Low-dose naltrexone for post-COVID fatigue syndrome: a study protocol for a double-blind, randomised trial in British Columbia.

INTRODUCTION: A significant proportion of individuals suffering from post COVID-19 condition (PCC, also known as long COVID) can present with persistent, disabling fatigue similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-viral fatigue syndromes. There remains no clear pharmacological therapy for patients with this subtype of PCC, which can be referred to as post-COVID fatigue syndrome (PCFS). A low dose of the opioid antagonist naltrexone (ie, low-dose naltrexone (LDN)) has emerged as an off-label treatment for treating fatigue and other symptoms in PCC. However, only small, non-controlled studies have assessed LDN in PCC, so randomised trials are urgently required. METHODS AND ANALYSIS: A prospective, randomised, double-blind, parallel arm, placebo-controlled phase II trial will be performed to assess the efficacy of LDN for improving fatigue in PCFS. The trial will be decentralised and open to eligible individuals throughout the Canadian province of British Columbia (BC). Participants will be recruited through the province-wide Post-COVID-19 Interdisciplinary Clinical Care Network (PC-ICCN) and research volunteer platform (REACH BC). Eligible participants will be 19-69 years old, have had a confirmed or physician-suspected SARS-CoV-2 infection at least 3 months prior and meet clinical criteria for PCFS adapted from the Institute of Medicine ME/CFS criteria. Individuals who are taking opioid medications, have a history of ME/CFS prior to COVID-19 or history of significant liver disease will be excluded. Participants will be randomised to an LDN intervention arm (n=80) or placebo arm (n=80). Participants in each arm will be prescribed identical capsules starting at 1 mg daily and follow a prespecified schedule for up-titration to 4.5 mg daily or the maximum tolerated dose. The trial will be conducted over 16 weeks, with assessments at baseline, 6, 12 and 16 weeks. The primary outcome will be fatigue severity at 16 weeks evaluated by the Fatigue Severity Scale. Secondary outcomes will include pain Visual Analogue Scale score, overall symptom severity as measured by the Patient Phenotyping Questionnaire Short Form, 7-day step count and health-related quality of life measured by the EuroQol 5-Dimension questionnaire. ETHICS AND DISSEMINATION: The trial has been authorised by Health Canada and approved by The University of British Columbia/Children's and Women's Health Centre of British Columbia Research Ethics Board. On completion, findings will be disseminated to patients, caregivers and clinicians through engagement activities within existing PCC and ME/CFS networks. Results will be published in academic journals and presented at conferences. TRIAL REGISTRATION NUMBER: NCT05430152.

A case of naltrexone-induced acute eosinophilic pneumonia.

Acute eosinophilic pneumonia (AEP) is a rare cause of acute respiratory failure. Clinical presentations can range from dyspnoea, fever and cough, to rapidly progressive and potentially fulminant respiratory failure. While its exact cause is often unknown, associations with inhalational injuries and exposures to new medications have been described.We report a case of a middle-aged, non-smoking man with a history of alcohol use disorder. He presented with 4 days of shortness of breath that started hours after taking injectable naltrexone (Vivitrol). The patient had rapidly worsening hypoxaemia, necessitating emergent bronchoscopy with transbronchial biopsies and bronchoalveolar lavage which showed 66% eosinophils. The patient was intubated for the procedure and unable to get extubated due to worsening hypoxaemic respiratory failure with high fractional inspired oxygen requirements. Chest radiograph showed worsening lung infiltrates and with a high index of suspicion for AEP, he was started empirically on methylprednisolone. He had rapid improvement in his respiratory status and was extubated on day 5 of admission then discharged on day 8. Histopathological examination confirmed acute/subacute eosinophilic pneumonia. A 3-week post-discharge follow-up chest radiograph confirmed the full resolution of pulmonary infiltrates.Naltrexone-induced AEP is rare, with only six other cases reported in the literature. Careful history taking and prompt evaluation for AEP are important given the potential for rapid progression to acute hypoxic respiratory failure and the excellent response to steroid treatment.

