Opioid-induced constipation, use of laxatives, and health-related quality of life

Case report: Comprehensive management of painful diabetic neuropathy-Addressing opioid-induced hyperalgesia through multimodal approaches

RATIONALE

Diabetic neuropathy is a prevalent and debilitating complication of diabetes, necessitating effective pain management strategies. While pharmacological treatments, including opioids, are commonly employed, they pose significant challenges due to the risk of developing opioid-induced hyperalgesia (OIH). This case report aims to illustrate the efficacy of a comprehensive, multidisciplinary approach in managing painful diabetic neuropathy complicated by OIH.

PATIENT CONCERNS

A 64-year-old male patient presented to the Pain Treatment Clinic with severe lower limb pain due to diabetic polyneuropathy. He had a history of multiple comorbidities.

DIAGNOSES

The patient's condition and physical examination suggested the presence of opioid-induced hyperalgesia (OIH). Despite the increased dose of opioids, the patient did not report significant constipation or breathing difficulties but experienced drowsiness and dry mouth. A diagnosis of opioid and benzodiazepine dependence was made.

INTERVENTIONS

The treatment plan involved the initiation of pregabalin and duloxetine, gradual reduction of opioid use, and psychiatric support for addiction management.

OUTCOMES

Over 12 months, the patient experienced significant pain reduction and minimal adverse effects.

LESSONS

Effective management of OIH involves gradual opioid tapering and a multimodal therapeutic approach. However, the optimal treatment strategies and the frequency of OIH occurrence remain areas of uncertainty, relying heavily on clinical expertise and individualized patient care. Further research is needed to refine these treatment strategies and improve patient outcomes.

Pharmacological prevention and treatment of opioid-induced constipation in cancer patients: A systematic review and meta-analysis

BACKGROUND

Cancer-related pain often requires opioid treatment with opioid-induced constipation (OIC) as its most frequent gastrointestinal side-effect. Both for prevention and treatment of OIC osmotic (e.g. polyethylene glycol) and stimulant (e.g. bisacodyl) laxatives are widely used. Newer drugs such as the peripherally acting µ-opioid receptor antagonists (PAMORAs) and naloxone in a fixed combination with oxycodone have become available for the management of OIC. This systematic review and meta-analysis aims to give an overview of the scientific evidence on pharmacological strategies for the prevention and treatment of OIC in cancer patients.

METHODS

A systematic search in PubMed, Embase, Web of Science and the Cochrane Library was completed from inception up to 22 October 2022. Randomized and non-randomized studies were systematically selected. Bowel function and adverse drug events were assessed.

RESULTS

Twenty trials (prevention: five RCTs and three cohort studies; treatment: ten RCTs and two comparative cohort studies) were included in the review. Regarding the prevention of OIC, three RCTs compared laxatives with other laxatives, finding no clear differences in effectivity of the laxatives used. One cohort study showed a significant benefit of magnesium oxide compared with no laxative. One RCT found a significant benefit for the PAMORA naldemedine compared with magnesium oxide. Preventive use of oxycodone/naloxone did not show a significant difference in two out of three other studies compared to oxycodone or fentanyl. A meta-analysis was not possible. Regarding the treatment of OIC, two RCTs compared laxatives, of which one RCT found that polyethylene glycol was significantly more effective than sennosides. Seven studies compared an opioid antagonist (naloxone, methylnaltrexone or naldemedine) with placebo and three studies compared different dosages of opioid antagonists. These studies with opioid antagonists were used for the meta-analysis. Oxycodone/naloxone showed a significant improvement in Bowel Function Index compared to oxycodone with laxatives (MD -13.68; 95 % CI -18.38 to -8.98; I2 = 58 %). Adverse drug event rates were similar amongst both groups, except for nausea in favour of oxycodone/naloxone (RR 0.51; 95 % CI 0.31-0.83; I2 = 0 %). Naldemedine (NAL) and methylnaltrexone (MNTX) demonstrated significantly higher response rates compared to placebo (NAL: RR 2.07, 95 % CI 1.64-2.61, I2 = 0 %; MNTX: RR 3.83, 95 % CI 2.81-5.22, I2 = 0 %). With regard to adverse events, abdominal pain was more present in treatment with methylnaltrexone and diarrhea was significantly more present in treatment with naldemedine. Different dosages of methylnaltrexone were not significantly different with regard to both efficacy and adverse drug event rates.

CONCLUSIONS

Magnesium oxide and naldemedine are most likely effective for prevention of OIC in cancer patients. Naloxone in a fixed combination with oxycodone, naldemedine and methylnaltrexone effectively treat OIC in cancer patients with acceptable adverse events. However, their effect has not been compared to standard (osmotic and stimulant) laxatives. More studies comparing standard laxatives with each other and with opioid antagonists are necessary before recommendations for clinical practice can be made.

Effect of opioids on constipation in critically ill patients: A meta-analysis

OBJECTIVES

This meta-analysis evaluated the effect of opioids on constipation in ICU patients.

REVIEW METHOD USED

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang DATA databases.

REVIEW METHODS

Random or fixed-effects meta-analyses were used. Subgroup analysis was performed according to the definition of constipation (three vs. six days), opioids (fentanyl vs. morphine), study design (prospective vs. retrospective), adjustment of confounders (No vs. Yes), and patient's age (adults vs. children). We used sensitivity analysis to test the robustness of results with significant statistical heterogeneity.

RESULTS

Seven studies (2264 patients) were included. Opioid use in ICU patients was associated with an increased risk of constipation (relative risk [RR]=1.14; 95% confidence interval [CI]=1.05 to 1.24; I2=49.8%). Subgroup analysis further showed that adjustment form, category of opioid, study design, and patient's age significantly influenced the relationship between opioid use and the risk of constipation. Sensitivity analysis confirmed the robustness of pooled results.

CONCLUSION

Opioids significantly increase the risk of constipation in critically ill patients, especially children. It is worth noting that the adjustment of the constipation definition used for ICU significantly influenced the relationship between opioid use and the risk of constipation. Therefore, It is necessary to clearly define ICU constipation and conduct time-based layered treatment. Additional prospective studies are needed to investigate the consistent definition of ICU constipation.

