenteric plexus. Western blotting (WB) was performed to evaluate the expression changes of P2Y1 proteins in the myenteric layer, and the electrophysiological approaches were carried out to determine the regulatory roles of P2Y1 receptors on distal colonic motor function. IF showed that P2Y1 receptors are co-expressed MOR in the enteric nerve cells of the distal colonic myenteric plexus. Moreover, the WB revealed that the protein levels of P2Y1 were significantly decreased in the distal colonic myenteric layer of OIC rats. In vitro tension experiments exhibited that the P2Y1 receptor antagonist MRS2500 enhanced the spontaneous contraction amplitude, adding EM2 and β-FNA did not have any effect on MRS2500. Therefore, P2Y1 receptor expression could be associated with the occurrence of OIC in this rat model and the regulation of colonic motility by MOR may be related to the release of purine neurotransmitters such as ATP in the colonic nervous system.

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

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

Subcutaneous Methylnaltrexone as Treatment for Opioid-Induced Constipation in Patients with Advanced Cancer and Noncancer Illnesses: A Post Hoc Analysis of Two Clinical Trials

Purpose

To evaluate the efficacy and safety of subcutaneous (SC) methylnaltrexone for opioid-induced constipation (OIC) in patients with and without active cancer.

Patients and Methods

We analyzed two randomized, double-blind, placebo-controlled, Phase 3/4 trials (NCT00402038, NCT00672477). Patients received SC methylnaltrexone (study 302, 0.15 mg/kg; study 4000, 8 mg or 12 mg based on body weight) or placebo every other day for 2 weeks. Patients were stratified by cancer status. Primary efficacy endpoints included proportion of patients achieving rescue-free laxation (RFL); secondary endpoints included time to RFL, pain intensity scores, and safety/tolerability. Trial results were evaluated separately.

Results

The safety population (patients receiving ≥1 study drug dose) included 364 patients (study 302, n=134; study 4000, n=230). Study 302 had 78 patients with active cancer (methylnaltrexone, n=37; placebo, n=41) and 56 without cancer (methylnaltrexone, n=26; placebo, n=30); study 4000 had 152 patients with active cancer (methylnaltrexone, n=79; placebo, n=73) and 78 without cancer (methylnaltrexone, n=37; placebo, n=41). A significantly greater proportion of patients treated with methylnaltrexone achieved a laxation response within 4 hours after at least 2 of the first 4 doses versus placebo, dosed by body weight (cancer, 54.1% [methylnaltrexone] vs 7.3% [placebo], P<0.0001; noncancer, 48.0% vs 10.0%; P<0.005) or given as a weight-adjusted fixed dose (cancer, 59.5% vs 6.8%; noncancer, 70.3% vs 14.6%; P<0.0001 each). With fixed-dose methylnaltrexone, average time to RFL for patients with and without cancer was <1 hour of the first dose; with methylnaltrexone dosed by body weight, the first RFL occurred in <4 and <7 hours of treatment in patients with and without cancer, respectively. No significant differences were found in pain scores. SC methylnaltrexone was well tolerated at all doses in all patient cohorts.

Conclusion

SC methylnaltrexone was efficacious in inducing rapid RFL and safe among patients with and without active cancer suffering from OIC.

Opioids and constipation therapy in the last week of life: Their impact on patients, caregivers, and the location of death

The use of opioids to control pain at the end of life may cause constipation, a symptom that can negatively influence the well-being of patients and caregivers. The main aim of this study was to evaluate the impact of constipation on symptomatic control and patients' overall quality of life at this stage. A particular focus was placed on opioids. We also intended to investigate whether constipation and caregiver fatigue is related to the place of death (hospital vs home). The approach of 121 patients followed in 2021 in their last week of life by a home team specialized in palliative care was analyzed in an observational, retrospective, non-interventional study. The patients were followed up for an average of 39.7 days. A total of 82.6% wished to die at home, which occurred in 74% of the cases. The constipation prevention protocol reduced constipation by 55.1%. It seems that morphine is more related with constipation and tapentadol seems to reduce constipation induced by opioids. Patients tended to die in hospitals when their caregivers were exhausted; however, it was not possible to determine a cutoff point using the Zarit scale, which was used to assess caregiver burden. Constipation in the last week of life does not seem to influence the well-being of patients or their caregivers significantly and the individualization of intensive treatment of constipation is needed. Different opioids have different probabilities of causing adverse effects such as constipation. Future special support mechanisms can be created and activated for the most tired caregivers to avoid exhaustion and promote death at home, if that is the patient's will.

A Survey of the Incidence of Constipation in Patients with Chronic Non-cancer Pain Using Opioid Analgesics in Japan

INTRODUCTION

Although opioids have potent analgesic properties, their use is associated with side effects, including opioid-induced constipation (OIC). This study investigated the incidence of OIC based on the Rome IV diagnostic criteria in patients using opioid analgesics for chronic non-cancer pain and to explore and compare the risk factors for the development of OIC in opioid analgesic users.

METHODS

We surveyed patients aged 20 years or more living in Japan via the internet; who had been using opioid or non-opioid analgesics (N = 500 each) for at least 3 months for relief from chronic non-cancer musculoskeletal pain (low back pain or osteoarthritis); and who provided electronic consent to participate in and complete the survey. The groups were matched for age and sex.