Bystander-application of a novel nasal swab optimized for drug delivery is safe and non-traumatic for the general population.

OBJECTIVE: The PN Naloxone Nasal Swab (Pocket Naloxone Corp., Bethesda, MD) is a swab optimized for drug delivery and intended for use by non-medical personnel for the emergency treatment of opioid overdose. The aim of this study (PNC-20-003) is to determine the safety of this nasal swab in a real-world environment. METHODS: This was a single-institution, quantitative-qualitative prospective trial performed at an outpatient clinic. Patients with normal or abnormal nasal structure were recruited. A non-medically trained individual placed the nasal (soaked in fluorescein dye) on each side of the patient's nose. Endoscopy with recording was performed before and after swab placement. An independent reviewer rated degree of staining, mucosal bleeding, and trauma at nasal subsites. RESULTS: Videos from 32 nasal cavities (16 participants) were reviewed. All cavities had high intensity staining at the septum and the inferior turbinate. No patients had staining within the middle meatus, agger nasi, or olfactory regions. In patients with normal anatomy, obstructive nasal anatomy or prior nasal surgery, all cavities had staining near the nasal septum. Only 7 cavities (22 %) had minor bleeding defined as ooze that stopped in 1-2min, and 3 (9 %) had minor trauma defined as mucosal disruption less than 5mm. There were no significant differences in comparing pre- and post-swab nasal cavity, trauma, or bleeding exams. CONCLUSIONS: These study results showed that this swab is atraumatic to the nasal mucosal membranes when administered by non-medical personnel. Analysis suggests contact with targeted sites for drug absorption regardless of anatomy.

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

BACKGROUND: Cancer-related pain often requires opioid treatment with opioid-induced constipation (OIC) as its most frequent gastrointestinal side-effect. Both for prevention and treatment of OIC osmotic (e.g. polyethylene glycol) and stimulant (e.g. bisacodyl) laxatives are widely used. Newer drugs such as the peripherally acting µ-opioid receptor antagonists (PAMORAs) and naloxone in a fixed combination with oxycodone have become available for the management of OIC. This systematic review and meta-analysis aims to give an overview of the scientific evidence on pharmacological strategies for the prevention and treatment of OIC in cancer patients. METHODS: A systematic search in PubMed, Embase, Web of Science and the Cochrane Library was completed from inception up to 22 October 2022. Randomized and non-randomized studies were systematically selected. Bowel function and adverse drug events were assessed. RESULTS: Twenty trials (prevention: five RCTs and three cohort studies; treatment: ten RCTs and two comparative cohort studies) were included in the review. Regarding the prevention of OIC, three RCTs compared laxatives with other laxatives, finding no clear differences in effectivity of the laxatives used. One cohort study showed a significant benefit of magnesium oxide compared with no laxative. One RCT found a significant benefit for the PAMORA naldemedine compared with magnesium oxide. Preventive use of oxycodone/naloxone did not show a significant difference in two out of three other studies compared to oxycodone or fentanyl. A meta-analysis was not possible. Regarding the treatment of OIC, two RCTs compared laxatives, of which one RCT found that polyethylene glycol was significantly more effective than sennosides. Seven studies compared an opioid antagonist (naloxone, methylnaltrexone or naldemedine) with placebo and three studies compared different dosages of opioid antagonists. These studies with opioid antagonists were used for the meta-analysis. Oxycodone/naloxone showed a significant improvement in Bowel Function Index compared to oxycodone with laxatives (MD -13.68; 95 % CI -18.38 to -8.98; I2 = 58 %). Adverse drug event rates were similar amongst both groups, except for nausea in favour of oxycodone/naloxone (RR 0.51; 95 % CI 0.31-0.83; I2 = 0 %). Naldemedine (NAL) and methylnaltrexone (MNTX) demonstrated significantly higher response rates compared to placebo (NAL: RR 2.07, 95 % CI 1.64-2.61, I2 = 0 %; MNTX: RR 3.83, 95 % CI 2.81-5.22, I2 = 0 %). With regard to adverse events, abdominal pain was more present in treatment with methylnaltrexone and diarrhea was significantly more present in treatment with naldemedine. Different dosages of methylnaltrexone were not significantly different with regard to both efficacy and adverse drug event rates. CONCLUSIONS: Magnesium oxide and naldemedine are most likely effective for prevention of OIC in cancer patients. Naloxone in a fixed combination with oxycodone, naldemedine and methylnaltrexone effectively treat OIC in cancer patients with acceptable adverse events. However, their effect has not been compared to standard (osmotic and stimulant) laxatives. More studies comparing standard laxatives with each other and with opioid antagonists are necessary before recommendations for clinical practice can be made.

