Opioid-Related Constipation in Patients With Non-cancer Pain Syndromes: a Review of Evidence-Based Therapies and Justification for a Change in Nomenclature

Supportive pain therapy in dermatology

In conservative dermatology, significant pain frequently presents as an accompanying symptom of complex and severe diseases, severely impacting patients' quality of life. Herpes zoster and pyoderma gangrenosum are two conditions commonly associated with pain. Supportive therapy refers to measures designed to alleviate and improve disease-related symptoms, such as pain, in addition to disease-specific treatments. This review focuses on strategies for targeted pharmacological pain management, addressing contraindications, usage restrictions, dosing, dose adjustments, and potential drug interactions. While nonopioid analgesics are central to pain management, carefully selected opioids are also utilized. However, these may negatively affect patients' well-being and treatment adherence due to side effects like constipation and nausea. As a result, a supportive adjunctive therapy to address these side effects is crucial. The principles of targeted pharmacological pain therapy, consistent with current guidelines and recommendations from professional societies, are outlined in this article for use in dermatological practice.

[Opioid-induced constipation: Update on management and treatment]

Opioids are effective for acute and chronic pain management and are therefore an important treatment option for supportive care, especially in patients with cancer. They often induce digestive adverse effects, the most frequent being opioid-induced constipation (OIC), which is related to their action on μ receptors in the gastro-intestinal tract. These receptors play a role in the regulation of the gut motility and secretions. OIC has frequently been overlooked, although it can impair patients' comfort and compromise their compliance with opioid treatment. The consensus definition of OIC was established in 2016, and targeted therapies, the peripherally acting μ-opioid receptor antagonist (PAMORA) can yet specifically treat OIC without compromising pain relief. This review aims to explore the definition, pathophysiology, epidemiology, and diagnostic criteria of OIC. Risk factors and the necessary testing for the diagnostic work-up will be detailed. Finally, the impact of OIC on opioid treatment will be explained, and the treatment options, including non-pharmacological treatments, and pharmacological first-line and second-line therapies will be developed. A summary of the current therapeutic recommendations will be provided.

Perioperative bowel regimens following posterior spinal fusions for adolescent idiopathic scoliosis: a systematic review

Background

Bowel morbidity after posterior spinal fusions (PSFs) for adolescent idiopathic scoliosis (AIS) delays the advancement of postoperative oral diet and discharge. This systematic review aims to investigate the effectiveness of perioperative bowel regimens in reducing length of stay and postoperative bowel morbidity in these patients.

Materials and methods

We systematically searched MEDLINE, Embase, Cochrane, SPORTDiscus, and CINAHL for articles reporting on clinical results of PSFs for AIS patients. Demographic data, mean operative time and estimated blood loss, length of stay, time to first flatus and/or bowel movement, first oral intake, and postoperative pain scores were extracted from the selected studies.

Results

Six articles (n = 468 patients) met the final inclusion criteria. Only one study, which assessed oral methylnaltrexone, reported a significant reduction in the mean hospital length of stay (0.60 days, P < 0.05) and postoperative abdominal distension (17% versus 40%, P < 0.05); however, it was also the only study to report a significantly increased mean operative time (38.9 min, P = 0.03) and estimated blood loss (111.1 mL, P = 0.05) compared to the treatment group. Time to flatus, regular diet, postoperative opioid consumption, and pain scores did not differ significantly in any of the reported studies.

Conclusion

There is limited evidence to demonstrate any specific perioperative bowel regimen will decrease postpreparative bowel morbidity and/or length of stay. While not a treatment in isolation, oral methylnaltrexone may be a safe and effective adjunct to standard postoperative bowel regimens and may have a better patient tolerance profile.