Naldemedine and Magnesium Oxide as First-Line Medications for Opioid-Induced Constipation: A Comparative Database Study in Japanese Patients With Cancer Pain

Introduction Naldemedine and magnesium oxide are common first-line early laxative medications used in the real-world scenario in Japan, for patients with cancer pain who receive opioid prescriptions, as per a nationwide hospital claims database study. However, the real-world prescription patterns and associated outcomes are unknown. Methods In this retrospective, cohort study using the Medical Data Vision (MDV) database (January 2018 to December 2020), data were collected from eligible patients (who had a long-term prescription of strong opioids, for >30 days) in Japan with naldemedine or magnesium oxide as the first-line laxative prescription, for a long-term opioid prescription for cancer pain with ≥6 months post-opioid observation period. A laxative prescription within three days after the opioid prescription date was termed an "early" prescription. The composite incidence of dose increase or addition/change of laxatives at three months after the start of the opioid prescription was the primary endpoint after adjusting baseline characteristics between the treatment arms by propensity score matching. Results After propensity score matching, 1717 and 544 patients who were prescribed naldemedine and magnesium oxide each were included in the early prescription and non-early prescription groups, respectively. Even after matching, the incidence of death was not adjusted enough and was significantly higher in the naldemedine arm than in the magnesium oxide arm in the non-early group but comparable in the early group. The incidence of addition, change, or dose increase was significantly higher in the naldemedine arm than in the magnesium oxide arm of the early prescription group (hazard ratio (95% confidence interval), 1.08 (1.00, 1.17); p=0.0402); the incidence was comparable between the arms of the non-early group. Conclusion These findings may provide valuable insights into real-world clinical treatment patterns and preliminary evidence for the selection of first-line medications to mitigate opioid-induced constipation in Japanese patients with cancer pain.

Naldemedine versus placebo in opioid-induced constipation: a meta-analysis

OBJECTIVE

Opioid-induced constipation (OIC) is a frequent adverse event among patients receiving chronic pain therapy that is requiring opioids. Naldemedine was approved by the Food and Drug Administration to treat OIC and appears to be more efficient than any other peripherally acting µ-opioid receptor antagonist. This meta-analysis aimed at assessing the available data on naldemedine in terms of efficacy.

METHODS

We searched the Cochrane Library, PubMed and ClinicalTrials on 24 May 2022 to identify randomised controlled trials (RCTs) comparing naldemedine to placebo among patients reporting OIC.

RESULTS

Evaluation of 6 RCTs enrolling 2769 participants showed significantly greater respondence to treatment (OR=2.48; 95% CI: 2.02 to 3.06; p<0.00001), change in weekly spontaneous bowel movements (SBMs) (mean difference=1.45; 95% CI: 1.14 to 1.76; p<0.00001), complete SBMs (mean difference=0.89; 95% CI: 0.62 to 1.17; p<0.00001) and SBMs without straining (mean difference=0.89; 95% CI: 0.61 to 1.17; p<0.00001) for patients treated with naldemedine. We found no difference in numeric pain rating scales after one (mean difference=0.05; 95% CI: -0.22 to 0.31; p=0.73) and two weeks of treatment (mean difference= -0.04; 95% CI: -0.31 to 0.22; p=0.75). Funding and clinical diversity were possible risks of bias.

CONCLUSIONS

Naldemedine improves a variety of bowel function parameters while preserving analgesia, confirming its efficacy for patients with OIC. However, head-to-head trials are needed to establish naldemedine as treatment of first choice for laxative-refractory OIC.

PROSPERO REGISTRATION NUMBER

CRD42022281353.

Magnesium hydroxide versus macrogol/electrolytes in the prevention of opioid-induced constipation in incurable cancer patients: study protocol for an open-label, randomized controlled trial (the OMAMA study)

BACKGROUND

Opioid-induced constipation (OIC) is a common symptom in cancer patients treated with opioids with a prevalence of up to 59%. International guidelines recommend standard laxatives such as macrogol/electrolytes and magnesium hydroxide to prevent OIC, although evidence from randomized controlled trials is largely lacking. The aim of our study is to compare magnesium hydroxide with macrogol /electrolytes in the prevention of OIC in patients with incurable cancer and to compare side-effects, tolerability and cost-effectiveness.

METHODS

Our study is an open-label, randomized, multicenter study to examine if magnesium hydroxide is non-inferior to macrogol/electrolytes in the prevention of OIC. In total, 330 patients with incurable cancer, starting with opioids for pain management, will be randomized to treatment with either macrogol/electrolytes or magnesium hydroxide. The primary outcome measure is the proportion of patients with a score of < 30 on the Bowel Function Index (BFI), measured on day 14. The Rome IV criteria for constipation, side effects of and satisfaction with laxatives, pain scores, quality of life (using the EQ-5D-5L), daily use of laxatives and escape medication, and cost-effectiveness will also be assessed.

DISCUSSION

In this study we aim to examine if magnesium hydroxide is non-inferior to macrogol/electrolytes in the prevention of OIC. The outcome of our study will contribute to prevention of OIC and scientific evidence of guidelines on (opioid-induced) constipation.

TRIAL REGISTRATION

This trial is registered at clinicaltrials.gov: NCT05216328 and in the Dutch trial register: NTR80508. EudraCT number 2022-000408-36.

Cost-Effectiveness of Icosapent Ethyl (IPE) for the Reduction of the Risk of Ischemic Cardiovascular Events in Canada

Background

Despite the use of statins, many patients with cardiovascular disease (CVD) have persistent residual risk. In a large Phase III trial (REDUCE-IT), icosapent ethyl (IPE) was shown to reduce the first occurrence of the primary composite endpoint of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina.

Methods

We conducted a cost-utility analysis comparing IPE to placebo in statin-treated patients with elevated triglycerides, from a publicly funded, Canadian healthcare payer perspective, using a time-dependent Markov transition model over a 20-year time horizon. We obtained efficacy and safety data from REDUCE-IT, and costs and utilities from provincial formularies and databases, manufacturer sources, and Canadian literature sources.