The Management of Opioid-Induced Constipation in Cancer and Advanced Illness: A Meta-Analysis.

CONTEXT: Constipation is a common problem among patients with cancer. By some accounts, about 60% of cancer patients experience constipation. There is limited empirical evidence of the clinical effectiveness of pharmacologic agents in opioid-induced constipation in advanced diseases. OBJECTIVES: We sought to quantitatively summarize the therapeutic effectiveness of the pharmacologic means of managing opioid-induced constipation. METHODS: Randomized control trials (RCTs) identified from medical literature databases that reported quantitative measures of the effect of pharmacotherapeutic agents to treat opioid induced constipation in patients with cancers and other advanced illnesses were included in this study. A conventional random effects meta-analysis was conducted including >3 trials with the same exposure and outcome assessed, and a network-meta-analysis was conducted for all placebo-controlled trials. RESULTS: Eighteen studies that examined the effect of various pharmacotherapeutic agents were included. The medications were Methylnatrexone (N = 5), Naldemedine (N = 5), other conventional agents (N = 4) and herbal medicines (N = 4). In conventional meta-analysis, methylnaltrexone increased the proportion achieving rescue-free laxation by 2.68 fold (95% CI: 1.34, 5.37; P = 0.0054) within 4 hours of the administration compared to placebo. In network meta-analysis, the pooled RR of the pharmacotherapeutic agents on rescue-free bowel movements as 2.26 (95% CI: 1.52, 3.36) for methylnaltrexone, 1.58 (95% CI: 0.94, 2.66) for naldemedine, and 0.74 (95% CI: 0.45, 1.23) for polyethylene glycol, compared to placebo. CONCLUSION: Methylnatrexone and Naldemedine have currently shown promise in randomized trials concerning opioid-induced constipation in cancer and advanced illness. It is imperative that future research ascertain not just the relative therapeutic efficacy but also the cost-benefit analyses of these newer regimens with more commonly used and accessible laxatives.

The Effect of Postoperative Naloxone in Certain Otolaryngologic Surgeries.

OBJECTIVE: To evaluate the association of postoperative naloxone with the development of new substance use disorder (SUD), overdose, and death within 6 months of otolaryngologic surgery. STUDY DESIGN: Retrospective cohort database study on TriNetX. METHODS: Adult patients who underwent tonsil surgery (noncancerous), thyroid/parathyroid, septorhinoplasty, otology/neurotology, sinus/anterior skull base, and head and neck cancer surgeries between January 2003 and April 2023. Patients were excluded if they had an instance of SUD or overdose recorded in their charts prior to surgery, or had undergone another surgery within that 6-month time frame. We hypothesized that patients prescribed naloxone postoperatively would have decreased odds for experiencing new SUD, overdose, and/or death within 6 months of surgery compared to patients who did not receive naloxone. P < .01 was considered statistically significant. RESULTS: There were 2,305,655 patients in this study. The average age was 36.7 ± 19.5 years old, with 46% female patients. Before matching, cohorts showed equivocal odds for developing new SUD, increased odds for overdose, and mixed odds for dying. After matching for demographic variables and comorbidities such as other substance use, opioid use for other pathologies, and psychiatric conditions, these effects diminished (P > .01). CONCLUSION: Our results suggest that postoperative naloxone may not significantly affect development of new SUD and incident overdose and death in certain otolaryngologic surgeries after controlling for prior SUD and psychiatric conditions. Clinicians should be aware of these comorbidities when considering their postoperative pain management protocol, which may or may not include naloxone.

