The prevalence, severity, and impact of opioid-induced bowel dysfunction: results of a US and European Patient Survey (PROBE 1)

Efficacy of naloxegol on symptoms and quality of life related to opioid-induced constipation in patients with cancer: a 3-month follow-up analysis

Objectives

Opioid-induced constipation (OIC) can affect up to 63% of all patients with cancer. The objectives of this study were to assess quality of life as well as efficacy and safety of naloxegol, in patients with cancer with OIC.

Methods

An observational study was made of a cohort of patients with cancer and with OIC exhibiting an inadequate response to laxatives and treated with naloxegol. The sample consisted of adult outpatients with a Karnofsky performance status score ≥50. The Patient Assessment of Constipation Quality of Life Questionnaire (PAC-QOL) and the Patient Assessment of Constipation Symptoms (PAC-SYM) were applied for 3 months.

Results

A total of 126 patients (58.2% males) with a mean age of 61.3 years (range 34–89) were included. Clinically relevant improvements (>0.5 points) were recorded in the PAC-QOL and PAC-SYM questionnaires (p<0.0001) from 15 days of treatment. The number of days a week with complete spontaneous bowel movements increased significantly (p<0.0001) from 2.4 to 4.6 on day 15, 4.7 after 1 month and 5 after 3 months. Pain control significantly improved (p<0.0001) during follow-up. A total of 13.5% of the patients (17/126) presented some gastrointestinal adverse reaction, mostly of mild (62.5%) or moderate intensity (25%).

Conclusions

Clinically relevant improvements in OIC-related quality of life, number of bowel movements and constipation-related symptoms were recorded as early as after 15 days of treatment with naloxegol in patients with cancer and OIC, with a good safety profile.

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.

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.

Clinical Drug-Drug Interaction Studies to Evaluate the Effects of a P-Glycoprotein Inhibitor, CYP3A Inhibitors, and a CYP3A Inducer on the Pharmacokinetics of Naldemedine in Healthy Subjects

Background

Naldemedine is a peripherally acting μ-opioid receptor antagonist that is indicated to treat opioid-induced constipation.

Objectives

To assess the potential for drug-drug interactions between a single oral dose of naldemedine and the oral P-glycoprotein inhibitor cyclosporine, cytochrome P450 (CYP) 3A inhibitors itraconazole and fluconazole, and CYP3A inducer rifampin.

Methods

Three Phase 1, open-label studies were conducted in healthy subjects. In the P-glycoprotein inhibitor study, subjects received naldemedine 0.4 mg alone or coadministered with cyclosporine 600 mg. In the CYP3A inhibitors study, subjects in separate cohorts received naldemedine 0.2 mg alone or with itraconazole or fluconazole. In the CYP3A inducer study, subjects received naldemedine 0.2 mg alone or with rifampin 600 mg. Geometric mean ratios and 90 % confidence intervals were used to evaluate the effects of coadministered drugs on naldemedine maximum plasma concentration (C_max) and the area under the concentration-time curve (AUC). Safety assessments included occurrence of adverse events (AEs), laboratory parameters, vital signs, and electrocardiography results.

Results

A total of 56 subjects were enrolled (n = 14 in each cohort). Cyclosporine increased naldemedine AUC_0–inf 1.78-fold and C_max 1.45-fold. Itraconazole and fluconazole increased naldemedine AUC_0–inf 2.91-fold and 1.90-fold, and C_max 1.12-fold and 1.38-fold, respectively. Rifampin decreased naldemedine AUC_0–inf by 83% and C_max by 38%. Across studies, AEs were generally mild. Laboratory, vital sign, or electrocardiogram assessments produced no clinically significant findings.

Conclusions

Coadministration of naldemedine with a P-glycoprotein inhibitor or a strong/moderate CYP3A inhibitor increases naldemedine exposure; coadministration with a strong CYP3A inducer decreases its exposure. Coadministration of naldemedine with cyclosporine, itraconazole, fluconazole, or rifampin was generally safe and well tolerated.

Naldemedine is a targeted medication approved in the USA, Europe, and Japan for the treatment of opioid-induced constipation. Symptoms of constipation may include passing fewer stools than usual, having lumpy or hard stools, and/or straining to have bowel movements. In some cases, these symptoms are side effects of regular opioid use, which is often medically necessary for the management of moderate-to-severe pain. For naldemedine to be prescribed safely, doctors must know what other medications a patient is taking and how these medications may affect one another. This is commonly known as drug-drug interactions. Some drug-drug interactions may decrease how well a medication works, while other drug-drug interactions may increase the side effects experienced by a patient. In this paper, researchers report the results of three Phase 1 studies in healthy subjects examining how naldemedine interacts with other drugs. The drugs chosen for investigation are commonly evaluated in DDI studies and may affect the transport or metabolic pathway of naldemedine, including the P-glycoprotein inhibitor cyclosporine, the CYP3A inhibitors itraconazole and fluconazole, and the CYP3A inducer rifampin. These studies demonstrate that co-administration of naldemedine with each of these drugs impacted the pharmacokinetics of naldemedine. Cyclosporine, itraconazole, or fluconazole all increased naldemedine exposure, while rifampin decreased naldemedine exposure. For all drug combinations, observed side effects were generally mild and well tolerated. Additional testing, including vital signs and heart monitoring, did not reveal any other safety concerns. In conclusion, these findings support the cautious use of naldemedine in combination with cyclosporine, itraconazole or fluconazole. Concomitant use with rifampin should be avoided.

The Use of Peripheral μ-Opioid Receptor Antagonists (PAMORA) in the Management of Opioid-Induced Constipation: An Update on Their Efficacy and Safety

Peripherally acting μ-opioid receptor antagonists (PAMORAs) constitute a class of drugs which reverse opioid-induced constipation (OIC) with similar opioid analgesic effects. OIC differs from other forms of constipation in that it is an iatrogenic condition that occurs when an opioid acts on the dense network of μ-opioid receptors in the enteric system, which affect a variety of functions including gastrointestinal motility, secretion, and other factors that can cause bowel dysfunction. Unfortunately, laxative products, bowel regimens, dietary changes, and lifestyle modifications have limited effectiveness in preventing OIC, Opioid-associated adverse effect which occurs in 40% to 80% of opioid patients and may led to cessation of the treatment. PAMORAs are μ-receptor opioid antagonists specifically developed so that they have very limited ability to cross the blood-brain barrier and thus they are able to antagonize peripheral but not central μ-opioid receptors. PAMORAs are designed to have no effect on the analgesic benefits of opioid pain relievers but to relieve but antagonizing the effects of the opioid in the gastrointestinal system. The three main PAMORAS are methyltrexone (oral or parenteral), naldemedine (oral only), and naloxegol (oral only). Clinical studies demonstrate the safety and efficacy of these agents for alleviating constipation without diminishing the analgesic effect of opioid therapy. The aim of this narrative review to update the current status of PAMORAs for treating OIC in terms of safety and efficacy.

Prolonged-Release (PR) Oxycodone/Naloxone Improves Bowel Function Compared with Oxycodone PR and Provides Effective Analgesia in Chinese Patients with Non-malignant Pain: A Randomized, Double-Blind Trial

Introduction

Prolonged-release oxycodone/naloxone (OXN PR), combining an opioid analgesic with selective blockade of enteric µ-opioid receptors, provided effective analgesia and improved bowel function in patients with moderate-to-severe pain and opioid-induced constipation in clinical trials predominantly conducted in Western countries. This double-blind randomized controlled trial investigated OXN PR (N = 116) versus prolonged-release oxycodone (OXY PR, N = 115) for 8 weeks at doses up to 50 mg/day in patients with moderate-to-severe, chronic, non-malignant musculoskeletal pain and opioid-induced constipation recruited in China.