The ketogenic diet mitigates opioid-induced hyperalgesia by restoring short-chain fatty acids-producing bacteria in the gut

ABSTRACT

Opioids are commonly prescribed to patients with chronic pain. Chronic opioid usage comes with a slew of serious side effects, including opioid-induced hyperalgesia (OIH). The patients with long-term opioid treatment experience paradoxical increases in nociceptive hypersensitivity, namely, OIH. Currently, treatment options for OIH are extremely lacking. In this study, we show that the ketogenic diet recovers the abnormal pain behavior caused by chronic morphine treatment in male mice, and we further show that the therapeutic effect of the ketogenic diet is mediated through gut microbiome. Our 16S rRNA sequencing demonstrates that chronic morphine treatment causes changes in mouse gut microbiota, specifically a decrease in short-chain fatty acids-producing bacteria, and the sequencing data also show that the ketogenic diet rescues those bacteria in the mouse gut. More importantly, we show that supplementation with short-chain fatty acids (butyrate, propionate, and acetate) can delay the onset of OIH, indicating that short-chain fatty acids play a direct role in the development of OIH. Our findings suggest that gut microbiome could be targeted to treat OIH, and the ketogenic diet can be used as a complementary approach for pain relief in patients with chronic opioid treatment. We only used male mice in this study, and thus, our findings cannot be generalized to both sexes.

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.

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

BACKGROUND

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

METHODS

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

PRIMARY OUTCOMES

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

SECONDARY OUTCOMES

gastric residual volumes and adverse events.

KEY RESULTS

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

CONCLUSIONS & INFERENCES

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

Prevalence and Burden of Illness of Rome IV Chronic Idiopathic Constipation, Opioid-Induced Constipation, and Opioid-Exacerbated Constipation in the United States

INTRODUCTION

Chronic idiopathic constipation (CIC) and opioid-induced constipation (OIC) are disorders that negatively affect quality of life. We sought to assess the prevalence, symptom severity, and medication use among people with Rome IV CIC, OIC, and opioid-exacerbated constipation (OEC) using a nationally representative data set with nearly 89,000 people in the United States.

METHODS

From May 3, 2020, to June 24, 2020, we recruited a representative sample of people in the United States ≥ 18 years to complete an online national health survey. The survey guided participants through the Rome IV CIC and OIC questionnaires, Patient-Reported Outcome Measurement Information System gastrointestinal scales (percentile 0-100; higher = more severe), and medication questions. Individuals with OEC were identified by asking those with OIC whether they experienced constipation before starting an opioid and whether their symptoms worsened afterward.

RESULTS

Among the 88,607 participants, 5,334 (6.0%) had Rome IV CIC, and 1,548 (1.7%) and 335 (0.4%) had Rome IV OIC and OEC, respectively. When compared with people with CIC (Patient-Reported Outcome Measurement Information System score, 53.9 ± 26.5; reference), those with OIC (62.7 ± 28.0; adjusted P < 0.001) and OEC (61.1 ± 25.8, adjusted P = 0.048) had more severe constipation symptoms. People with OIC (odds ratio 2.72, 95% confidence interval 2.04-3.62) and OEC (odds ratio 3.52, 95% confidence interval 2.22-5.59) were also more likely to be taking a prescription medication for their constipation vs those with CIC.

DISCUSSION

In this nationwide US survey, we found that Rome IV CIC is common (6.0%) while Rome IV OIC (1.7%) and OEC (0.4%) are less prevalent. Individuals with OIC and OEC have a higher burden of illness with respect to symptom severity and prescription constipation medication use.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Recommendations for the management of opioid-induced constipation - how to improve usability in clinical practice

INTRODUCTION

Opioid-induced constipation remains undertreated despite effective and safe treatment options exists. Previous guidelines have only been partially effective in improving management, possibly due to their complexity, and studies suggest that a simple setup of concise and behaviorally-orientated steps improves usability.

AREAS COVERED

This article introduces the concept of opioid-induced constipation and provides an overview of existing guidelines in this field. We also propose simplified recommendations for managing opioid-induced constipation, derived from a synthesis of current guidelines and the principles of optimal guideline design theory.

EXPERT OPINION

Despite standard treatment with laxatives and fluid intake in patients with opioid-induced constipation, escalation of treatment is often needed where μ-opioid receptor antagonists or newer medications such as lubiprostone, linaclotide, or prucalopride are used. Previous guidelines have not been used sufficiently and thus management of the condition is often insufficient. We therefore propose simplified recommendations to management, which we believe can come into broader use. It was validated in primary care for credibility, clarity, relevance, usability, and overall benefit. We believe that this initiative can lead to better management of the substantial proportion of patients suffering from side effects of opioids.