Effects of inhaled low-concentration xenon gas on naltrexone-precipitated withdrawal symptoms in morphine-dependent mice.

BACKGROUND: Opioid withdrawal symptoms (OWS) are highly aversive and prompt unprescribed opioid use, which increases morbidity, mortality, and, among individuals being treated for opioid use disorder (OUD), recurrence. OWS are driven by sympathetic nervous system (SNS) hyperactivity that occurs when blood opioid levels wane. We tested whether brief inhalation of xenon gas, which inhibits SNS activity and is used clinically for anesthesia and diagnostic imaging, attenuates naltrexone-precipitated withdrawal-like signs in morphine-dependent mice. METHODS: Adult CD-1 mice were implanted with morphine sulfate-loaded (60 mg/ml) minipumps and maintained for 6 days to establish morphine dependence. On day 7, mice were given subcutaneous naltrexone (0.3 mg/kg) and placed in a sealed exposure chamber containing either 21% oxygen/balance nitrogen (controls) or 21% oxygen/added xenon peaking at 30%/balance nitrogen. After 10 minutes, mice were transferred to observation chambers and videorecorded for 45 minutes. Videos were scored in a blind manner for morphine withdrawal behaviors. Data were analyzed using 2-way ANOVAs testing for treatment and sex effects. RESULTS AND CONCLUSIONS: Xenon-exposed mice exhibited fewer jumps (P = 0.010) and jumping suppression was detectible within the first 10-minute video segment, but no sex differences were detected. Brief inhalation of low concentration xenon rapidly and substantially attenuated naltrexone-precipitated jumping in morphine-dependent mice, suggesting that it can inhibit OWS. If xenon effects translate to humans with OUD, xenon inhalation may be effective for reducing OWS, unprescribed opioid use, and for easing OUD treatment initiation, which could help lower excess morbidity and mortality associated with OUD.

Comparing Three Formulations of Buprenorphine in an Incisional Pain Model in Mice.

This study compared the therapeutic effects in mice of 3 different formulations of buprenorphine. These formulations were standard buprenorphine hydrochloride (Bup-HCL) and 2 different extended-release buprenorphine formulations (Bup-ER and Ethiqa-XR [Bup-XR]). Drugs were evaluated based on their ability to attenuate thermal hypersensitivity in a mouse plantar incisional pain model. We hypothesized that Bup-HCL would attenuate postoperative thermal hypersensitivity at 20 min after administration, and that Bup-ER and Bup-XR would attenuate thermal hypersensitivity at 40 min after administration. Male C57BL6/J mice were randomly assigned to 1 of 4 treatment groups: 1) saline, 5 mL/kg SC, once; 2) Bup-HCL, 0.1 mg/kg SC, once; 3) Bup-ER, 1 mg/kg, SC, once; and 4) Bup-XR, 3.25 mg/kg, SC, once. Thermal hypersensitivity was assessed on the day before surgery and again on the day of surgery at 20, 40, 60, 90, and 120 min after drug administration. Thermal hypersensitivity after surgery was not different among the Bup-HCL, Bup-ER and Bup-XR groups at any timepoint. In addition, all buprenorphine treatment groups showed significantly less thermal hypersensitivity after surgery than did the saline group. Subjective observations suggested that mice that received Bup-ER or Bup-XR became hyperactive after drug administration (83 and 75% of mice tested, respectively). Our results indicate that Bup-HCL, Bup-ER, or Bup-XR attenuate thermal hyper- sensitivity related to foot incision by 20 min after administration.