Methods

A total of 234 patients at least 18 years of age with non-malignant musculoskeletal pain for more than 4 weeks that was moderate-to-severe in intensity and required round-the-clock opioid therapy were randomized (1:1) to OXN PR or OXY PR. The primary endpoint was bowel function using the Bowel Function Index (BFI). Secondary endpoints included safety, Brief Pain Inventory-Short Form (BPI-SF), use of analgesic and laxative rescue medication, and health-related quality of life (EQ-5D).

Results

While BFI scores were comparable at baseline, at week 8 improvements were greater with OXN PR vs OXY PR (least squares mean [LSM] difference (95% CI) − 9.1 (− 14.0, − 4.2); P < 0.001. From weeks 2 to 8, mean BFI scores were in the range of normal bowel function (≤ 28.8) with OXN PR but were in the range of constipation (> 28.8) at all timepoints with OXY PR. Analgesia with OXN PR was similar and non-inferior to OXY PR on the basis of modified BPI-SF average 24-h pain scores at week 8: LSM difference (95% CI) − 0.3 (− 0.5, − 0.1); P < 0.001. The most frequent treatment-related AEs were nausea (OXN PR 5% vs OXY PR 6%) and dizziness (4% vs 4%).

Conclusion

OXN PR provided clinically meaningful improvements in bowel function and effective analgesia in Chinese patients with moderate-to-severe musculoskeletal pain and pre-existing opioid-induced constipation.

Trial Registration

ClinicalTrials.gov, identifier NCT01918098.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01244-x) contains supplementary material, which is available to authorized users.

Subcutaneous methylnaltrexone for opioid-induced constipation in advanced-illness patients with or without active cancer

Aim: To evaluate methylnaltrexone for opioid-induced constipation in patients with and without cancer. Methods: This post hoc analysis comprises two Phase III, multicenter, double-blind, randomized studies of advanced-illness patients who received methylnaltrexone subcutaneous injection or placebo. Results: Significantly more patients treated with methylnaltrexone than placebo experienced laxation within 4 (cancer = 55.5 vs 15.5%; noncancer = 55.6 vs 12.8%) and 24 (cancer = 64.7 vs 29.8%; noncancer = 64.4 vs 30.8%) h after the first dose (p < 0.01 vs placebo). Regardless of cancer status, methylnaltrexone reduced median time to laxation and improved constipation relief without impacting opioid analgesia or withdrawal symptoms. Conclusion: Methylnaltrexone provided significant improvements in opioid-induced constipation over placebo in advanced-illness patients with and without cancer. Clinical trial registration numbers: study 301: NCT00401362; study 302: NCT00402038.

Prevention and management of diarrhea associated with naldemedine among patients receiving opioids: a retrospective cohort study

BACKGROUND

Naldemedine, a novel peripherally-acting mu-opioid receptor antagonist, has improved opioid-induced constipation in randomized controlled trials. The most frequent adverse event of naldemedine is diarrhea, which can cause abdominal pain and often leads to treatment discontinuation. We aimed to identify risk factors and appropriate management strategies for key adverse events including diarrhea associated with naldemedine, since those have not been extensively studied.

METHODS

We conducted a multi-center retrospective cohort study. Eligible patients had cancer, had undergone palliative care at participating centers, had been prescribed regular opioids, and had taken at least one dose of naldemedine between June 2017 and March 2018. The primary endpoint was the incidence of diarrhea according to baseline characteristics. Secondary endpoints included the duration of naldemedine administration, daily defecation counts before and after starting naldemedine, duration and severity of diarrhea as an adverse event of naldemedine, other adverse events, and the incidence of constipation within 7 days after recovery from diarrhea. We defined patients who started naldemedine within three days of starting a regularly prescribed opioid as the early group, and the remainder as the late group.

RESULTS

Among 103 patients who received naldemedine, 98 fulfilled the eligibility criteria. The median age was 68 years and 48% of the patients were female. Median performance status was 3, and the median oral intake was 50%. The median duration of naldemedine administration and overall survival were 25 and 64 days, respectively. The incidence of diarrhea in the early group (n = 26) was significantly lower than in the late group (n = 72) (3.9% vs. 22.2%, p = 0.02). Daily defecation counts increased after late (median 0.43 to 0.88, p < 0.001), but remained stable after early naldemedine administration (median 1.00 to 1.00, p = 0.34). Constipation after the diarrhea was resolved was common (53%), especially among patients who stopped naldemedine (78%). The diarrhea was improved within three days in 92% of patients who stopped other laxatives.

CONCLUSIONS

The early administration of naldemedine is beneficial because it reduces adverse events including diarrhea. Diarrhea caused by naldemedine can be effectively managed by stopping other laxatives while continuing naldemedine.

Implant-Related Complications Among Patients With Opioid Use Disorder Following Primary Total Hip Arthroplasty: A Matched-Control Analysis of 42,097 Medicare Patients

BACKGROUND

Opioid use disorders (OUD) are a major cause of morbidity and mortality. The authors of this study hypothesize that patients who have an OUD will have greater relative risk of implant-related complications, periprosthetic joint infections (PJIs), readmission rates, and will incur greater costs compared to non-opioid use disorder (NUD) patients following primary total hip arthroplasty (THA).

METHODS

OUD patients who underwent a THA between 2005 and 2014 were identified and matched to controls in a 1:5 ratio according to age, sex, a comorbidity index, and various medical comorbidities yielding 42,097 patients equally distributed in both cohorts. Pearson's chi-square analyses were used to compare patient demographics. Relative risk (RR) was used to analyze and compare risk of 2-year implant-related complications, 90-day PJIs, and 90-day readmission rates. Welch's t-tests were used to compare day of surgery and 90-day episode-of-care costs between the cohorts. A P value less than .006 was considered statistically significant.

RESULTS

OUD patients had higher incidences and risks of implant-related complications (11.99% vs 6.68%; RR, 1.74; P < .001), developing PJIs within 90 days (2.38% vs 1.81%; RR, 1.32; P = .001), and 90-day readmissions (21.49% vs 17.35%; RR, 1.23; P < .001). Additionally, the study demonstrated OUD patients incurred greater day of surgery ($14,384.30 vs $13,150.12, P < .0001) and 90-day costs ($21,183.82 vs $18,709.02, P < .0001) compared to controls.

CONCLUSION

After controlling for age, sex, a comorbidity index, and various medical complications, OUD patients are at greater risk to experience implant-related complications, PJIs, readmissions, and have greater costs following primary THA compared to non-OUD patients. This study should help orthopedic surgeons counsel their patients of potential complications which may arise following their primary THA.

A Longitudinal Study of Predictors of Constipation Severity in Oncology Outpatients With Unrelieved Pain

CONTEXT

Although constipation is a common symptom in oncology patients, it often goes unrecognized and untreated. In addition, little is known about characteristics associated with interindividual differences in constipation severity.

OBJECTIVES

To describe prevalence, characteristics, and management of constipation; evaluate interindividual differences in constipation severity over 10 weeks; and identify demographic, clinical, and symptom characteristics associated with higher constipation severity scores.

METHODS

In this prospective, longitudinal study, 175 oncology patients with unrelieved pain were recruited from eight outpatient cancer settings in the U.S. Patients completed demographic and symptom questionnaires at enrollment. Constipation severity was evaluated over 10 weeks using the Constipation Assessment Scale (CAS). Hierarchical linear modeling was used to identify characteristics associated with higher CAS scores.