Results

In the probabilistic base-case analysis, IPE was associated with an incremental cost of $12,523 and an estimated 0.29 more quality-adjusted life years (QALYs), corresponding to an incremental cost-effectiveness ratio (ICER) of $42,797/QALY gained. At a willingness-to-pay of $50,000 and $100,000/QALY gained, there is a probability of 70.4% and 98.8%, respectively, that IPE is a cost-effective strategy over placebo. The deterministic model yielded similar results. In the deterministic sensitivity analyses, the ICER varied between $31,823-$70,427/QALY gained. Scenario analyses revealed that extending the timeframe of the model to a lifetime horizon resulted in an ICER of $32,925/QALY gained.

Conclusion

IPE represents an important new treatment for the reduction of ischemic CV events in statin-treated patients with elevated triglycerides. Based on the clinical trial evidence, we found that IPE could be a cost-effective strategy for treating these patients in Canada.

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.

Budget Impact and Cost-Effectiveness of Intravenous Meloxicam to Treat Moderate-Severe Postoperative Pain

INTRODUCTION

This study assesses the budget impact and cost-effectiveness of intravenous meloxicam (MIV) to treat moderate-severe acute postoperative pain in adults.

METHODS

A two-part Markov cohort model captured the pharmacoeconomic impact of MIV versus non-opioid intravenous analgesics (acetaminophen, ibuprofen, ketorolac) among a hypothetical adult cohort undergoing selected inpatient procedures and experiencing moderate-severe acute postoperative pain: Part 1 (postoperative hour 0 to discharge, cycled hourly), health states were defined by pain level. Pain transition rates, adverse event probabilities, and concomitant opioid utilization were derived from a network meta-analysis. Part 2 (discharge to week 52, cycled weekly), health states were defined by the presence/absence of pain-related readmission and opioid use disorder as determined by literature-based inputs relating to pain control outcomes. Healthcare utilization and direct medical costs were derived from an administrative claims database analysis. Primary outcomes were the incremental cost per member per month (PMPM) and cost per quality-adjusted life year (QALY) gained. Scenario, univariate, and probabilistic sensitivity analyses were conducted. The model assumed a private payer perspective in the USA (no discounting, 2019 US$).

RESULTS

Modeled outcomes indicated MIV was associated with lower accumulated postoperative pain, fewer adverse events, and less opioid utilization for most procedures and comparators, with longer-term outcomes also generally favoring MIV. The budget impact of MIV was - $0.028 PMPM. From a cost-effectiveness perspective, MIV had lower costs and better outcomes for all comparisons except against ketorolac in orthopedic procedures where the former was cost-effective but not cost saving ($95,925/QALY). Scenario and sensitivity analyses indicated that modeled outcomes were robust to alternative inputs and underlying input uncertainty. Differences in direct medical costs were driven by reduced costs attributable to length of stay and opioid-related adverse drug events.

CONCLUSION

MIV was associated with modeled clinical and economic benefits compared to commonly used non-opioid intravenous analgesics.

The quality of life and comfort levels of hemodialysis patients with constipation: A descriptive and cross-sectional study

INTRODUCTION

This study was conducted to determine the constipation-related quality of life, bowel habits, and comfort levels of constipated hemodialysis patients. It is known that the prevalence of constipation is high in hemodialysis patients.

METHODS

This was a cross-sectional and correlational study. The study included 164 hemodialysis patients who were determined to have constipation by examining the constipation statuses of 385 patients based on the Rome-IV criteria. The study was reported according to the STrengthening the Reporting of OBservational studies in Epidemiology Declaration.

FINDINGS

It was determined that as the constipation-related quality of life of the patients increased, their comfort levels also increased. Constipation-related quality of life increased in parallel with an increasing Bristol Stool Scale (BSS) score and an increasing number of bowel movements. The BSS scores of the patients were found to have a significant positive correlation with the patients' bowel movement frequencies and a significant negative correlation with their constipation frequencies. There was a negative correlation between years of dialysis and bowel movement frequencies. The presence of a previous gastrointestinal system complaint, the presence of an impact of constipation on the patient's dialysis session, and comfort levels were determined to be significant predictors of constipation-related quality of life that explained 26.3% of the total variance in constipation-related quality of life.

DISCUSSION

In patients receiving hemodialysis treatment, constipation is an important and frequently encountered problem. Constipation leads to a reduction in quality of life and hemodialysis-related comfort.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICALTRIALS

gov Registration: NCT01965158; NCT01993940.

[Tapentadol versus classical WHO-III opioids for chronic back pain. Health services research study based on representative data from health insurance funds]

BACKGROUND/OBJECTIVE

In clinical trials, tapentadol prolonged release (PR) showed a more favourable gastrointestinal tolerability profile compared to other strong opioids in the treatment of pain. The present analysis compared tapentadol PR and classical WHO-III PR opioids in routine clinical practice.

METHOD

Retrospective cohort study (matched pair approach) using anonymised health insurance data of patients with chronic low back pain who were prescribed strong opioids following pretreatment with WHO-I/II analgesics. Data were analysed from the date of first prescription in 2015 over a maximum period of two years. The primary analysis parameter was the prescription of laxatives.

RESULTS

Data of 227 patients per cohort could be included in the analysis. Significantly fewer tapentadol PR than WHO-III PR patients were prescribed laxatives (20.3% vs. 37%; p < 0.0001). In addition, laxative dosages were significantly lower in the tapentadol PR cohort (26.4 vs. 82.5 defined daily doses; p < 0.0001). A significant difference in laxative prescription was also observed under long-term treatment (tapentadol PR patients 27.7% vs. WHO-III PR patients 50%; p = 0.0029).

