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Expert Opinion on Pharmacotherapy Feb 2023With the growing rate of aging and the incidence of chronic diseases, there has been an upsurge in opioid prescription and abuse worldwide. This has been associated with...
INTRODUCTION
With the growing rate of aging and the incidence of chronic diseases, there has been an upsurge in opioid prescription and abuse worldwide. This has been associated with increased reports of opioid-related adverse events, particularly opioid-induced bowel dysfunction (OIBD), calling for a rational clinical management strategy.
AREAS COVERED
Through searching PubMed, Scopus, Cochrane Library, and Web of Science, English literature was gathered as of 1 January 2017. Furthermore, the USFDA, EMA, TGA, Clinicaltrials.Gov, WHO-ICTRP databases, and the latest guidelines were reviewed to extract ongoing clinical studies and provide an evidence-based expert opinion with detailed information on efficacy, safety, approval status, and pharmacokinetics of the currently used medications.
EXPERT OPINION
Despite the significant burden of OIBD, the clinical development of agents lags behind disease progress. Although in most places, management of opioid-induced constipation (OIC) is initiated by lifestyle modifications followed by laxatives, opioid antagonists, and secretagogue agents, there are still major conflicts among global guidelines. The fundamental reason is the lack of head-to-head clinical trials providing inter- and intragroup comparisons between PAMORAs, laxatives, and secretagogue agents. These investigations must be accompanied by further valid biopharmaceutical and economic evaluations, paving the way for rational clinical judgment in each context.
Topics: Humans; Analgesics, Opioid; Laxatives; Constipation; Opioid-Induced Constipation; Secretagogues; Receptors, Opioid, mu; Narcotic Antagonists
PubMed: 36548911
DOI: 10.1080/14656566.2022.2161883 -
The Medical Letter on Drugs and... Dec 2022
Topics: Humans; Analgesics, Opioid; Pain; Oxycodone; Morphine
PubMed: 36541938
DOI: No ID Found -
Journal of Clinical Gastroenterology Jan 2023Opioid-induced constipation (OIC) is a common condition in older adults who may not be responsive to traditional laxative therapy. OIC is defined as new or worsening... (Review)
Review
Opioid-induced constipation (OIC) is a common condition in older adults who may not be responsive to traditional laxative therapy. OIC is defined as new or worsening constipation symptoms that occur with initiation of or altering the dose of opioid analgesia. For adult patients with OIC and noncancer pain, we recommend considering nonpharmacologic interventions (eg, dietary measures, increased physical activity, and biofeedback training) and over-the-counter laxatives, followed by prescription opioid receptor antagonists (methylnaltrexone, naloxegol, and naldemedine) if traditional over-the-counter laxatives fail. Other options may include lubiprostone, linaclotide, plecanatide, and prucalopride; however, these are not indicated for OIC specifically or studied in older adults. Because of the complex nature of absorption, distribution, metabolism, and excretion in the aging population, all agents used to treat OIC must be evaluated individually and reevaluated as patients continue to age. This review will serve as a guide to managing OIC in older adults.
Topics: Humans; Aged; Opioid-Induced Constipation; Analgesics, Opioid; Constipation; Laxatives; Aging
PubMed: 36504229
DOI: 10.1097/MCG.0000000000001801 -
American Journal of Health-system... May 2023Peripherally acting μ-opioid receptor antagonists (PAMORAs) are indicated to treat laxative-refractory opioid-induced constipation (OIC). While several PAMORAs exist,...
PURPOSE
Peripherally acting μ-opioid receptor antagonists (PAMORAs) are indicated to treat laxative-refractory opioid-induced constipation (OIC). While several PAMORAs exist, no head-to-head comparative data are available. This study evaluated the efficacy, safety, and cost of oral naloxegol vs subcutaneous methylnaltrexone for OIC in the hospital.
METHODS
In this multicenter retrospective chart review, patients who received oral naloxegol or subcutaneous methylnaltrexone as an inpatient were included if they were at least 18 years old, were still admitted to the hospital 48 hours after the first PAMORA dose, and either had an outpatient opioid prescription or received at least 30 morphine milligram equivalents in the 24 hours before the first PAMORA dose. The primary outcome was achievement of a bowel movement (BM) within 48 hours of the first dose. Secondary outcomes included a BM in 24 hours, time to the first BM, antimotility agent use, PAMORA cost per patient, and use of a second PAMORA due to failure of the first agent.