A Case of Acute Opioid Withdrawal after Liposuction Surgery in a Patient on Extended-release Buprenorphine.

BACKGROUND: The US Food and Drug Administration approved the once-monthly injectable extended-release buprenorphine product to treat moderate-to-severe opioid use disorders. The patient in our case report had a liposuction procedure and immediately started having opioid withdrawal symptoms after the procedure. CASE DESCRIPTION: The patient is a 27-year-old African-American woman who injects drugs and has morbid obesity. She enrolled in a medications for addiction treatment program and opted to get treated with extended-release buprenorphine monthly injections. She tolerated them well for a span of 6 months. In one clinic visit, she reported opioid withdrawal symptoms and started purchasing and using sublingual buprenorphine from her acquaintances. On review of history, she underwent liposuction surgery and this triggered the opioid withdrawal symptoms. Examining her abdomen revealed surgical scars at the site of the buprenorphine injection and the residual buprenorphine depot was not palpable.A subcutaneous injection of 300-mg extended release buprenorphine was administered in the right periumbilical area in this clinic visit. The following week, she was doing well and denied any withdrawal symptoms. DISCUSSION: This is a unique case of "iatrogenic opioid withdrawal" after a fairly common surgical procedure. The extended-release buprenorphine formulation solidifies when it comes into contact with bodily fluids forming a depot. The depot and surrounding adipose tissue may have been removed during the patient's liposuction procedure, causing an immediate drop in buprenorphine levels leading to acute opioid withdrawal.This case report highlights the precautions that need to be taken before patients go for a surgical procedure like liposuction.

Pharmacokinetics of Extended-release Buprenorphine in Mongolian Gerbils (Meriones unguiculatus).

Both the Guide for the Care and Use of Laboratory Animals and the Animal Welfare Act and Regulations require animals in research to receive adequate analgesia unless an exception can be scientifically justified and IACUC approved. Extended- release buprenorphine (BUP-XR) is a pharmaceutical-grade formulation that is FDA-indexed for use in mice and rats. However, this new formulation has not been evaluated in adult Mongolian gerbils (Meriones unguiculatus). Our goal was to determine whether the extrapolated dose (1 mg/kg SC) would achieve plasma buprenorphine concentrations above the murine therapeutic threshold (> 1.0 ng/mL) in male and female gerbils. We hypothesized that BUP-XR administered at 1 mg/kg would achieve the murine therapeutic threshold in both male and female gerbils until at least 48 h after injection. Gerbils received one injection of BUP-XR (1 mg/kg SC) and underwent 4 serial blood collections (0.5, 1, 2, and 4, or 0.5, 24, 48, and 72 h after injection). The average plasma buprenorphine concentrations were above 1 ng/mL within 30 min of administration for both males and females. Plasma buprenorphine concentrations remained above 1.0 ng/mL for 48 h after administration. In males, plasma buprenorphine concentrations were significantly higher at 1 h after injection as compared with females; no other significant differences were observed between sexes. Mild to moderate injection-site granulomas were observed in five of nine gerbils, presumably due to the lipid matrix of the BUP-XR formulation. Our findings demonstrate that a single BUP-XR dose (1 mg/kg SC) achieves plasma buprenorphine levels that remain above the murine therapeutic threshold of 1.0 ng/mL for up to 48 h in both sexes.

Patient's perceptions of buprenorphine use receiving treatment for cancer.