CONCLUSION

Routine clinical practice indirectly confirmed the more favourable gastrointestinal tolerability of tapentadol PR in the treatment of chronic pain which had previously been demonstrated in clinical trials and non-interventional studies.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Involvement of the Peripheral μ-Opioid Receptor in Tramadol-Induced Constipation in Rodents

Tramadol is a weak opioid that produces analgesic effect via both the μ-opioid receptor (MOR) and non-opioid targets. Constipation is the most common opioid-related side effect in patients with cancer and non-cancer pain. However, the contribution of MOR to tramadol-induced constipation is unclear. Therefore, we used naldemedine, a peripherally acting MOR antagonist, and MOR-knockout mice to investigate the involvement of peripheral MOR in tramadol-induced constipation using a small intestinal transit model. A single dose of tramadol (3-100 mg/kg, per os (p.o.)) inhibited small intestinal transit dose-dependently in rats. Naldemedine (0.01-10 mg/kg, p.o.) blocked the inhibition of small intestinal transit induced by tramadol (30 mg/kg, p.o.) in rats. The transition rate increased dose-dependently over the range of naldemedine 0.01-0.3 mg/kg, and complete recovery was observed at 0.3-10 m/kg. Additionally, tramadol (30 and 100 mg/kg, subcutaneously (s.c.)) inhibited small intestinal transit in wild-type mice but not in MOR-knockout mice. These results suggest that peripheral MOR participates in tramadol-induced constipation.

Tapentadol results in less deterioration of gastrointestinal function and symptoms than standard opioid therapy in healthy male volunteers

BACKGROUND

Tapentadol is a combined opioid agonist and norepinephrine reuptake inhibitor with fewer gastrointestinal side effects at equianalgesic doses compared with classical strong opioids. Previous studies on tapentadol have included multi-morbid patients in whom confounders exclude detailed assessment of the mechanistic effects and strict comparison with other opioids or placebo. This study aimed at investigating the effects of tapentadol and oxycodone on gastrointestinal motility and gastrointestinal side effects.

METHODS

21 healthy males participated in a randomized, double-blind, placebo-controlled, crossover study. Tapentadol (50 mg twice daily), oxycodone (10 mg twice daily), or placebo tablets were administered for 14 days. Segmental gastrointestinal transit times and colonic motility parameters were measured with electromagnetic capsules. Gastrointestinal side effects were assessed using questionnaires.

KEY RESULTS

During dosing with tapentadol, gastrointestinal side effects and motility parameters were on placebo level. Compared with tapentadol, oxycodone increased whole gut transit time by 17.9 hours (p = .015) and rectosigmoid transit time by 6.5 hours (p = .005). Compared with tapentadol, oxycodone also reduced long, fast antegrade colonic movements (p = .001). In comparison with placebo, oxycodone prolonged whole gut transit time by 31.6 hours, (p < .001). Moreover, less long, fast antegrade colonic movements (p = .002) were observed during oxycodone. For oxycodone only, slow colonic movements were associated with gastrointestinal side effects.

CONCLUSIONS & INFERENCES

In this mechanistic study, tapentadol caused significantly less colonic dysmotility and gastrointestinal side effects as compared with oxycodone in equianalgesic doses.

Health-Related Quality of Life in Patients With Different Diseases Measured With the EQ-5D-5L: A Systematic Review

Background: The EQ-5D-5L is a generic preference-based questionnaire developed by the EuroQol Group to measure health-related quality of life (HRQoL) in 2005. Since its development, it has been increasingly applied in populations with various diseases and has been found to have good reliability and sensitivity. This study aimed to summarize the health utility elicited from EQ-5D-5L for patients with different diseases in cross-sectional studies worldwide.

Methods: Web of Science, MEDLINE, EMBASE, and the Cochrane Library were searched from January 1, 2012, to October 31, 2019. Cross-sectional studies reporting utility values measured with the EQ-5D-5L in patients with any specific disease were eligible. The language was limited to English. Reference lists of the retrieved studies were manually searched to identify more studies that met the inclusion criteria. Methodological quality was assessed with the Agency for Health Research and Quality (AHRQ) checklist. In addition, meta-analyses were performed for utility values of any specific disease reported in three or more studies.

Results: In total, 9,400 records were identified, and 98 studies met the inclusion criteria. In the included studies, 50 different diseases and 98,085 patients were analyzed. Thirty-five studies involving seven different diseases were included in meta-analyses. The health utility ranged from 0.31 to 0.99 for diabetes mellitus [meta-analysis random-effect model (REM): 0.83, (95% CI = 0.77–0.90); fixed-effect model (FEM): 0.93 (95% CI = 0.93–0.93)]; from 0.62 to 0.90 for neoplasms [REM: 0.75 (95% CI = 0.68–0.82); FEM: 0.80 (95% CI = 0.78–0.81)]; from 0.56 to 0.85 for cardiovascular disease [REM: 0.77 (95% CI = 0.75–0.79); FEM: 0.76 (95% CI = 0.75–0.76)]; from 0.31 to 0.78 for multiple sclerosis [REM: 0.56 (95% CI = 0.47–0.66); FEM: 0.67 (95% CI = 0.66–0.68)]; from 0.68 to 0.79 for chronic obstructive pulmonary disease [REM: 0.75 (95% CI = 0.71–0.80); FEM: 0.76 (95% CI = 0.75–0.77)] from 0.65 to 0.90 for HIV infection [REM: 0.84 (95% CI = 0.80–0.88); FEM: 0.81 (95% CI = 0.80–0.82)]; from 0.37 to 0.89 for chronic kidney disease [REM: 0.70 (95% CI = 0.48–0.92; FEM: 0.76 (95% CI = 0.74–0.78)].

Conclusions: EQ-5D-5L is one of the most widely used preference-based measures of HRQoL in patients with different diseases worldwide. The variation of utility values for the same disease was influenced by the characteristics of patients, the living environment, and the EQ-5D-5L value set.

Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42020158694.

