Development of opioid-induced constipation: post hoc analysis of data from a 12-week prospective, open-label, blinded-endpoint streamlined study in low-back pain patients treated with prolonged-release WHO step III opioids

Naldemedine for Opioid-Induced Constipation in Patients With Cancer: A Multicenter, Double-Blind, Randomized, Placebo-Controlled Trial

PURPOSE

Opioid-induced constipation is the most frequent and non-self-limiting adverse effect of opioid analgesia, reducing adherence and interfering with pain relief. This clinical trial aimed to clarify the preventive effect of naldemedine versus placebo for constipation in patients with cancer starting regularly dosed strong opioids therapy.

METHODS

This multicenter, double-blinded, randomized, placebo-controlled, confirmatory trial was conducted between July 2021 and May 2023 at four academic hospitals in Japan (ClinicalTrials.gov identifier: jRCTs031200397). Patients with cancer starting a first-time regularly dosed strong opioid for cancer pain and age 20+ years were included. Eligible patients were randomly assigned to the naldemedine (Symproic 0.2 mg) or placebo group in a 1:1 ratio for 14 days with protocol treatment. The primary end point was the proportion of patients with a Bowel Function Index (BFI) of <28.8 on day 14. The secondary end points included frequency of spontaneous bowel movements (SBM), quality of life (QOL), and frequency of opioid-induced nausea and vomiting (OINV).

RESULTS

Of the 103 patients assessed for eligibility, 99 received either naldemedine (n = 49) or placebo (n = 50). A BFI of <28.8 on day 14 was significantly more likely to occur in the naldemedine group (64.6%; 95% CI, 51.1 to 78.1) versus placebo (17.0%; 95% CI, 6.3 to 27.8), and the difference between groups was 47.6% (95% CI, 30.3 to 64.8; P < .0001). The frequency of SBM, QOL, and the severity of OINV were nominally significant in the naldemedine group than in the control group.

CONCLUSION

Naldemedine prevented constipation and improved constipation-related QOL, with possible preventive effect on OINV in patients with cancer starting regularly dosed opioids therapy.

Prolonged-release oxycodone/naloxone reduces opioid-induced constipation and improves quality of life in laxative-refractory patients: results of an observational study

Background

Opioids are an effective treatment for moderate-to-severe pain. However, they are associated with a number of gastrointestinal side effects, most commonly constipation. Laxatives do not target the underlying mechanism of opioid-induced constipation (OIC), so many patients do not have their symptoms resolved. Fixed-dose prolonged-release (PR) oxycodone/naloxone (OXN) tablets contain the opioid agonist oxycodone and the opioid antagonist naloxone. Nal-oxone blocks the action of oxycodone in the gut without compromising its analgesic effects.

Aim

To evaluate the effectiveness of PR OXN in patients with severe pain who had laxative-refractory OIC with their previous opioid.

Methods

The study was carried out in 13 centers across the UK and Ireland, using a bespoke online tool to capture patients’ data. Patients were reviewed according to normal clinical practice of each center and rated any changes in their constipation and quality of life (QoL) since starting PR OXN. Any change in patients’ laxative use was also recorded.

Results

One hundred and seven patients were entered into the database, and 81 went on to attend at least one review. Of these, 54 (66.7%) reported an improvement in constipation and 50 (61.7%) reported an improvement in QoL since starting PR OXN. Fifty-seven patients (70.4%) said they had reduced laxative intake; 48 (59.3%) only needed laxatives as required.

Conclusion

PR OXN reduced symptoms of constipation, improved QoL and reduced laxative intake in patients with OIC. It has a potential place early in any treatment strategy for severe pain in patients using opioids, particularly in patients who may be predisposed to constipation.

[Real-life efficacy and tolerability of methocarbamol in patients suffering from refractory muscle-related low/back pain - Results of a health care research project based on data from the German pain practice registry]

BACKGROUND

Subacute, muscle-related low/back pain (L/BP) is known to be difficult to treat and frequently requires more specific causal-oriented treatments with agents improving the increased muscle tone. Currently, only methocarbamol is approved and available for the 1st-line treatment of patients with muscle-related L/BP in Germany - however, without sufficient data on longer lasting effects (> 1 week) in elsewhere refractory patients.