RESULTS

Of the patients using opioid analgesics, 89% were taking weak opioids. The proportion of patients perceiving constipation was comparable between the opioid and non-opioid analgesic groups (34% vs 29%, respectively); however, a significantly higher proportion of patients in the opioid group, compared to the non-opioid group, reported self-assessed constipation (40% vs 18%, respectively) after using an analgesic and fulfilled two or more symptoms of the Rome IV diagnostic criteria for constipation (28% vs 19%, respectively). A higher proportion of patients were taking prescribed medicine for constipation in the opioid group compared with the non-opioid group (33% vs 18%, respectively). Low back pain, but not opioid strength and scheduled dosing, was identified as a risk factor for OIC among various covariates assessed in the logistic regression analysis in 81 patients with OIC and Rome IV diagnosis vs 419 patients without OIC in the opioid group.

CONCLUSION

Use of opioid analgesics, including weak opioids, for treating chronic non-cancer musculoskeletal pain is associated with OIC. This finding highlights the need for appropriate treatment of constipation in patients with chronic non-cancer pain in Japan.

TRIAL REGISTRATION

UMIN000043985.

Risk and main contributing factors for constipation in patients with gastrointestinal cancer: a multicenter cross-sectional study in China

BACKGROUND AND OBJECTIVES

The purpose of this study is to determine the risk of constipation and to identify the significant risk factors for constipation in patients with gastrointestinal cancer using the Chinese version of the constipation risk assessment scale (CRAS-C), as well as to explore the complementary constipation risk factors in patients with gastrointestinal cancer, to improve the specificity of the CRAS-C in this population, and finally to provide a theoretical basis for constipation prevention.

RESEARCH DESIGN AND METHODS

A cross-sectional study involving multiple centers was conducted. A total of 190 patients with gastrointestinal cancer completed surveys that included demographic information, defecation habits, and the CRAS-C. The mean, SD, median, maximum, minimum, frequency, and percentage were used as indicators for the constipation risk and significant risk factors. The t test and Chi-square tests were used to analyze constipation indicators in patients with gastrointestinal cancer.

RESULTS

The mean (SD) age of the 190 participants was 61.68 (12.35) years. The total CRAS-C mean (SD) score was 13.22 (4.69). Fifty-one patients (26.8%) scored lower than 11, who were at the low-risk level of constipation. One hundred thirty-nine patients (73.2%) scored 11 or above, who were at the high-risk level of constipation. The top 10 factors were insufficient liquid intake (81.1%), failure to consume bran products daily (78.9%), insufficient fiber intake (77.9%), antiemetics (74.7%), cytotoxic chemotherapy (52.6%), colorectal/abdominal diseases (42.6%), female (35.3%), opioid analgesics(26.8%), calcium channel blockers (16.3%), and endocrine disorders (14.2%). Chi-square test showed that constipating for most of the past 3 months, ascites and ECOG score were complementary constipation risk factors in gastrointestinal cancer patients.

CONCLUSION

The findings indicate that most gastrointestinal cancer patients were at a high risk of constipation. There are also several complementary constipation risk factors, and CRAS-C can be further revised in future studies to make it more specific in gastrointestinal cancer patients. Integrating CRAS into the pathway of constipation management, carrying out constipation risk screening for hospitalized cancer patients, and building systematic constipation prevention plan based on risk assessment are important to reduce the incidence of constipation in patients with gastrointestinal cancer and improve the quality of life.

Acupuncture Relieves Opioid-Induced Constipation in Clinical Cancer Therapy - A Meta-Analysis and Systematic Review

Cancer pain is a common problem in clinical cancer therapy. Opioid analgesia is one of the most effective drugs for pain relief with satisfying performance besides the side effect of opioid-induced constipation (OIC). Acupuncture, as a Chinese traditional non-invasive intervention, has been applied to clinical cancer pain management and functional constipation therapy. However, only a few studies have adopted this treatment for OIC patients. Due to limited numbers of investigated subjects and variability of application methods, including treatment apparatus, acupoints, durations, and sessions, the interpretation of acupuncture’s therapy effects from single-site randomized clinical trials (RCT) is limited. Therefore, we conducted a meta-analysis by collecting published data from Pubmed, Embase, Cochrane library, and Web of Science. Five RCTs focusing on the application of acupuncture with or without medication in OIC patients were included. An overall remission rate of 86.8% in the acupuncture-treated group was achieved, higher than the control group (78.9%; RR, 1.10, 95% CI [1.03, 1.18]). The symptom scores, reporting on defecation frequency, defecation straining, abdominal pain, defection time, and stool property, in acupuncture groups were lower than control groups with a standardized mean difference (SMD) of −2.21 [−4.15, −0.27]. The quality of life (QOL) for patients in the acupuncture treated group increased compared to the control group with reduced PAC-QOL scores (SMD, −1.02 [−1.78, −0.26]). Referring to the effects from pure acupuncture treatment (SMD, −0.43 [−0.83, −0.03]), the co-intervention of acupuncture and drugs (SMD, −1.77 [−2.51, −1.02]) improved the life quality of patients more remarkably (P < 0.05). Overall, our data confirmed the therapeutic effects of acupuncture in the treatment of OIC. The co-intervention of acupuncture with drugs improves the outcomes of OIC patients better than a single strategy. Combined therapy with both medicine and acupuncture has insightful potential for future clinical cancer patient management on constipation problems.

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

PURPOSE

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

METHODOLOGIC APPROACH

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

FINDINGS

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

IMPLICATIONS FOR NURSING

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

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