Insights into the Use of Peripherally Acting μ-Opioid Receptor Antagonists (PAMORAs) in Oncologic Patients: from Scientific Evidence to Real Clinical Practice

OPINION STATEMENT

Management of chronic pain is crucial to improve the quality of life of cancer and palliative care patients. Opioid-based treatments used to control pain can be prolonged over time. Unfortunately, constipation is one of the most disturbing adverse effects of long-term use of opioids. Opioid-induced constipation (OIC) occurs when opioids bind to the specific receptors present in the gastrointestinal (GI) tract, and can affect any patients receiving chronic opioid therapy, including cancer patients. The limited efficacy of laxatives to treat OIC symptoms prompted the search for new therapeutic strategies. Peripherally acting μ-opioid receptor antagonists (PAMORAs) have recently emerged as new effective drugs for OIC management due to their specific binding to enteric μ-receptors. Little information is available on the use of PAMORAs in real-life practice for OIC treatment in cancer patients. In this paper, a panel of experts specializing in cancer and palliative care pools their clinical experience with PAMORAs in cancer patients presenting OIC and highlights the importance of timing and choice of therapy in achieving prompt OIC management and benefitting patients.

Drug-disease interactions in Swedish senior primary care patients were dominated by non-steroid anti-inflammatory drugs and hypertension - a population-based registry study

OBJECTIVE

Drug-disease interactions (DDSIs) are present when a drug prescribed for one disease worsens a concomitant disease. The prevalence of DDSIs in older patients in primary care is largely unknown, as well as to what extent physicians individualize drug prescribing in relation to concomitant diseases. We therefore analysed the prevalence of DDSIs in older patients in primary care and explored to what extent physicians take possible DDSIs into account when prescribing. Design and Setting: Cross-sectional population-based register study in primary care in Region Stockholm, Sweden. Thirty-one DDSIs derived from Irish STOPP-START-Criteria were assessed. We derived data from a regional administrative healthcare database including information on all healthcare consultations and dispensed prescription drugs in the region. Data on demography, diagnoses, drug dispensations and healthcare consumption were extracted. Drugs were assessed during 2016.

SUBJECTS

A total of 336,295 patients aged ≥65 registered with one of the 206 primary care practices in Region Stockholm.

MAIN OUTCOME MEASURES

Prevalence and prevalence differences for DDSIs.

RESULTS

In 10.8% of older patients, at least one DDSI was observed. Non-steroidal anti-inflammatory drugs (NSAIDs) were implicated in more than 75% of cases. The most common DDSI was NSAID/hypertension (8.1%), followed by NSAID/cardiovascular disease and loop diuretics/urinary incontinence (both 0.7%). The use of NSAIDs among patients with heart failure or impaired renal function was 15% lower than among patients without these diseases.

CONCLUSION

DDSIs were present in every tenth older patient in primary care. Patients with cardiovascular disease receive NSAIDs to a lower extent, possibly indicating physician awareness of DDSI. Key points Evidence on the prevalence of drug-disease interactions in older patients in primary care is sparse despite their potential to cause harm. In this study, we found that every 10th older patient attending primary care had at least one drug-disease interaction. Interactions with NSAIDs were far more common than interactions with other drugs. The use of NSAIDs among patients with heart failure or impaired renal function was 15% lower than among patients without these diseases.

Living with opioids: A qualitative study with patients with chronic low back pain

BACKGROUND

Opioids are one of the most prescribed treatments for chronic pain (CP). However, their long-term use (>3 months) has been surrounded by controversy, due to loss of beneficial effects.

OBJECTIVE

To explore the experiences of people with chronic non-malignant low back pain in Spain undergoing long-term treatment with opioids.

DESIGN

Qualitative study.

SETTING AND PARTICIPANTS

We conducted 15 semi-structured interviews at the Pain Clinic with persons taking opioid treatment.

METHODS

The interviews were analysed by qualitative content analysis as described by Graneheim and Lundman, and developed categories and themes discussed in light of a biomedicalization framework.

MAIN RESULTS

We developed one overarching theme-Living with opioids: dependence and autonomy while seeking relief-and three categories: The long pathway to opioids due to the invisibility of pain; Opioids: from blind date to a long-term relationship; and What opioids cannot fix.

DISCUSSION

The long and difficult road to find effective treatments was a fundamental part of coping with pain, involving long-term relationships with the health system. This study reflects the benefits, and drawbacks of opioids, along with struggles to maintain autonomy and make decisions while undergoing long-term treatment with opioids. The paper also highlights the consequences of pain in the economy, family and social life of patients.

CONCLUSIONS

Patients' experiences should be considered to a greater extent by health-care professionals when giving information about opioids and setting treatment goals. Greater consideration of the social determinants of health that affect CP experiences might lead to more effective solutions to CP.

Patients' Self-Assessment of the Symptoms and Impact of Opioid-Induced Constipation: Results From a Prospective Observational Cohort Study of Japanese Patients With Cancer

CONTEXT

Many patients who have cancer consider opioid-induced constipation (OIC) to be a burdensome side effect of opioid treatment.

OBJECTIVES

To evaluate patient-reported outcomes in Japanese patients with cancer pain and OIC.

METHODS

This prospective observational study evaluated OIC incidence for two weeks in patients with cancer after they initiated strong opioid therapy. Rome IV diagnostic criteria, a physician's diagnosis, spontaneous bowel movements, Bowel Function Index score, and patients' daily self-assessments were used. Changes from baseline in Patient Assessment of Constipation Symptoms and Patient Assessment of Constipation Quality of Life (PAC-QOL) scores were compared between patients with and without OIC. Patients and health care providers (HCPs) completed study-specific questionnaires regarding OIC burden, treatment satisfaction, and patient-provider communications.

RESULTS

Among 212 enrolled patients, the incidence of OIC was 47.6% by patients' self-assessments, with a cumulative incidence of 30.2% by Day 3 and 43.5% by Day 7. Patient Assessment of Constipation Symptoms and PAC-QOL overall scores from patients with OIC worsened significantly from baseline compared with patients without OIC by all diagnostic criteria, except for spontaneous bowel movement frequency for PAC-QOL. Patients and HCPs were generally satisfied with OIC treatment; however, 53.5% of patients and approximately 40.0% of HCPs reported that OIC affected pain management. Most patients and HCPs reported that OIC conditions were sufficiently or essentially communicated.