METHOD

Noninterventional cohort study, based on anonymized routine data of the German pain practice registry; retrospective evaluation of patients with refractory L/BP, who first time received a treatment with methocarbamol between October 1st until December 31st, 2015, and who documented their response to treatment with the standardized and validated instruments of the German pain questionnaire over at least 4 weeks (n = 251 patients).

RESULTS

During the 4-week evaluation period, patients reported a highly significant and clinically relevant improvement of pain intensity (from 53.0 ± 10.5 to 19.0 ± 10.0 mm VAS), pain-related disability in daily life (mPDI: from 42.1 ± 12.5 to 15.5 ± 10.8) and quality of life (QLIP: from 18.6 ± 6.3 to 34.0 ± 5.5; all changes p < 0.001 vs. baseline). Corresponding 50% response rates were 81.7 (n = 205), 68.5 (n = 172) und 91.6 (n = 230) %. In parallel, lumbar mobility (measured with the Schober's test) improved from 10.7 ± 0.7 to 14.7 ± 0.7 cm (p < 0,001). Overall, seven patients recorded eight minor treatment-related adverse events, which all resolved spontaneously during treatment without any specific countermeasures.

CONCLUSION

Under the conditions of daily life, patients with elsewhere refractory L/BP reported a significant and clinically relevant improvement of pain intensity, pain-related disability and quality of life in response to a 4-week treatment with methocarbamol.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Impact of Treatment with Naloxegol for Opioid-Induced Constipation on Patients' Health State Utility

Introduction

Opioid-induced constipation (OIC) is the most common side effect of opioid treatment. Treatment for OIC typically involves a laxative. However, some patients have an inadequate response to these (laxative inadequate responders, or LIR). This has led to the development of treatments such as naloxegol. This analysis estimates the impact of naloxegol on the health state utility of LIR patients, examines if this utility impact is driven by the change in OIC status, and estimates the utility impact of relief of OIC.

Methods

The analysis was conducted using data from two 12-week randomized controlled trials, KODIAC 4 (ClinicalTrials.gov identifier, NCT01309841) and KODIAC 5 (ClinicalTrials.gov identifier, NCT01323790), plus KODIAC 7 (ClinicalTrials.gov identifier, NCT01395524), a 12-week extension to KODIAC 4. All were designed to assess the efficacy and safety of oral naloxegol (12.5 and 25 mg) compared to placebo. Health state utility data were collected through the EuroQol—five dimensions questionnaire (EQ-5D-3L). Descriptive analysis was undertaken to estimate how EQ-5D utility scores and EQ-5D domain responses varied with treatment, OIC status, and over time. A repeated measure mixed-effects model was used to predict the change from baseline in health state utility score over time.

Results

Compared with placebo, LIR patients treated with naloxegol 25 mg reported a 0.08 improvement in the EQ-5D overall score after 12 weeks of treatment. The analyses also suggest that change in OIC status is a key driver of the impact of OIC treatment on health state utility. When other factors are controlled, relieving OIC is associated with a 0.05 improvement in health state utility, although treatment with naloxegol is associated with an improvement in health state utility over and above the improvement in OIC status.

Conclusion

These analyses suggest that treatment with naloxegol improves patients’ health state utility; driven predominantly by the relief of patients’ constipation.

Funding

AstraZeneca.

Pharmacokinetic and pharmacodynamic evaluation of oxycodone and naltrexone for the treatment of chronic lower back pain

INTRODUCTION

Chronic low back pain (CLBP) is a common and difficult illness to manage. Some individuals with CLBP have pain processing disorders and are also at risk for opioid abuse, misuse; addiction and diversion. Guidelines have been published to guide management; neuromodulation, exercise, mindfulness-based stress reduction and cognitive behavior therapies among other non-pharmacological reduce the pain of CLBP with minimal toxicity. Pharmacological management includes acetaminophen, NSAIDs and antidepressants, mainly duloxetine. Abuse-deterrent opioids have been developed which have been shown to reduce pain and opioid abuse risk. ALO-02 is a tamper-resistant sustained release opioid consisting of extended release oxycodone and sequestered naltrexone. Pivotal studies of ALO-02 have centered on patients with CLBP.