RESULTS
A total of 330 patients were included with 2:1 allocation (220 patients receiving methylnaltrexone vs 110 patients receiving naloxegol). Baseline characteristics were similar between the groups, except for body mass index and weight. Naloxegol met a prespecified noninferiority margin of 15% in production of a BM within 48 hours (risk difference, -4.6%; 90% confidence interval, -13.6% to 4.5%; P = 0.028). Achievement of a BM within 24 hours and time to first BM were also noninferior. Antimotility agent use was higher with naloxegol, naloxegol cost $193.16 less per patient, and 2 patients switched from naloxegol to methylnaltrexone.
CONCLUSION
Oral naloxegol may be an effective, cost-efficient alternative to subcutaneous methylnaltrexone for treatment of OIC in the hospital setting.
Topics: Humans; Adolescent; Analgesics, Opioid; Opioid-Induced Constipation; Retrospective Studies; Constipation; Narcotic Antagonists; Hospitals
PubMed: 36440903
DOI: 10.1093/ajhp/zxac356 -
The Annals of Pharmacotherapy Jul 2023Opioid-induced constipation (OIC) may occur in up to 81% of critically ill patients and can lead to many complications. Opioid antagonists are a reasonable approach and...
BACKGROUND
Opioid-induced constipation (OIC) may occur in up to 81% of critically ill patients and can lead to many complications. Opioid antagonists are a reasonable approach and may be used for managing OIC.
OBJECTIVE
The purpose of this study was to assess the efficacy of enteral naloxone (NLX) versus subcutaneous methylnaltrexone (MNTX) for the management of OIC in critically ill patients.
METHODS
A retrospective analysis was conducted on adult patients who received NLX or MNTX and a continuous opioid infusion for at least 48 hours. The primary end point was time to resolution of constipation, defined as hours to first bowel movement (BM) after the first dose of an opioid antagonist. Reversal of analgesia was assessed by comparing the total number of morphine milligram equivalents (MME) 24 hours preopioid and postopioid antagonist administration. Univariate and multivariate analyses were conducted to assess treatment response within 48 hours.
RESULTS
Baseline characteristics were similar between patients receiving NTX (n = 89) and MNTX (n = 71). However, the time to the first BM with NLX was 18 hours compared with 41 hours with MNTX ( = 0.004). There was no difference in MME requirements 24 hours pre/post NLX or MNTX administration. Naloxone administration was identified as a statistically significant predictor of BM within 48 hours (odds ratio [OR] = 2.68 [1.33-5.38]).
CONCLUSION AND RELEVANCE
The time to first BM was shorter with enteral NLX. Both NLX and MNTX appear to be effective for the management of OIC without causing reversal of analgesia. Future controlled, prospective trials comparing these agents are warranted.
Topics: Adult; Humans; Naloxone; Analgesics, Opioid; Opioid-Induced Constipation; Critical Illness; Retrospective Studies; Prospective Studies; Constipation; Naltrexone; Narcotic Antagonists; Quaternary Ammonium Compounds; Pain
PubMed: 36314271
DOI: 10.1177/10600280221132851 -
The Cochrane Database of Systematic... Sep 2022Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events... (Review)
Review
BACKGROUND
Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events (AEs) of treatment for pain in cancer and palliative care, resulting in increased morbidity and reduced quality of life. This review is a partial update of a 2008 review, and critiques as previous update (2018) trials only for people with cancer and people receiving palliative care.
OBJECTIVES
To assess for OIBD in people with cancer and people receiving palliative care the effectiveness and safety of mu-opioid antagonists (MOAs) versus different doses of MOAs, alternative pharmacological/non-pharmacological interventions, placebo, or no treatment.
SEARCH METHODS
We searched CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science (December 2021), clinical trial registries and regulatory websites. We sought contact with MOA manufacturers for further data.
SELECTION CRITERIA
Randomised controlled trials (RCTs) assessing the effectiveness and safety of MOAs for OIBD in people with cancer and people at a palliative stage irrespective of the type of terminal disease.
DATA COLLECTION AND ANALYSIS
Two review authors assessed risk of bias and extracted data. The appropriateness of combining data from the trials depended upon sufficient homogeneity across trials. Our primary outcomes were laxation response, effect on analgesia, and AEs. We assessed the certainty of evidence using GRADE and created summary of findings tables.
