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Trials Dec 2021Moderate to severe acute pancreatitis (AP) is associated with a high rate of complications and increased mortality, yet no targeted pharmacologic treatment currently...
Effects of the peripherally acting μ-opioid receptor antagonist methylnaltrexone on acute pancreatitis severity: study protocol for a multicentre double-blind randomised placebo-controlled interventional trial, the PAMORA-AP trial.
BACKGROUND
Moderate to severe acute pancreatitis (AP) is associated with a high rate of complications and increased mortality, yet no targeted pharmacologic treatment currently exists. As pain is a dominant symptom in AP, patients are exposed to excess levels of both endo- and exogenous opioids, which may have harmful effects on the course of AP. This trial investigates the effects of the peripherally acting μ-opioid receptor antagonist (PAMORA) methylnaltrexone on disease severity and clinical outcomes in patients with moderate to severe AP.
METHODS
PAMORA-AP is a multicentre, investigator-initiated, double-blind, randomised, placebo-controlled, interventional trial, which will be conducted at four referral centres for acute pancreatitis in Denmark. Ninety patients with early-onset AP (pain onset within 48 h) as well as predicted moderate to severe disease (two or more systemic inflammatory response syndrome criteria upon admission) will be prospectively included. Subsequently, participants will be randomised (1:1) to intravenous treatment with either methylnaltrexone or matching placebo (Ringer's lactate) during 5 days of admission. The primary endpoint will be the group difference in disease severity as defined and measured by the Pancreatitis Activity Scoring System (PASS) score 48 h after randomisation. Secondary endpoints include daily PASS scores; disease severity according to the Atlanta classification; quantification of need for analgesics, nutritional support, intravenous fluid resuscitation and antibiotics; duration of hospital admissions, readmission rates and mortality. Pain intensity and gut function will be self-reported using validated questionnaires. Exploratory endpoints include circulating levels of pro-and anti-inflammatory markers, polyethylene glycol recovery from the urine, circulating levels of blood markers of intestinal permeability, the prevalence of pancreatic complications on computed tomography (CT) scans, and colon transit time assessed using a CT-based radiopaque marker method.
DISCUSSION
This trial aims to evaluate the PAMORA methylnaltrexone as a novel targeted pharmacotherapy in patients with moderate to severe AP with the potential benefit of improved patient outcomes.
TRIAL REGISTRATION
ClinicalTrials.gov NCT04743570 . Registered on 28 January 2021. EudraCT 2020-002313-18.
Topics: Acute Disease; Humans; Multicenter Studies as Topic; Naltrexone; Narcotic Antagonists; Pancreatitis; Quaternary Ammonium Compounds; Randomized Controlled Trials as Topic; Research Design
PubMed: 34924020
DOI: 10.1186/s13063-021-05885-3 -
The Journal of Emergency Medicine Feb 2022Opioid-induced constipation (OIC) is a frequent consequence of opioid analgesia that may increase patient risk for emergency department visits and hospitalization.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Opioid-induced constipation (OIC) is a frequent consequence of opioid analgesia that may increase patient risk for emergency department visits and hospitalization. Methylnaltrexone is a peripherally acting µ-opioid receptor antagonist indicated for the treatment of OIC.
OBJECTIVE
To assess the safety and efficacy of a single methylnaltrexone dose.
METHODS
Results were pooled from three randomized, placebo-controlled methylnaltrexone (MNTX) studies in opioid-treated patients with advanced illness and OIC, despite treatment with conventional laxatives. Baseline assessments included demographics, disease/treatment characteristics, and functional levels. Efficacy endpoints included rescue-free laxation (RFL) rates within 4 and 24 h, time to first RFL, pain score change, and adverse events (AEs) after a single MNTX dose or placebo.
RESULTS
The analysis included 281 patients receiving MNTX and 237 receiving placebo. Mean age was 66.2 years for MNTX and 65.8 for placebo; ∼50% were men. The most frequent primary diagnosis was cancer (MNTX = 70.5%; placebo = 66.2%) and most (∼98%) were receiving at least one laxative at baseline. RFL occurred in 61.4% vs. 16.0%, and 72.1% vs. 40.1% MNTX vs. placebo patients, within 4 and 24 h of the initial dose, respectively. Relative to placebo, MNTX use reduced the time to first RFL, with most MNTX-treated patients achieving RFL within 2 h. Baseline and posttreatment pain scores were similar (p = 0.9556 vs. placebo for current and worst pain change from baseline), demonstrating that MNTX did not negatively affect opioid analgesia. Most AEs were gastrointestinal related and dissipated by the second dose.