RESULTS

At enrollment, 70.1% of the patients reported constipation [i.e., CAS score of >2; mean CAS score: 3.72 (±3.11)]. While over the first week of the study patients used one to two constipation treatments per day, a large amount of interindividual variability was found in CAS scores. Higher percentage of days with no bowel movement, higher number of constipation treatments, higher state anxiety scores, and higher analgesic side effects scores were associated with higher CAS scores at enrollment. Higher percentage of days with no bowel movement was associated with interindividual differences in the trajectories of constipation.

CONCLUSION

Our findings underscore the high prevalence of and large amount of interindividual variability in constipation severity. The characteristics associated with worse CAS scores can assist clinicians to identify high-risk patients and initiate prompt interventions.

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 Disorders Are Associated With Thromboemboli Following Primary Total Knee Arthroplasty

BACKGROUND

Opioid use disorder (OUD) is defined as a problematic pattern of opioid abuse and dependency leading to problems or distress. The purpose of this study is to investigate whether OUD patients undergoing primary total knee arthroplasty (TKA) have higher rates of venous thromboembolisms (VTEs), readmissions, and costs of care.

METHODS

Patients undergoing TKA with OUD were identified and matched to controls in a 1:4 ratio according to age, gender, comorbidity index, and comorbidities within the Medicare database. Ninety-day VTEs, 90-day readmissions, and costs of care were compared. A P-value less than .01 was considered statistically significant.

RESULTS

The study yielded 54,480 patients with (n = 10,929) and without (n = 43,551) OUD undergoing primary TKA. Matching was successful as there were no significant differences in baseline characteristics. OUD patients were found to have greater odds of VTEs (odds ratio 2.27, P < .0001) 90 days following primary TKA. OUD patients were found to have greater odds of 90-day readmissions (odds ratio 1.39, P < .0001) in addition to incurring higher day of surgery ($13,360.73 vs $11,911.94, P < .0001) and 90-day costs ($18,380.89 vs $15,565.57, P < .0001) compared to controls.

CONCLUSION

After adjusting for confounders, this analysis of 54,480 patients identified that patients with OUD have higher rates of VTEs, readmissions, and costs following primary TKA. In addition to using these data to help educate and counsel patients, the study should be used to help further regulate and control opioid prescriptions written by healthcare professionals.

Patient and provider differences in the treatment of opioid-induced constipation: a qualitative study

BACKGROUND

Patients using opioids to treat chronic non-cancer pain often experience side effects that may affect health-related quality of life (HRQOL). These side effects include opioid-induced constipation (OIC), sedation, dizziness, and nausea. OIC can significantly affect HRQOL for patients on a daily basis. However, it is not well understood whether patients and clinicians view OIC management similarly.

AIMS

In this study, we sought to elucidate the decision-making process around managing OIC by assessing patient and provider treatment preferences, experiences, and communication regarding this condition.

METHODS

We conducted semi-structured interviews with 33 clinicians, and held three focus groups with patients who were currently using or had used opioids for chronic non-cancer pain. We then analyzed transcribed interviews using descriptive qualitative methods based on grounded theory methodology.

RESULTS

Clinicians recognized OIC as a concern but prioritized pain management over constipation. They focused on medication-based treatments for OIC, but also recommended lifestyle changes (e.g., diet) and reducing opioids to relieve symptoms. Patients reported using over-the-counter treatments, but the majority focused on diet-related constipation management. Patients reported not receiving adequate information from clinicians about OIC and relevant treatments. Cost of treatment was a major concern for both patients and clinicians.

CONCLUSIONS

Assessing experiences with and preferences for OIC treatment, including cost, ease of access, and side effects, could improve patient-provider communication and HRQOL. Quality improvement efforts can target uncovered misalignments between patients and clinicians to improve communication about opioid medication adverse effects and relevant treatment options, which may help improve quality of life for patients with chronic pain.

The Burden of Opioid-Induced Constipation in Younger Patients with Chronic Noncancer Pain

Objective

The purpose of this analysis was to evaluate the experience of opioid-induced constipation in younger patients and identify differences in the experience of opioid-induced constipation and its symptoms between younger patients (<50 years) and older patients (50-64 years).

Design

Post hoc analysis of data from a 24-week prospective, multinational, longitudinal observational cohort study (NCT01928953).

Setting

Outpatient clinics in the United States, Canada, Germany, and United Kingdom.

Subjects

Two age-based subgroups of adult patients with chronic noncancer pain receiving four or more weeks of daily opioid therapy and experiencing opioid-induced constipation within the previous two weeks.

Methods

The number of spontaneous bowel movements, frequency of constipation symptoms, amount of bother associated with symptoms, Patient Assessment of Constipation-Symptoms questionnaire, and health-related quality of life and function outcomes.

Results

Overall, 419 patients were included in this analysis (younger patients, N = 184; older patients, N = 235). Among younger and older patients, respectively, constipation occurred within the first week after initiating opioid therapy for 32.8% and 35.9%. At baseline, the mean numbers of spontaneous bowel movements/week were 1.3 and 1.5, and moderate opioid-induced constipation-related interference with pain management was reported by 46.6% and 44.5%. Younger patients generally reported that opioid-induced constipation symptoms were more bothersome than did older patients. The impact of opioid-induced constipation on health-related quality of life, work productivity, and day-to-day activities was comparable.

Conclusions

In these patients receiving opioid therapy for chronic noncancer pain, the burden of opioid-induced constipation was comparable or greater for patients aged <50 years compared with that for patients aged 50-64 years.

Incidence of opioid-induced constipation in Japanese patients with cancer pain: A prospective observational cohort study

This multicenter, prospective, observational cohort study assessed opioid induced constipation (OIC) in Japanese patients with cancer. Eligible patients had stable cancer and an ECOG PS of 0-2. OIC incidence based on the Rome IV diagnostic criteria was determined by patient diary entries during the first 14 days of opioid therapy. The proportion of patients with OIC was calculated for each 1-week period and the overall 2-week study period. Secondary measurements of OIC included the Bowel Function Index (BFI) score (patient assessment administered by physician), spontaneous bowel movements (SBMs) per week (patient assessment), and physician assessments. Medication for constipation was allowed. Two hundred and twenty patients were enrolled. The mean morphine-equivalent dose was 22 mg/day. By Rome IV criteria, the cumulative incidence of OIC was 56% (95% CI: 49.2%-62.9%); week 1, 48% (95% CI: 40.8%-54.6%); week 2, 37% (95% CI: 30.1%-43.9%). The cumulative incidence of OIC was lower in patients who received prophylactic agents for constipation (48% [95% CI: 38.1%-57.5%]) than in patients who did not (65% [95% CI: 55.0%-74.2%]). The cumulative incidences of OIC were 59% (95% CI: 51.9%-66.0%), 61% (95% CI: 54.3%-68.1%), and 45% (95% CI: 38.0%-51.8%) based on BFI scores, physician assessments, and SBM frequency, respectively. Frequency of BMs/week before starting opioids was the most influential factor for the occurrence of OIC. Utilization of prophylactic agents for constipation was associated with a modest effect on reducing the incidence of OIC. The incidences of OIC reported were variable depending on the diagnostic tool involved.

More opioids, more constipation? Evaluation of longitudinal total oral opioid consumption and self-reported constipation in patients with cancer

PURPOSE

Opioid-induced constipation (OIC) is a distressing physical symptom for patients with cancer taking opioids. Total opioid consumption may contribute to developing worsening OIC-related symptoms. We completed a retrospective analysis examining the association of total daily opioid consumption on self-reported constipation in patients with cancer.

METHODS

In over 5 clinic visits, we collected self-reported constipation scores and 24-h oral morphine equivalents (OME). We examined the association between OME and the presence of constipation (i.e., score > 3) and the relationship of OME between patients with or without constipation.