MAIN RESULTS
We included 10 studies (two new trials) randomising in-total 1343 adults with cancer irrespective of stage, or at palliative care stage of any disease. The MOAs were oral naldemedine and naloxone (alone or in combination with oxycodone), and subcutaneous methylnaltrexone. The trials compared MOAs with placebo, MOAs at different doses, or in combination with other drugs. Two trials of naldemedine and three of naloxone with oxycodone were in people with cancer irrespective of disease stage. The trial on naloxone alone was in people with advanced cancer. Four trials on methylnaltrexone were in palliative care where most participants had advanced cancer. All trials were vulnerable to biases; most commonly, blinding of the outcome assessor was not reported. Oral naldemedine versus placebo Risk (i.e. chance) of spontaneous laxations in the medium term (over two weeks) for naldemedine was over threefold greater risk ratio (RR) 2.00, 95% confidence interval (CI) 1.59 to 2.52, 2 trials, 418 participants, I² = 0%. Number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 3 to 4; moderate-certainty evidence). Earlier risk of spontaneous laxations and patient assessment of bowel change was not reported. Very low-certainty evidence showed naldemedine had little to no effect on opioid withdrawal symptoms. There was little to no difference in the risk of serious (non-fatal) AEs (RR 3.34, 95% CI 0.85 to 13.15: low-certainty evidence). Over double the risk of AEs (non-serious) reported with naldemedine (moderate-certainty evidence). Low-dose oral naldemedine versus higher dose Risk of spontaneous laxations was lower for the lower dose (medium term, 0.1 mg versus 0.4 mg: RR 0.69, 95% CI 0.53 to 0.89, 1 trial, 111 participants (low-certainty evidence)). Earlier risk of spontaneous laxations and patient assessment of bowel change not reported. Low-certainty evidence showed little to no difference on opioid withdrawal symptoms (0.1 mg versus 0.4 mg mean difference (MD) -0.30, 95% CI -0.85 to 0.25), and occurrences of serious AEs (0.1 mg versus 0.4 mg RR 0.25, 95% CI 0.03 to 2.17). Low-certainty evidence showed little to no difference on non-serious AEs. Oral naloxone versus placebo Risk of spontaneous laxations and AEs not reported. Little to no difference in pain intensity (very low-certainty evidence). Full data not given. The trial reported that no serious AEs occurred. Oral naloxone + oxycodone versus oxycodone Risk of spontaneous laxations within 24 hours and in the medium term not reported. Low-certainty evidence showed naloxone with oxycodone reduced the risk of opioid withdrawal symptoms. There was little to no difference in the risk of serious (non-fatal) AEs (RR 0.68, 95% CI 0.44 to 1.06), 3 trials, 362 participants, I² = 55%: very low-certainty evidence). There was little to no difference in risk of AEs (low-certainty evidence). Subcutaneous methylnaltrexone versus placebo Risk of spontaneous laxations within 24 hours with methylnaltrexone was fourfold greater than placebo (RR 2.97, 95% CI 2.13 to 4.13. 2 trials, 287 participants, I² = 31%. NNTB 3, 95% CI 2 to 3; low-certainty evidence). Risk of spontaneous laxations in the medium term was over tenfold greater with methylnaltrexone (RR 8.15, 95% CI 4.76 to 13.95, 2 trials, 305 participants, I² = 47%. NNTB 2, 95% CI 2 to 2; moderate-certainty evidence). Low-certainty evidence showed methylnaltrexone reduced the risk of opioid withdrawal symptoms, and did not increase risk of a serious AE (RR 0.59, 95% CI 0.38 to 0.93. I² = 0%; 2 trials, 364 participants). The risk of AEs was higher for methylnaltrexone (low-certainty evidence). Lower-dose subcutaneous methylnaltrexone versus higher dose There was little to no difference in risk of spontaneous laxations in the medium-term (1 mg versus 5 mg or greater: RR 2.91, 95% CI 0.82 to 10.39; 1 trial, 26 participants very low-certainty evidence), or in patient assessment of improvement in bowel status (RR 0.98, 95% CI 0.71 to 1.35, 1 trial, 102 participants; low-certainty evidence). Medium-term assessment of spontaneous laxations and serious AEs not reported. There was little to no difference in symptoms of opioid withdrawal (MD -0.25, 95% CI -0.84 to 0.34, 1 trial, 102 participants) or occurrence of AEs (low-certainty evidence).