OBJECTIVE: To assess knowledge and attitudes toward opioids and buprenorphine (BUP) of patients with cancer. DESIGN: Single-site, single-intervention telephone survey of patients under palliative care at the cancer center. OUTCOMES: Forty percent of the participants recognized the word "buprenorphine," and 28 percent recognized BUP indication for addiction treatment. Four percent addressed potential BUP misuse. None recognized BUP indication for pain. Seventy-one percent were not worried about addiction or dependency while using opioids to treat their cancer-related-pain, and 73 percent were not worried about being stigmatized in the healthcare setting about their pain regimens. Patients on opioids for less than 3 months were most strongly correlated with the fear of addiction and stigma. CONCLUSION: This study identifies patients' knowledge gap regarding BUP products for pain, which gives professionals the opportunity to provide education. This study identified that patients are most worried early on about addiction and stigma when using opioids.

The Utilization of Low Dose Naltrexone for Chronic Pain.

Naltrexone is a mu-opioid receptor antagonist with a long half-life compared with naloxone. Both of these drugs, along with others, were developed with the intention of reversing the effects of opioid abuse or toxicity. Evidence has also shown that naltrexone has a benefit in preventing relapse by reducing opioid cravings and reducing symptoms of opioid withdrawal. The benefits of this drug were not only shown with opioid abuse. In 1984 this drug was also approved for alcohol abuse. Naltrexone has been proven to decrease alcohol relapse by decreasing the craving. Apart from these approved indications for the use of naltrexone, with time, it has been seen that this drug has a benefit in treating chronic pain. A number of studies have shown the benefits of this drug with inflammatory bowel disease, fibromyalgia, multiple sclerosis, diabetic neuropathy, and complex regional pain syndrome, among others. More studies are needed to approve this medication for specific chronic pain conditions.

Theophylline reverses oxycodone's but not fentanyl's respiratory depression in mice while caffeine is ineffective against both opioids.

RATIONALE: The opioid epidemic remains a pressing public health crisis in the United States. Most of these overdose deaths are a result of lethal respiratory depression. In recent years the increasing incidence of opioid-involved overdose deaths has been driven by fentanyl, which is more resistant to adequate reversal by naloxone (NARCAN ®) than semi-synthetic or classical morphinan predecessors like oxycodone and heroin. For this and other reasons (e.g., precipitating withdrawal) non-opioidergic pharmacotherapies to reverse opioid-depressed respiration are needed. Methylxanthines are a class of stimulant drugs including caffeine and theophylline which exert their effects primarily via adenosine receptor antagonism. Evidence suggests methylxanthines can stimulate respiration by enhancing neural activity in respiratory nuclei in the pons and medulla independent of opioid receptors. This study aimed to determine whether caffeine and theophylline can stimulate respiration in mice when depressed by fentanyl and oxycodone. METHODS: Whole-body plethysmography was used to characterize fentanyl and oxycodone's effects on respiration and their reversal by naloxone in male Swiss Webster mice. Next, caffeine and theophylline were tested for their effects on basal respiration. Finally, each methylxanthine was evaluated for its ability to reverse similar levels of respiratory depression induced by fentanyl or oxycodone. RESULTS AND CONCLUSIONS: Oxycodone and fentanyl dose-dependently reduced respiratory minute volume (ml/min; MVb) that was reversible by naloxone. Caffeine and theophylline each significantly increased basal MVb. Theophylline, but not caffeine, completely reversed oxycodone-depressed respiration. In contrast, neither methylxanthine elevated fentanyl-depressed respiration at the doses tested. Despite their limited efficacy for reversing opioid-depressed respiration when administered alone, the methylxanthines safety, duration, and mechanism of action supports further evaluation in combination with naloxone to augment its reversal of opioid-depressed respiration.

Naldemedine-induced opioid withdrawal with restlessness as the predominant symptom in a palliative care setting.