RESULTS

Of 297 patients with cancer, we observed 57.8% with constipation and 42.4% without constipation at the first clinic visit. Age was similar in both groups (54.2 ± 14.5 vs. 56.4 ± 14.8 years [mean ± SD]) and the majority of patients were women (63.7% vs. 61.1%). The most common cancer type in patients with constipation was non-colorectal gastrointestinal (n = 25, 14.6%), while in patients without constipation was colorectal gastrointestinal (n = 25; 19.8%). Across visits, we observed weak or no association between OME and self-reported constipation (r = 0.01-0.27). At the first visit, higher mean OME was seen in patients who self-reported constipation (133.4 vs 76; p < 0.05). Age, sex, metastatic disease, and stimulant laxative use were not associated with constipation.

CONCLUSIONS

We observed weak to no association between OME and constipation in patients with cancer. These results suggest a lack of a clear association between total opioid consumption and self-reported constipation.

PEG vs. sennosides for opioid-induced constipation in cancer care

PURPOSE

This randomized double-blind, double-dummy, 2-treatment, 2-period crossover study aimed to compare the efficacy and tolerability of polyethylene glycol (PEG) and sennosides in ambulatory cancer patients with opioid-induced constipation.

METHODS

Outpatients ≥ 18 years old with cancer, at risk of or already experiencing opioid-induced constipation, were randomly assigned to begin a standard bowel protocol of escalating doses of sennosides or PEG, plus a dummy preparation. After 3 weeks, the patients switched to the alternate active product and dummy preparation. Constipation was assessed using the revised Victoria Bowel Performance Scale (rBPS) at the end of each of the 2 consecutive 21-day study periods for the number of days with a satisfactory bowel movement, the time in days to goal rBPS (G), and the treatment preference of each patient.

RESULTS

Seventy patients were recruited, with 42 completing their first treatment period and 28 completing both treatment periods. For the typical patient, the expected number of days with a satisfactory bowel movement per days of treatment was found to be 1.21 times higher on PEG than on sennosides in a particular period (95% credible interval 0.96 to 1.55). Patients taking PEG were 1.47 times more likely to reach a rBPS of G before patients taking sennosides in the first period (95% confidence interval 0.74 to 2.94). There was no evidence of a difference in patient preference between laxatives.

CONCLUSION

Our study found weak evidence that PEG is superior to sennosides with respect to overall effectiveness in cancer patients with opioid-induced constipation.

Relationship Between Constipation and Medication

Constipation is very common and can be caused by adverse drug reactions as a result of many drugs. While the adverse effects of several medications such as opioids and anticholinergic agents are well established and well known, other commonly prescribed drugs, such as hypnotics, are less well understood. This review presents the results of an analysis of the relationship between constipation and drugs.

Efficacy and Safety of Lubiprostone in Patients with Opioid-Induced Constipation: Phase 3 Study Results and Pooled Analysis of the Effect of Concomitant Methadone Use on Clinical Outcomes

Objective

The efficacy and safety of oral lubiprostone for relieving symptoms of opioid-induced constipation (OIC) in patients with chronic noncancer pain were evaluated in a randomized, double-blind, placebo-controlled study. These data were also pooled with those from two similar phase 3 studies to explore the effects of methadone on treatment response.

Methods

In the primary study, adults with OIC (fewer than three spontaneous bowel movements [SBMs] per week) were randomized to receive lubiprostone 24 mcg or placebo twice daily for 12 weeks. The primary end point was a change from baseline in the frequency of SBMs at week 8 in patients without a prior dose reduction. For the pooled analysis, the efficacy of lubiprostone was compared with placebo in patients receiving methadone or nonmethadone opioids. Responders were defined as patients with nine or more weeks of nonmissing SBM data who had one or more additional SBMs per week from baseline for each week that data were available and three or more SBMs per week for nine or more weeks.

Results

In the primary study, the change from baseline at week 8 in SBM frequency was similar in the lubiprostone and placebo groups (P = 0.842). In the pooled analysis, the response rate was significantly higher with lubiprostone treatment vs placebo for patients receiving nonmethadone opioids (P = 0.002) but was similar between lubiprostone treatment and placebo in patients receiving methadone (P = 0.692). The safety profile of lubiprostone was unaffected by methadone use.

Conclusions

The phase 3 study did not meet its primary efficacy end point. However, analysis of pooled data from all phase 3 studies in the OIC clinical development program, stratified by methadone opioid usage, confirmed that lubiprostone is effective for treatment of OIC in patients taking nonmethadone opioids; no safety concerns were identified based on the type of opioid used.

Efficacy of Lubiprostone for the Treatment of Opioid-Induced Constipation, Analyzed by Opioid Class

Objectives

To examine the efficacy and safety of lubiprostone for the treatment of opioid-induced constipation (OIC) in patients by opioid class received.

Design

Data were pooled from three phase III, randomized, double-blind, placebo-controlled studies.

Subjects/Setting

Adults with chronic noncancer pain receiving opioid therapy for 30 or more days and diagnosed with OIC.

Methods

Overall mean change from baseline in spontaneous bowel movement (SBM) frequency, overall treatment response (≥1 SBM/week improvement over baseline SBM frequency in all treatment weeks with available data and ≥3 SBMs/week for ≥9 of the 12 weeks of treatment), and OIC-related symptoms were examined in patients taking opioids. Data were pooled and analyzed by opioid group.

Results

In patients receiving phenanthrene opioids (e.g., oxycodone; N = 1,159), lubiprostone significantly increased overall mean changes in SBM frequency from baseline (P = 0.0001), increased overall response rate (P = 0.0024), and improved OIC symptoms (P ≤ 0.0229) vs placebo. Patients receiving phenylpiperidine opioids (e.g., fentanyl; N = 137) had significant improvement in SBM frequency (P = 0.0129) and favorable trends in response rates (21.4% vs 9.8%; P = 0.0723) and OIC symptoms vs placebo. Efficacy was not observed in overall analyses of patients receiving diphenylheptane opioids (e.g., methadone), although an increase in SBM frequency was observed in patients who received a morphine-equivalent daily dose of 200 or fewer mg, suggesting a dose-dependent negative interference of this opioid class on lubiprostone effects. For all groups, the lubiprostone adverse event profile was similar; the most common treatment-emergent adverse events were nausea and diarrhea.

Conclusions

In patients using commonly prescribed opioids, lubiprostone is effective and generally well tolerated for the treatment of OIC.

Clozapine: why wait to start a laxative?

Clozapine, the antipsychotic of choice for treatment-resistant schizophrenia, has a number of side-effects, some of which are potentially life-threatening. Historically viewed as a relatively minor side-effect, there is increasing awareness of the potentially severe sequalae of constipation secondary to clozapine-induced gastrointestinal hypomotility (CIGH). These include ileus, intestinal obstruction, bowel ischaemia, gastrointestinal necrosis, toxic megacolon and death. CIGH is significantly more common than clozapine-induced blood dyscrasias and has a higher mortality rate. Although strict criteria must be followed to assertively monitor, detect and treat blood dyscrasias in patients taking clozapine, no such framework exists for CIGH. We recommend that prescribing guidelines, regulatory agencies and information from manufacturers should more clearly highlight the risks identified in the literature. Furthermore, we recommend that, in people taking clozapine, constipation should be prevented by prophylactic treatment with laxatives rather than treated only when clinically identified.

LEARNING OBJECTIVES:

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Gastrointestinal motility, dysbiosis and opioid-induced tolerance: is there a link?