CONCLUSIONS
Methylnaltrexone provides early RFL without compromising analgesia in patients receiving chronic opioid therapy.
Topics: Aged; Analgesics, Opioid; Constipation; Humans; Male; Naltrexone; Opioid-Induced Constipation; Quaternary Ammonium Compounds
PubMed: 34893381
DOI: 10.1016/j.jemermed.2021.10.012 -
Cancer Cell International Nov 2021Morphine, a µ-opioid receptor (MOR) agonist, has been shown to be related to the activity of cancer cells, and a higher morphine dosage reduces the survival time of...
BACKGROUND
Morphine, a µ-opioid receptor (MOR) agonist, has been shown to be related to the activity of cancer cells, and a higher morphine dosage reduces the survival time of patients with lung cancer. However, the effect of morphine on the malignant behavior of lung cancer cells remains unclear. The aim of this study was to investigate the specific molecular mechanism by which morphine regulates the malignant biological behavior of non-small cell lung cancer.
METHODS
Immunofluorescence staining and Western blot analyses were performed to detect MOR expression. H460 non-small cell lung cancer cells were used in this study, and cell proliferation, the cell cycle and apoptosis were evaluated using Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. Cell migration and invasion were detected using wound healing and Transwell assays. The effect of morphine on lung cancer development in vivo was examined by performing a xenograft tumor assay following morphine treatment.
RESULTS
Morphine promoted the growth of H460 cells both in vivo and in vitro. Morphine enhanced cell migration and invasion, modified cell cycle progression through the S/G transition and exerted an antiapoptotic effect on H460 cells. Additionally, morphine increased Rous sarcoma oncogene cellular homolog (Src) phosphorylation and activated the phosphoinositide 3 kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Treatment with the MOR antagonist methylnaltrexone (MNTX) and the Src inhibitor protein phosphatase 1 (PP1) reduced the phosphorylation induced by morphine. Furthermore, MNTX, PP1, and the PI3K/AKT inhibitor deguelin reversed the antiapoptotic effect of morphine on lung cancer cells.
CONCLUSION
Morphine promotes the malignant biological behavior of H460 cells by activating the MOR and Src/mTOR signaling pathways.
PubMed: 34823532
DOI: 10.1186/s12935-021-02334-8 -
F1000Research 2021Opioids prescribed for the management of chronic noncancer pain are associated with nausea, vomiting, and constipation. Methylnaltrexone, a peripherally acting...
Attrition of methylnaltrexone treatment-emergent adverse events in patients with chronic noncancer pain and opioid-induced constipation: a post hoc pooled analysis of two clinical trials.
Opioids prescribed for the management of chronic noncancer pain are associated with nausea, vomiting, and constipation. Methylnaltrexone, a peripherally acting µ-opioid receptor antagonist, has demonstrated robust efficacy and was well-tolerated in treating opioid-induced constipation without affecting central analgesia. Our objective was to assess changes in the frequency of treatment-emergent adverse events (TEAEs) after the first or second dose of methylnaltrexone or placebo. This post hoc analysis pooled data from two randomized, placebo-controlled clinical trials assessing methylnaltrexone for opioid-induced constipation in the outpatient setting. Patients received subcutaneous methylnaltrexone (12 mg once daily or 12 mg once every other day), oral methylnaltrexone (150, 300, or 450 mg daily), or placebo. TEAEs, opioid withdrawal symptoms, pain intensity, and rescue-free bowel movements (RFBMs) within 4 hours of the first dose (i.e., RFBM responders) were assessed. Associations between TEAE frequencies and RFBM response were also evaluated. The analysis included 1263 adult patients with chronic noncancer pain. TEAE rates declined from treatment day 1 to 2 (methylnaltrexone: 16.2%-5.3%; placebo: 6.6%-5.4%). Among methylnaltrexone-treated patients, significantly greater proportions of RFBM responders versus nonresponders reported gastrointestinal TEAEs on day 1. No associations between RFBM response and the frequency of TEAEs were observed in the placebo group. No meaningful changes in opioid withdrawal symptoms or pain intensity were observed. Early-onset TEAEs following methylnaltrexone treatment, particularly gastrointestinal TEAEs, are at least partially due to laxation. Methylnaltrexone treatment effectively relieves opioid-induced constipation without affecting the central analgesic effects of opioids.
PubMed: 34631030
DOI: 10.12688/f1000research.51073.2 -
Journal of Pediatric Intensive Care Mar 2024Methylnaltrexone is U.S. Food and Drug Administration (FDA) approved as a subcutaneous injection for adults with opioid-induced constipation (OIC). Case series have...