AUTHORS' CONCLUSIONS
This update's findings for naldemedine and naloxone with oxycodone have been strengthened with two new trials, but conclusions have not changed. Moderate-certainty evidence for oral naldemedine on risk of spontaneous laxations and non-serious AEs suggests in people with cancer that naldemedine may improve bowel function over two weeks and increase the risk of AEs. There was low-certainty evidence on serious AEs. Moderate-certainty evidence for methylnaltrexone on spontaneous laxations over two weeks suggests subcutaneous methylnaltrexone may improve bowel function in people receiving palliative care, but certainty of evidence for AEs was low. More trials are needed, more evaluation of AEs, outcomes patients rate as important, and in children.
Topics: Adult; Analgesics, Opioid; Child; Humans; Naloxone; Naltrexone; Narcotic Antagonists; Neoplasms; Opioid-Induced Constipation; Oxycodone; Palliative Care; Quaternary Ammonium Compounds; Substance Withdrawal Syndrome
PubMed: 36106667
DOI: 10.1002/14651858.CD006332.pub4 -
Pain Medicine (Malden, Mass.) Mar 2023Preclinical and clinical studies suggest that activation of the µ-opioid receptor may reduce overall survival and increase the risk for all-cause mortality in patients... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Preclinical and clinical studies suggest that activation of the µ-opioid receptor may reduce overall survival and increase the risk for all-cause mortality in patients with cancer and noncancer pain. Methylnaltrexone, a selective, peripherally acting µ-opioid receptor antagonist, has demonstrated efficacy for the treatment of opioid-induced constipation. This retrospective analysis of 12 randomized, double-blind, placebo-controlled studies of methylnaltrexone evaluated the treatment of opioid-induced bowel disorders in patients with advanced illness or noncancer pain.
METHODS
The risk of all-cause mortality within 30 days after the last dose of study medication during the double-blind phase was compared between methylnaltrexone and placebo groups. The data were further stratified by cancer vs noncancer, age, gender, and acute vs chronic diagnoses.
RESULTS
Pooled data included 2,526 methylnaltrexone-treated patients of which 33 died, and 1,192 placebo-treated patients of which 35 died. The mortality rate was 17.8 deaths/100 person-years of exposure in the methylnaltrexone group and 49.5 deaths/100 person-years of exposure for the placebo group. The all-cause mortality risk was significantly lower among patients receiving methylnaltrexone compared with placebo (hazard ratio: 0.399, 95% confidence interval: 0.25, 0.64; P = .0002), corresponding to a 60% risk reduction. Significant risk reductions were observed for those receiving methylnaltrexone who had cancer or chronic diagnoses. Methylnaltrexone-treated patients had a significantly reduced mortality risk compared with placebo regardless of age or gender.
CONCLUSIONS
Methylnaltrexone reduced all-cause mortality vs placebo treatment across multiple trials, suggesting methylnaltrexone may confer survival benefits in patients with opioid-induced bowel disorders taking opioids for cancer-related or chronic noncancer pain.
Topics: Humans; Analgesics, Opioid; Retrospective Studies; Constipation; Chronic Pain; Naltrexone; Narcotic Antagonists; Double-Blind Method; Randomized Controlled Trials as Topic
PubMed: 36102822
DOI: 10.1093/pm/pnac136 -
Current Oncology Reports Oct 2022Antagonists of mu-opioid receptor role in cancer progression remains to be elucidated. The objective of this review was to summarize the available evidence on... (Review)
Review
PURPOSE OF REVIEW
Antagonists of mu-opioid receptor role in cancer progression remains to be elucidated. The objective of this review was to summarize the available evidence on antagonists of mu-opioid receptor effect on tumor progression and prognosis in different types of cancers and an evaluation of the available findings on their mechanism of action.
RECENT FINDINGS
We have found studies related to methylnaltrexone (MNTX) and naltrexone (NTX) usage in cancer outcomes-related setting. We found consistent preclinical evidence of a potential action of MNTX and NTX on cancer growth and spread mediated mainly by effect on the opioid growth factor receptor (OGFr) axis, which results in depressed cell replication. However, clinical results are scarce and limited to poor-quality evidence. Further high-quality studies are warranted to study antagonists of mu-opioid receptor role as a therapeutic option in different types of cancer, especially in patients where the classical treatment causes unacceptable side effects.