Studies show that gut microbial dysbiosis induced by chronic opioid use is linked to central opioid tolerance. Here, we suggest that a persistent decrease in gastrointestinal motility by opioids is a primary cause of gut microbial dysbiosis and that improving gastrointestinal transit might be a strategy in preventing opioid analgesic tolerance.

Outcomes Associated with Treatment of Chronic Pain with Tapentadol Compared with Morphine and Oxycodone: A UK Primary Care Observational Study

Introduction

This study compared adverse outcomes and resource use for patients with a diagnosis of pain treated with tapentadol prolonged-release (PR) versus those treated with morphine controlled-release (CR) and oxycodone CR.

Methods

Data were sourced from the Clinical Practice Research Datalink (CPRD), a database derived from UK primary care. Patients prescribed tapentadol PR between May 2011 and December 2016 were selected and matched to two groups of controls treated with either morphine CR or oxycodone CR on gender, age, pain duration, pain site, pain aetiology, Charlson index and prior analgesia. Times to first adverse event (constipation or nausea/vomiting) were compared within a Cox proportional hazards model. Rates of primary care contacts, accident and emergency contacts and, for a subset of patients linked to Hospital Episode Statistics (HES), inpatient admissions and outpatient contacts were compared using incidence rate ratios (IRRs) derived from Poisson regression.

Results

A total of 1907 patients prescribed tapentadol PR were identified and 1791 (93.9%) had a pain diagnosis. Of these 1246 (65.3%) were matched to morphine controls and 829 (43.4%) to oxycodone controls. Compared to controls, gastrointestinal adverse events with tapentadol PR treatment were reduced; aHR = 0.532 (0.402–0.703; p < 0.001) versus morphine CR and 0.517 (0.363–0.735; p < 0.001) versus oxycodone CR. Compared with morphine CR, primary care contacts [IRR = 0.831 (0.802–0.861)], accident and emergency attendance [0.739 (0.572–0.951)], outpatient contacts [0.917 (0.851–0.989)] and inpatients contacts [0.789 (0.664–0.938)] were reduced. For oxycodone, the respective figures were 0.735 (0.703–0.768), 0.971 (0.699–1.352), 0.877 (0.799–0.962) and 0.748 (0.601–0.932).

Conclusion

Tapentadol PR was associated with significantly fewer adverse gastrointestinal events than morphine CR and oxycodone CR in patients with a diagnosis of pain. There was also significantly reduced primary and secondary care resource use. As with all observational studies, potential bias due to residual confounding and confounding by indication should be considered.

Funding

Grünenthal Ltd.

Electronic supplementary material

The online version of this article (10.1007/s12325-019-00932-7) contains supplementary material, which is available to authorized users.

Efficacy and Practicality of Opioid Therapy in Japanese Chronic Noncancer Pain Patients

BACKGROUND

Many Japanese adults suffer from chronic pain. However, 50% of these individuals discontinue treatment despite the persistence of pain. Both clinicians and patients in Japan tend to be concerned about the safety and efficacy of opioid therapy, and the use of opioids in chronic non-cancer pain remains less common in Japan than elsewhere.

AIMS

This study examined the effects of opioid therapy on the daily lives of patients with chronic noncancer pain in Japan, where use of opioids for this type of pain remains uncommon.

DESIGN

Prospective cross-sectional questionnaire study.

SETTING

Data were collected over two periods, between March and April 2014 at one hospital, and between February and April 2015 at the other hospital. Subjects were recruited at the respective clinics by the study interviewer between March 1, 2014 and April 15, 2014 and between February 1, 2015 and April 15, 2015.

PARTICIPANTS/SUBJECTS

This study included 34 outpatients with chronic non-cancer pain who were being treated with opioid analgesics at pain clinics in two hospitals in Sapporo.

METHODS

Thirty-four Japanese patients receiving opioid medications for chronic noncancer pain in outpatient pain clinics were enrolled. Participants underwent interviews and completed the Japanese versions of the Short Form 36 (SF-36v2) and the Coping Strategies Questionnaire (CSQ).

RESULTS

Sleep disruption, claiming compensation for work-related accidents, and current pain level were negatively correlated with opioid effectiveness (p < .05). Additionally, opioid effectiveness was negatively correlated with the catastrophizing subscale of the CSQ (r = -0.50, p < .01). The effects of opioid therapy had a low positive correlation with the emotional functioning role subscale of the SF-36v2 (r = 0.38, p < .05). Daily equivalent morphine dose was positively correlated with opioid therapy duration, interference with appetite, and current pain intensity. Morphine dose was also positively correlated with scores for the catastrophizing subscale of the CSQ (r = 0.36, p < .05) and negatively correlated with scores in all subdomains of the SF-36v2.

CONCLUSIONS

It is important to focus on adaptive, cognitive, and emotional factors, such as emotional role functioning, to determine the efficacy of opioid treatment for chronic noncancer pain. Moreover, patients with catastrophizing significantly increased their morphine doses, resulting in an increased risk of overdose.

Opioid use disorder is associated with increased mortality and morbidity in patients with gastroparesis

Background

Opioid use disorder (OUD) epidemic has been declared a nationwide public health emergency by the Department of Health and Human Services. There are limited data regarding OUD in patients with gastroparesis. This study aimed to evaluate the impact of OUD on the outcomes in patients hospitalized with gastroparesis and to delineate the trends associated with OUD and gastroparesis using a nationally representative sample.

Methods

We used the National (Nationwide) Inpatient Sample database from 2005-2014 to identify patients hospitalized with a primary diagnosis of gastroparesis (ICD 9 Code: 536.3) and a concurrent diagnosis of OUD. We used Pearson chi-square analysis to compare demographics, the independent samples t-test to assess differences in length of stay and cost of care, and multivariate regression analysis to adjust for confounders.

Results

Between 2005 and 2014, a total of 145,700 patients with a primary diagnosis of gastroparesis were hospitalized in the United States, of whom 4519 (3.1%) had a concurrent diagnosis of OUD. The prevalence of OUD in gastroparesis doubled from 2.1% in 2005 to 4.3% in 2014. After adjusting for confounders, patients with OUD had greater in-hospital mortality (adjusted odds ratio 2.7, 95% confidence interval: 2.1-3.5). Patients with OUD also had significantly longer hospital stays and higher costs. Independent predictors of OUD in patients with gastroparesis were younger age, female sex, alcohol use, depression, and Medicaid insurance.

Conclusion

OUD in patients with gastroparesis is associated with greater mortality and healthcare resource utilization.

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

BACKGROUND

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

METHODS

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

KEY RESULTS

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

CONCLUSIONS & INFERENCES

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

Peripherally acting μ-opioid antagonist for the treatment of opioid-induced constipation: Systematic review and meta-analysis

BACKGROUND AND AIM

Opioid-induced constipation (OIC) is a frequent adverse event (AE) that impairs patients' quality of life (QOL). Peripherally acting μ-opioid receptor antagonists (PAMORAs) have been recognized as a treatment option for OIC, but the effect consistent across the studies has not been evaluated.

METHODS

We conducted a quantitative meta-analysis to explore the efficacy of PAMORA for OIC (registered with PROSPERO: CRD42018085298). We systematically searched randomized controlled trials (RCTs) in Medline, Embase, and Central databases. Change from baseline in spontaneous bowel movements, pooled proportion of responders, QOL, and AEs were calculated and compared with results in placebo cases.