Methylnaltrexone is U.S. Food and Drug Administration (FDA) approved as a subcutaneous injection for adults with opioid-induced constipation (OIC). Case series have described the use of methylnaltrexone for OIC in the pediatric oncology population. There are limited data describing its intravenous use in critically ill pediatric patients. We conducted a retrospective observational study at St. Louis Children's Hospital. Patients less than 18 years old who received at least one dose of intravenous methylnaltrexone while admitted to an intensive care unit between January 2016 and August 2019 were included. The primary outcome was documented laxation within 24 hours of methylnaltrexone administration. Sixteen patients received a total of 34 doses of intravenous methylnaltrexone. Patients received a median of 1.69 (interquartile range [IQR], 0.9-4.86) morphine milligram equivalents per kilogram per 24 hours, over a median of 14 days (IQR, 11-30), before methylnaltrexone administration. The median dose of methylnaltrexone was 0.15 mg/kg (IQR, 0.15-0.16). Ten patients (63%) responded to the first dose of methylnaltrexone, and 14 patients (88%) responded to at least one dose. Overall, 26 doses (76%) led to patient response. Four patients (25%) experienced adverse events (emesis, abdominal pain) after methylnaltrexone administration. No signs or symptoms of opioid withdrawal were documented. Intravenous methylnaltrexone appears to be safe and effective in treating OIC in critically ill pediatric patients. No serious adverse events or signs of opioid withdrawal were observed after single and repeat dosing. Patients responded to methylnaltrexone with varying opioid dosing and durations prior to administration.
PubMed: 38571990
DOI: 10.1055/s-0041-1736335 -
JCO Oncology Practice Feb 2022The financial toxicity of anticancer drugs is well-documented, but little is known about the costs of drugs used to manage cancer-associated symptoms. (Review)
Review
PURPOSE
The financial toxicity of anticancer drugs is well-documented, but little is known about the costs of drugs used to manage cancer-associated symptoms.
METHODS
We reviewed relevant guidelines and compiled drugs used to manage seven cancer-associated symptoms (anorexia and cachexia, chemotherapy-induced peripheral neuropathy, constipation, diarrhea, exocrine pancreatic insufficiency, cancer-associated fatigue, and chemotherapy-induced nausea and vomiting). Using GoodRx website, we identified the retail price (cash price at retail pharmacies) and lowest price (discounted, best-case scenario of out-of-pocket costs) for patients without insurance for each drug or formulation for a typical fill. We describe lowest prices here.
RESULTS
For anorexia and cachexia, costs ranged from $5 US dollars (USD; generic olanzapine or mirtazapine tablets) to $1,156 USD (brand-name dronabinol solution) and varied widely by formulation of the same drug or dosage: for olanzapine 5 mg, $5 USD (generic tablet) to $239 USD (brand-name orally disintegrating tablet). For chemotherapy-induced peripheral neuropathy, costs of duloxetine varied from $12 USD (generic) to $529 USD (brand-name). For constipation, the cost of sennosides or polyethylene glycol was <$15 USD, whereas newer agents such as methylnaltrexone were expensive ($1,001 USD). For diarrhea, the cost of generic loperamide or diphenoxylate-atropine tablets was <$15 USD. For exocrine pancreatic insufficiency, only brand-name formulations were available, range of cost, $1,072 USD-$1,514 USD. For cancer-associated fatigue, the cost of generic dexamethasone or dexmethylphenidate was <$15 USD, whereas brand-name modafinil was more costly ($1,284 USD). For a 4-drug nausea and vomiting prophylaxis regimen, costs ranged from $181 USD to $1,430 USD.
CONCLUSION
We highlight the high costs of many symptom control drugs and the wide variation in the costs of these drugs. These findings can guide patient-clinician discussions about cost-effectively managing symptoms, while promoting the use of less expensive formulations when possible.
Topics: Antineoplastic Agents; Drug Costs; Drugs, Generic; Financial Stress; Humans; Neoplasms; Pharmacies
PubMed: 34558297
DOI: 10.1200/OP.21.00466 -
Journal of Pain Research 2021Methylnaltrexone inhibits opioid-induced constipation (OIC) by binding to peripheral µ-opioid receptors without impacting central opioid receptor mediated analgesia....
Subcutaneous Methylnaltrexone for Treatment of Opioid-Induced Constipation in Cancer versus Noncancer Patients: An Analysis of Efficacy and Safety Variables from Two Studies.