OBJECTIVES: Opioid analgesics play a central role in cancer pain treatment; however, it has been reported that opioid-induced constipation (OIC) develops in 80% of patients using opioid analgesics and leads to a decrease in quality of life. Naldemedine improves constipation without affecting the analgesic action of opioid analgesics via peripheral µ-opioid receptors. METHODS: We report a terminally ill cancer patient who was diagnosed with opioid withdrawal syndrome (OWS) based on symptoms centered around restlessness and sweating that developed 43 days after administration of naldemedine for OIC. RESULTS: The patient was a 78-year-old woman who was diagnosed with stage IVB uterine sarcoma in October, 1 year prior to her visit to our clinic,  and underwent chemotherapy after surgery, but the disease became progressive. Thereafter, metastasis to the fourth thoracic vertebrae (Th4) was identified, and loxoprofen and acetaminophen were started for pain at the metastatic site. Oxycodone hydrochloride hydrate 10 mg/day was additionally administered on postoperative day 11, followed by naldemedine 0.2 mg/day for OIC. On the 43rd day after administration, the patient began to wander the hospital ward in a wheelchair and became noticeably restless. OWS due to naldemedine administration was suspected, and naldemedine was discontinued. The symptoms improved 7 days later, and no similar symptoms were observed thereafter. SIGNIFICANCE OF RESULTS: Patients receiving palliative care often exhibit psychiatric symptoms such as anxiety and depression, but OWS due to naldemedine should also be considered as a potential cause.

Effects and Limitations of Naldemedine for Opioid-Induced Urinary Retention: A Case Report.

A 78-year-old man with postoperative recurrence of esophageal cancer was admitted to the hospital due to chest pain and dyspnea. Oral short-acting opioids provided some relief, but chest pain persisted and worsened, leading to the initiation of a transdermal fentanyl patch. However, the patient developed opioid-induced urinary retention, which was treated with a naldemedine, a medication used for opioid-induced constipation and urinary retention. Opioid switching led to recurrent urinary retention, requiring placement of a urinary catheter. The patient ultimately required continuous deep sedation for refractory symptoms and died several days later.

Efforts to Improve Naloxone Co-Prescription for Patients With Cancer Pain at Risk of Opioid Overdose.

Importance: Naloxone can be lifesaving in an opioid-related overdose (OD). However, the co-prescription of take-home naloxone (THN) is not widely adopted in routine clinical practice. We implemented a pilot program focused on increasing clinicians' awareness of THN and observed if this impacts THN prescriptions for our patients with cancer pain receiving opioids. Intervention: In January 2020, we initiated an educational program by twice-weekly video presentations and installed pamphlets in all clinic workstations highlighting the risk factors for ODs. We retrospectively reviewed electronic health records (EHR) of randomly selected patient visits, 200 each from eight weeks before intervention (BI) and eight weeks after the intervention (AI). Data on patient characteristics, risk factors for ODs, and THN prescriptions were collected. Results: In all, 380 unique patients were eligible for analysis. The median age was 60, 53% female, and 70% Caucasian. Eighty-two percent (152) BI and 73% (142) AI carried risk factors for ODs (p = 0.13). THN was prescribed to 21% (32/152) BI and 26% (37/142) AI (p = 0.53). Morphine-equivalent daily dose (MEDD) ≥100 mg (30%) and pulmonary disease (25%) were the most prevalent risk factors. The patient's likelihood of receiving a THN prescription increased by 0.9% for every 1-milligram increase in MEDD (p < 0.001, 95% confidence interval: 1.006-1.011). Conclusion: The educational intervention did not significantly increase the frequency of THN prescriptions. More direct interventions, including automatic EHR triggers, may need to be tested in future trials.

Efficacy and Safety of Naldemedine Administration for Opioid-Induced Constipation in Cancer Patients with Poor Performance Status.