CONCLUSION

After starting opioid therapy, patients recognized OIC onset and its impact on cancer pain management, highlighting the need for effective patient-provider communications, diagnosis, and treatment of OIC to improve QOL for patients with cancer receiving opioid analgesics.

Prevalence of Rome IV Functional Bowel Disorders Among Adults in the United States, Canada, and the United Kingdom

BACKGROUND & AIMS

Little is known about the population prevalence or demographic distributions of Rome IV functional bowel disorders (FBDs) or their effects on quality of life. We examined these in a multinational survey.

METHODS

We analyzed data from a population-based survey of adults in the United States, Canada, and United Kingdom (5931 valid responders; 49.2% female; mean age, 47.4 years; range, 18-92 years). The survey included the Rome IV Diagnostic Questionnaire, Rome III irritable bowel syndrome (IBS) and constipation questions, and the SF-8 quality of life questionnaire.

RESULTS

The prevalence values of census-adjusted Rome IV FBDs were similar among the 3 countries; ranges were: 4.4%-4.8% for IBS, 7.9%-8.6% for functional constipation, 3.6%-5.3% for functional diarrhea, 2.0%-3.9% for functional bloating or distention, 1.1%-1.9% for opioid-induced constipation, 7.5%-10.0% for unspecified FBDs, and 28.6%-31.7% for any Rome IV FBD. FBDs were less common in older individuals, and all except functional diarrhea were more common in women. IBS was only half as prevalent by Rome IV as by Rome III criteria (4.6% vs 9.0% overall), primarily due to higher Rome IV minimum pain frequency. Functional diarrhea and functional constipation were more prevalent by Rome IV than Rome III criteria. Subjects with FBD had significant reductions in quality of life and reported more gastrointestinal doctor consultations than other subjects.

CONCLUSIONS

More than 1 in 4 adults in the general population meet the Rome IV criteria for FBDs. These disorders affect quality of life and increase use of gastrointestinal health care. The switch from Rome III to Rome IV criteria reduces the prevalence of IBS by half, but increases the prevalence of functional constipation and functional diarrhea.

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.

Is Dyssynergic Defecation an Unrecognized Cause of Chronic Constipation in Patients Using Opioids?

OBJECTIVES

The impact of opioids on anorectal function is poorly understood but potentially relevant to the pathogenesis of opioid-induced constipation (OIC). To evaluate anorectal function testing (AFT) characteristics, symptom burden, and quality of life in chronically constipated patients prescribed an opioid (OIC) in comparison with constipated patients who are not on an opioid (NOIC).

METHODS

Retrospective analysis of prospectively collected data on 3,452 (OIC = 588 and NOIC = 2,864) chronically constipated patients (Rome 3) who completed AFT. AFT variables included anal sphincter pressure and response during simulated defecation, balloon expulsion test (BET), and rectal sensation. Dyssynergic defecation (DD) was defined as an inability to relax the anal sphincter during simulated defecation and an abnormal BET. Patients completed Patient Assessment of Constipation Symptoms (PAC-SYM) and Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaires.

RESULTS

The mean age of the study cohort was 49 years. Most patients were women (82%) and whites (83%). Patients with OIC were older than NOIC patients (50.7 vs 48.3, P = 0.001). OIC patients were significantly more likely to have DD (28.6% vs 21.4%, P < 0.001), an abnormal simulated defecation response on anorectal manometry (59% vs 43.8%, P < 0.001), and an abnormal BET (48% vs 42.5%, P = 0.02) than NOIC patients. OIC patients reported more severe constipation symptoms (P < 0.02) and worse quality of life (P < 0.05) than NOIC patients.

DISCUSSION

Chronically constipated patients who use opioids are more likely to have DD and more severe constipation symptoms than NOIC.

Effects of Naloxegol on Gastrointestinal Transit and Colonic Fecal Volume in Healthy Participants Receiving Oxycodone

Background/Aims

Opioids cause gastrointestinal (GI) dysmotility, decrease gut secretion, and affect gut sphincters. Symptoms of opioid-induced bowel dysfunction may be alleviated by peripherally acting opioid antagonists like naloxegol, but detailed knowledge on GI effects of this drug is lacking. We hypothesized that naloxegol, compared to placebo, would reduce GI transit time and colonic fecal volume in opioid-treated healthy participants.

Methods

We conducted a randomized, double-blinded, single-center, 2-way cross-over study in 24 healthy males, randomized to a 6 day treatment period of oxycodone (15 mg twice a day) co-administered with either naloxegol (25 mg once a day) or matching placebo. Participants swallowed an electromagnetic capsule which determined GI transit times. Colonic fecal volume was quantified with magnetic resonance imaging both pre-treatment and post-treatment.

Results

Naloxegol reduced total GI transit time by 21% (56 hours vs 71 hours, P = 0.02) and colonic transit time by 23% (45 hours vs 59 hours, P < 0.01), compared to placebo. However, no difference in colonic fecal volume was found (818 mL vs 884 mL, P = 0.20).

Conclusions

Short-term administration of naloxegol in healthy participants reverses the retardation of total GI and colonic transit induced by oxycodone. This supports the use of naloxegol in the treatment of GI side effects to opioid treatment, and add knowledge to the current understanding of mechanisms behind peripherally-acting opioid antagonists.

A Randomized, Multicenter, Prospective, Crossover, Open-Label Study of Factors Associated With Patient Preferences for Naloxegol or PEG 3350 for Opioid-Induced Constipation

OBJECTIVES

To determine patient preference for treating opioid-induced constipation (OIC) using naloxegol or polyethylene glycol (PEG) 3350 in patients receiving opioids for noncancer pain.

METHODS

This crossover study included two 2-week active treatment periods, each preceded by a 1-week washout period (NCT03060512). Individuals with baseline Bowel Function Index scores ≥30 were randomized to 1 of 2 treatment sequences (naloxegol/PEG 3350 or PEG 3350/naloxegol). Patient preference (primary end point) was measured at the end of the second treatment period.