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.

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.

Can Naloxegol Therapy Improve Quality of Life in Patients with Advanced Cancer?

This observational study aims to evaluate the efficacy of naloxegol therapy in resolving opioid-induced constipation (OIC) and in improving the quality of life in a home palliative care cancer setting. Advanced cancer patients with OIC (Rome IV criteria) not relieved by laxatives started a naloxegol therapy 25 mg/day for 4 weeks. Quality of life was evaluated by Patient Assessment of Constipation Quality-of-Life (PAC-QoL) at day 0 and day 28; background pain by Numerical Rating Scale, number of weekly spontaneous bowel movements and Bowel Function Index (BFI) were evaluated at day 0 and every week. Seventy-eight patients who completed the 4-week study improved all four PAC-QoL dimensions (physical and psychological discomfort, worries/concerns and satisfaction level). Weekly spontaneous bowel movements increased and BFI improved. Background pain reduced after seven days and remained lower during the following weeks. Seventy-two patients dropped out the study before day 28 with a reduced survival compared to patients completing the study. Even in these patients, an improvement of bowel function was observed after two weeks. Naloxegol was effective in improving the quality of life, resolving OIC and reducing overall pain in patients with advanced cancer.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

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

What to Do and What Not to Do in the Management of Opioid-Induced Constipation: A Choosing Wisely Report

Introduction

Despite the essential utility of opioids for the clinical management of pain, opioid-induced constipation (OIC) remains an important obstacle in clinical practice. In patients, OIC hinders treatment compliance and has negative effects on quality of life. From a clinician perspective, the diagnosis and management of OIC are hampered by the absence of a clear, universal diagnostic definition across disciplines and a lack of standardization in OIC treatment and assessment.

Methods

A multidisciplinary panel of physician experts who treat OIC was assembled to identify a list of ten corrective actions—five “things to do” and five “things not to do”—for the diagnosis and management of OIC, utilizing the Choosing Wisely methodology.

Results

The final list of corrective actions to improve the diagnosis and clinical management of OIC emphasized a need for: (i) better physician and patient education regarding OIC; (ii) systematic use of diagnostically validated approaches to OIC diagnosis and assessment (i.e., Rome IV criteria and Bristol Stool Scale, respectively) across various medical contexts; and (iii) awareness about appropriate, evidence-based treatments for OIC including available peripheral mu-opioid receptor antagonists (PAMORAs).

Conclusions

Physicians who prescribe long-term opioids should be forthcoming with patients about the possibility of OIC and be adequately versed in the most recent guideline recommendations for its management.

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

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

Efficacy and safety of linaclotide for opioid-induced constipation in patients with chronic noncancer pain syndromes from a phase 2 randomized study

Constipation is the most common adverse event (AE) of opioid therapy. This multicenter, phase 2 study evaluated the efficacy and safety of linaclotide in treating opioid-induced constipation (OIC) in patients with chronic noncancer pain syndromes (NCT02270983). Adults with OIC (<3 spontaneous bowel movements [SBMs]/week) related to chronic noncancer pain were randomized 1:1:1 to receive linaclotide 145 µg, linaclotide 290 µg, or placebo once daily for 8 weeks. The primary endpoint was change from baseline in 8-week SBM frequency rate (SBMs/week). Secondary efficacy endpoints included 6/8-week SBM 3 + 1 responders, time to first SBM, and changes from baseline in 8-week stool consistency, abdominal bloating, and straining. Additional endpoints included treatment satisfaction and adequate relief responders. In total, 254 patients were randomized: 87, 88, and 79 received linaclotide 145 µg, linaclotide 290 µg, and placebo, respectively. The mean changes from baseline in SBMs/week during the treatment period were 2.9 and 3.5 in the linaclotide 145 and 290 µg groups (P < 0.01 for both doses), respectively, vs 1.6 in the placebo group. Diarrhea, the most common AE, was generally mild, resulting in 1.1%, 5.7%, and 1.3% of patients discontinuing in the linaclotide 145 μg, linaclotide 290 μg, and placebo groups, respectively. No serious AEs related to diarrhea were reported in any treatment group. Compared with placebo, linaclotide-treated patients had significant improvements in stool consistency, straining, abdominal bloating, and treatment satisfaction scores (P < 0.05). Linaclotide significantly improved OIC symptoms and was well tolerated in patients with chronic noncancer pain.