PURPOSE
Methylnaltrexone inhibits opioid-induced constipation (OIC) by binding to peripheral µ-opioid receptors without impacting central opioid receptor mediated analgesia. This analysis compared methylnaltrexone efficacy and safety among advanced illness patients with and without active cancer and OIC.
PATIENTS AND METHODS
This post hoc analysis included two multicenter, randomized, double-blind, placebo-controlled studies in adults with advanced illness and OIC who received subcutaneous methylnaltrexone. Efficacy endpoints included the proportion of patients achieving rescue-free laxation (RFL), time to RFL, weekly laxations within 24 hours after dosing, rescue laxative use, and pain scores. Adverse events were monitored for safety.
RESULTS
After pooling, 178 patients received methylnaltrexone (n = 116 with cancer) and 185 received placebo (n = 114 with cancer). Median baseline daily opioid morphine equivalents (mg/d) were higher in cancer (methylnaltrexone: 180; placebo: 188) versus noncancer patients (methylnaltrexone: 120; placebo: 80). The proportions of patients achieving RFL within 4 hours after ≥2 of the first 4 doses were significantly greater with methylnaltrexone (cancer: 56.9%; noncancer: 58.1%) versus placebo (cancer: 5.3%; noncancer: 11.3%; < 0.0001). The median time to laxation within 24 hours after the first methylnaltrexone dose was significantly shorter in cancer and noncancer patients versus placebo (cancer: 0.96 vs 22.53 hours, < 0.0001; noncancer: 1.25 vs >24 hours, = 0.0002). The mean number of weekly laxations within 24 hours after dosing by week 2 was significantly higher in methylnaltrexone- vs placebo-treated cancer and noncancer patients (cancer: 7.9 vs 4.9, < 0.0001; noncancer: 8.4 vs 5.0, < 0.0001). Methylnaltrexone reduced rescue laxative use without impacting pain scores. Consistent with previous data, methylnaltrexone was well tolerated in cancer and noncancer patients, and the AE profile did not suggest symptoms of opioid withdrawal.
CONCLUSION
Methylnaltrexone reduced RFL time in advanced-illness patients with and without active cancer, while maintaining pain control with opioid treatment despite higher baseline opioid use among cancer patients.
PubMed: 34512008
DOI: 10.2147/JPR.S312731 -
Cureus Jul 2021In treating chronic and acute pain, opioids are widely used. Although they do provide analgesia, their usage does come with adverse events (AEs). One of the most... (Review)
Review
In treating chronic and acute pain, opioids are widely used. Although they do provide analgesia, their usage does come with adverse events (AEs). One of the most burdensome is opioid-induced bowel dysfunction, and more specifically opioid-induced constipation (OIC). The pathogenesis of these AEs is well known as the consequence of the action of opioids on m-receptors in the enteric nervous system. In recent years, medicines counteracting this specific action at the receptors have been registered for clinical use: the peripherally acting μ-opioid receptor antagonists (PAMORAs). The knowledge of their comparative efficacy and tolerability is very important for physicians and patients in opioid therapy. This systematic review of the existing literature on PAMORAs aimed to study the relative clinical advantages and disadvantages. The most important data banks, including "PubMed," "Embase," "CT.gov," "ICTRP" and "CINAHL" were used to find the published material on PAMORAs. The selected publications were examined to systematically analyze the efficacy and safety of the four existing PAMORAs. All of the medications are superior to placebo in reducing OIC. There are few published data on alvimopan used to treat OIC, and it is only indicated for the treatment of post-abdominal surgery ileus. Methylnaltrexone is studied mainly in its subcutaneous (SC) formulation. When used in its oral formulation, it seems more rapid than naloxegol and placebo in the reduction of OIC. Naldemedine is able to produce more spontaneous bowel movements (SBMs) when compared to alvimopan and naloxegol. Tolerability was found to be similar for all of them. In particular, they affect the gastrointestinal tract (GI), with flatulence and diarrhea, especially at high dosages. For some of them, nasopharyngitis and abdominal pain were observed as treatment adverse effects (TEAs). Several cardiovascular TEAs were reported after methylnaltrexone use, but it is not clear whether they were consequences of the drug or related to the general conditions of the patients. Considering the existing data, naloxegol and naldemedine seem to be the best choices, with a higher number of spontaneous bowel movements following naldemedine administration.
PubMed: 34367804
DOI: 10.7759/cureus.16201 -
Scientific African Sep 2021The current crisis of the COVID-19 pandemic around the world has been devastating as many lives have been lost to the novel SARS CoV-2 virus. Thus, there is an urgent...