Topics: Cell Proliferation; Humans; Naltrexone; Narcotic Antagonists; Neoplasms; Quaternary Ammonium Compounds; Receptors, Opioid
PubMed: 35648340
DOI: 10.1007/s11912-022-01295-z -
Experimental Cell Research Sep 2022Acute respiratory distress syndrome (ARDS), a severe medical condition, is among the major causes of death in critically ill patients. Morphine is used as a therapeutic...
PURPOSE
Acute respiratory distress syndrome (ARDS), a severe medical condition, is among the major causes of death in critically ill patients. Morphine is used as a therapeutic agent against severe pain. The mechanisms of its reactions over ARDS are not fully understood. The aim of this study was to assess the mechanism of morphine in rats with ARDS.
METHODS
Rats were injected with lipopolysaccharide to induce ARDS, and some rats were pre-treated with graded doses of morphine in the lateral ventricles to assess survival and non-infected mortality. Immunohistochemical and HE staining were performed to measure MPO and CD68 activity in the lungs and lung injury. ELISA was conducted to detect the inflammatory factor levels in the plasma and BALF. Co-labeling of μ-opioid receptor (MOR) and c-Fos was observed in the brain tissues. MOR-positive cells in brain tissues were evaluated using immunohistochemistry. The effect of MOR antagonists on ARDS was examined in rats by pre-injection of naloxone or methylnaltrexone. The expression of MyD88, TLR4, and NF-κB was lastly assessed.
RESULTS
Dose-independent improvement was observed in respiratory capacity and lung injury in ARDS rats after morphine pre-injection, along with reduced inflammatory factors in the plasma and BALF. MOR-positive cells were elevated after morphine, which occurred within the ventral part of the gigantocellular reticular nucleus (GiV). Naloxone and methylnaltrexone blocked the effects of morphine via central and peripheral MOR. Morphine activated TLR pathway in a MyD88-dependent manner.
CONCLUSION
Morphine activates MOR within the GiV and the TLR pathway to attenuate ARDS in rats.
Topics: Animals; Lipopolysaccharides; Lung Injury; Morphine; Myeloid Differentiation Factor 88; Naloxone; Rats; Receptors, Opioid; Respiratory Distress Syndrome
PubMed: 35643178
DOI: 10.1016/j.yexcr.2022.113224 -
The Journal of Pediatric Pharmacology... 2022To evaluate the association between methylnaltrexone and urine output (UOP) in critically ill children with opioid-associated urinary retention.
OBJECTIVE
To evaluate the association between methylnaltrexone and urine output (UOP) in critically ill children with opioid-associated urinary retention.
METHODS
This retrospective study included patients admitted to the pediatric intensive care unit between December 1, 2019, and November 30, 2020, who received methylnaltrexone for opioid-associated oliguria (spontaneous UOP below 1 mL/kg/hr and at least 1 dose of an opioid within the preceding 6 hours).
RESULTS
Twenty-five patients (median age = 5.5 years, IQR 1.7-16.4; median weight = 19 kg, IQR 9-45) were included. Mean methylnaltrexone dose was 0.15 ± 0.006 mg/kg. A statistically significant increase in UOP from baseline to 6 hours following methylnaltrexone was observed (p = 0.001), but not all patients responded. Fourteen patients (56%) had no UOP following methylnaltrexone administration, while 11 (44%) demonstrated a robust increase (median = 0 mL/kg/hr at baseline [IQR 0-0] to 1.96 mL/kg/hr [IQR 1.08-2.22; p = 0.001]) within 6 hours following methylnaltrexone administration. Younger patients responded better than older patients (responder age = 2.5 years [IQR 0.8-7]) versus 11.4 years [IQR 1.75-17.5] for non-responders) (p = 0.04). Both intravenous (IV) and subcutaneous (SQ) routes were associated with an increase in UOP (IV, p = 0.04; SQ, p = 0.02). The effect persisted for up to 24 hours after administration. Sixty-four percent of patients required urinary catheter placement. Pain scores (averaged 6 hours before and after methylnaltrexone) remained unchanged (p = 0.44).
CONCLUSIONS
Methylnaltrexone may increase spontaneous UOP in some children with opioid-associated urinary retention, but urinary catheterization rates remain high.
PubMed: 35558358
DOI: 10.5863/1551-6776-27.4.373