Opioid-Induced Constipation in Oncological Patients: New Strategies of Management

OPINION STATEMENT

Cancer-associated pain has traditionally been treated with opioid analgesics, often in escalating doses. Opioid-induced constipation (OIC) is a common problem associated with chronic use of opioid analgesics. Typical treatment strategies to alleviate constipation are based on dietary changes, exercise, and laxatives. However, laxatives have a nonspecific action and do not target underlying mechanisms of OIC. This article will review prevalent, clinical presentation and recommendations for the treatment of OIC. An independent literature search was carried out by the authors. We reviewed the literature for randomized controlled trials that studied the efficacy of laxatives, naloxone, and naloxegol in treating OIC. Newer strategies addressing the causal pathophysiology of OIC are needed for a more effective assessment and management of OIC. Finally, traditional recommended therapies are appraised and compared with the latest pharmacological developments. Future research should address whether naloxegol is more efficacious by its comparison directly with first-line treatments, including laxatives.

Opioid-induced constipation: a narrative review of therapeutic options in clinical management

Pain therapy often entails gastrointestinal adverse events. While opioids are effective drugs for pain relief, the incidence of opioid-induced constipation (OIC) varies greatly from 15% to as high as 81%. This can lead to a significant impairment in quality of life, often resulting in discontinuation of opioid therapy. In this regard, a good doctor-patient relationship is especially pivotal when initiating opioid therapy. In addition to a detailed history of bowel habits, patient education regarding the possible gastrointestinal side effects of the drugs is crucial. In addition, the bowel function must be regularly evaluated for the entire duration of treatment with opioids. Furthermore, if the patient has preexisting constipation that is well under control, continuation of that treatment is important. In the absence of such history, general recommendations should include sufficient fluid intake, physical activity, and regular intake of dietary fiber. In patients of OIC with ongoing opioid therapy, the necessity of opioid use should be critically reevaluated in terms of an with acceptable quality of life, particularly in cases of non-cancer pain. If opioids must be continued, lowering the dose may help, as well as changing the type of opioid. If these measures do not suffice, the next step for persistent OIC is the administration of laxatives. If these are ineffective as well, treatment with peripherally active μ-opioid receptor antagonists should be considered. Enemas and irrigation are emergency measures, often used as a last resort.

Pathophysiology and management of opioid-induced constipation: European expert consensus statement

BACKGROUND

Opioid-induced bowel dysfunction is a complication of opioid therapy, in which constipation is the most common and problematic symptom. However, it is frequently under-recognised and thus effective management is often not instituted despite a number of treatment options.

OBJECTIVE

The central objective of this study is to provide a summary of the pathophysiology and clinical evaluation of opioid-induced constipation and to provide a pragmatic management algorithm for day-to-day clinical practice.

METHODS

This summary and the treatment algorithm is based on the opinion of a European expert panel evaluating current evidence in the literature.

RESULTS

The pathophysiology of opioid-induced constipation is multi-faceted. The key aspect of managing opioid-induced constipation is early recognition. Specific management includes increasing fluid intake, exercise and standard laxatives as well as addressing exacerbating factors. The Bowel Function Index is a useful way of objectively evaluating severity of opioid-induced constipation and monitoring response. Second-line treatments can be considered in those with recalcitrant symptoms, which include gut-restricted or peripherally acting mu-opioid receptor antagonists. However, a combination of interventions may be needed.

CONCLUSION

Opioid-induced constipation is a common, yet under-recognised and undertreated, complication of opioid therapy. We provide a pragmatic step-wise approach to opioid-induced constipation, which should simplify management for clinicians.