The current crisis of the COVID-19 pandemic around the world has been devastating as many lives have been lost to the novel SARS CoV-2 virus. Thus, there is an urgent need for the right therapeutic drug to curb the disease. However, there is time constraint in drug development, hence the need for drug repurposing approach, a relatively fast and less expensive alternative. In this study, 1,100 Food and Drug Administration (FDA) approved drugs were obtained from DrugBank and trimmed to 791 ligands based on illicitness, withdrawal from the market, being chemical agents rather than drugs, being investigational drugs and having molecular weight greater than 500 (Kg/mol). The ligands were docked against six drug targets of the novel SARS CoV-2 - 3-chymotrypsin-like protease (3CLpro), Angiotensin-converting enzyme (ACE2), ADP ribose phosphatase of NSP3 (NSP3), NSP9 RNA binding protein (NSP9), RNA dependent RNA polymerase (RdRp) and Replicase Polyprotein 1a (RP1a). UCSF Chimera, PyRx and Discovery Studio, were used to prepare the proteins, dock the ligands and visualize the complexes, respectively. Remdesivir, Lopinavir and Hydroxychloroquine were used as reference drugs. Pharmacokinetic properties of the ligands were obtained using AdmetSAR. The binding energies of the standard drugs ranged from -5.4 to -8.7 kcal/mol while over 400 of the ligands screened showed binding energy lower than -5.4 kcal/mol. Out of the 791 number of compounds docked, 10, 91, 132, 92, 54 and 96 compounds showed lower binding energies than all the controls against 3CLPro, ACE2, NSP3, NSP9, RP1a and RdRp, respectively. Ligands that bound all target proteins, and showed the lowest binding energies with good ADMET properties and particularly showed the lowest binding against ACE2 are ethynodiol diacetate (-15.6 kcal/mol), methylnaltrexone (-15.5 kcal/mol), ketazolam (-14.5 kcal/mol) and naloxone (-13.6 kcal/mol). Further investigations are recommended for ethynodiol diacetate, methylnaltrexone, ketazolam and naloxone through preclinical and clinical studies to ascertain their effectiveness.
PubMed: 34308004
DOI: 10.1016/j.sciaf.2021.e00845 -
American Journal of Physiology.... Oct 2021Remifentanil impairs swallowing, and disturbed accommodation to bolus volume may be one of the underlying causes. It is not fully understood whether remifentanil-induced... (Clinical Trial)
Clinical Trial
Remifentanil impairs swallowing, and disturbed accommodation to bolus volume may be one of the underlying causes. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. So, this study aimed to investigate if remifentanil-induced swallowing dysfunction is dependent on the bolus volume and whether the effect of remifentanil could be counteracted by methylnaltrexone, a peripherally acting opioid antagonist. Nineteen healthy volunteers were included in this double-blinded, randomized, placebo-controlled, crossover study. Study participants received target-controlled remifentanil infusions and placebo infusions in a randomized order. Methylnaltrexone was administered by intravenous injection of doses of 0.3 mg/kg. Recordings of pressure and impedance data were acquired using a combined manometry and impedance solid-state catheter. Data were analyzed from three series of bolus swallows, baseline, during study medication exposure, and 15 min after methylnaltrexone. Remifentanil induced significant effects on multiple pharyngeal and esophageal function parameters. No significant differences in remifentanil-induced swallowing dysfunction related to different bolus volumes were found. Pharyngeal effects of remifentanil were not significantly counteracted by methylnaltrexone, whereas on the distal esophageal level, effects on distension pressures were counteracted. Changes in pharyngeal and esophageal pressure flow variables were consistent with previous results on remifentanil-induced swallowing dysfunction and uniform across all bolus volumes. The effects of remifentanil on the pharyngeal level and on the proximal esophagus appear to be predominantly centrally mediated, whereas the effects of remifentanil on the distal esophagus may be mediated by both central and peripheral mechanisms. In this randomized controlled trial, we used the "Swallow Gateway" online platform to analyze the effects of remifentanil on pharyngeal and esophageal swallowing. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. By using methylnaltrexone, we demonstrated that effects of remifentanil on pharyngeal swallowing were predominantly centrally mediated, whereas its effects on the distal esophagus may be mediated by both central and peripheral mechanisms.
Topics: Adult; Analgesics, Opioid; Deglutition; Drug Antagonism; Esophagus; Female; Healthy Volunteers; Humans; Injections, Intravenous; Male; Muscle Contraction; Muscle Relaxation; Naltrexone; Narcotic Antagonists; Pharynx; Quaternary Ammonium Compounds; Remifentanil
PubMed: 34261364
DOI: 10.1152/ajpgi.00137.2021