RESULTS

We included 31 RCTs with 7849 patients. A meta-analysis revealed that patients under PAMORA therapy had considerably improved spontaneous bowel movement from baseline compared with those given placebo (20 RCTs; mean difference, 1.43; 95% confidence interval [CI], 1.18-1.68; n = 5622) and more responded (21 RCTs; risk ratio [RR], 1.81; 95% CI, 1.55-2.12; n = 4821). Moreover, QOL of patients receiving PAMORA was significantly better (8 RCTs; mean difference, -0.22; 95% CI, -0.28 to -0.17; n = 2884). AEs were increased significantly in the PAMORA group (26 RCTs; RR, 1.10; 95% CI, 1.06-1.15; n = 7715), especially in gastrointestinal disorders, whereas serious AEs were not significant (17 RCTs; RR, 1.04; 95% CI, 0.85-1.28; n = 5890).

CONCLUSION

Peripherally acting μ-opioid receptor antagonist has been shown to be effective and durable for patients with OIC and is the only drug with confirmed evidence in meta-analysis. The possibility of publication bias was the limitation of this study.

Medicate or Meditate? Greater Pain Acceptance is Related to Lower Pain Medication Use in Persons With Chronic Pain and Spinal Cord Injury

OBJECTIVES

There is little information about whether use of pain self-management skills that are common targets of psychosocial interventions for pain are associated with reduced reliance on pain medications. The aim of this study was to test whether higher chronic pain acceptance, which is a readily modified pain self-management approach, is related to lower use of pain medications (eg, opioid medications, and gabapentinoids) in a sample with chronic pain and spinal cord injury (SCI).

MATERIALS AND METHODS

This is a cross-sectional survey study of pain medication use, pain severity and distribution (Brief Pain Inventory [BPI]), depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]), and chronic pain acceptance (Chronic Pain Acceptance Questionnaire [CPAQ]) administered to a sample of 120 adults with chronic pain and SCI.

RESULTS

Regression results indicated that, above and beyond the effects of pain intensity, pain distribution, and depressive symptoms, higher pain acceptance was related to lower use of all types of pain medications, and lower odds of using opioid medications or gabapentinoids. Pain intensity was not related to pain medication use, but greater pain distribution was related to using more pain medications in general and to greater odds of using gabapentinoids.

DISCUSSION

Findings from this study indicate that those with chronic pain and SCI who have a more accepting orientation to pain are less reliant on pain medications, and thereby experience lower risks associated with medication consumption. Longitudinal, daily process, and clinical trial studies are needed to better understand the association between pain acceptance and pain medication consumption.

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

Background

Opioids are prescribed in over 40% of patients with advanced cancer, but side effects occur frequently. In this study we evaluated the development and treatment of opioid induced constipation (OIC), and OIC resolving effect of methylnaltrexone for different opioid subtypes in daily clinical practice.

Methods

Patients with cancer using opioids were included in a retrospective chart analysis. Baseline characteristics, data on opioid use, laxative use, and OIC were collected. Patients with OIC who were prescribed methylnaltrexone, were included in a prospective observational trial (NCT01955213).

Results

Thirty-nine of 327 patients (pts) with cancer who were treated with opioids suffered from OIC (overall prevalence 12%; 95%-CI: 8–15%). The prevalence of OIC was similar in patients treated with oxycodone or fentanyl (12 of 81 pts. vs. 18 of 110 pts., RR 0.9; 95%CI 0.4–2.0). The morphine equivalent daily dose did not significantly differ between opioid subtypes (fentanyl 89 mg (IQR 60–180) vs. oxycodone 40 mg (40–80), P = 0.231). Twenty-two individual patients (7%) were admitted for OIC. Most effective laxatives in admitted patients were enemas, methylnaltrexone, or 4-l polyethylene-glycol solution. In the prospective observational study, the effect of methylnaltrexone could be evaluated in 23 patients. Eleven patients achieved the primary endpoint of ≥2 laxation responses out of the first four doses methylnaltrexone, independent of opioid subtype.

Conclusions

OIC is a burdensome clinical problem independent of opioid subtype. Timely intensification of prophylactic laxative treatment, especially when opioid doses increase, may help to prevent OIC. Clinically overt OIC requires a more intensive laxative regimen with for example methylnaltrexone.

Trial registration

NCT01955213.

Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: systematic review and network meta-analysis

OBJECTIVE

Opioids are increasingly prescribed in the West and have deleterious GI consequences. Pharmacological therapies to treat opioid-induced constipation (OIC) are available, but their relative efficacy is unclear. We performed a systematic review and network meta-analysis to address this deficit in current knowledge.

DESIGN

We searched MEDLINE, EMBASE, EMBASE Classic and the Cochrane central register of controlled trials through to December 2017 to identify randomised controlled trials (RCTs) of pharmacological therapies in the treatment of adults with OIC. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Efficacy and safety of pharmacological therapies was reported as a pooled relative risk (RR) with 95% CIs to summarise the effect of each comparison tested and ranked treatments according to their P-score.

RESULTS

Twenty-seven eligible RCTs of pharmacological therapies, containing 9149 patients, were identified. In our primary analysis, using failure to achieve an average of ≥3 bowel movements (BMs) per week with an increase of ≥1 BM per week over baseline or an average of ≥3 BMs per week, to define non-response, the network meta-analysis ranked naloxone first in terms of efficacy (RR=0.65; 95% CI 0.52 to 0.80, P-score=0.84), and it was also the safest drug. When non-response to therapy was defined using failure to achieve an average of ≥3 BMs per week, with an increase of ≥1 BM per week over baseline, naldemedinewas ranked first (RR=0.66; 95% CI 0.56 to 0.77, P score=0.91) and alvimopan second (RR=0.74; 95% CI 0.57 to 0.94, P-score=0.71).

CONCLUSION

In network meta-analysis, naloxone and naldemedine appear to be the most efficacious treatments for OIC. Naloxone was the safest of these agents.

Long-term treatment patterns of prophylactic and acute migraine medications and incidence of opioid-related adverse events in patients with migraine

Objectives

To describe long-term treatment patterns in migraine patients initiating prophylactic therapy and to evaluate acute medication use and adverse events associated with opioids.

Methods

This study used the 2005–2014 IBM MarketScan® databases to evaluate migraine patients initiating prophylactic medication. Outcome measures included persistence with prophylactic migraine medications over 2–5 years. Acute medication use and gastrointestinal-related adverse events and opioid abuse following opioid use were evaluated. Cox proportional hazards models were used to evaluate predictors of non-persistence and predictors of gastrointestinal-related AEs and opioid abuse associated with long-term opioid use.

Results

In total, 147,832 patients were analyzed. Non-persistence was observed in 90% of patients; 39% switched, 30% restarted, and 31% discontinued treatment. Over the follow-up, 59.9% of patients received triptans, 66.6% non-steroidal anti-inflammatory drugs, 77.4% opioids, and 2.6% ergotamines. Among opioid users, 16.6% experienced nausea/vomiting, 12.2% had constipation, and 10.4% had diarrhea. Opioid abuse was reported in <1% of opioid users. Gastrointestinal-related adverse events increased with increasing number of days’ supply of opioids.

Conclusions

Non-persistence to prophylactic treatment was frequent among migraine patients. Opioid use was common in migraine patients and the risk of gastrointestinal-related adverse events and opioid abuse increased with long-term use of opioids. These results suggest a need for more effective prophylactic migraine treatments.

Clinical Overview and Considerations for the Management of Opioid-induced Constipation in Patients With Chronic Noncancer Pain

OBJECTIVES

Opioid analgesics may be associated with chronic adverse effects, such as opioid-induced constipation (OIC). Available and emerging prescription medications for OIC in patients with chronic noncancer pain are described, including concerns and challenges associated with OIC management.

METHODS

Narrative review.