AREAS COVERED

This manuscript will review CLBP, the pivotal analgesic and clinical abuse potential studies of ALO-02. The opinion will cover whether opioids should be used for CLBP, when they should be used and opioid choices.

EXPERT OPINION

ALO-02 is one of several opioids which can be considered in the management of CLBP. The outcome to a trial of opioids should be function rather than analgesia. Most analgesic trials for CLBP have had analgesia as the primary outcome and function has not been vigorously studied as an outcome. Opioids should be considered as a trial only when other non-opioid analgesics have failed to improve analgesia and function. Universal precautions should be routinely part of phase III analgesic trial particularly for chronic non-malignant pain.

Quality of life under oxycodone/naloxone, oxycodone, or morphine treatment for chronic low back pain in routine clinical practice

OBJECTIVE

To compare the quality of life of patients with moderate-to-severe chronic low back pain under treatment with the WHO-step III opioids oxycodone/naloxone, oxycodone, or morphine in routine clinical practice.

STUDY DESIGN

Prospective, 12-week, randomized, open-label, blinded end-point study in 88 medical centers in Germany.

PATIENTS AND METHODS

A total of 901 patients requiring around-the-clock pain treatment with a WHO-step III opioid were randomized to either morphine, oxycodone, or oxycodone/naloxone (1:1:1). Changes from baseline to week 12 in quality of life were assessed using different validated tools (EuroQoL-5 Dimensions [EQ-5D], Short Form 12 [SF-12], quality of life impairment by pain inventory [QLIP]).

RESULTS

EQ-5D weighted index scores significantly improved over the 12-week treatment period under all three opioids (P<0.001) with significantly greater improvements under oxycodone/naloxone (65.2% vs 49.6% for oxycodone and 48.2% for morphine, P<0.001). The proportion of patients without EQ-5D complaints was also significantly higher under oxycodone/naloxone (P<0.001). Although quality of life ratings with the QLIP inventory showed significant improvements in all the three treatment arms, improvements were significantly higher under oxycodone/naloxone than under oxycodone and morphine (P<0.001): 90.7% of all oxycodone/naloxone patients achieved ≥30% improvements in quality of life, 72.8% had ≥50%, and 33.2% ≥70% improvements. Similarly, both physical and mental SF-12 component scores showed significantly greater improvements under oxycodone/naloxone with both scores close to the German population norm after 12 weeks.

CONCLUSION

Treatment with morphine, oxycodone, or oxycodone/naloxone under routine daily practice conditions significantly improved state of health and quality of life of patients with moderate-to-severe low back pain over a 12-week treatment period. Comparison between the treatment groups showed significantly greater improvements for oxycodone/naloxone than for the other two opioids.

Expression and physiology of opioid receptors in the gastrointestinal tract

PURPOSE OF REVIEW

Stimulation of opioid receptors elicits analgesic effect not only in the central nervous system, but also in the gastrointestinal tract, where a high concentration of opioid receptors can be found within the enteric nervous system as well as muscular and immune cells. Along with antinociception, opioid receptors in the stomach and intestine relay signals crucial for secretory and motor gastrointestinal function.

RECENT FINDINGS

The review focuses on the utility of opioid receptor antagonists, which is generally contributing to the management of postoperative ileus and opioid bowel dysfunction in chronic pain patients nonetheless, opioid receptor antagonists can also be useful in the treatment of irritable bowel syndrome and chronic idiopathic constipation. The study also discusses several antidiarrheal opioid agonists, as well as opioids and opioid mimetics encompassing the concept of ligand-biased agonism and truncated opioid receptor splice variants.

SUMMARY

Good understanding of the localization and the role of opioid receptors is vital for regulation of various pathophysiological processes in the gastrointestinal tract and may simultaneously provide a tempting approach in eliminating adverse effects related to centrally acting opioids.