Chronic preoperative opioid use is a risk factor for increased complications, resource use, and costs after cervical fusion

BACKGROUND CONTEXT

As health-care transitions to value-based models, there has been an increased focus on patient factors that can influence peri- and postoperative adverse events, resource use, and costs. Many studies have reported risk factors for systemic complications after cervical fusion, but none have studied chronic opioid therapy (COT) as a risk factor.

PURPOSE

The objective of this study was to answer the following questions from a large cohort of patients who underwent primary cervical fusion for degenerative pathology: (1) What is the patient profile associated with preoperative COT? (2) Is preoperative COT a risk factor for 90-day systemic complications, emergency department (ED) visits, readmission, and 1-year adverse events? (3) What are the risk factors and 1-year adverse events related to long-term postoperative opioid use? (4) How much did payers reimburse for management of complications and adverse events?

STUDY DESIGN

This is a retrospective review of Humana commercial insurance data (2007-Q3 2015).

PATIENT SAMPLE

The patient sample included 29,101 patients undergoing primary cervical fusion for degenerative pathology.

METHODS

Patients and procedures of interest were included using International Classification of Diseases (ICD) coding. Patients with opioid prescriptions for >6 months before surgery were considered as having preoperative COT. Patients with continued opioid use until 1-year after surgery were considered as long-term users. Descriptive analysis of patient cohorts has been done. Multiple-variable logistic regression analyses adjusting for approach, number of levels of surgery, discharge disposition, and comorbidities were done to answer first three study questions. Reimbursement data from insurers have been reported to answer our fourth study question.

RESULTS

Of the entire cohort, 6,643 (22.8%) had preoperative COT. Preoperative COT was associated with a higher risk of 90-day wound complications (odds ratio [OR] 1.39, 95% confidence interval [CI]: 1.16-1.66), all-cause 90-day ED visits (adjusted OR 1.22, 95% CI: 1.13-1.32), and pain-related ED visits (adjusted OR 1.39, 95% CI: 1.24-1.55). Patients who had preoperative COT were more likely to receive epidural or facet joint injections within 1 year after surgery (adjusted OR 1.68, 95% CI: 1.47-1.92). These patients were also more likely to undergo a repeat cervical fusion within a year than patients who did not have preoperative COT (adjusted OR 1.21, 95% CI: 1.01-1.43). Preoperative COT had a higher likelihood of long-term use after surgery (adjusted OR 4.72, 95% CI: 4.41-5.06). Long-term opioid use after surgery was associated with a higher risk of new-onsetconstipation (adjusted OR 1.34, 95% CI: 1.22-1.48). The risk of complications and adverse events was not found to be significant in patients with <3 months of preoperative opioid use or those who stopped opioids for at least 6 weeks before surgery. The cost of additional resource use for medications, ED visits, constipation, injections, and revision fusion ranged from $623 to $27,360 per patient.

CONCLUSIONS

Preoperative opioid use among patients who underwent cervical fusion increases complication rates, postoperative opioid usage, health-care resource use, and costs. These risks may be reduced by restricting the duration of preoperative opioid use or weaning off before surgery. Better understanding and management of pain in the preoperative period with judicious use of opioids is critical to enhance outcomes after cervical fusion surgery.

Preoperative Chronic Opioid Therapy: A Risk Factor for Complications, Readmission, Continued Opioid Use and Increased Costs After One- and Two-Level Posterior Lumbar Fusion

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

To study patient profile associated with preoperative chronic opioid therapy (COT), and study COT as a risk factor for 90-day complications, emergency department (ED) visits, and readmission after primary one- to two-level posterior lumbar fusion (PLF) for degenerative spine disease. We also evaluated associated costs, risk factors, and adverse events related to long-term postoperative opioid use.

SUMMARY OF BACKGROUND DATA

Chronic opioid use is associated with poor outcomes and dependence after spine surgery. Risk factors, complications, readmissions, adverse events, and costs associated with COT in patients undergoing lumbar fusion are not entirely known. As providers look to reduce healthcare costs and improve outcomes, identification of modifiable risk factors is important.