RESULTS

Of 276 patients randomized, 246 completed both treatment periods and reported preference (per protocol). Similar proportions of patients reported overall preference for naloxegol (50.4%) or PEG 3350 (48.0%; P = 0.92); 1.6% reported no preference. Medication characteristics influencing preference were similar for both treatments, except convenience and working quickly, which were strong influences of preference for higher proportions of patients preferring naloxegol (69.9% and 39.0%, respectively) vs those preferring PEG 3350 (29.9% and 27.4%, respectively). Patients aged <50 years or receiving laxatives within the previous 2 weeks generally preferred naloxegol. Changes from baseline in overall Bowel Function Index and Patient Global Impression of Change scores were similar between treatments, but analyses according to treatment preference revealed clinical improvement aligned with reported preference. Safety profiles were generally consistent with known medication profiles.

CONCLUSIONS

Almost equal proportions of patients with OIC reported similar preference for daily naloxegol or PEG 3350 treatment, and their preference was generally supported by clinically relevant and measurable improvements in OIC symptoms.

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.

Pharmacological Treatment of Opioid-Induced Constipation Is Effective but Choice of Endpoints Affects the Therapeutic Gain

BACKGROUND

Widespread opioid use has led to increase in opioid-related adverse effects like constipation. We examined the impact of study endpoints on reported treatment benefits.

METHODS

Using MEDLINE, EMBASE, and ClinicalTrials.gov, we searched for randomized control trials targeting chronic opioid-induced constipation (OIC) and subjected them to meta-analysis. Data are given with 95% confidence intervals.

RESULTS

Thirty trials met our inclusion criteria. Combining all dichotomous definitions of responders, active drugs were consistently more effective than placebo, with an odds ratio (OR): 2.30 [2.01-2.63; 15 studies], independent of the underlying drug mechanism. The choice of endpoints significantly affected the therapeutic gain. When time from drug administration to defecation was used, the OR decreased from 4.74 [2.71-4.74] at 6 h or less to 2.46 [1.80-3.30] at 24 h (P < 0.05). Using other response definitions, the relative benefit over placebo was 2.10 [1.77-2.50; 12 studies] for weekly bowel frequency, 2.03 [1.39-2.95; 9 studies] for symptom scores, 2.21 [1.25-3.90; 4 studies] for global assessment scales, and 1.27 [0.79-2.03; 7 studies] for rescue laxative use.

CONCLUSION

While treatment of OIC with active drugs is more effective than placebo, the relative gain depends on the choice of endpoints. The commonly used time-dependent response definition is associated with the highest response rate but is of questionable relevance in a chronic disorder. The limited data do not clearly demonstrate a unique advantage of the peripherally restricted opioid antagonists, suggesting that treatment with often cheaper agents should be optimized before shifting to these novel expensive agents.

Clinical Pharmacokinetics and Pharmacodynamics of Naloxegol, a Peripherally Acting µ-Opioid Receptor Antagonist

Naloxegol is a peripherally acting µ-opioid receptor antagonist approved for use as an orally administered tablet (therapeutic doses of 12.5 and 25 mg) for the treatment of opioid-induced constipation. Over a wide dose range (i.e. single supratherapeutic doses up to 1000 mg in healthy volunteers), the pharmacokinetic properties of naloxegol appear to be time- and dose-independent. Naloxegol is rapidly absorbed, with mean time to maximum plasma concentration of <2 h. Following once-daily administration, steady state is achieved within 2-3 days and minimal accumulation is observed. The primary route of naloxegol elimination is via hepatic metabolism, with renal excretion playing a minimal role. In clinical studies, six metabolites were found in feces, urine or plasma, none of which have been identified as unique or disproportionate human metabolites. The major plasma circulating species is naloxegol. There are small effects of mild and moderate renal impairment, age, race, and body mass index on the systemic exposure of naloxegol; however, gender has no effect on the pharmacokinetics of this agent. Naloxegol is a sensitive substrate of cytochrome P450 (CYP) 3A4 and its exposure can be significantly altered by strong or moderate CYP3A modulators. Food increases the bioavailability of naloxegol, and the relative bioavailability of the tablet formulation was not limited by dissolution. Naloxegol in the dose range of 8-125 mg can antagonize morphine-induced peripheral effects without impacting the effect of morphine on the central nervous system, consistent with a peripheral mode of action.

The impact of naloxegol on anal sphincter function - Using a human experimental model of opioid-induced bowel dysfunction

BACKGROUND AND AIMS

Opioid treatment interferes with anal sphincter function and its regulation during defecation. This may result in straining, incomplete evacuation, and contribute to opioid-induced bowel dysfunction (OIBD). Employing an experimental model of oxycodone-induced OIBD, we hypothesized that co-administration of the peripherally acting μ-opioid antagonist naloxegol would improve anal sphincter function in comparison to placebo.

METHODS

In a double-blind randomized crossover trial, 24 healthy males were assigned to a six-day treatment of oral oxycodone 15 mg twice daily in combination with either oral naloxegol 25 mg once daily or placebo. At baseline and at day 6, anal resting pressure and the recto-anal inhibitory reflex (RAIR) were evaluated using manometry and rectal balloon distension. Furthermore, the functional lumen imaging probe was used to measure distensibility of the anal canal. Gastrointestinal symptoms were assessed with the Patient Assessment of Constipation Symptom (PAC-SYM) questionnaire and the Bristol Stool Form Scale.

RESULTS

During oxycodone treatment, naloxegol improved RAIR-induced sphincter relaxation by 15% (-45.9 vs -38.8 mm Hg; P < 0.01). No differences in anal resting pressure and anal canal distensibility were found between treatments (all P > 0.5). Naloxegol improved PAC-SYM symptoms (mean score over days; 2.6 vs 4.5, P < 0.001) and improved stool consistency scores (mean score over days; 3.3 vs 2.9, P < 0.01).

CONCLUSIONS

In this experimental model of OIBD, naloxegol improved the RAIR and reduced gastrointestinal symptoms. Hence, in contrast to conventional laxatives, naloxegol may regulate opioid-induced anal sphincter dysfunction and facilitate the defecation process.

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.