RESULTS

OIC is characterized by a change in bowel habits and defecation patterns that occurs when initiating opioid therapy and is associated with reduced bowel frequency, straining, sensation of incomplete evacuation, and/or patient distress related to bowel habits. Prescription medications are indicated when OIC persists despite conservative approaches (eg, increased fiber and fluid intake, exercise, over-the-counter laxatives and stool softeners). Phase 3 studies have demonstrated the efficacy of peripherally acting µ-opioid receptor antagonists (PAMORA; methylnaltrexone, naloxegol, naldemedine), and a chloride channel activator (lubiprostone) for improving OIC in patients with chronic noncancer pain. Although head-to-head studies are lacking, a meta-analysis demonstrated that μ-opioid receptor antagonists were more effective than placebo for the treatment of OIC. The most common adverse effects associated with prescription medications for OIC are gastrointestinal related (eg, nausea, diarrhea, abdominal pain, or distention), with most being mild or moderate in severity. Therapy currently in development for OIC includes the PAMORA axelopran.

DISCUSSION

Health care providers should be aware of this complication in patients receiving opioids and should monitor and address constipation-related symptoms to optimize pain management and improve patient quality of life.

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.

Physiological Response to Opioids

The clinical setting in which women's health physicians practice, whether as generalist, obstetricians and gynecologists, or subspecialists, dictates our frequent clinical interaction with "pain." Opioid-containing medications are frequently prescribed within our specialty as a means of immediate pain relief. Opioid-containing medication causes a deep physiological alteration of several systems resulting in potential harm to acute and chronic opioid users. This article includes a thorough system-based review of opioid-containing medications on physiological systems. Women's health providers should have an in-depth understanding of such reverberations on patients' wellbeing to maintain the safest level of care. A solid grasp of physiological repercussions of opioid use would encourage physicians to seek alternative treatment options. Such practice is essential in curbing the opioid epidemic our patients are facing.

[Management of chronic pain using extended release tilidine : Quality of life and implication of comedication on tilidine metabolism]

BACKGROUND AND OBJECTIVES

The synthetic opioid tilidine is often used in chronic pain treatment. However, the activation via metabolism in patients with concomitant medication and reduced liver or kidney function is not thoroughly investigated. We therefore studied pain treatment efficacy, health-related quality of live and the metabolism of tilidine in patients with chronic pain.

METHODS AND MATERIALS

In all, 48 patients, who were on a stable dose of oral prolonged release tilidine for at least 7 days, were included in this observational multicenter study. Liver and kidney function were assessed in routine blood samples, concentrations of tilidine, nortilidine and bisnortilidine were determined using a validated LC/MS/MS method. Comedication was registered and patients experience with regard to quality of life, pain, gastrointestinal symptoms and adverse events was assessed in standardised questionnaires.

RESULTS

On average a daily dose of 180 mg tilidine was taken. Dose normalized plasma concentrations of the active metabolite nortilidine ranged between 1.6 ng/ml and 76.5 ng/ml (mean 29.2 ± 25.1 ng/ml). Ratios between tilidine and nortilidine were on average 0.28 (median = 0.13, standard deviation = 0.67). Patients were on 1 to 14 different concomitant medications. About 66% of the patients had sufficient pain treatment. Almost no opioid-induced constipation was observed. Only few patients had decreased kidney or liver function which did not result in elevated nortilidine concentrations.

CONCLUSION

Pain treatment using tilidine resulted in variable nortilidine concentrations which are obviously not strongly influenced by comedication or reduced liver or kidney function. Only a few side effects were observed with almost no opioid-induced constipation.

Absorption, distribution, metabolism, and excretion of radiolabeled naldemedine in healthy subjects

1. Naldemedine is a peripherally acting μ-opioid receptor antagonist for the treatment of opioid-induced constipation. 2. This phase 1 study investigated the absorption, distribution, metabolism and excretion of naldemedine, following a single oral 2-mg dose of [oxadiazole-¹⁴C]-naldemedine or [carbonyl-¹⁴C]-naldemedine to 12 healthy adult male subjects. Pharmacokinetic assessments were performed on blood, urine and fecal samples collected at defined intervals. 3. Naldemedine was the major circulating component in plasma with a median T_max of approximately 0.8-0.9 h and a geometric mean t_1/2,z of approximately 11 h. Total systemic exposures, AUC, of metabolites nor-naldemedine were less abundant than those of naldemedine (9% or 13% of AUC of naldemedine) and 16.2% or 18.1% of naldemedine was excreted as unchanged in urine after administration of [oxadiazole-¹⁴C]-naldemedine or [carbonyl-¹⁴C]-naldemedine, respectively, and benzamidine was the major radioactive component after administration of [oxadiazole-¹⁴C]-naldemedine (32.5% of administered dose). Overall, the recovery of total radioactivity was 92% (57.3% in urine; 34.8% in feces) after administration of [oxadiazole-¹⁴C]-naldemedine and 85% (20.4% in urine; 64.3% in feces) after administration of [carbonyl-¹⁴C]-naldemedine. 4. Our findings suggest that naldemedine is mainly metabolized to nor-naldemedine. Naldemedine was rapidly absorbed and well tolerated, with no major safety signals observed.

Naldemedine in Japanese patients with opioid-induced constipation and chronic noncancer pain: open-label Phase III studies

Introduction

Naldemedine is a peripherally-acting µ-opioid-receptor antagonist, approved in Japan for opioid-induced constipation (OIC). In two open-label, single-arm, Phase III studies, we evaluated the safety and efficacy of naldemedine in Japanese patients with OIC receiving regular-use opioids (COMPOSE-6) or prolonged-release oxycodone (COMPOSE-7) for chronic noncancer pain.

Methods

Eligible Japanese adults with OIC and chronic noncancer pain received once-daily oral naldemedine 0.2 mg for 48 weeks, irrespective of food intake. Primary end points included measures of treatment-emergent adverse events (TEAEs), pain intensity, and opioid withdrawal. Secondary efficacy end points were evaluated at treatment week 2. Patient Assessment of Constipation Symptoms (PAC-SYM) and Quality of Life (PAC-QOL) scores were evaluated in both 48-week studies.

Results

Of patients enrolled in COMPOSE-6 (N = 43) and COMPOSE-7 (N = 10), TEAEs were reported in 88% (95% CI 74.9–96.1) and 90% (95% CI 55.5–99.7), respectively. The most frequently reported TEAEs, nasopharyngitis and diarrhea, were mostly mild or moderate in severity. Assessments of pain intensity and opioid withdrawal remained stable over the 48-week treatment periods of both studies. The proportion of spontaneous bowel-movement responders at week 2 in COMPOSE-6 was 81.0% (95% CI 65.9–91.4) and 90.0% (95% CI 55.5–99.7) in COMPOSE-7. Significant and sustained improvements in PAC-SYM and PAC-QOL scores were also observed in both studies (all P<0.05).

Conclusion

Side effects that occurred with naldemedine were mostly mild or moderate in severity, and the data suggested that naldemedine can improve bowel function and QOL in Japanese patients with OIC receiving regular-use opioids or prolonged-release oxycodone for chronic noncancer pain.

Safety of oral methylnaltrexone for opioid-induced constipation in patients with chronic noncancer pain

Purpose

Oral methylnaltrexone was shown to be effective in treating opioid-induced constipation (OIC) in patients with chronic noncancer pain in a Phase III randomized controlled trial. This report provides a detailed safety analysis from that study.