Background: Constipation is a concern among patients with Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 3 and 4. Objectives: To assess naldemedine's efficacy and safety in cancer patients on opioids with poor PS. Design: Multicenter, retrospective study. Setting/Subjects: Japanese cancer patients with ECOG performance status 3 or 4 who received naldemedine. Measurements: Frequency of defecations before/after naldemedine use. Responders were patients whose defecation frequency increased to ≥3 times/week, from baseline ≥1 defecations/week over seven days after naldemedine administration. Results: Seventy-one patients were analyzed; 66.1% were responders (95% confidence interval: 54.5%-76.1%). Defecation frequency increased significantly after naldemedine in the overall population (6 vs. 2, p < 0.0001) and among those who defecated <3 times/week before naldemedine (4.5 vs. 1, p < 0.0001). Diarrhea (38.0%) of all grades was the most common adverse event; 23 (85.2%) events were classified as Grade 1 or 2. Conclusion: Naldemedine is effective and safe among cancer patients with poor PS.

A Retrospective Study of the Efficacy and Safety of Naldemedine for Treatment of Opioid-Induced Constipation in Patients with Hepatobiliary Pancreatic Cancer.

Background and Objectives: Opioid analgesics, which are used for cancer-related pain management, cause opioid-induced constipation (OIC). Naldemedine, a peripheral opioid receptor antagonist, is an OIC-modifying agent, but no focused efficacy and safety analysis has been conducted for its use in hepatobiliary pancreatic cancers. We performed a multi-institutional study on the efficacy and safety of naldemedine in patients with hepatobiliary pancreatic cancer using opioids in clinical practice. Materials and Methods: We retrospectively evaluated patients with hepatobiliary pancreatic cancer (including liver, biliary tract, and pancreatic cancers) treated with opioids and naldemedine during hospitalization at ten institutions in Japan from June 2017 to August 2019. We assessed the frequency of bowel movements before and after the initiation of naldemedine therapy. Responders were defined as patients who defecated ≥3 times/week, with an increase from a baseline of ≥1 defecations/week over seven days after the initiation of naldemedine administration. Results: Thirty-four patients were observed for one week before and one week after starting naldemedine. The frequency of bowel movements increased by one over the baseline frequency or to at least thrice per week in 21 patients. The response rate was 61.7% (95% confidence interval: 45.4-78.0%). The median number of weekly bowel movements before and after naldemedine treatment was 2 (range: 0-9) and 6 (range: 1-17), respectively, in the overall population (n = 34); the increase in the number of bowel movements following naldemedine administration was statistically significant (Wilcoxon signed-rank test, p < 0.0001). Diarrhea was the predominant gastrointestinal symptom, and 10 (29.4%) patients experienced grade 1, grade 2, or grade 3 adverse events. The only other adverse event included fatigue in one patient; grade 2-4 adverse events were absent. Conclusions: Naldemedine is effective, and its use may be safe in clinical practice for patients with hepatobiliary pancreatic cancer receiving opioid analgesics.

[Survey of Prophylactic Administration of Naldemedine for Opioid-induced Constipation].

Opioid-induced constipation (OIC), an adverse event that occurs due to opioid analgesics, reportedly causes poor quality of life and adherence to opioid analgesics in patients. Therefore, this issue must be addressed appropriately. Naldemedine (NAL), a peripherally-acting µ-opioid receptor antagonist, is currently recommended for treating OIC when other laxatives are ineffective, but there have been no clinical reports of NAL being used prophylactically for OIC. Therefore, we conducted a retrospective survey of hospitalized patients who received NAL as prophylaxis for OIC with strong opioid analgesics to clarify the reality of this situation and to consider points to be taken into account in its clinical implementation. In this study, 61.7% of the subjects had an Eastern Cooperative Oncology Group performance status score of 3 or higher. The rate of addition of new laxatives and increased laxatives during seven days of NAL prophylaxis was 46.8%, and the rate of diarrhea was 6.1%. This study suggests that patients initiated with strong opioid analgesics during hospitalization often presented with poor performance status, and it is important to pay attention to constipation even under NAL prophylaxis. However, the incidence of diarrhea was low, and the safety of NAL prophylaxis was considered to be good.