METHODS

Commercial insurance data from 2007 to Q3-2015 was used to study preoperative opioid use in patients undergoing primary one- to two-level PLF. Ninety-day complications, ED visits, readmissions, 1-year adverse events, and associated costs have been described. Multiple-variable regression analyses were done to study preoperative COT patient profile and opioid use as a risk factor for complications and adverse events.

RESULTS

A total of 24,610 patients with a mean age of 65.6 ± 11.5 years were included. Five thousand five hundred (22.3%) patients had documented opioid use for more than 6 months before surgery, and 87.4% of these had continued long-term use postoperatively. On adjusted analysis, preoperative COT was found to be a risk factor for 90-day wound complications, pain diagnoses, ED visits, readmission, and continued use postoperatively. Postspinal fusion long-term opioid users had an increased utilization of epidural/facet joint injections, risk for revision fusion, and increased incidence of new onset constipation within 1 year postsurgery. The cost associated with increase resource use in these patients has been reported.

CONCLUSION

Preoperative COT is a modifiable risk factor for complications, readmission, adverse events, and increased costs after one- or two-level PLF.

LEVEL OF EVIDENCE

3.

Refractory Constipation: What is the Clinician to Do?

Most clinicians will agree that chronic constipation is characterized by abnormal bowel movement consistency and/or frequency plus or minus evacuation symptoms, but patient perception of constipation varies widely and includes symptoms that may or may not meet official defining criteria. Although intermittent constipation is extremely common, only a small minority of patients seek care for their symptoms. Among these patients, dissatisfaction with the currently available laxative options is not uncommon, and many patients will require specialized care for severe or refractory symptoms-especially those with abdominal pain, irritable bowel syndrome overlap, bloating or distention, and psychological comorbidities. This review outlines a physiological assessment of the patient with refractory constipation, exploring treatment options among patients with slow transit, rectal evacuation disorders, and normal transit. In addition, we explore nonlaxative approaches to normal-transit patients bothered by ongoing symptoms, with an emphasis on the biopsychosocial model of functional gastrointestinal disease and treatment of visceral hypersensitivity using neuromodulators. Finally, we propose a comprehensive evaluation algorithm for the management of patients with refractory slow-transit constipation considering surgery and examine surgical options including colectomy and cecostomy using an antegrade continent enema.

Safe Opioid Use: Management of Opioid-Related Adverse Effects and Aberrant Behaviors

Opioids are highly effective for cancer pain but are associated with multiple adverse effects and risk of addiction. This article provides a synopsis on the management of various opioid-related adverse effects and strategies to minimize aberrant opioid use in patients who have cancer. Many adverse effects can be effectively managed. Some patients on chronic opioid therapy may demonstrate aberrant behaviors suggestive of opioid misuse or diversion. Through intensive education, longitudinal monitoring, early identification, and timely management, clinicians can optimize the risk to benefit ratio to support safe opioid use.

Insights on efficacious doses of PAMORAs for patients on chronic opioid therapy or opioid-naïve patients

BACKGROUND

Opioid-induced constipation (OIC) is a major side effect of opioid use. Centrally acting antagonists result in opioid withdrawal or worsening of pain and lead to use of peripherally acting mu-opioid receptor antagonists (PAMORAs). The required doses of the PAMORAs, methylnaltrexone and naloxegol, in the treatment of OIC are well established in chronic opioid users. OIC may occur after short duration of opioid treatment; the required doses of naloxone, naltrexone, and PAMORAs in opioid-naïve subjects (with no opioid use for at least 3 months) are unclear. The aim of this review was to evaluate the PAMORA dose required for opioid-naïve subjects to achieve similar beneficial effects on symptoms or valid surrogates to those observed in chronic opioid users.

METHODS

A PubMed search of μ-opioid antagonists to counter μ-opioid effects included terms: naloxone, naltrexone, methylnaltrexone, alvimopan, and naloxegol, as well as OIC and colonic transit.