Methods

Adults (n=803) with chronic noncancer pain for ≥2 months and confirmed OIC while receiving opioid doses ≥50 mg morphine equivalent per day for ≥14 days were randomized 1:1:1:1 to oral methylnaltrexone (150, 300, or 450 mg) or placebo once daily for 4 weeks, followed by as-needed use for 8 weeks. Safety was evaluated by examining treatment-emergent adverse events (TEAEs), clinical laboratory parameters, vital signs, electrocardiography, rescue-laxative and opioid use, Objective Opioid Withdrawal Scale (OOWS) and Subjective Opioid Withdrawal Scale (SOWS), and pain-intensity scores.

Results

TEAEs occurred at a similar incidence in the methylnaltrexone groups (59.0%) and placebo group (63.0%). The most common TEAEs with methylnaltrexone were abdominal pain (8.0% vs 8.5% with placebo), nausea (6.8% vs 9.0%), and diarrhea (6.0% vs 3.5%). Cardiac-related TEAEs occurred in 1.8% and 1.0% of patients, respectively, and no major adverse cardiovascular events were reported. No patient had a cluster of TEAEs associated with opioid withdrawal after excluding gastrointestinal TEAEs. Changes in laboratory parameters, vital signs, and electrocardiography were generally small and similar across treatment groups. Rescue-laxative use was more common with placebo than methylnaltrexone 450 mg (6.20% vs 4.27% of study days, P=0.024). Changes in opioid dose, OOWS and SOWS scores, and pain-intensity scores during treatment were minimal.

Conclusion

Oral methylnaltrexone had a safety profile comparable with placebo in the treatment of OIC in patients with chronic noncancer pain, with no evidence of cardiac toxicity or opioid withdrawal.

Methylation Products of 6β- N-Heterocyclic Substituted Naltrexamine Derivatives as Potential Peripheral Opioid Receptor Modulators

Two 6β- N-heterocyclic naltrexamine derivatives, NAP and NMP, have been identified as peripherally selective mu opioid receptor (MOR) antagonists. To further enhance the peripheral selectivity of both compounds, the 17-amino group and the nitrogen atom of the pyridine ring in both NAP and NMP were methylated to obtain dMNAP and dMNMP, respectively. Compared with NAP and NMP, the binding affinities of dMNAP and dMNMP shifted to MOR and KOR (kappa opioid receptor) dual selective and they acted as moderate efficacy partial agonists. The results from radioligand binding studies were further confirmed by molecular docking studies. In vivo studies demonstrated that dMNAP and dMNMP did not produce antinociception nor did they antagonize morphine's antinociceptive activity, indicating that these compounds did not act on the central nervous system. Meanwhile, both dMNAP and dMNMP significantly slowed down fecal excretion, which indicated that they were peripherally acting opioid receptor agonists. All together, these results suggested that dMNAP and dMNMP acted as peripheral mu/kappa opioid receptor modulators and may be applicable in the treatment of diarrhea in patients with bowel dysfunction.

Peripherally Acting μ-Opioid Receptor Antagonists for the Treatment of Opioid-Related Side Effects: Mechanism of Action and Clinical Implications

Opioid receptors are distributed throughout the central and peripheral nervous systems and on many nonneuronal cells. Therefore, opioid administration induces effects beyond analgesia. In the enteric nervous system (ENS), stimulation of µ-opioid receptors triggers several inhibitory responses that can culminate in opioid-induced bowel dysfunction (OBD) and its most common side effect, opioid-induced constipation (OIC). OIC negatively affects patients' quality of life (QOL), ability to work, and pain management. Although laxatives are a common first-line OIC therapy, most have limited efficacy and do not directly antagonize opioid effects on the ENS. Peripherally acting µ-opioid receptor antagonists (PAMORAs) with limited ability to cross the blood-brain barrier have been developed. The PAMORAs approved by the U S Food and Drug Administration for OIC are subcutaneous and oral methylnaltrexone, oral naloxegol, and oral naldemedine. Although questions of cost-effectiveness and relative efficacy versus laxatives remain, PAMORAs can mitigate OIC and improve patient QOL. PAMORAS may also have applications beyond OIC, including reducing the increased cardiac risk or potential tumorigenic effects of opioids. This review discusses the burden of OIC and OBD, reviews the mechanism of action of new OIC therapies, and highlights other potential opioid-related side effects mediated by peripheral opioid receptors in the context of new OIC therapies.

Increases in controlled-release oxycodone utilisation following the subsidy of oxycodone with naloxone formulations: An Australian population-based study

PURPOSE

Despite increasing use of oxycodone/naloxone controlled-release (CR) in Australia, little is known about how it has affected the overall oxycodone CR market since its subsidy in 2011.

METHODS

We used Pharmaceutical Benefits Scheme dispensing claims (2006-2016) and interrupted time series analysis to examine changes in the quarterly rates of dispensing of oral oxycodone CR formulations (oxycodone/naloxone CR and single-ingredient oxycodone CR) and new oxycodone CR treatment episodes. We also performed a retrospective cohort study in a sample of people initiating a new oxycodone CR treatment episode in 2009, 2012/2013, and 2016 to compare opioid utilisation patterns over time.

RESULTS

The subsidy of oxycodone/naloxone CR was associated with a 1.6-fold increase in the growth rate of oxycodone CR dispensing, resulting from rapid uptake of low strength (≤5 mg) oxycodone/naloxone CR. In our cohort of initiators, the number of new oxycodone CR treatment episodes increased 2.1-fold between 2009 and 2016; in 2016, 91.4% of new treatment episodes involved oxycodone/naloxone CR. Comparing 2016 with 2009, we observed an increase in people initiating with a tablet strength less than or equal to 5-mg (risk difference [RD] = 21.1%, 95% CI, 19.9%-22.4%) in people initiating with no other opioid dispensing 90 days prior to initiation (RD = 5.2%, 3.8%-6.6%) and with no further opioid dispensing 90 days after initiation (RD = 8.8%, 7.4%-10.2%).

CONCLUSIONS

After its subsidy, the uptake of low-dose oxycodone/naloxone CR was greater than expected if it were substituting the single-ingredient oxycodone CR, resulting in an expansion of the oxycodone CR market.

Lower prevalence of gastroesophageal reflux disease in patients with noncardiac chest pain on opiates: a cross-sectional study

Opiates can cause heartburn and spastic esophageal dysmotility but their role in noncardiac chest pain (NCCP) is not known. Our aim was to characterize opiate effects on esophageal function using esophageal pH monitoring and high-resolution manometry (HREM) in these patients.We performed a cross sectional study of opiate users with NCCP who underwent HREM and esophageal pH study from 2010 to 2017 using opiate nonusers as a comparison group. Demographic data, symptoms, opiate use, endoscopic findings, esophageal pH study parameters, and HREM data were abstracted.Thirty three patients with NCCP on opiates were compared to 144 opiate non-users. Compared to opiate nonusers, opiate users had lower total acid exposure (2.3% vs. 3%, P = 0.012), lower upright acid exposure (1.2% vs. 3.1%, P = 0.032) and lower DeMeester score (6.5 vs. 12.7, P = 0.016). Opiate users also had higher lower esophageal sphincter integrated relaxation pressure (LES-IRP) (7.0 mm Hg [2.2, 11.7] vs. 3.7 mm Hg [1.1, 6.2] P = 0.011) and greater mean distal contractile integral (DCI) (2575 mm.Hg.s.cm [1134, 4466] vs. 1409 mm.Hg.s.cm [796, 3003] P = 0.03) than opiate non-users. The prevalence of hypertensive motility disorders (15.2% vs. 11.1%) and achalasia (12.1% vs. 2.1%) was higher in opiate users (P = 0.039) but did not reach significance on multivariate analysis.In patients presenting with NCCP, opiate users had lower esophageal acid exposure compared to opiate nonusers. This might be due to higher LES pressures preventing reflux and higher DCI leading to more rapid acid esophageal clearance.