Long-term treatment in chronic noncancer pain: Results of an observational study comparing opioid and nonopioid therapy

Background and aims

Recent studies reveal high prevalence rates of patients receiving long-term opioids. However, well designed studies assessing effectiveness with longer than 3 months follow-up are sparse. The present study investigated the outcomes of long-term opioid therapy compared to nonopioid treatment in CNCP patients with respect to measures of pain, functional disability, psychological wellbeing, and quality of life (QoL).

Methods

Three hundred and thirty three consecutive patients at our pain clinic were included and divided into patients with continuous opioid treatment for at least 3 months (51%) and patients receiving nonopioid analgesics (49%). Further, outcome of different doses of opioid (<120 mg vs. >120 mg morphine equivalents) and differences between high and low potency opioids were examined.

Results

The opioid and nonopioid groups did not differ with regard to pain intensity or satisfaction with analgesic. Patients with continuous opioids treatment reported higher neuropathic like pain, longer duration of pain disorder, lower functional level, wellbeing, and physical QoL in comparison to patients receiving nonopioid analgesics. Higher opioid doses were associated with male gender, intake of high potency opioids and depression but there were no differences with regard to pain relief or improvement of functional level between high and low doses. Similarly, patients on high potency opioids reported more psychological impairment than patients on low potency opioids but no advantage with regard to pain relief. Overall, remaining level of pain, functional disability and poor QoL were quite high irrespective of the analgesic used or opioid dosing.

Conclusions

In the long-term no clear advantage of opioid vs. non-opioid analgesics could be revealed. In terms of remaining pain intensity, functional disability and quality of life, treatment with pain medication proved insufficient. Additionally, with higher doses of opioids the benefit to risk relationship becomes worse and patients on high potency opioids reported more psychological impairment than patients on low potency opioids but no advantage with regard to pain relief.

Implications

Our results raise questions about the long-term effectiveness of analgesic treatment regimens irrespective of analgesics type employed and call for more multidisciplinary treatment strategies.

Healthcare resource use and costs of opioid-induced constipation among non-cancer and cancer patients on opioid therapy: A nationwide register-based cohort study in Denmark

BACKGROUND AND AIM

Opioid analgesics are often effective for pain management, but may cause constipation. The aim of this study was to determine healthcare resource use and costs in non-cancer and cancer patients with opioid-induced constipation (OIC).

METHODS

This was a nationwide register-based cohort study including patients ≥18 years of age initiating ≥4 weeks opioid therapy (1998-2012) in Denmark. A measure of OIC was constructed based on data from Danish national health registries, and defined as ≥1 diagnosis of constipation, diverticulitis, mega colon, ileus/subileus, abdominal pain/acute abdomen or haemorrhoids and/or ≥2 subsequent prescription issues of laxatives. Total healthcare resource utilization and costs (including pharmacy dispense, inpatient-, outpatient-, emergency room- and primary care) were estimated according to OIC status, opioid treatment dosage and length, gender, age, marital status, and comorbidities using Generalised Linear Model.

RESULTS

We identified 97169 eligible opioid users (77568 non-cancer and 19601 patients with a cancer diagnosis). Among non-cancer patients, 15% were classified with OIC, 10% had previous constipation, and 75% were without OIC. Patients characteristics of non-cancer OIC patients showed a higher frequency of strong opioid treatment (69% versus 41%), long-term opioid treatment (1189 days versus 584 days), advanced age (73 years versus 61 years), and cardiovascular disease (31% versus 19%) compared to those without OIC (P<0.001 for all comparisons). Non-cancer patients with OIC had 34% higher total healthcare costs compared to those without OIC (P<0.001) after adjusting for age, gender, opioid usage, marital status and comorbidities. Among cancer patients, 35% were classified with OIC, 14% had previous constipation, and 51% were without OIC. A higher proportion of cancer patients with OIC were continuous opioid users (85% versus 83%) and strong opioid users (97% versus 85%), compared to those without OIC (P<0.001 for both comparisons). Further, the mean number of days on opioids were higher for cancer patients with versus without OIC (329 days versus 238 days, P<0.001). Total healthcare costs were 25% higher for cancer patients with versus without OIC (P<0.001) after adjusting for age, gender, opioid usage, marital status and comorbidities.

CONCLUSIONS

The results of this nationwide study based on real life data suggested that both non-cancer patients and cancer patients suffering from opioid-induced constipation (OIC) may have higher healthcare resource utilization and higher associated costs compared to those without OIC.

IMPLICATIONS

Reducing the number of OIC patients has potential cost savings for the health care system. Special attention should be on patients at potential high risk of OIC, such as strong and long-term opioid treatment, advanced age, and concomitant cardiovascular disease.

An Open-Label, Randomized Bioavailability Study of Alternative Methods of Oral Administration of Naloxegol in Healthy Subjects

Naloxegol is a peripherally acting μ-opioid receptor antagonist approved as an orally administered tablet for the treatment of opioid-induced constipation. Patients with swallowing difficulties may benefit from alternative approaches to the oral administration of the whole-tablet formulation of naloxegol. This open-label, randomized, 4-period, 4-treatment, crossover, single-dose study (NCT02446171) evaluated the pharmacokinetic (PK) characteristics of crushed naloxegol 25-mg tablets (suspended in water) administered orally or by nasogastric tube and a naloxegol solution compared with the commercially available 25-mg tablet formulation in healthy volunteers. The PK profiles for the crushed tablet, whether administered orally or by nasogastric tube, and the 25-mg oral solution were similar to that of the 25-mg tablet administered orally. Compared with naloxegol commercial tablets, the relative bioavailability of naloxegol using 3 alternative methods of administration was approximately 100%. For each pairwise treatment comparison of the 3 alternative methods with the approved whole tablet, the geometric least-squares mean ratio ranges were 94.37%-100.04%, 94.83%-100.44%, and 97.05%-102.05% for area under the curve (AUC), AUC_0-t , and maximum plasma concentration, respectively, and their 90% confidence intervals were entirely within the predefined 80% to 125% bioequivalence limits. Naloxegol was well tolerated when administered in both liquid and solid form.

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.