KEY RESULTS

The approved dose of methylnaltrexone in chronic opioid users, 0.3 mg/kg subcutaneous (SQ), did not affect motility in opioid-naïve subjects. Trials investigating the required dose of alvimopan showed 0.5-1 mg dose was efficacious in treating OIC; a 10-fold higher dose (12 mg) of alvimopan is needed to block effects of codeine on small bowel and colonic transit in opioid-naïve subjects compared to chronic opioid users. Opioid-naïve users need 125 mg of naloxegol to reverse the effects of opioids on transit; this is in contrast to the 12.5 to 25 mg needed to treat OIC in chronic opioid users.

CONCLUSIONS & INFERENCES

Opioid-naïve subjects require a higher dose of PAMORA than chronic opioid users to achieve μ-opioid antagonist effect.

Spotlight on naldemedine in the treatment of opioid-induced constipation in adult patients with chronic noncancer pain: design, development, and place in therapy

Opioid-induced constipation (OIC) is an increasingly prevalent problem in the USA due to the growing use of opioids. A novel class of therapeutics, the peripherally acting μ-opioid receptor antagonists (PAMORAs), has been developed to mitigate the deleterious effects of opioids in the gastrointestinal tract while maintaining central analgesia and minimizing opioid withdrawal. This review aimed to summarize the literature on naldemedine, the third PAMORA to gain US Food and Drug Administration (FDA) approval for the treatment of OIC in adults with chronic noncancer pain-related syndromes. Naldemedine has a chemical structure similar to naltrexone, an opioid receptor antagonist, with chemical modifications that limit its ability to cross the blood-brain barrier. Naldemedine was evaluated in two Phase II and three Phase III clinical trials prior to gaining FDA approval. In two pivotal identical Phase III trials, COMPOSE-I (NCT 01965158) and COMPOSE-II (NCT 01993940), patients receiving naldemedine were significantly more likely to respond when compared with placebo (COMPOSE-I: 47.6 vs 34.6%, P=0.002 and COMPOSE-II: 52.5 vs 33.6%, P<0.0001). The most frequent adverse events were abdominal pain (8%) and diarrhea (7%) - rates similar to the other PAMORAs. Based on the available data, naldemedine appears to be an effective and safe drug for the treatment of OIC in adults with chronic noncancer pain.

Formulation of a Peribulbar Block for Prolonged Postoperative Pain Management in Vitreoretinal Surgery: A Randomized Clinical Trial

PURPOSE

To evaluate postoperative pain level using a supplemental peribulbar injection at the conclusion of retinal surgery.

DESIGN

Prospective, parallel-assigned, single-masked, randomized clinical trial.

PARTICIPANTS

Fifty-eight patients undergoing scleral buckle, vitrectomy, or combined surgery.

METHODS

In a single academic institutional practice, 58 patients undergoing scleral buckle, vitrectomy, or combined surgery were enrolled. Exclusion criteria included those with a risk for glaucoma, a pre-existing chronic pain disorder, among others. Patients were assigned randomly to receive a postoperative peribulbar formulation of either bupivacaine, triamcinolone acetonide, and cefazolin (group A) or bupivacaine, balanced salt solution, and cefazolin (group B). The postoperative pain score and ocular motility were assessed by a masked observer on the first postoperative day.

MAIN OUTCOME MEASURES

The primary outcome measure was the postoperative pain score. Secondary outcome measures included oral analgesic use, ocular motility, and intraocular pressure (IOP).

RESULTS

The mean pain scores were 2.8±2.9 for group A and 3.8±2.6 for group B (P = 0.095). Pain was absent in 28% of group A patients versus 14% of group B patients (P = 0.11). Group A required less narcotic pain medication (hydroxycodone: group A, 0.7±3 mg vs. group B, 3±6 mg; P = 0.05; oxycodone: group A, 7±7 mg vs. 9±13 mg; P = 0.2) than group B. Motility was full in group B and limited in group A (P ≤ 0.001), with no differences in mean IOP measurements at any point after surgery.

CONCLUSIONS

We did not demonstrate a statistically significant reduction in mean postoperative pain scores. However, patients in group A required less hydroxycodone use and had greater akinesia, suggesting prolonged neural blockade.